android jump start: application development

Android Jump Start: Application Development

Marcus Chou

Smartphone?

Market trend

Close to 20% of U.S. smartphone owners spent $100 on apps in 2008 -- ABI Research Survey

Market trend (cont.)

App Store

Smart phone of nowadays

Blonde??

Wallpaper of Android

Installed applications

Applications menu

Notification

Preference

Android Market

Android Market (cont.)

Prerequisites

• Java programming skills • Android SDK

Java

• Simple, Object Oriented, and familiar• Interface, Abstract, extends, implement Reference:http://java.sun.com/docs/books/tutorial/

Android SDK

• Emulator• Tools• Document• Library• Sample code

Reference:http://code.google.com/android/documentation.html

Four building block...

• Activity• Broadcast Intent Receiver• Service• Content Provider

Activity

• A activity is usually a single screen in an application

• A user interface compsed of Views and respond to events

• A application may consist of many activities

Activity (cont.) Resource

• Drawable• Layout• Values

Activity (cont.) UI Layout Design<TabHost> <LinearLayout> <LinearLayout> <ImageView/> <ScrollView> <TextView/> </ScrollView> </LinearLayout> <LinearLayout> <TabWidget/> <FrameLayout/> </LinearLayout> </LinearLayout></TabHost>

Activity (cont.)

public class About extends Activity{ protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.about); String about = this.getIntent().getExtras().getString("about"); TextView tv=(TextView)this.findViewById(R.id.about); tv.setText(about);}}

Activity (cont.)

• Use "Intent" to activate the screen (Activity) • The two most important parts of the intent

data structure are the action and the data to act upon.

Explicit Intents

Explicit Intents (cont.)

Intent intent = new Intent(ItemList.this,VideoPlayer.class); intent.putExtra("file_path", selectedItem.getFilePath());

startActivity(intent);

Implicit Intents

Uri uri = Uri.parse("http://tw.youtube.com/watch?v=S6o7rwrxt4g"); Intent intent = new Intent(Intent.ACTION_VIEW, uri); try { if (startActivity(intent)) { // success } } catch (ActivityNotFoundException ex) { // fail }

Broadcast Intent Receiver

• Broadcast Receiver • Notification

Broadcast Receiver (cont.)

private void registerBroadcastListener(){ IntentFilter filter = new IntentFilter(Intent.ACTION_TIME_TICK ); this.registerReceiver(this.mBlackdidiListener, filter);} private class BlackdidiBroadcastListener extends BroadcastReceiver { public void onReceive(Context context, Intent intent) { startActivity((new Intent(BlackdidiSample.this, About.class)).putExtra("about", "time tick")); }}

Broadcast Receiver (cont.)

Broadcast Receiver (cont.)<receiver android:name="com.blackdidi.comp.BootReceiver"> <intent-filter> <action android:name="android.intent.action.BOOT_COMPLETED" /> </intent-filter> </receiver> <receiver android:name="com.blackdidi.comp.ConnectivityReceiver"> <intent-filter> <action android:name="android.net.conn.CONNECTIVITY_CHANGE" /> </intent-filter> </receiver>

Notification (cont.)

public class BlackdidiSample extends Activity { private NotificationManager mNM; ... public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mNM = (NotificationManager) getSystemService(NOTIFICATION_SERVICE); ... } ...}


private void showNotification() { CharSequence text = getText(R.string.hello_notification);

Notification notification = new Notification(R.drawable.star_big_on, text, System.currentTimeMillis());

PendingIntent contentIntent = PendingIntent.getActivity(this, 0,( new Intent(this, About.class)).putExtra("about", "yoho, blackdidi"), 0);

notification.setLatestEventInfo(this, getText(R.string.hello_notification),text, contentIntent);

mNM.notify(R.string.app_name, notification);}

Service

• A Service is code that is long-lived and runs

without a UI• Use Context.bindService() to connect to the

service

Service (cont.)

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0.0" package="com.blackdidi.podcast"> <application android:icon="@drawable/icon" android:label="@string/app_name"> <service android:name=".xml.ChannelService" /> <service android:name=".download.DownloadService" />....

Content Provider

A content provider is only required if you need to share data between multiple applications.

• Querying for Data• Modifying Data• Adding a Record• Deleting a Record

Content Provider (cont.)public class BlackdidiList extends ListActivity{ protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Cursor c = getContentResolver().query(CallLog.Calls.CONTENT_URI, null, null, null, null); startManagingCursor(c); ListAdapter adapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_2, c, new String[] {CallLog.Calls.NUMBER , CallLog.Calls.CACHED_NAME }, new int[] { android.R.id.text1, android.R.id.text2 }); setListAdapter(adapter); }}

Content Provider (cont.)

Security<uses-permission android:name="android.permission.INTERNET"></uses-permission> <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/><uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission><uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission><uses-permission android:name="android.permission.WAKE_LOCK"></uses-permission><uses-permission android:name="android.permission.BATTERY_STATS"></uses-permission>

Security (cont.)

Reference

Android Developers Site http://developer.android.com/

Android Developers Blog http://developer.android.com/

Android Developers Group http://groups.google.com/group/android-developers

Android Platform Discussion Grouphttp://groups.google.com/group/android-platform

android jump start: application development

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