Mobile Programming Kalmesh Nyamagoudar 9th August 2013

Why Mobile sites/apps??

§  Users carry the device wherever they go §  Better interaction with users §  Great monetization benefits

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Issues §  Smaller screens §  Limited computing power §  Limited network connectivity

Smart Phones

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§  iPhone : What I do §  Android : What we will talk today…. §  Windows 8 : Hidden gem §  …. §  …. §  ….

Installations

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§  JDK : http://jdk7.java.net/ §  ADT : http://developer.android.com/sdk/index.html

›  Installs both eclipse and android SDK

§  Create AVD : Android Virtual Device

Let’s create an android project

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Decide your App UI

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What each UI element represents in Android

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Text Field Button

Grid Of Images

Go to Eclipse : Things to do

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§  Create all the UI elements(TextField, Button, GridView) ›  Give ids to all UI elements ›  Create a variable for each UI element

›  Connect each variable with its corresponding UI element

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§  Create a method for Button : OnClick

§  Add Internet permission to Android Manifest

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§  Implement the method that has to execute on click of button

REST Query

•  Where to store the results ??? : ArrayList Of ImageResult Objects •  Create a separate class : ImageResult with two variables

•  thumbUrl •  fullUrl

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§  Run your code once on Emulator ›  Check the output on LogCat’s DEBUG section ›  URLs of image results are printed

§  How to show these images in GridView? ›  Create an adapter(A subclass of ArrayAdapter<ImageResult) class ›  Create an adapter object in main activity ›  Attach it to gridView

›  Populate entries of arraylist into adapter once response is parsed.

§  Run it ›  URLs instead of images in the Grid View

Adding Images to GridView

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§  Create a new layout (Android XML file) ›  Add a SmartImageView to the new layout created

§  Change the name of layout in adapter ›  Dear adapter, please make use of SmartImageView whenever you try to display

something

§  How to load the url into image view?? ›  Job of adapter

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§  ~~ Launching another screen(activity) ›  Demo : YahooImageSearch

§  Google Image Search ›  Demo : GridImageSearch

§  ListView Instead of a GridView?? ›  Demo : YahooExtendedAnswersClient

§  Oauth?? My Images from Flickr?? ›  Scribe.jar ›  https://github.com/thecodepath/android-rest-client-template ›  Demo : FlickrClient