Android小挂件(APP Widgets)设计指导

<FrameLayout  android:layout_width="match_parent"  android:layout_height="match_parent"  android:padding="@dimen/widget_margin">    <LinearLayout   android:layout_width="match_parent"   android:layout_height="match_parent"   android:orientation="horizontal"   android:background="@drawable/my_widget_background">     <TextView    android:id="@+id/song_info"    android:layout_width="0dp"    android:layout_height="match_parent"    android:layout_weight="1" />     <Button    android:id="@+id/play_button"    android:layout_width="@dimen/my_button_width"    android:layout_height="match_parent" />     <Button    android:id="@+id/skip_button"    android:layout_width="@dimen/my_button_width"    android:layout_height="match_parent" />  </LinearLayout> </FrameLayout> 

/*  * Copyright (C) 2009 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.wiktionary;  import com.example.android.wiktionary.SimpleWikiHelper.ApiException; import com.example.android.wiktionary.SimpleWikiHelper.ParseException;  import android.app.PendingIntent; import android.app.Service; import android.appwidget.AppWidgetManager; import android.appwidget.AppWidgetProvider; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.res.Resources; import android.net.Uri; import android.os.IBinder; import android.text.format.Time; import android.util.Log; import android.widget.RemoteViews;  import java.util.regex.Matcher; import java.util.regex.Pattern;  /**  * Define a simple widget that shows the Wiktionary "Word of the day." To build  * an update we spawn a background {@link Service} to perform the API queries.  */ public class WordWidget extends AppWidgetProvider {   /**    * Regular expression that splits "Word of the day" entry into word    * name, word type, and the first description bullet point.    */   public static final String WOTD_PATTERN =     "(?s)//{//{wotd//|(.+?)//|(.+?)//|([^#//|]+).*?//}//}";    @Override   public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {     Log.d("WordWidget.UpdateService", "onUpdate()");     // To prevent any ANR timeouts, we perform the update in a service     context.startService(new Intent(context, UpdateService.class));   }   public static class UpdateService extends Service {     @Override     public void onStart(Intent intent, int startId) {       Log.d("WordWidget.UpdateService", "onStart()");        // Build the widget update for today       RemoteViews updateViews = buildUpdate(this);       Log.d("WordWidget.UpdateService", "update built");              // Push update for this widget to the home screen       ComponentName thisWidget = new ComponentName(this, WordWidget.class);       AppWidgetManager manager = AppWidgetManager.getInstance(this);       manager.updateAppWidget(thisWidget, updateViews);       Log.d("WordWidget.UpdateService", "widget updated");     }      @Override     public IBinder onBind(Intent intent) {       return null;     }     /**      * Build a widget update to show the current Wiktionary      * "Word of the day." Will block until the online API returns.      */     public RemoteViews buildUpdate(Context context) {       // Pick out month names from resources       Resources res = context.getResources();       String[] monthNames = res.getStringArray(R.array.month_names);              // Find current month and day       Time today = new Time();       today.setToNow();        // Build the page title for today, such as "March 21"       String pageName = res.getString(R.string.template_wotd_title,           monthNames[today.month], today.monthDay);       String pageContent = null;              try {         // Try querying the Wiktionary API for today's word         SimpleWikiHelper.prepareUserAgent(context);         pageContent = SimpleWikiHelper.getPageContent(pageName, false);       } catch (ApiException e) {         Log.e("WordWidget", "Couldn't contact API", e);       } catch (ParseException e) {         Log.e("WordWidget", "Couldn't parse API response", e);       }              RemoteViews views = null;       Matcher matcher = null;                Prefs prefs = new Prefs(this);       if (pageContent == null) {         // could not get content, use cache         // could be null         pageContent = prefs.getPageContent();       }              if (pageContent != null) {         // we have page content         // is it valid?         matcher = Pattern.compile(WOTD_PATTERN).matcher(pageContent);       }       if (matcher != null && matcher.find()) {         // valid content, cache it          // ensure that latest valid content is         // always cached in case of failures         prefs.setPageContent(pageContent);          // Build an update that holds the updated widget contents         views = new RemoteViews(context.getPackageName(), R.layout.widget_word);                  String wordTitle = matcher.group(1);         views.setTextViewText(R.id.word_title, wordTitle);         views.setTextViewText(R.id.word_type, matcher.group(2));         views.setTextViewText(R.id.definition, matcher.group(3).trim());                  // When user clicks on widget, launch to Wiktionary definition page         String definePage = String.format("%s://%s/%s", ExtendedWikiHelper.WIKI_AUTHORITY,             ExtendedWikiHelper.WIKI_LOOKUP_HOST, wordTitle);         Intent defineIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(definePage));         PendingIntent pendingIntent = PendingIntent.getActivity(context,             0 /* no requestCode */, defineIntent, 0 /* no flags */);         views.setOnClickPendingIntent(R.id.widget, pendingIntent);                } else {         // Didn't find word of day, so show error message         views = new RemoteViews(context.getPackageName(), R.layout.widget_message);         views.setTextViewText(R.id.message, context.getString(R.string.widget_error));       }       return views;     }   } }