Android Programming Tutorials

More Home Cooking

Finally, remove all of the code from the onUpdate() implementation in

AppWidget, and replace it with a single call to startService():

package apt.tutorial;

import android.appwidget.AppWidgetManager;

import android.appwidget.AppWidgetProvider;

import android.content.ComponentName;

import android.content.Context;

import android.content.Intent;

import android.database.Cursor;

import android.widget.RemoteViews;

import android.database.sqlite.SQLiteDatabase;

public class AppWidget extends AppWidgetProvider {

@Override

public void onUpdate(Context ctxt,

AppWidgetManager mgr,

int[] appWidgetIds) {

ctxt.startService(new Intent(ctxt, WidgetService.class));

}

}

At this point, if you rebuild and reinstall the project, you will see that things

work as they did before, despite this fairly radical implementation shift.

Step #4: Get Control on Button Clicks

Now, we need to arrange to execute some code when the user presses our

new button. Specifically, we want to simply update the app widget itself, so

we get a new random restaurant.

Since we pulled our updating logic into the WidgetService, we need to have

that button call startService() to request WidgetService to do another

update. However, this is an app widget, so we cannot simply add an

OnClickListener to the button – the button is not in our code, but is in the

home screen, configured via the RemoteViews object.

Instead, we can register a PendingIntent, to tell Android what to do when

the button is clicked.

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