Android example source code file (ExampleAppWidgetProvider.java)

This example Android source code file (ExampleAppWidgetProvider.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, app, appwidgetmanager, charsequence, componentname, content, exampleappwidgetprovider, n, os, override, packagemanager, remoteviews, string, tag, utilities, widget

The ExampleAppWidgetProvider.java Android example source code

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.appwidget;

import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.SystemClock;
import android.util.Log;
import android.widget.RemoteViews;

// Need the following import to get access to the app resources, since this
// class is in a sub-package.
import com.example.android.apis.R;

/**
 * A widget provider.  We have a string that we pull from a preference in order to show
 * the configuration settings and the current time when the widget was updated.  We also
 * register a BroadcastReceiver for time-changed and timezone-changed broadcasts, and
 * update then too.
 *
 * <p>See also the following files:
 * <ul>
 *   <li>ExampleAppWidgetConfigure.java
 *   <li>ExampleBroadcastReceiver.java
 *   <li>res/layout/appwidget_configure.xml
 *   <li>res/layout/appwidget_provider.xml
 *   <li>res/xml/appwidget_provider.xml
 * </ul>
 */
public class ExampleAppWidgetProvider extends AppWidgetProvider {
    // log tag
    private static final String TAG = "ExampleAppWidgetProvider";

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        Log.d(TAG, "onUpdate");
        // For each widget that needs an update, get the text that we should display:
        //   - Create a RemoteViews object for it
        //   - Set the text in the RemoteViews object
        //   - Tell the AppWidgetManager to show that views object for the widget.
        final int N = appWidgetIds.length;
        for (int i=0; i<N; i++) {
            int appWidgetId = appWidgetIds[i];
            String titlePrefix = ExampleAppWidgetConfigure.loadTitlePref(context, appWidgetId);
            updateAppWidget(context, appWidgetManager, appWidgetId, titlePrefix);
        }
    }
    
    @Override
    public void onDeleted(Context context, int[] appWidgetIds) {
        Log.d(TAG, "onDeleted");
        // When the user deletes the widget, delete the preference associated with it.
        final int N = appWidgetIds.length;
        for (int i=0; i<N; i++) {
            ExampleAppWidgetConfigure.deleteTitlePref(context, appWidgetIds[i]);
        }
    }

    @Override
    public void onEnabled(Context context) {
        Log.d(TAG, "onEnabled");
        // When the first widget is created, register for the TIMEZONE_CHANGED and TIME_CHANGED
        // broadcasts.  We don't want to be listening for these if nobody has our widget active.
        // This setting is sticky across reboots, but that doesn't matter, because this will
        // be called after boot if there is a widget instance for this provider.
        PackageManager pm = context.getPackageManager();
        pm.setComponentEnabledSetting(
                new ComponentName("com.example.android.apis", ".appwidget.ExampleBroadcastReceiver"),
                PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
                PackageManager.DONT_KILL_APP);
    }

    @Override
    public void onDisabled(Context context) {
        // When the first widget is created, stop listening for the TIMEZONE_CHANGED and
        // TIME_CHANGED broadcasts.
        Log.d(TAG, "onDisabled");
        PackageManager pm = context.getPackageManager();
        pm.setComponentEnabledSetting(
                new ComponentName("com.example.android.apis", ".appwidget.ExampleBroadcastReceiver"),
                PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
                PackageManager.DONT_KILL_APP);
    }

    static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
            int appWidgetId, String titlePrefix) {
        Log.d(TAG, "updateAppWidget appWidgetId=" + appWidgetId + " titlePrefix=" + titlePrefix);
        // Getting the string this way allows the string to be localized.  The format
        // string is filled in using java.util.Formatter-style format strings.
        CharSequence text = context.getString(R.string.appwidget_text_format,
                ExampleAppWidgetConfigure.loadTitlePref(context, appWidgetId),
                "0x" + Long.toHexString(SystemClock.elapsedRealtime()));

        // Construct the RemoteViews object.  It takes the package name (in our case, it's our
        // package, but it needs this because on the other side it's the widget host inflating
        // the layout from our package).
        RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.appwidget_provider);
        views.setTextViewText(R.id.appwidget_text, text);

        // Tell the widget manager
        appWidgetManager.updateAppWidget(appWidgetId, views);
    }
}