The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...
/* * Copyright (C) 2011 The Android开源工程 * * 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.weatherlistwidget; import android.app.PendingIntent; import android.appwidget.AppWidgetManager; import android.appwidget.AppWidgetProvider; import android.content.Context; import android.content.Intent; import android.content.ComponentName; import android.content.ContentValues; import android.content.ContentResolver; import android.content.ContentUris; import android.database.Cursor; import android.database.ContentObserver; import android.net.Uri; import android.os.Handler; import android.os.HandlerThread; import android.widget.RemoteViews; import android.widget.Toast; import java.util.Random; /** * Our data observer just notifies an update for all weather widgets when it detects a change. */ class WeatherDataProviderObserver extends ContentObserver { private AppWidgetManager mAppWidgetManager; private ComponentName mComponentName; WeatherDataProviderObserver(AppWidgetManager mgr, ComponentName cn, Handler h) { super(h); mAppWidgetManager = mgr; mComponentName = cn; } @Override public void onChange(boolean selfChange) { // The data has changed, so notify the widget that the collection view needs to be updated. // In response, the factory's onDataSetChanged() will be called which will requery the // cursor for the new data. mAppWidgetManager.notifyAppWidgetViewDataChanged( mAppWidgetManager.getAppWidgetIds(mComponentName), R.id.weather_list); } } /** * The weather widget's AppWidgetProvider. */ public class WeatherWidgetProvider extends AppWidgetProvider { public static String CLICK_ACTION = "com.example.android.weatherlistwidget.CLICK"; public static String REFRESH_ACTION = "com.example.android.weatherlistwidget.REFRESH"; public static String EXTRA_CITY_ID = "com.example.android.weatherlistwidget.city"; private static HandlerThread sWorkerThread; private static Handler sWorkerQueue; private static WeatherDataProviderObserver sDataObserver; public WeatherWidgetProvider() { // Start the worker thread sWorkerThread = new HandlerThread("WeatherWidgetProvider-worker"); sWorkerThread.start(); sWorkerQueue = new Handler(sWorkerThread.getLooper()); } @Override public void onEnabled(Context context) { // Register for external updates to the data to trigger an update of the widget. When using // content providers, the data is often updated via a background service, or in response to // user interaction in the main app. To ensure that the widget always reflects the current // state of the data, we must listen for changes and update ourselves accordingly. final ContentResolver r = context.getContentResolver(); if (sDataObserver == null) { final AppWidgetManager mgr = AppWidgetManager.getInstance(context); final ComponentName cn = new ComponentName(context, WeatherWidgetProvider.class); sDataObserver = new WeatherDataProviderObserver(mgr, cn, sWorkerQueue); r.registerContentObserver(WeatherDataProvider.CONTENT_URI, true, sDataObserver); } } @Override public void onReceive(Context ctx, Intent intent) { final String action = intent.getAction(); if (action.equals(REFRESH_ACTION)) { // BroadcastReceivers have a limited amount of time to do work, so for this sample, we // are triggering an update of the data on another thread. In practice, this update // can be triggered from a background service, or perhaps as a result of user actions // inside the main application. final Context context = ctx; sWorkerQueue.removeMessages(0); sWorkerQueue.post(new Runnable() { @Override public void run() { final ContentResolver r = context.getContentResolver(); final Cursor c = r.query(WeatherDataProvider.CONTENT_URI, null, null, null, null); final int count = c.getCount(); final int maxDegrees = 96; // We disable the data changed observer temporarily since each of the updates // will trigger an onChange() in our data observer. r.unregisterContentObserver(sDataObserver); for (int i = 0; i < count; ++i) { final Uri uri = ContentUris.withAppendedId(WeatherDataProvider.CONTENT_URI, i); final ContentValues values = new ContentValues(); values.put(WeatherDataProvider.Columns.TEMPERATURE, new Random().nextInt(maxDegrees)); r.update(uri, values, null, null); } r.registerContentObserver(WeatherDataProvider.CONTENT_URI, true, sDataObserver); final AppWidgetManager mgr = AppWidgetManager.getInstance(context); final ComponentName cn = new ComponentName(context, WeatherWidgetProvider.class); mgr.notifyAppWidgetViewDataChanged(mgr.getAppWidgetIds(cn), R.id.weather_list); } }); } else if (action.equals(CLICK_ACTION)) { // Show a toast final int appWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID); final String city = intent.getStringExtra(EXTRA_CITY_ID); final String formatStr = ctx.getResources().getString(R.string.toast_format_string); Toast.makeText(ctx, String.format(formatStr, city), Toast.LENGTH_SHORT).show(); } super.onReceive(ctx, intent); } @Override public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) { // Update each of the widgets with the remote adapter for (int i = 0; i < appWidgetIds.length; ++i) { // Specify the service to provide data for the collection widget. Note that we need to // embed the appWidgetId via the data otherwise it will be ignored. final Intent intent = new Intent(context, WeatherWidgetService.class); intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]); intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME))); final RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.widget_layout); rv.setRemoteAdapter(appWidgetIds[i], R.id.weather_list, intent); // Set the empty view to be displayed if the collection is empty. It must be a sibling // view of the collection view. rv.setEmptyView(R.id.weather_list, R.id.empty_view); // Bind a click listener template for the contents of the weather list. Note that we // need to update the intent's data if we set an extra, since the extras will be // ignored otherwise. final Intent onClickIntent = new Intent(context, WeatherWidgetProvider.class); onClickIntent.setAction(WeatherWidgetProvider.CLICK_ACTION); onClickIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]); onClickIntent.setData(Uri.parse(onClickIntent.toUri(Intent.URI_INTENT_SCHEME))); final PendingIntent onClickPendingIntent = PendingIntent.getBroadcast(context, 0, onClickIntent, PendingIntent.FLAG_UPDATE_CURRENT); rv.setPendingIntentTemplate(R.id.weather_list, onClickPendingIntent); // Bind the click intent for the refresh button on the widget final Intent refreshIntent = new Intent(context, WeatherWidgetProvider.class); refreshIntent.setAction(WeatherWidgetProvider.REFRESH_ACTION); final PendingIntent refreshPendingIntent = PendingIntent.getBroadcast(context, 0, refreshIntent, PendingIntent.FLAG_UPDATE_CURRENT); rv.setOnClickPendingIntent(R.id.refresh, refreshPendingIntent); appWidgetManager.updateAppWidget(appWidgetIds[i], rv); } super.onUpdate(context, appWidgetManager, appWidgetIds); } }