android 2

CS 696 Mobile Phone Application DevelopmentFall Semester, 2009

Doc 2 Activity States & GUI View ExamplesSept 8, 2009

Copyright , All rights reserved. 2009 SDSU & Roger Whitney, 5500 Campanile Drive, San Diego, CA 92182-7700 USA. OpenContent (http://www.opencontent.org/opl.shtml) license defines the copyright on this document.

2Contents

Mercurial & Example RepositoryAndroid PartsActivity Life CycleAndroid Examples

3Mercurial & Example Repository

Mercurial

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http://mercurial.selenic.com/wiki/

Distributed Source Control System

Written in Python

Mercurial Eclipse

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http://www.vectrace.com/mercurialeclipse/

Eclipse Plugin for Mercurial

Add functionality to Team menu item

Course Examples Mercurial Repository

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http://bismarck.sdsu.edu/cgi-bin/hg/

Web interfaceView onlineDownload zipped fileYou can import the unzipped file using Mercurial Eclipse plugin

Mercurial clonehg clone http://bismarck.sdsu.edu/cgi-bin/hg/android/HelloWorldYou can import the unzipped file using Mercurial Eclipse plugin

Load directly into EclipseImport...Select "Clone repository using MercialEclipse"Enter URL:

http://bismarck.sdsu.edu/cgi-bin/hg/android/HelloWorldYou may have to clean the project

History

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8Android Parts

Building Blocks Of Android Application

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AndroidManifest.xmlActivitiesViewsIntentsServicesNotificationsContent Providers

AndroidManifest.xml

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Contains information about the application needed by the phone to run it

@string/app_name indicates that the string is to be found in the string resource file under the label app_name.

Activities

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Code that does some work

Has a life cyclePaused, Killed, etc.

Views have an associated activity

Activities can be viewless

View

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An object that knows how to draw itself to the screen

Set of existing views or widgets

Can create your own viewGamesNew widgets

Intent

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Used to move from screen to screen

ContainsDataAction

What you want doneMAIN, VIEW, PICK, EDIT, etc

Intent filterWhat intents an activity can handle

To move to a new screen register an intentstartActivity(anIntent).

Service

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Code that runs in the background

Can be long lived

No UI

Example music player

Notifications

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Icon that appears in the status bar

Used to notify userSMSVoicemail

Content Holder

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Set of methods to let applications access content provider data

Used to allow multiple applications access data

Address book

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Activity Life Cycle

Activity

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Single, focused thing that a user can do

Usually each screen has its own activity

An application may have multiple screens, hence multiple activities

An application runs in its own Linux process

Activity States

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ActiveRunning activity in foreground of screen

PausedLost focus, but still visibleRetains all state informationIn extreme memory situations may be killed

StoppedNot visibleRetains all state informationOften will be killed

Killed

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Activity Example

package edu.sdsu.cs696;

import android.app.Activity;import android.os.Bundle;import android.widget.TextView;

public class CountStates extends Activity { int paused = 0; int killed = 0; int stopped = 0; TextView text;

Activity Example

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public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); if (savedInstanceState != null) { paused = savedInstanceState.getInt("paused"); killed = savedInstanceState.getInt("killed"); stopped = savedInstanceState.getInt("stopped"); } text = new TextView(this); text.setText("Paused: " + paused + " stopped: " + stopped + " killed " + killed); setContentView(text); }

Activity Example

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protected void onResume() { super.onResume(); text.setText("Paused: " + paused + " stopped: " + stopped + " killed " + killed); }

protected void onStart() { super.onStart(); text.setText("Paused: " + paused + " stopped: " + stopped + " killed " + killed); }

protected void onStop() { stopped++; super.onStop(); }

Activity Example

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protected void onPause() { paused++; super.onPause(); }

protected void onDestroy() { killed++; super.onDestroy(); }

protected void onSaveInstanceState(Bundle outState) { outState.putInt("paused", paused); outState.putInt("killed", killed); outState.putInt("stopped", stopped); }

}

Sample Run

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Android Examples

String ResourcesLoggingEditTextClick ListenerButtonMenus

Some Android Views

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AutoCompleteTextViewButtonCheckBoxCheckedTextViewChronometerDatePickerDigitalClockEditTextExpandableListViewGalleryGridViewImageButtonListViewMapView,

MultiAutoCompleteTextViewRadioButtonRatingBarScrollViewSeekBarSpinnerTabHostTabWidgetTableRowTimePickerToggleButtonTwoLineListItemVideoViewViewAnimatorWebViewZoomButtonZoomControls

Using String Resources Example

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package sdsu.cs696;

import android.app.Activity;import android.os.Bundle;

public class HelloAndroid extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); }}

src/com.android/hello2/R.java

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package sdsu.cs696;

public final class R { public static final class attr { } public static final class drawable { public static final int icon=0x7f020000; } public static final class layout { public static final int main=0x7f030000; } public static final class string { public static final int app_name=0x7f040001; public static final int hello=0x7f040000; }}

//Autogenerated

res/layout/main.xml

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res/values/strings.xml

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Hello using String resources! HelloWorldApp

The easiest way to create String resources is to first put the string in you source code and then use the Anrdoid "Extract Android String" refactoring.

Using Text in main.xml

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res/layout/main.xml

Measurement Units

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px pixels

dip device independent pixels

sp scaled pixels best for text size

pt points

in inches

mm millimeters

XML Attributes

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android.R.styleableDefines all xml attributeshttp://code.google.com/android/reference/android/R.styleable.html

Widget class docs contain links to classes attributes

http://code.google.com/android/reference/android/R.styleable.html#View contains list of attributes for View class

Logging Example

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package sdsu.cs696;

import android.app.Activity;import android.os.Bundle;import android.util.Log;

public class HelloAndroid extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Log.i("test","me"); }

Viewing the Log

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Start the emulator

Run your program from eclipse

In eclipse select DDMS perspective

Use Filters

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Log Methods

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Errore(String tag, String message, Throwable throw)e(String tag, String message)

WARNw(String tag, String message, Throwable throw)w(String tag, String message)

INFOi(String tag, String message, Throwable throw)i(String tag, String message)

DEBUGd(String tag, String message, Throwable throw)d(String tag, String message)

VERBOSE (only for development)v(String tag, String message, Throwable throw)v(String tag, String message)

In order of verbosity

EditText Example

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package sdsu.cs696;

import android.app.Activity;import android.os.Bundle;import android.widget.EditText;

public class HelloAndroid extends Activity { private EditText messageText;

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); messageText = (EditText) this.findViewById(R.id.message); messageText.setText("From onCreate"); }}

main.xml with id

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@ symbol in the id tells the XML parser should parse and expand the rest"+" indicates that a resource should be created if is does not already exist

See id.message exists now

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public final class R { public static final class attr { } public static final class drawable { public static final int icon=0x7f020000; } public static final class id { public static final int message=0x7f050000; } public static final class layout { public static final int main=0x7f030000; } public static final class string { public static final int Foo=0x7f040002; public static final int app_name=0x7f040001; public static final int hello=0x7f040000; }}

Click Listener Example

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public class HelloAndroid extends Activity implements View.OnClickListener { private EditText messageText;

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); messageText = (EditText) this.findViewById(R.id.message); messageText.setText("From onCreate"); messageText.setOnClickListener(this); } public void onClick(View v) { messageText.setText(messageText.getText() + " click"); }}

Listeners

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GestureDetector.OnGestureListener Notify when gestures occur

MenuItem.OnMenuItemClickListener a menu item is clicked.

View.OnClickListener a view is clicked.

View.OnCreateContextMenuListener the context menu for this view is being built.

View.OnFocusChangeListener the focus state of a view changed.

View.OnKeyListener a key event is dispatched to this view.

View.OnLongClickListener a view has been clicked and held.

View.OnTouchListener a touch event is dispatched to this view.

ViewGroup.OnHierarchyChangeListener the hierarchy within this view changed.

ViewStub.OnInflateListener ViewStub has successfully inflated its layout resource.

ViewTreeObserver.OnGlobalFocusChangeListener the focus state within the view tree changes.

ViewTreeObserver.OnGlobalLayoutListenerthe global layout state or the visibility of views within the view tree changes.

ViewTreeObserver.OnPreDrawListener the view tree is about to be drawn.

ViewTreeObserver.OnTouchModeChangeListener the touch mode changes.

See View overview at: http://code.google.com/android/reference/android/view/package-summary.html for more information and links to each listener

Button Example

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import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;

public class HelloAndroid extends Activity implements View.OnClickListener { private EditText messageText;

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); messageText = (EditText) this.findViewById(R.id.message); messageText.setText("From onCreate"); Button ok = (Button) findViewById(R.id.ok); ok.setOnClickListener(this); } public void onClick(View v) { messageText.setText(messageText.getText() + " click"); }}

res/layout/main.xml

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@string/hello = use the string resource hello


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Hello using String resources! HelloWorldApp Ok

Menus Example

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import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Button;import android.widget.EditText;

public class HelloAndroid extends Activity implements View.OnClickListener { private EditText messageText; private static final int DAD_ID = Menu.FIRST; private static final int MOM_ID = Menu.FIRST + 1;

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); messageText = (EditText) this.findViewById(R.id.message); messageText.setText("From onCreate"); Button ok = (Button) findViewById(R.id.ok); ok.setOnClickListener(this); }

Menus Cont.

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public void onClick(View v) { messageText.setText(messageText.getText() + " click"); } public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu);

menu.add(0, DAD_ID, 0, R.string.menu_dad).setShortcut('0', 'd'); menu.add(0, MOM_ID, 0, R.string.menu_mom); return true; } public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case DAD_ID: messageText.setText(messageText.getText() + " Dad"); return true; case MOM_ID: messageText.setText(messageText.getText() + " Mom"); return true; } return super.onOptionsItemSelected(item); } }

Menus Cont.

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public boolean onPrepareOptionsMenu(Menu menu) { super.onPrepareOptionsMenu(menu); }}

This method is called just before your menu is to be displayed. In it you can modify the menu to meet the current needs. In this example it is not needed, but is here to make sure you know about it.


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From String resource Lecture Examples OK Hi Dad Hi Mom

Display

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android 2

Documents