1 /*
2  * Copyright (C) 2006 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.appwidget;
18 
19 import android.content.BroadcastReceiver;
20 import android.content.Context;
21 import android.content.Intent;
22 import android.os.Bundle;
23 
24 /**
25  * A convenience class to aid in implementing an AppWidget provider.
26  * Everything you can do with AppWidgetProvider, you can do with a regular {@link BroadcastReceiver}.
27  * AppWidgetProvider merely parses the relevant fields out of the Intent that is received in
28  * {@link #onReceive(Context,Intent) onReceive(Context,Intent)}, and calls hook methods
29  * with the received extras.
30  *
31  * <p>Extend this class and override one or more of the {@link #onUpdate}, {@link #onDeleted},
32  * {@link #onEnabled} or {@link #onDisabled} methods to implement your own AppWidget functionality.
33  * </p>
34  *
35  * <div class="special reference">
36  * <h3>Developer Guides</h3>
37  * <p>For more information about how to write an app widget provider, read the
38  * <a href="{@docRoot}guide/topics/appwidgets/index.html#AppWidgetProvider">App Widgets</a>
39  * developer guide.</p>
40  * </div>
41  */
42 public class AppWidgetProvider extends BroadcastReceiver {
43     /**
44      * Constructor to initialize AppWidgetProvider.
45      */
AppWidgetProvider()46     public AppWidgetProvider() {
47     }
48 
49     /**
50      * Implements {@link BroadcastReceiver#onReceive} to dispatch calls to the various
51      * other methods on AppWidgetProvider.
52      *
53      * @param context The Context in which the receiver is running.
54      * @param intent The Intent being received.
55      */
56     // BEGIN_INCLUDE(onReceive)
onReceive(Context context, Intent intent)57     public void onReceive(Context context, Intent intent) {
58         // Protect against rogue update broadcasts (not really a security issue,
59         // just filter bad broacasts out so subclasses are less likely to crash).
60         String action = intent.getAction();
61         if (AppWidgetManager.ACTION_APPWIDGET_UPDATE.equals(action)) {
62             Bundle extras = intent.getExtras();
63             if (extras != null) {
64                 int[] appWidgetIds = extras.getIntArray(AppWidgetManager.EXTRA_APPWIDGET_IDS);
65                 if (appWidgetIds != null && appWidgetIds.length > 0) {
66                     this.onUpdate(context, AppWidgetManager.getInstance(context), appWidgetIds);
67                 }
68             }
69         } else if (AppWidgetManager.ACTION_APPWIDGET_DELETED.equals(action)) {
70             Bundle extras = intent.getExtras();
71             if (extras != null && extras.containsKey(AppWidgetManager.EXTRA_APPWIDGET_ID)) {
72                 final int appWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID);
73                 this.onDeleted(context, new int[] { appWidgetId });
74             }
75         } else if (AppWidgetManager.ACTION_APPWIDGET_OPTIONS_CHANGED.equals(action)) {
76             Bundle extras = intent.getExtras();
77             if (extras != null && extras.containsKey(AppWidgetManager.EXTRA_APPWIDGET_ID)
78                     && extras.containsKey(AppWidgetManager.EXTRA_APPWIDGET_OPTIONS)) {
79                 int appWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID);
80                 Bundle widgetExtras = extras.getBundle(AppWidgetManager.EXTRA_APPWIDGET_OPTIONS);
81                 this.onAppWidgetOptionsChanged(context, AppWidgetManager.getInstance(context),
82                         appWidgetId, widgetExtras);
83             }
84         } else if (AppWidgetManager.ACTION_APPWIDGET_ENABLED.equals(action)) {
85             this.onEnabled(context);
86         } else if (AppWidgetManager.ACTION_APPWIDGET_DISABLED.equals(action)) {
87             this.onDisabled(context);
88         } else if (AppWidgetManager.ACTION_APPWIDGET_RESTORED.equals(action)) {
89             Bundle extras = intent.getExtras();
90             if (extras != null) {
91                 int[] oldIds = extras.getIntArray(AppWidgetManager.EXTRA_APPWIDGET_OLD_IDS);
92                 int[] newIds = extras.getIntArray(AppWidgetManager.EXTRA_APPWIDGET_IDS);
93                 if (oldIds != null && oldIds.length > 0) {
94                     this.onRestored(context, oldIds, newIds);
95                     this.onUpdate(context, AppWidgetManager.getInstance(context), newIds);
96                 }
97             }
98         }
99     }
100     // END_INCLUDE(onReceive)
101 
102     /**
103      * Called in response to the {@link AppWidgetManager#ACTION_APPWIDGET_UPDATE} and
104      * {@link AppWidgetManager#ACTION_APPWIDGET_RESTORED} broadcasts when this AppWidget
105      * provider is being asked to provide {@link android.widget.RemoteViews RemoteViews}
106      * for a set of AppWidgets.  Override this method to implement your own AppWidget functionality.
107      *
108      * {@more}
109      *
110      * @param context   The {@link android.content.Context Context} in which this receiver is
111      *                  running.
112      * @param appWidgetManager A {@link AppWidgetManager} object you can call {@link
113      *                  AppWidgetManager#updateAppWidget} on.
114      * @param appWidgetIds The appWidgetIds for which an update is needed.  Note that this
115      *                  may be all of the AppWidget instances for this provider, or just
116      *                  a subset of them.
117      *
118      * @see AppWidgetManager#ACTION_APPWIDGET_UPDATE
119      */
onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds)120     public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
121     }
122 
123     /**
124      * Called in response to the {@link AppWidgetManager#ACTION_APPWIDGET_OPTIONS_CHANGED}
125      * broadcast when this widget has been layed out at a new size.
126      *
127      * {@more}
128      *
129      * @param context   The {@link android.content.Context Context} in which this receiver is
130      *                  running.
131      * @param appWidgetManager A {@link AppWidgetManager} object you can call {@link
132      *                  AppWidgetManager#updateAppWidget} on.
133      * @param appWidgetId The appWidgetId of the widget whose size changed.
134      * @param newOptions The appWidgetId of the widget whose size changed.
135      *
136      * @see AppWidgetManager#ACTION_APPWIDGET_OPTIONS_CHANGED
137      */
onAppWidgetOptionsChanged(Context context, AppWidgetManager appWidgetManager, int appWidgetId, Bundle newOptions)138     public void onAppWidgetOptionsChanged(Context context, AppWidgetManager appWidgetManager,
139             int appWidgetId, Bundle newOptions) {
140     }
141 
142     /**
143      * Called in response to the {@link AppWidgetManager#ACTION_APPWIDGET_DELETED} broadcast when
144      * one or more AppWidget instances have been deleted.  Override this method to implement
145      * your own AppWidget functionality.
146      *
147      * {@more}
148      *
149      * @param context   The {@link android.content.Context Context} in which this receiver is
150      *                  running.
151      * @param appWidgetIds The appWidgetIds that have been deleted from their host.
152      *
153      * @see AppWidgetManager#ACTION_APPWIDGET_DELETED
154      */
onDeleted(Context context, int[] appWidgetIds)155     public void onDeleted(Context context, int[] appWidgetIds) {
156     }
157 
158     /**
159      * Called in response to the {@link AppWidgetManager#ACTION_APPWIDGET_ENABLED} broadcast when
160      * the a AppWidget for this provider is instantiated.  Override this method to implement your
161      * own AppWidget functionality.
162      *
163      * {@more}
164      * When the last AppWidget for this provider is deleted,
165      * {@link AppWidgetManager#ACTION_APPWIDGET_DISABLED} is sent by the AppWidget manager, and
166      * {@link #onDisabled} is called.  If after that, an AppWidget for this provider is created
167      * again, onEnabled() will be called again.
168      *
169      * @param context   The {@link android.content.Context Context} in which this receiver is
170      *                  running.
171      *
172      * @see AppWidgetManager#ACTION_APPWIDGET_ENABLED
173      */
onEnabled(Context context)174     public void onEnabled(Context context) {
175     }
176 
177     /**
178      * Called in response to the {@link AppWidgetManager#ACTION_APPWIDGET_DISABLED} broadcast, which
179      * is sent when the last AppWidget instance for this provider is deleted.  Override this method
180      * to implement your own AppWidget functionality.
181      *
182      * {@more}
183      *
184      * @param context   The {@link android.content.Context Context} in which this receiver is
185      *                  running.
186      *
187      * @see AppWidgetManager#ACTION_APPWIDGET_DISABLED
188      */
onDisabled(Context context)189     public void onDisabled(Context context) {
190     }
191 
192     /**
193      * Called in response to the {@link AppWidgetManager#ACTION_APPWIDGET_RESTORED} broadcast
194      * when instances of this AppWidget provider have been restored from backup.  If your
195      * provider maintains any persistent data about its widget instances, override this method
196      * to remap the old AppWidgetIds to the new values and update any other app state that may
197      * be relevant.
198      *
199      * <p>This callback will be followed immediately by a call to {@link #onUpdate} so your
200      * provider can immediately generate new RemoteViews suitable for its newly-restored set
201      * of instances.
202      *
203      * {@more}
204      *
205      * @param context
206      * @param oldWidgetIds
207      * @param newWidgetIds
208      */
onRestored(Context context, int[] oldWidgetIds, int[] newWidgetIds)209     public void onRestored(Context context, int[] oldWidgetIds, int[] newWidgetIds) {
210     }
211 }
212