advanced android development course – concepts...title advanced android development course –...
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Understanding device rotationIfyourappdrawsviewsonthescreeninpositions asedonsensordatayouneedtotransformthesensorscoordinatesystem(whichdoesnotrotate)withthescreenoractivityscoordinatesystem(whichdoesrotate)
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41 Rendering and layoutContents
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43 Best practices network batterycompressionContents
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
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71 Location servicesContents
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
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121Animations
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ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
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Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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Updating the widg pro d -info fileTheprovider-infofiledefinesmetadataandinitialpropertiesforyourappwidgetincludingthewidgetsinitialsizeupdateintervalandc figurati activityThesepropertiesareusedtodisplayyourwidgetinthewidgetpickertoc figurethewidget(ifc figurati is
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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BestPracticesforPerformancePerformanceProfilingTools(thelandingpageforallthetools)AndroidProfilerSearchdeveloperandroidcomforperformanceforafulllistofthelatestperformancedocs
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MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
TheAndroidDeveloperFundamentalscoursetalkedabouthowtomakeyourappslookinterestingandvisuallycompellingusingMaterialDesi idelinesandittau tyouhowtousetheLayoutEdi
Forexampleanappmightdrawastackof52overlappingcardswithonlythelastcardfullyvisibleCompletelydrawingthe51cardsthatareunderneathandpartiallycoveredisan
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43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
InsideyourmobiledeviceisasmallpieceofhardwarethatsessentiallyaradioThepurposeofthisradioistocommunicatewithlocalcelltowersandtransmitdataHoweverthisradioisnotalwaysactiveanddrawingpowerItstartsinapowereddownstateandwhenthedeviceneedstosenddatatheradioturnsonandtransfersthedataAfterthedatapacketissent
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
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Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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Understanding device rotationIfyourappdrawsviewsonthescreeninpositions asedonsensordatayouneedtotransformthesensorscoordinatesystem(whichdoesnotrotate)withthescreenoractivityscoordinatesystem(whichdoesrotate)
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41 Rendering and layoutContents
MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
TheAndroidDeveloperFundamentalscoursetalkedabouthowtomakeyourappslookinterestingandvisuallycompellingusingMaterialDesi idelinesandittau tyouhowtousetheLayoutEdi
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43 Best practices network batterycompressionContents
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
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71 Location servicesContents
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
21 App widgetsContents
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NewAppWidgetConfigurationActivityjavaisaddedtoyourprojectTheAndroidmanifestisupdatedtoincludetheproviderandc figurati activityclasses
Updating the widg pro d -info fileTheprovider-infofiledefinesmetadataandinitialpropertiesforyourappwidgetincludingthewidgetsinitialsizeupdateintervalandc figurati activityThesepropertiesareusedtodisplayyourwidgetinthewidgetpickertoc figurethewidget(ifc figurati is
eeded)andtoplacethewidgetintherightnumberofcells theh escreen
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Detecting sensors at runtime
IfyourappusesaspecifictypeofsensorbutdoesntrelyonityoucanusethesensorframeworktodetectthesensoratruntimethenturnofforturnonappfeaturesasappropriateForexampleaweatherappmightusethetemperaturesensorpressuresenso
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Understanding device rotationIfyourappdrawsviewsonthescreeninpositions asedonsensordatayouneedtotransformthesensorscoordinatesystem(whichdoesnotrotate)withthescreenoractivityscoordinatesystem(whichdoesrotate)
Tohandledeviceandactivityrotationinsensor- aseddrawingquerythecurrentdeviceorientationwiththegetRotation()me odThe iremaptherotationmatrixfromthesensordataontothedesiredaxeswiththe emapCoordinateSystem() e od
The et Rot at i on( )e od returnsoneoffourintegerconstants
Follow the Performance Improv
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Learn moreAndroiddeveloperdocumentation
BestPracticesforPerformancePerformanceProfilingTools(thelandingpageforallthetools)AndroidProfilerSearchdeveloperandroidcomforperformanceforafulllistofthelatestperformancedocs
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41 Rendering and layoutContents
MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
TheAndroidDeveloperFundamentalscoursetalkedabouthowtomakeyourappslookinterestingandvisuallycompellingusingMaterialDesi idelinesandittau tyouhowtousetheLayoutEdi
Forexampleanappmightdrawastackof52overlappingcardswithonlythelastcardfullyvisibleCompletelydrawingthe51cardsthatareunderneathandpartiallycoveredisan
exampleofoverdraw
Themostlikelysympt dy willseeinanappwithoverdrawisslowrenderingandstutteringanimationsThisisthemostgenericofsympt dSinceoverdrawiscop onandstraightforwardt testformakeitahabitt checkforiteverytimey changethe
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Profile GPU Rendering
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43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
InsideyourmobiledeviceisasmallpieceofhardwarethatsessentiallyaradioThepurposeofthisradioistocommunicatewithlocalcelltowersandtransmitdataHoweverthisradioisnotalwaysactiveanddrawingpowerItstartsinapowereddownstateandwhenthedeviceneedstosenddatatheradioturnsonandtransfersthedataAfterthedatapacketissent
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
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PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
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MaterialDesignUsability-Bidirectionality
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71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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Detecting sensors at runtime
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Understanding device rotationIfyourappdrawsviewsonthescreeninpositions asedonsensordatayouneedtotransformthesensorscoordinatesystem(whichdoesnotrotate)withthescreenoractivityscoordinatesystem(whichdoesrotate)
Tohandledeviceandactivityrotationinsensor- aseddrawingquerythecurrentdeviceorientationwiththegetRotation()me odThe iremaptherotationmatrixfromthesensordataontothedesiredaxeswiththe emapCoordinateSystem() e od
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41 Rendering and layoutContents
MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
TheAndroidDeveloperFundamentalscoursetalkedabouthowtomakeyourappslookinterestingandvisuallycompellingusingMaterialDesi idelinesandittau tyouhowtousetheLayoutEdi
Forexampleanappmightdrawastackof52overlappingcardswithonlythelastcardfullyvisibleCompletelydrawingthe51cardsthatareunderneathandpartiallycoveredisan
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43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
InsideyourmobiledeviceisasmallpieceofhardwarethatsessentiallyaradioThepurposeofthisradioistocommunicatewithlocalcelltowersandtransmitdataHoweverthisradioisnotalwaysactiveanddrawingpowerItstartsinapowereddownstateandwhenthedeviceneedstosenddatatheradioturnsonandtransfersthedataAfterthedatapacketissent
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
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Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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Understanding device rotationIfyourappdrawsviewsonthescreeninpositions asedonsensordatayouneedtotransformthesensorscoordinatesystem(whichdoesnotrotate)withthescreenoractivityscoordinatesystem(whichdoesrotate)
Tohandledeviceandactivityrotationinsensor- aseddrawingquerythecurrentdeviceorientationwiththegetRotation()me odThe iremaptherotationmatrixfromthesensordataontothedesiredaxeswiththe emapCoordinateSystem() e od
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MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
TheAndroidDeveloperFundamentalscoursetalkedabouthowtomakeyourappslookinterestingandvisuallycompellingusingMaterialDesi idelinesandittau tyouhowtousetheLayoutEdi
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43 Best practices network batterycompressionContents
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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Best practices for localizing text
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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51 Languages and layoutsContents
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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43 Best practices network batterycompressionContents
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51 Languages and layoutsContents
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Best practices for localizing text
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Detecting sensors at runtime
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Learn moreAndroiddeveloperdocumentation
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41 Rendering and layoutContents
MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
TheAndroidDeveloperFundamentalscoursetalkedabouthowtomakeyourappslookinterestingandvisuallycompellingusingMaterialDesi idelinesandittau tyouhowtousetheLayoutEdi
Forexampleanappmightdrawastackof52overlappingcardswithonlythelastcardfullyvisibleCompletelydrawingthe51cardsthatareunderneathandpartiallycoveredisan
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Themostlikelysympt dy willseeinanappwithoverdrawisslowrenderingandstutteringanimationsThisisthemostgenericofsympt dSinceoverdrawiscop onandstraightforwardt testformakeitahabitt checkforiteverytimey changethe
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43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
InsideyourmobiledeviceisasmallpieceofhardwarethatsessentiallyaradioThepurposeofthisradioistocommunicatewithlocalcelltowersandtransmitdataHoweverthisradioisnotalwaysactiveanddrawingpowerItstartsinapowereddownstateandwhenthedeviceneedstosenddatatheradioturnsonandtransfersthedataAfterthedatapacketissent
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Themoststraightforwardsolutionistopicksomenon-maximumvalueandusethatvalueHoweverbeawarethatthequalityvalueaffectseveryimagedifferentlyWhileaqualityof75forexamplemaylookfineonmostimagestheremaybesomecasesthatdonotfareaswellYoushouldmakesuretotestyourchosenmaximumvalueagainsta
YourappshouldnotdownloadanyimagemorethanonceImageloadinglibr
43Bestpracticesnetworkbatterycompression
112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
Todecidewhichlanguagesto
Youmayalsoneedtoidentifymediaresourcessuchasaudioandvideothatneedcaptions
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1 App nameThechoia oftranslatingtheappnameisuptoyouManyappsaddtranslatednamessothattheusersinotherlanguagesunderstandtheappspurposeandcanfindtheappinGooglePlayintheirownlanguagesAppsthatuseb
usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
examplethelocalecountrysflagappears
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PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
onusingformatstringsceeAndroidSDKauickPipFormattingResourceStringsPoensurethatformatstringsarenottranslatedusedtheP(Piffgplaceholdertagto
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71 Location servicesContents
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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Learn moreAndroiddeveloperdocumentation
BestPracticesforPerformancePerformanceProfilingTools(thelandingpageforallthetools)AndroidProfilerSearchdeveloperandroidcomforperformanceforafulllistofthelatestperformancedocs
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41 Rendering and layoutContents
MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
TheAndroidDeveloperFundamentalscoursetalkedabouthowtomakeyourappslookinterestingandvisuallycompellingusingMaterialDesi idelinesandittau tyouhowtousetheLayoutEdi
Forexampleanappmightdrawastackof52overlappingcardswithonlythelastcardfullyvisibleCompletelydrawingthe51cardsthatareunderneathandpartiallycoveredisan
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Themostlikelysympt dy willseeinanappwithoverdrawisslowrenderingandstutteringanimationsThisisthemostgenericofsympt dSinceoverdrawiscop onandstraightforwardt testformakeitahabitt checkforiteverytimey changethe
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43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
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43Bestpracticesnetworkbatterycompression
112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
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Best practices for localizing text
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MaterialDesignUsability-Bidirectionality
AndroidDevelopersBlog
AndroidDesignSupportLibraryNativeRTLsupportinAndroid42
AndroidPlayConsoleTranslateamplocalizeyourapp
VideoWelcometofrac34llefrac34randLocalizaap to l l ҧ
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Donotassumethatthedevicerunningyourappisusingoneofthebppisuo opisusot ai g p pcerunnin ece uev s suo ms thede r r sume i u aeems edot r r evu apiquest pisuse ssede e ayo thsumd us frac34de uo ms thet us mt gr mp t ruau uototgu i appisuo s thume i an t i g prapdett appi n us m ce pisuse rbumot gbruppi p
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71 Location servicesContents
IntroductionS
1 OpenAndroidStu
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
32 Motion and position senso
Understanding device rotationIfyourappdrawsviewsonthescreeninpositions asedonsensordatayouneedtotransformthesensorscoordinatesystem(whichdoesnotrotate)withthescreenoractivityscoordinatesystem(whichdoesrotate)
Tohandledeviceandactivityrotationinsensor- aseddrawingquerythecurrentdeviceorientationwiththegetRotation()me odThe iremaptherotationmatrixfromthesensordataontothedesiredaxeswiththe emapCoordinateSystem() e od
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41 Rendering and layoutContents
MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
TheAndroidDeveloperFundamentalscoursetalkedabouthowtomakeyourappslookinterestingandvisuallycompellingusingMaterialDesi idelinesandittau tyouhowtousetheLayoutEdi
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43 Best practices network batterycompressionContents
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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51 Languages and layoutsContents
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121 AnimationsContents
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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BestPracticesforPerformancePerformanceProfilingTools(thelandingpageforallthetools)AndroidProfilerSearchdeveloperandroidcomforperformanceforafulllistofthelatestperformancedocs
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YouYourAppandAndroidPerformance
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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Best practices for localizing text
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Adjusting layouts for
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LocalizingwithResourcesLocalizationchecklistLanguageandLocaleTestingforDefaultResources
MaterialDesignUsability-Bidirectionality
AndroidDevelopersBlog
AndroidDesignSupportLibraryNativeRTLsupportinAndroid42
AndroidPlayConsoleTranslateamplocalizeyourapp
VideoWelcometofrac34llefrac34randLocalizaap to l l ҧ
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Learn moreAndroiddeveloperdocumentation
BestPracticesforPerformancePerformanceProfilingTools(thelandingpageforallthetools)AndroidProfilerSearchdeveloperandroidcomforperformanceforafulllistofthelatestperformancedocs
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41 Rendering and layoutContents
MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
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43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
InsideyourmobiledeviceisasmallpieceofhardwarethatsessentiallyaradioThepurposeofthisradioistocommunicatewithlocalcelltowersandtransmitdataHoweverthisradioisnotalwaysactiveanddrawingpowerItstartsinapowereddownstateandwhenthedeviceneedstosenddatatheradioturnsonandtransfersthedataAfterthedatapacketissent
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Themoststraightforwardsolutionistopicksomenon-maximumvalueandusethatvalueHoweverbeawarethatthequalityvalueaffectseveryimagedifferentlyWhileaqualityof75forexamplemaylookfineonmostimagestheremaybesomecasesthatdonotfareaswellYoushouldmakesuretotestyourchosenmaximumvalueagainsta
YourappshouldnotdownloadanyimagemorethanonceImageloadinglibr
43Bestpracticesnetworkbatterycompression
112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
Todecidewhichlanguagesto
Youmayalsoneedtoidentifymediaresourcessuchasaudioandvideothatneedcaptions
orsubtitles
Forexampleinthefigureabove
1 App nameThechoia oftranslatingtheappnameisuptoyouManyappsaddtranslatednamessothattheusersinotherlanguagesunderstandtheappspurposeandcanfindtheappinGooglePlayintheirownlanguagesAppsthatuseb
usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
examplethelocalecountrysflagappears
PipPhefloatingactionbuttonatthebottomofthescreeninthisexampledoesnotneedtobeadjustedforanRPLlanguagebecauseitfloatsonthescreenandisadjustedautomaticallybyAndroidslayoutmirroringfeature
PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
onusingformatstringsceeAndroidSDKauickPipFormattingResourceStringsPoensurethatformatstringsarenottranslatedusedtheP(Piffgplaceholdertagto
markitasdescribedinthe
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Addressing design and layout issues
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anothercultureAvoidjargonregionalphrasesandmetaphorsFormxamplbrvbarusersmaynotmnowenoughaboutmmericanbasebalccediltounderstand nockingitmutmfmhepark arm r d
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Adjusting layouts for
Tote
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LocalizingwithResourcesLocalizationchecklistLanguageandLocaleTestingforDefaultResources
MaterialDesignUsability-Bidirectionality
AndroidDevelopersBlog
AndroidDesignSupportLibraryNativeRTLsupportinAndroid42
AndroidPlayConsoleTranslateamplocalizeyourapp
VideoWelcometofrac34llefrac34randLocalizaap to l l ҧ
rc ӑLanguigt n ul Icircc ilitt rc ט
rc ᴒrc ᴸgeNi tp Ɗd ang geidaR p ľ
UK
Androidprovidesclassesandmethodsyoucanusetoapplytheformatoftheuser-chosenlocaleortouseaformatfromanotherlocaleStorealldatafortheappinadefaultformatandusethe
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Why default resources are important
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71 Location servicesContents
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
41 Rendering and layoutContents
MinimizeoverdrawSimplifycomplexviewhierarchiesRelatedpracticalsLearnmore
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43 Best practices network batterycompressionContents
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51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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51 Languages and layoutsContents
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Profile GPU Rendering
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43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
InsideyourmobiledeviceisasmallpieceofhardwarethatsessentiallyaradioThepurposeofthisradioistocommunicatewithlocalcelltowersandtransmitdataHoweverthisradioisnotalwaysactiveanddrawingpowerItstartsinapowereddownstateandwhenthedeviceneedstosenddatatheradioturnsonandtransfersthedataAfterthedatapacketissent
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43Bestpracticesnetworkbatterycompression
112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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Best practices for localizing text
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W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
3 ClickAndroidandLintintheright-handpane4 Selectorclearinspectioncheckboxesasdesired
ThefollowingaresomeofthelintinspectionsrelatedtotheviewhierarchyTheyarelistedunderAndroid gt Lint gt PerformanceintheEditor gt Inspectionspre rences
Node can be replaced by a T
theparentofadeep
AnalyzingwithProfileGPURendering
RRendering
43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
InsideyourmobiledeviceisasmallpieceofhardwarethatsessentiallyaradioThepurposeofthisradioistocommunicatewithlocalcelltowersandtransmitdataHoweverthisradioisnotalwaysactiveanddrawingpowerItstartsinapowereddownstateandwhenthedeviceneedstosenddatatheradioturnsonandtransfersthedataAfterthedatapacketissent
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YourappshouldnotdownloadanyimagemorethanonceImageloadinglibr
43Bestpracticesnetworkbatterycompression
112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
Todecidewhichlanguagesto
Youmayalsoneedtoidentifymediaresourcessuchasaudioandvideothatneedcaptions
orsubtitles
Forexampleinthefigureabove
1 App nameThechoia oftranslatingtheappnameisuptoyouManyappsaddtranslatednamessothattheusersinotherlanguagesunderstandtheappspurposeandcanfindtheappinGooglePlayintheirownlanguagesAppsthatuseb
usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
examplethelocalecountrysflagappears
PipPhefloatingactionbuttonatthebottomofthescreeninthisexampledoesnotneedtobeadjustedforanRPLlanguagebecauseitfloatsonthescreenandisadjustedautomaticallybyAndroidslayoutmirroringfeature
PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
onusingformatstringsceeAndroidSDKauickPipFormattingResourceStringsPoensurethatformatstringsarenottranslatedusedtheP(Piffgplaceholdertagto
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Addressing design and layout issues
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AndroidStudioshowslintwarningsforvariousaccessibilityissuesandprovideslinkstotheplacesinthesourcecodecontainingtheseissuesForexamp
71 Location servicesContents
IntroductionS
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2 Callthe
Creating a LocationRquest object
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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43 Best practices network batterycompressionContents
RadiosNetworkandbatterybestpracticesOptimizingimages
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112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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orsubtitles
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usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
examplethelocalecountrysflagappears
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PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
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71 Location servicesContents
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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51 Languages and layoutsContents
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
43 Best practices network batterycompressionContents
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112
51 Languages and layoutsContents
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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YourappshouldnotdownloadanyimagemorethanonceImageloadinglibr
43Bestpracticesnetworkbatterycompression
112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
Todecidewhichlanguagesto
Youmayalsoneedtoidentifymediaresourcessuchasaudioandvideothatneedcaptions
orsubtitles
Forexampleinthefigureabove
1 App nameThechoia oftranslatingtheappnameisuptoyouManyappsaddtranslatednamessothattheusersinotherlanguagesunderstandtheappspurposeandcanfindtheappinGooglePlayintheirownlanguagesAppsthatuseb
usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
examplethelocalecountrysflagappears
PipPhefloatingactionbuttonatthebottomofthescreeninthisexampledoesnotneedtobeadjustedforanRPLlanguagebecauseitfloatsonthescreenandisadjustedautomaticallybyAndroidslayoutmirroringfeature
PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
onusingformatstringsceeAndroidSDKauickPipFormattingResourceStringsPoensurethatformatstringsarenottranslatedusedtheP(Piffgplaceholdertagto
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AndroidStudioshowslintwarningsforvariousaccessibilityissuesandprovideslinkstotheplacesinthesourcecodecontainingtheseissuesForexamp
71 Location servicesContents
IntroductionS
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2 Callthe
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
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Best practices for localizing text
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angu gusand ay u s
Adjusting layouts for
Tote
te
e
e ee e et
LocalizingwithResourcesLocalizationchecklistLanguageandLocaleTestingforDefaultResources
MaterialDesignUsability-Bidirectionality
AndroidDevelopersBlog
AndroidDesignSupportLibraryNativeRTLsupportinAndroid42
AndroidPlayConsoleTranslateamplocalizeyourapp
VideoWelcometofrac34llefrac34randLocalizaap to l l ҧ
rc ӑLanguigt n ul Icircc ilitt rc ט
rc ᴒrc ᴸgeNi tp Ɗd ang geidaR p ľ
UK
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values-fr-rFRdire
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Donotassumethatthedevicerunningyourappisusingoneofthebppisuo opisusot ai g p pcerunnin ece uev s suo ms thede r r sume i u aeems edot r r evu apiquest pisuse ssede e ayo thsumd us frac34de uo ms thet us mt gr mp t ruau uototgu i appisuo s thume i an t i g prapdett appi n us m ce pisuse rbumot gbruppi p
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Touch regamgetsamethepamtsoathescreenthaeacuteresp=ndt=userinpfrac34tTheyextendbey=ndthevisual
Youshouldtestyourappmeensurethatitbehavestheway
IfyoutargetyourapptoAndroid42(APIlevel17)orhigherus
Thesetwoimagesshowexamplesoftextsetagainsmagalackorwhitemackground ThetextattheleftshowhighercontrasmOntherightthetextissetamagaowercontrasmwhimishardertoread emarativeelementssumasmogosmontneut tomeetminimumcontrasmratios vensoiv
demarativeelementsprovit eimportantinformationmakesuretheymreeasymot istinguish ee owcoangoeu naov
ornts rmaaive aiist urea roet mlaiialeowmntt t oovi tio
h owcoangoeu t symtit eo phtea owcot st oftmmnd mnai ecot inoaet fheymtoar
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Lint
AndroidStudioshowslintwarningsforvariousaccessibilityissuesandprovideslinkstotheplacesinthesourcecodecontainingtheseissuesForexamp
71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
Creating a LocationRquest object
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Thecameratargetisthelocationoftheceoerofthemapspecifiedaslatitudeaolooitude
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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51 Languages and layoutsContents
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
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121Animations
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Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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112
51 Languages and layoutsContents
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Best practices for localizing text
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Adjusting layouts for
Tote
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LocalizingwithResourcesLocalizationchecklistLanguageandLocaleTestingforDefaultResources
MaterialDesignUsability-Bidirectionality
AndroidDevelopersBlog
AndroidDesignSupportLibraryNativeRTLsupportinAndroid42
AndroidPlayConsoleTranslateamplocalizeyourapp
VideoWelcometofrac34llefrac34randLocalizaap to l l ҧ
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
YourappshouldnotdownloadanyimagemorethanonceImageloadinglibr
43Bestpracticesnetworkbatterycompression
112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
Todecidewhichlanguagesto
Youmayalsoneedtoidentifymediaresourcessuchasaudioandvideothatneedcaptions
orsubtitles
Forexampleinthefigureabove
1 App nameThechoia oftranslatingtheappnameisuptoyouManyappsaddtranslatednamessothattheusersinotherlanguagesunderstandtheappspurposeandcanfindtheappinGooglePlayintheirownlanguagesAppsthatuseb
usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
examplethelocalecountrysflagappears
PipPhefloatingactionbuttonatthebottomofthescreeninthisexampledoesnotneedtobeadjustedforanRPLlanguagebecauseitfloatsonthescreenandisadjustedautomaticallybyAndroidslayoutmirroringfeature
PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
onusingformatstringsceeAndroidSDKauickPipFormattingResourceStringsPoensurethatformatstringsarenottranslatedusedtheP(Piffgplaceholdertagto
markitasdescribedinthe
markmeccagepartsthatshoeldnotbgtranslatec
cectioo
ofLocalicingwithResourceseaLanguagesandlayoutd
Addressing design and layout issues
Fittingdesig elemeosaogotraglaedtextisacha g Th elemeosogth desig ao glogg fitaogotraglaed
anothercultureAvoidjargonregionalphrasesandmetaphorsFormxamplbrvbarusersmaynotmnowenoughaboutmmericanbasebalccediltounderstand nockingitmutmfmhepark arm r d
slamhef lccedilo ingare ipsonho topreparemedi insluding r hicsandimagus ea are fmrocs culturaldif ferunsesasnotmlccedilimagusandcymbolscarry hecamemeaningacrocsb rders apsfla sccediloca ionnamesandculturalhist rical dp liticalreferunsesmaybe f fensive ousersin otherc un ronotmnslude xtmithinimagusbecauseitmsnotmasily r sla dnslude r men sin hec ngsxmccedilfile ha y ucundmutmr r sla ionin arder odescribe he r xtmn ahicheachc ngmsused his nf rma ion ilccedilbe nvaluable ohe r sla rmndmucultinbe rau lity r sla ionr a oenuse ndroid tudios o dd langu gu oy urmppandcreahec ngmuc ursesf r he angu guouse he pun he fileandclick helinkinhe oprightc rnur ry u nuse shor cu right click hefilemndmelecdunr a m he
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angu gusand ay u s
Adjusting layouts for
Tote
te
e
e ee e et
LocalizingwithResourcesLocalizationchecklistLanguageandLocaleTestingforDefaultResources
MaterialDesignUsability-Bidirectionality
AndroidDevelopersBlog
AndroidDesignSupportLibraryNativeRTLsupportinAndroid42
AndroidPlayConsoleTranslateamplocalizeyourapp
VideoWelcometofrac34llefrac34randLocalizaap to l l ҧ
rc ӑLanguigt n ul Icircc ilitt rc ט
rc ᴒrc ᴸgeNi tp Ɗd ang geidaR p ľ
UK
Androidprovidesclassesandmethodsyoucanusetoapplytheformatoftheuser-chosenlocaleortouseaformatfromanotherlocaleStorealldatafortheappinadefaultformatandusethe
TheDirectory namenowincludesalocalizationqualifierthatspecifiesalanguageandoptionallyaregionThelocalizationqualifierisatwo-letterISO639-1languagecodesuchas9- ucl tie0a lʎoptiona l na
a
isa
-lett
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Tu Tl na
weer r u o l theti a ee r t iafi rth incluhelocali
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Why default resources are important
Donotassumethatthedevicerunningyourappisusingoneofthebppisuo opisusot ai g p pcerunnin ece uev s suo ms thede r r sume i u aeems edot r r evu apiquest pisuse ssede e ayo thsumd us frac34de uo ms thet us mt gr mp t ruau uototgu i appisuo s thume i an t i g prapdett appi n us m ce pisuse rbumot gbruppi p
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71 Location servicesContents
IntroductionS
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2 Callthe
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W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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112
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
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PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
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71 Location servicesContents
IntroductionS
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2 Callthe
Creating a LocationRquest object
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Stylingofthebase
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TheAPIfirstcalls
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
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121Animations
247
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
51 Languages and layoutsContents
UnderstandinglanguageandlocalesettingsPreparinganappforlocalizationUsingthe
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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usecurrencyexchangerates9 Image tie` to a localeYoucanchangeanimagedependingonthelocaleInthis
examplethelocalecountrysflagappears
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PhefollowingfigureshowsthesameappintheEnglishlanguageandUSlocale(left)inFrenchintheFrancelocale(center)andinHebrewanRPLlanguageintheIsraellocale(right)
Best practices for localizing text
KeeptextseparatedfromtherestofyourappNeverembedtextincoCcedilḸtTocreatestringresourcesforotherlanguagesusetheAndroidStudioPranslationsEditorwhichautomaticallyplacesstringsxmlfilesintoappropriatelynameddirectorieswithintheappprojectsproject_nameappsrcmainresdirectoryDontconcatenatepiecesoftexttomakeasentenceorphrasePhepiecesmaynotbeintheproperorderinthetranslatedversionofthesentenceorphraseIfyoumustcombinepiecesoftextuseformatstringsasplaceholdersanduseStringformat()tosupplytheargumentstocreatethecompletedstringFormatstringsareaconvenientwaytobuilduponestringthathasvariablecontentFordetails
onusingformatstringsceeAndroidSDKauickPipFormattingResourceStringsPoensurethatformatstringsarenottranslatedusedtheP(Piffgplaceholdertagto
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71 Location servicesContents
IntroductionS
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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71 Location servicesContents
IntroductionS
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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71 Location servicesContents
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Adjusting layouts for
Tote
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LocalizingwithResourcesLocalizationchecklistLanguageandLocaleTestingforDefaultResources
MaterialDesignUsability-Bidirectionality
AndroidDevelopersBlog
AndroidDesignSupportLibraryNativeRTLsupportinAndroid42
AndroidPlayConsoleTranslateamplocalizeyourapp
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71 Location servicesContents
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121Animations
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Tote
te
e
e ee e et
LocalizingwithResourcesLocalizationchecklistLanguageandLocaleTestingforDefaultResources
MaterialDesignUsability-Bidirectionality
AndroidDevelopersBlog
AndroidDesignSupportLibraryNativeRTLsupportinAndroid42
AndroidPlayConsoleTranslateamplocalizeyourapp
VideoWelcometofrac34llefrac34randLocalizaap to l l ҧ
rc ӑLanguigt n ul Icircc ilitt rc ט
rc ᴒrc ᴸgeNi tp Ɗd ang geidaR p ľ
UK
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TheDirectory namenowincludesalocalizationqualifierthatspecifiesalanguageandoptionallyaregionThelocalizationqualifierisatwo-letterISO639-1languagecodesuchas9- ucl tie0a lʎoptiona l na
a
isa
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weer r u o l theti a ee r t iafi rth incluhelocali
values-fr-rFRdire
Why default resources are important
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IfyoutargetyourapptoAndroid42(APIlevel17)orhigherus
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71 Location servicesContents
IntroductionS
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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71 Location servicesContents
IntroductionS
1 OpenAndroidStu
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Creating a LocationRquest object
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Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
Creating a LocationRquest object
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
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advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
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Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
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Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
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ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
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Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Why default resources are important
Donotassumethatthedevicerunningyourappisusingoneofthebppisuo opisusot ai g p pcerunnin ece uev s suo ms thede r r sume i u aeems edot r r evu apiquest pisuse ssede e ayo thsumd us frac34de uo ms thet us mt gr mp t ruau uototgu i appisuo s thume i an t i g prapdett appi n us m ce pisuse rbumot gbruppi p
itemstogetherishelpfularuserswh=haIcircelowvision=rtroubleacusing=neacutehescreen
T=uch regargets
Touch regamgetsamethepamtsoathescreenthaeacuteresp=ndt=userinpfrac34tTheyextendbey=ndthevisual
Youshouldtestyourappmeensurethatitbehavestheway
IfyoutargetyourapptoAndroid42(APIlevel17)orhigherus
Thesetwoimagesshowexamplesoftextsetagainsmagalackorwhitemackground ThetextattheleftshowhighercontrasmOntherightthetextissetamagaowercontrasmwhimishardertoread emarativeelementssumasmogosmontneut tomeetminimumcontrasmratios vensoiv
demarativeelementsprovit eimportantinformationmakesuretheymreeasymot istinguish ee owcoangoeu naov
ornts rmaaive aiist urea roet mlaiialeowmntt t oovi tio
h owcoangoeu t symtit eo phtea owcot st oftmmnd mnai ecot inoaet fheymtoar
h owceoetumntiveelet eeo a
t e rea ngoeut g tamnao u taoymtiveelnd mnpnao el ino
oumnentspr sofea ec es mno
t wdirnoyma h mwl o mwhiti oshowexaletnthe hes ostow ampl o
tce gsmmnostow t symomae oar
h owceoetuataoe hes t e mnaew amo t eCcedilḸ g ialeow ghtoaetostow t syml ineow gof l howohe t
amnaeou taow ght
Lint
AndroidStudioshowslintwarningsforvariousaccessibilityissuesandprovideslinkstotheplacesinthesourcecodecontainingtheseissuesForexamp
71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
Creating a LocationRquest object
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T optio youc urfora Locationquest i lud
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YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
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9 d t
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Thetypesofoperationsyoucanperformonacanvasinclude
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121 AnimationsContents
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121Animations
247
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Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
Creating a LocationRquest object
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
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121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
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ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
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Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
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Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
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T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
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UpdatetheUIinthitdseaTextView
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6 H H W K H LiveData
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Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Youshouldtestyourappmeensurethatitbehavestheway
IfyoutargetyourapptoAndroid42(APIlevel17)orhigherus
Thesetwoimagesshowexamplesoftextsetagainsmagalackorwhitemackground ThetextattheleftshowhighercontrasmOntherightthetextissetamagaowercontrasmwhimishardertoread emarativeelementssumasmogosmontneut tomeetminimumcontrasmratios vensoiv
demarativeelementsprovit eimportantinformationmakesuretheymreeasymot istinguish ee owcoangoeu naov
ornts rmaaive aiist urea roet mlaiialeowmntt t oovi tio
h owcoangoeu t symtit eo phtea owcot st oftmmnd mnai ecot inoaet fheymtoar
h owceoetumntiveelet eeo a
t e rea ngoeut g tamnao u taoymtiveelnd mnpnao el ino
oumnentspr sofea ec es mno
t wdirnoyma h mwl o mwhiti oshowexaletnthe hes ostow ampl o
tce gsmmnostow t symomae oar
h owceoetuataoe hes t e mnaew amo t eCcedilḸ g ialeow ghtoaetostow t syml ineow gof l howohe t
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Lint
AndroidStudioshowslintwarningsforvariousaccessibilityissuesandprovideslinkstotheplacesinthesourcecodecontainingtheseissuesForexamp
71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
Creating a LocationRquest object
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121Animations
247
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
IfyoutargetyourapptoAndroid42(APIlevel17)orhigherus
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71 Location servicesContents
IntroductionS
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2 Callthe
Creating a LocationRquest object
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Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
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121Animations
247
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advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
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ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
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Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
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T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
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6 H H W K H LiveData
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Thesetwoimagesshowexamplesoftextsetagainsmagalackorwhitemackground ThetextattheleftshowhighercontrasmOntherightthetextissetamagaowercontrasmwhimishardertoread emarativeelementssumasmogosmontneut tomeetminimumcontrasmratios vensoiv
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ornts rmaaive aiist urea roet mlaiialeowmntt t oovi tio
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Lint
AndroidStudioshowslintwarningsforvariousaccessibilityissuesandprovideslinkstotheplacesinthesourcecodecontainingtheseissuesForexamp
71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
Creating a LocationRquest object
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Stylingofthebase
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Thetypesofoperationsyoucanperformonacanvasinclude
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Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
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ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
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Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Lint
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71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
Creating a LocationRquest object
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Target (location)
Thecameratargetisthelocationoftheceoerofthemapspecifiedaslatitudeaolooitude
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Thecamerabearioisthedirectioniowhi averticallioonthemappoiosmeasuredioegreesclockwisefromorthSomeoodrivioacaroftenturoaroadmaptoalignitwith
theirMec
Tľptih tigw eieoo ala
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d
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l e loob dmapoelsehecamerrosgnx ohashecamerae^asurediod
_miractolio ocamth
theirM them gnpo lon ᵐ
U G H JG H U H PE V X P H H H F D W L R Q
themi orM he llioo la
w dgwthh o ra o apf l tiBcal tif lcatiBo n )
roti
l e li on aeoo h
ection i o bear oaroao di gwthh f ctox qrioCcedilḸeuecadiao
Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
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TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
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advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
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m
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Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
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Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
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ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
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overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
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forchan ea edatathatthe Iwi eseordisp acothat
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mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
71 Location servicesContents
IntroductionS
1 OpenAndroidStu
2 Callthe
Creating a LocationRquest object
Ifyourappre iresprecisetr ki th i olvesperiodicupd esyou edtocre eaLocationquest objeceacuteth c= t re ireme soft loc io upd esT fusedloc io providerattemptstob c loc io re estsfromdiffere appstoget ri ordertopreserveb tery
T optio youc urfora Locationquest i lud
omioRetoo
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Theuserssettingsmayreduce
locationisdeterminedbytheavailablelocationproviders(netwrkandGS)thelocationpermissionsyourequestedandtheoptionsyousetinthelocationrequest
Torequestandstartlocationupd
3ODFHV$3
andlongitudebounds
TheMapsAPIdefinesasetofcustomXMLattributesforaMapFragmentoraMapViewobject
mapTypeSpecifythetypeofmaptodisplayValidvaluesincludenone
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Target (location)
Thecameratargetisthelocationoftheceoerofthemapspecifiedaslatitudeaolooitude
Bearing (orientation)
Thecamerabearioisthedirectioniowhi averticallioonthemappoiosmeasuredioegreesclockwisefromorthSomeoodrivioacaroftenturoaroadmaptoalignitwith
theirMec
Tľptih tigw eieoo ala
d ohobei
d
i sep ellioon llfgnowhi avaiothemwisefro t a t ommmro hmbs ti
l e loob dmapoelsehecamerrosgnx ohashecamerae^asurediod
_miractolio ocamth
theirM them gnpo lon ᵐ
U G H JG H U H PE V X P H H H F D W L R Q
themi orM he llioo la
w dgwthh o ra o apf l tiBcal tif lcatiBo n )
roti
l e li on aeoo h
ection i o bear oaroao di gwthh f ctox qrioCcedilḸeuecadiao
Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
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121 AnimationsContents
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Af lip
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121Animations
247
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
1 OpenAndroidStu
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Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
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Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
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7 K H F K D O O H Q J H L V W K D W R X K D Y H
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Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
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121Animations
247
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ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
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ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
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Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
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T hefollow ingcodeshow show toattachanobservertoLiveData
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Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
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Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
2 Callthe
Creating a LocationRquest object
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Torequestandstartlocationupd
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TheMapsAPIdefinesasetofcustomXMLattributesforaMapFragmentoraMapViewobject
mapTypeSpecifythetypeofmaptodisplayValidvaluesincludenone
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Target (location)
Thecameratargetisthelocationoftheceoerofthemapspecifiedaslatitudeaolooitude
Bearing (orientation)
Thecamerabearioisthedirectioniowhi averticallioonthemappoiosmeasuredioegreesclockwisefromorthSomeoodrivioacaroftenturoaroadmaptoalignitwith
theirMec
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Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
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uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
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Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
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Thetypesofoperationsyoucanperformonacanvasinclude
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
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121 AnimationsContents
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What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
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121Animations
247
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
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121 AnimationsContents
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Af lip
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ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
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121Animations
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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theirMec
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Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
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Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
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Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
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ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
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Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
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6 H H W K H LiveData
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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Target (location)
Thecameratargetisthelocationoftheceoerofthemapspecifiedaslatitudeaolooitude
Bearing (orientation)
Thecamerabearioisthedirectioniowhi averticallioonthemappoiosmeasuredioegreesclockwisefromorthSomeoodrivioacaroftenturoaroadmaptoalignitwith
theirMec
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Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
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Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
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Adding the constructors
1 OpentheJavaclassyoucreated2
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121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
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121Animations
247
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ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
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Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
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Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
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s alarc
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finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
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- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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Target (location)
Thecameratargetisthelocationoftheceoerofthemapspecifiedaslatitudeaolooitude
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theirMec
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Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
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9 d t
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Adding the constructors
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Thetypesofoperationsyoucanperformonacanvasinclude
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Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
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What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
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121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
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ditdc e
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SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
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objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
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Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
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per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
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mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
[
Target (location)
Thecameratargetisthelocationoftheceoerofthemapspecifiedaslatitudeaolooitude
Bearing (orientation)
Thecamerabearioisthedirectioniowhi averticallioonthemappoiosmeasuredioegreesclockwisefromorthSomeoodrivioacaroftenturoaroadmaptoalignitwith
theirMec
Tľptih tigw eieoo ala
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l e loob dmapoelsehecamerrosgnx ohashecamerae^asurediod
_miractolio ocamth
theirM them gnpo lon ᵐ
U G H JG H U H PE V X P H H H F D W L R Q
themi orM he llioo la
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ection i o bear oaroao di gwthh f ctox qrioCcedilḸeuecadiao
Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
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c
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TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Target (location)
Thecameratargetisthelocationoftheceoerofthemapspecifiedaslatitudeaolooitude
Bearing (orientation)
Thecamerabearioisthedirectioniowhi averticallioonthemappoiosmeasuredioegreesclockwisefromorthSomeoodrivioacaroftenturoaroadmaptoalignitwith
theirMec
Tľptih tigw eieoo ala
d ohobei
d
i sep ellioon llfgnowhi avaiothemwisefro t a t ommmro hmbs ti
l e loob dmapoelsehecamerrosgnx ohashecamerae^asurediod
_miractolio ocamth
theirM them gnpo lon ᵐ
U G H JG H U H PE V X P H H H F D W L R Q
themi orM he llioo la
w dgwthh o ra o apf l tiBcal tif lcatiBo n )
roti
l e li on aeoo h
ection i o bear oaroao di gwthh f ctox qrioCcedilḸeuecadiao
Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
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on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
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d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Thisisusefulifyouwanttoreplacethedefaultlevelpickerwithyourownlevelpickerforexampletocreateanaugmented-realityscavengerhuntinyourhome
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
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TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
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tp pae
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pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Stylingofthebase
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Note TheMy LocationlayerdoesnotreturnanydataToaccesslocat
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
TheAPIfirstcalls
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
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tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
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7
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F
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E
V
W
U
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F
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FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
YoucanusetransparenttileoverlaystoaddextrafeaturestothemapTomaketileoverlaystransparentsetatransparencyfactoronthetileoverlayprogrambrvbary
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Unlikewithamapitsnotpossibletoconfiguretheinitial theitheiepaipo te Ogravebmapntir i ni configuretheio te ioeue apia clc
osibfuinia l aoponftnitfui ne ooaig
uinoianfoitnioi l ao
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
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7
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Related practicalTherelatedpracticaldocumentationisin91 t tni ncap et pp pnni Mr
9 d t
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
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mpaAeAnhlasseo r seslaa
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meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
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W
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Withcustomviewsyoucan
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
IfyouextendtheViewclassdrawthecustomviewsshapeandcontrolitsappearancebyoverridingViewmethodssuchasonDraw()andonMeasure()
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
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7
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Adding the constructors
1 OpentheJavaclassyoucreated2
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
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pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
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W
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O
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
ThecodeusessetCompoundDrawablesRelativeWithIntrinsic
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Thissectionshowshowtodrawthe
Acirc Iuml
נ
o
d
a
c
h
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
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per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
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mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
TheobtainStyledAttributes()methodreturnsaTypedArrayufuattributevaluesuincludingthefanOnColorandfanOffColorcustomat
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
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SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
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methodwithaMed Pl rOnPreparedL
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objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
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YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
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UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
7 K H F K D O O H Q J H L V W K D W R X K D Y H
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
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VH
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Thetypesofoperationsyoucanperformonacanvasinclude
Fil
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
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isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
MyCanvas
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
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YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
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UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Clipping amp O L S S L Q J isamethodfordefiningregionsofanimagecanvasorbitmapthatareselectivelydrawnornotdrawnontothescreenOnepurposeofclippingistoreduceoverdrawWhenyoureduceoverdrawyouminimizethenumberoftimesapixelorregionofthedisplayisdrawninordertomaximizedrawingperformanceYoucanalsouseclippingtocreateinterestingeffectsinuserinterfacede nandanimationn
Thefollowingscreenshotfromtheepplyingclippinetoacanvapracticalshowshowyon canclipandsombineclippineregions nyonshlisusomfollpsor pi r nCshli
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
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W
H
D
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O
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F
D
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V
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U
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F
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FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
121 AnimationsContents
W hat is animat ionTypes of animat ions f or AndroidV iew animat ionPropert y animat ionDrawable animat ionPhysics-based animat ionRelat ed pract icalsLearn more
What is animationAnimat ion is t he t echnique f or creat ing t he illusion of a moving object by showing a series ofdiscret e images t hat change over t ime such as
Af lip
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
ThepropertyanimationsystemisarobustframeworkthatallowsyoutoanimatealmostanythingApropertyanimationchangesapropertysvalueoveraspecifiedlb gthoftimbForb( amplbyoucananimateacirclbtogrowbiggerbyincreasingi
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
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ampUH
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W
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D
E
V
W
U
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F
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FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
ATypeEvaluatorEvaluatorsmellmhemropertymnimationmystemmowmomalculatemaluesformmivenmropert
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
updatestheproperty
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Creating a physics-based animation
121Animations
247
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
adielos
eeca
vidu eit
di medihamhca dahehdhamt tcזheeediaioT
tca eia thdmediehamatcaitdelos
eiah ca mhei ldthsh nľľnh
t saruha it dmed
l la madt
ditdc e
edmh h dאit
diasaruf
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Theformatcanmeantheformatorencoding theindividualmediasamplesThisistencalledthe sample format codecanditdeterminesh themediasampleham c
ca codinthendileehmtThtillica iaiormatsodiahatľthenľľtThľte rmatsodiahatTccaiformahemeduaeiodit
iformahemodiaioe ldhformatcadmeantheformatcatheindielomiheca das
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vidu eit
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SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
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tp pae
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mpaAeAnhlasseo r seslaa
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tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
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7
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D
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V
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U
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FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
SeePlayamediafileontheCommonIntentspageformo
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
advancedtopicthatthiscoursedoesntexploreFormostdevelopersExoPlayerprovidesabetteroptionevenforcomplexmedia-playbackapps
ThecustomizabilityofExoPlayermakesitthepreferredchoiceformostmediaappsExoPlayersupportsmanyformatsandithasextensiblemodularf
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
ThemediasourcefortheVideoViewisthelocationofthevideocontenttobeplayedThislocationisspecifiedbyaUriobjectrepresentingaUniformResourceIdentifierTheURIcanbe
ThelocationofavideofileembeddedinyourappasanAndroidresourceThelocationofafileavailableonexternalstoragesuchasanSDcardTheURLofamediafilelocatedonawebserverontheinternetAURIcontainedinadatabaseandsuppliedbyacontentprovideryoucreateAnyotherlocationthatcanbespecifiedbyaURI
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
o
w
usethese nPreparedL
ner()
methodwithaMed Pl rOnPreparedL
ner
objecttodefinetheonPrepared()callbackImplementthiscallbacktoaddcodetobeexecutedoncethemediahasbeenprepared
m
o
wse nPrepare
ner(newMed Pl rnPrepare
ner(
O r
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
ApreparationlistenerandtheonPrepared()callbackenableyoutoprovideinformationtotheuser(suchasaLoadingmessage)whilepreparationtakesplaceWhenthecallbackisinvokedtoindicatethatthemediaisreadytoplayyoucanremovethatmessageandplaythemedia
YoucandefineyourmedialistenersinonCrea () oranytimeyousetupyourmediaFor
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Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
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YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Ifyouwanttocreateamedia-playerappofanycomplexityonAndroidExoPlayeristherecommendedstartingplaceSeetheExoPlayerdeveloperguideorExoPlayerprojectformoreinformation
Architecture for complex media appsFormorecomplexmediaplayerappsincludingthosewhosemainpurposeistoplaymediaitisabestpracticetoensurethatyourappplayswellwiththeoverallAndroidplatformecosystemThispracticeisespeciallyimportantformusic-playerappsbecauseusersoftenexpectmusic-playerappstoplayevenwhentheappisnotvisibleonscreenandusersexpecttocontrolmusic-playerappsfromhardwaredevicessuchasheadsetbuttonsorthroughAndroidAuto
TointegratewiththeAndroidplatformtheAndroidmediaAPIsincludeanumberofclassestoabstractvariousaspectsofmediaplaybackbetmpnyourappandthesystemincludingmediasessionsmediacontrollersandmediabromersYouimplementtheseclassesinadditiontoandalongsideofyourappstransportcontrolsandmediaplayer
N te TheAndroidv4supportlibraryincludesC mpatversionsoftheclassesdescribedinthissectionintheMedia-C mpatsupportlibrary AswithallAndroidappsitisabest
thepldsetCcedilḸamer sesdescrid iastpractbrarh $s yspfroc-p mpanthe
tp pae
p
]h medismpanthe
tp pae
я dmmedis mpaAe AuAoid roi mpAuhlasse patricontrolsa o de
mpaAeAnhlasseo r seslaa
ec lss r ia
meAnhlasse m] eia rn
tpalongsi o] eacute
pnaolmuseacutebrar mayera edrpwaresor
Aswih dיaҵdrbromicontrols ofaҵ
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
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7
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
YoucreateasinglemediasessionforyourappusuallyatthesametimeyoucreatethemediaplayerTheplayerisonlycalledfromthemediasessionthatcontrolsi
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
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VH
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D
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D
F
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FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Recommended Architecture ComponentsTointroducetheterminologyhereisashortintroductiontotheArchitectureCom
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
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VH
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W
H
D
S
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E
O
L
F
D
E
V
W
U
D
F
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FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Thedataforanappwithadatabasecentersa
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
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VH
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E
O
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F
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W
U
D
F
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FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
todataacrossmultiplecomponentsofyourappcancreateexplicitr canatal
c
s alarc
em
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
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W
H
D
S
X
E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
UIcomponentsjustobserverelevantdataanddontstoporresumeobservationLiveDataisawareofvantda
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
laec otem S
Rmter ees ce acutec ta
mtyhrver in R use2
s
7
R
X
VH
5R
R
P
ampUH
D
W
H
D
S
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E
O
L
F
D
E
V
W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
W K H Q X S G D W H W K H F D F K H G G D W D I R U H [ D P S O H L Q W K H D G D S W H U D Q G W K H D G D S W H U X S G D W H V Z K D W W K H
X V H U V H H V
8 V X D O O R X R E V H U Y H G D W D L Q D ViewModelnotdirectlyintheR epositoryorinR oom
ViewModelisdescribedinalatersection
T hefollow ingcodeshow show toattachanobservertoLiveData
CreatetheobserverwhidupdatestheUI
finalObserverltStringgtnameObserver=newObserverltStringgt()
Override
publidvoidon anged(NullablefinalStringnewName)
UpdatetheUIinthitdseaTextView
mNameTextViewsetText(newName)
Modelge nurrentName()observe(thitnameObserver)
6 H H W K H LiveData
docum entationtolearno chbw aystouse
LiveDataorw a h cis
A rchitectureC om ponentsLiveD a andLifecycle ėideo
Room da baseRoom is a database layhb on top of a SQLi m a n
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thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
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AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
7
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D
S
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E
O
L
F
D
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W
U
D
F
W
FODVVWK
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
thelifecyclelibraryForanintro$uctoryguidetothistopicseetheViewModel
overview
AViewModelhodsyourappsUIdatainalifecycle-consciouswaythatsurvivesconfigurationchangesSeparatingyo
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
deviceisrotatedIfyoustoreareferencetotheActivityintheViewModelyouendupwithreferencesthatpointtothedestroyed Activity hisisa e ory ea Ifyouneedthe
app icationconte tese
AndroidViewModel
instea of
ViewModel
IntheViewModel ese ive AdA
forchan ea edatathatthe Iwi eseordisp acothat
i oucana ano serveran respondtochan es ereistheco p etecode
per ic c Acc ordViewModel e dendc AndroidViewModel
privAde ordrepoc tor Mrepoc tor
privAde ive AdA ict ord MA ordc
per ic ordViewModel App icAdion App icAdion
ceper App icAdion
Mrepoc tor M new ordrepoc tor App icAdion
MA ordc M Mrepoc tor wed ordc
ive AdA icd ord wed ordc redern MA ordc
per ic void inc rd ord word Mrepoc tor inc rd word
IdadViewModel
isnotarep ace entfor
on Ave ncdAnc dAde ecaesethe ViewModeldoesnotservi e aprocesschetdown ee
avin Itatec
d o earn orewatchthisrchitectere o ponents iew odel video A rchitectere o ponents
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
mWordViewModelgetAllWords()observe(thisnewObserver
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
Theandroidarchlifecyclepackageprovidesclassesandi
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
- Table of Contents
- Introduction
- 11 Fragments
- 12 Fragment lifecycle and communications
- 21 App widgets
- 31 Sensor basics
- 32 Motion and position sensors
- 40 Performance
- 41 Rendering and layout
- 42 Memory
- 43 Best practices network battery compression
- 51 Languages and layouts
- 52 Locales
- 61 Accessibility
- 71 Location services
- 81 Places API
- 91 Google Maps API
- 101 Custom views
- 111 The Canvas class
- 112 The SurfaceView class
- 121 Animations
- 131 Simple media playback
- 141 Architecture Components
-
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