How to build a Simple Android Widget

Question

So I have a bit of experience building android applications. But now i would like to build a widget for android that would sit on the home screen and display a button, and when the button is pressed it plays a sound. I've been looking at tutorials online on how to set up an android widget but i cant seem to figure it out. Are there any good tutorials out there on how to make a standalone widget this simple or somewhere i can start? Thanks in advance, Peter

Answer 1

first Create a new layout file inside res/layout, under the project structure, that will define the widget layout (widgetlayout.xml) according to the following structure.

<TextView android:text="@string/widgettext"                android:layout_width="0dp"               android:layout_height="wrap_content"               android:layout_weight="0.8"               android:layout_gravity="center_vertical"               android:textColor="#000000"></TextView> <TextView android:text="@string/widgetmoodtext"               android:id="@+id/widgetMood" android:layout_width="0dp"                android:layout_height="wrap_content"                android:layout_weight="0.3"                android:layout_gravity="center_vertical"                android:textColor="#000000"></TextView> <ImageButton android:id="@+id/widgetBtn"               android:layout_width="0dp"               android:layout_height="wrap_content"               android:layout_weight="0.5"                android:src="@drawable/smile_icon"               android:layout_gravity="center_vertical">  </ImageButton> 

Create the res/xml folder under the project structure Create a xml file (widgetproviderinfo.xml) with the following parameters:

 <appwidget-provider            xmlns:android="http://schemas.android.com/apk/res/android"             android:minWidth="220dp"             android:minHeight="72dp"            android:updatePeriodMillis="86400000"             android:initialLayout="@layout/widgetlayout">        </appwidget-provider> 

Now you should create the service that reacts to the user interaction with the smiley image button (CurrentMoodService.java).

@Override public int onStartCommand(Intent intent, int flags, int startId) {     super.onStart(intent, startId);             updateMood(intent);     stopSelf(startId);     return START_STICKY; }  private void updateMood(Intent intent) {        if (intent != null){         String requestedAction = intent.getAction();         if (requestedAction != null &&  requestedAction.equals(UPDATEMOOD)){             this.currentMood = getRandomMood();             int widgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, 0);             AppWidgetManager appWidgetMan = AppWidgetManager.getInstance(this);             RemoteViews views = new RemoteViews(this.getPackageName(),R.layout.widgetlayout);             views.setTextViewText(R.id.widgetMood, currentMood);             appWidgetMan.updateAppWidget(widgetId, views);           }        }    } 

After defining the service, it is time to implement the widget provider class (CurrentMoodWidgetProvider.java).

    @Override public void onUpdate(Context context, AppWidgetManager appWidgetManager,         int[] appWidgetIds) {     super.onUpdate(context, appWidgetManager, appWidgetIds);      for (int i=0; i<appWidgetIds.length; i++) {         int appWidgetId = appWidgetIds[i];         RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.widgetlayout);         Intent intent = new Intent(context, CurrentMoodService.class);         intent.setAction(CurrentMoodService.UPDATEMOOD);         intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);         PendingIntent pendingIntent = PendingIntent.getService(context, 0, intent, 0);         views.setOnClickPendingIntent(R.id.widgetBtn, pendingIntent);         appWidgetManager.updateAppWidget(appWidgetId, views);     } }    

Finally it is necessary to declare the Service and the AppWidgetProvider in the Manifest (AndroidManifest.xml).

    <service android:name=".CurrentMoodService">     </service> <receiver android:name=".CurrentMoodWidgetProvider">     <intent-filter>         <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />     </intent-filter>     <meta-data android:name="android.appwidget.provider"                android:resource="@xml/widgetproviderinfo" /> </receiver> 

and if you want to download the whole source code then have a look at the url below...

http://sites.google.com/site/androidsourcecode/src/CurrentMoodWidgetProject.rar?attredirects=0