Android Widget 设计与开发

作者：徐建祥（[email protected]）

时间： 2010/12/15

来自： http://www.anymobile.org

Widget杂谈：最早Widget是指在PC的桌面上的小窗口程序；Web上的先行者似乎是Yahoo！；当然，OPhone也搞了一套Widget，HTML+CSS的东东。

我们这里谈的所谓Widget，就是窗口小部件，Android SDK从1.5版本开始支持AppWidget framework，返个框架允许开发者开发Widgets，这些Widgets可以被用户通过长按桌面进行添加，与应用程序进行数据交互。

需求：

在桌面上开发一个Widget，可以实时显示IM软件的状态更新变化；可以通过左右按钮，查看上次或下调更新内容。

(参考效果图)

设计思路：

(参考设计序列图)

代码：

Java：

/src/org.anymobile.demo.Globals //Intent.action 声明

/src/org.anymobile.demo.service.UpdateService extends Service //同步、更新Widget布局数据的Service

/src/org.anymobile.demo.widget.UpdateAppWidgetProvider extends AppWidgetProvider //Widget，接收器

XML:

/res/layout/update_appwidget.xml //布局设计

/res/values/strings.xml //常量声明

/res/xml/update_appwidget_info.xml //app widget定义

AndroidManifest.xml

#AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="org.anymobile.demo" android:versionCode="1" android:versionName="1.0"> <application android:icon="@drawable/icon" android:label="@string/app_name"> <receiver android:name=".widget.UpdateAppWidgetProvider" android:label="@string/app_widget_label" > <intent-filter> <action android:name="android.appwidget.action.APPWIDGET_UPDATE" /> </intent-filter> <meta-data android:name="android.appwidget.provider" android:resource="@xml/update_appwidget_info" /> </receiver> <service android:name=".service.UpdateService" android:label="@string/app_name"> <intent-filter> <action android:name="org.anymobile.demo.service.IMM_UPDATE_SERVICE" /> <category android:name="android.intent.category.DEFAULT" /> </intent-filter> </service> </application> </manifest>

#strings.xml

<?xml version="1.0" encoding="utf-8"?> <resources> <string name="app_name">AnymobileDemo</string> <string name="app_widget_label">AnymobileDemo Widget</string> <string name="app_widget_title">Updates</string> <string name="app_widget_error_message">No messages, please check to login.</string> </resources>

#update_appwidget_info.xml

<?xml version="1.0" encoding="utf-8"?> <appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android" android:minWidth="294dip" android:minHeight="120dip" android:updatePeriodMillis="0" android:initialLayout="@layout/update_appwidget"> </appwidget-provider>

#update_appwidget.xml

<?xml version="1.0" encoding="UTF-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <LinearLayout android:id="@+id/app_widget_top" android:gravity="center_vertical" android:orientation="horizontal" android:background="@drawable/widget_titlebar" android:layout_width="fill_parent" android:layout_height="wrap_content"> </LinearLayout> <LinearLayout android:id="@+id/app_widget_body" android:orientation="horizontal" android:background="@drawable/widget_body" android:layout_width="fill_parent" android:layout_height="100dip"> <LinearLayout android:id="@+id/app_widget_message" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/widget_message" android:text="@string/app_widget_error_message" android:paddingRight="5dip" android:paddingLeft="5dip" android:layout_width="wrap_content" android:layout_height="wrap_content"> </TextView> </LinearLayout> </LinearLayout> <LinearLayout android:id="@+id/app_widget_bottom" android:gravity="right" android:layout_width="fill_parent" android:layout_height="wrap_content"> </LinearLayout> </LinearLayout>

#Globals.java

package org.anymobile.demo; public final class Globals { public static final String ACTION_APP_WIDGET_SERVICE= "org.anymobile.demo.service.IMM_UPDATE_SERVICE"; public static final String ACTION_APP_WIDGET_PREV = "org.anymobile.demo.intent.action.APP_WIDGET_PREV"; public static final String ACTION_APP_WIDGET_NEXT = "org.anymobile.demo.intent.action.APP_WIDGET_NEXT"; public static final String ACTION_APP_WIDGET_RELOAD = "org.anymobile.demo.intent.action.APP_WIDGET_RELOAD"; }

#UpdateService.java

package org.anymobile.demo.service; import java.util.ArrayList; import android.app.Service; import android.appwidget.AppWidgetManager; import android.content.BroadcastReceiver; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.os.IBinder; import android.util.Log; import android.view.View; import android.widget.RemoteViews; import org.anymobile.demo.Globals; import org.anymobile.demo.R; import org.anymobile.demo.widget.UpdateAppWidgetProvider; public class UpdateService extends Service { public static final String TAG = "ANYMOBILE-DEMO--UpdateService"; private ArrayList<String> mList; private int mCount; private int mId; private BroadcastReceiver mIntentReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); Log.d(TAG, "onReceive() " + action); if (action.equals(Globals.ACTION_APP_WIDGET_RELOAD)) { doReload(); } } }; @Override public void onCreate() { Log.d(TAG, "onCreate()"); super.onCreate(); reloadQueue(); IntentFilter filter = new IntentFilter(); filter.addAction(Globals.ACTION_APP_WIDGET_RELOAD); registerReceiver(mIntentReceiver, filter); } @Override public void onStart(Intent intent, int startId) { super.onStart(intent, startId); String action = intent.getAction(); Log.d(TAG, "onStart() " + action); if (action.equals(Globals.ACTION_APP_WIDGET_PREV)) { doPrev(); } else if (action.equals(Globals.ACTION_APP_WIDGET_NEXT)) { doNext(); } else// if (action.equals(Globals.ACTION_APP_WIDGET_SERVICE)) { notifyWidget(); } } private void notifyWidget() { Log.d(TAG, "notifyWidget()"); ComponentName widget = new ComponentName(this, UpdateAppWidgetProvider.class); RemoteViews updateViews = buildUpdate(this); AppWidgetManager manager = AppWidgetManager.getInstance(this); manager.updateAppWidget(widget, updateViews); } @Override public void onDestroy() { Log.d(TAG, "onDestroy()"); unregisterReceiver(mIntentReceiver); super.onDestroy(); } @Override public IBinder onBind(Intent intent) { Log.d(TAG, "onBind()"); return null; } private RemoteViews buildUpdate(Context context) { RemoteViews updateViews = new RemoteViews(context.getPackageName(), R.layout.update_appwidget); String item = null; if (mCount > 0) { item = mList.get(mId); if (item != null) { updateViews.setViewVisibility(R.id.app_widget_content, View.GONE); updateViews.setViewVisibility(R.id.app_widget_message, View.VISIBLE); // updateViews.setViewVisibility(R.id.app_widget_content, View.VISIBLE); // updateViews.setViewVisibility(R.id.app_widget_message, View.GONE); // // updateViews.setImageViewResource(R.id.update_appwidget_icon, item.getTypeIconId()); // updateViews.setTextViewText(R.id.update_appwidget_name, item.getNickName()); // updateViews.setTextViewText(R.id.update_appwidget_time, item.getModifyTime()); // updateViews.setTextViewText(R.id.update_appwidget_content, item.getMessage()); updateViews.setTextViewText(R.id.widget_message, item); } } if (item == null) { updateViews.setViewVisibility(R.id.app_widget_content, View.GONE); updateViews.setViewVisibility(R.id.app_widget_message, View.VISIBLE); updateViews.setTextViewText(R.id.widget_message, context.getText(R.string.app_widget_error_message)); } Log.d(TAG, "buildUpdate: layoutId = " + updateViews.getLayoutId() + "; count = " + mCount + "; id = " + mId); return updateViews; } private void doReload() { Log.d(TAG, "doReload()"); reloadQueue(); notifyWidget(); } private void reloadQueue() { mList = new ArrayList<String>(); String[] arr = {"aa", "bb", "cc", "dd"}; for (int i = 0; i < arr.length; i++) { mList.add(arr[i]); } if (mList != null) { mCount = mList.size(); } else { mCount = 0; } mId = 0; //TODO check login and poll updates from buddie list } private void doPrev() { Log.d(TAG, "doPrev()"); mId -= 1; if (mId < 0) { mId = mCount - 1; } notifyWidget(); } private void doNext() { Log.d(TAG, "doNext()"); mId += 1; if (mId > mCount - 1) { mId = 0; } notifyWidget(); } }

#UpdateAppWidgetProvider.java

package org.anymobile.demo.widget; import android.app.PendingIntent; import android.appwidget.AppWidgetManager; import android.appwidget.AppWidgetProvider; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.util.Log; import android.view.View; import android.widget.RemoteViews; import org.anymobile.demo.Globals; import org.anymobile.demo.R; import org.anymobile.demo.service.UpdateService; public class UpdateAppWidgetProvider extends AppWidgetProvider { public static final String TAG = "ANYMOBILE-DEMO-UpdateAppWidgetProvider"; public static final String APP_WIDGET_UPDATE = "appwidgetupdate"; public static final ComponentName APPWIDGET_COMPONENT_NAME = new ComponentName("org.anymobile.demo", "org.anymobile.demo.widget.UpdateAppWidgetProvider"); @Override public void onReceive(Context context, Intent intent) { Log.d(TAG, "onReceive() " + intent.getAction()); super.onReceive(context, intent); } @Override public void onEnabled(Context context) { Log.d(TAG, "onEnabled()"); super.onEnabled(context); } @Override public void onDisabled(Context context) { Log.d(TAG, "onDisabled()"); super.onDisabled(context); } @Override public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) { Log.d(TAG, "onUpdate()"); defaultAppWidget(context, appWidgetIds); context.startService(new Intent(Globals.ACTION_APP_WIDGET_SERVICE)); } private void defaultAppWidget(Context context, int[] appWidgetIds) { final RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.update_appwidget); views.setViewVisibility(R.id.app_widget_content, View.GONE); views.setViewVisibility(R.id.app_widget_message, View.VISIBLE); // Link actions buttons to intents linkButtons(context, views); pushUpdate(context, appWidgetIds, views); } private void linkButtons(Context context, RemoteViews views) { Intent intent; PendingIntent pendingIntent; final ComponentName serviceName = new ComponentName(context, UpdateService.class); intent = new Intent(Globals.ACTION_APP_WIDGET_PREV); intent.setComponent(serviceName); pendingIntent = PendingIntent.getService(context, 0 /* no requestCode */, intent, 0 /* no flags */); views.setOnClickPendingIntent(R.id.widget_btn_prev_page, pendingIntent); intent = new Intent(Globals.ACTION_APP_WIDGET_NEXT); intent.setComponent(serviceName); pendingIntent = PendingIntent.getService(context, 0 /* no requestCode */, intent, 0 /* no flags */); views.setOnClickPendingIntent(R.id.widget_btn_next_page, pendingIntent); } private void pushUpdate(Context context, int[] appWidgetIds, RemoteViews views) { final AppWidgetManager gm = AppWidgetManager.getInstance(context); if (appWidgetIds != null) { gm.updateAppWidget(appWidgetIds, views); } else { gm.updateAppWidget(APPWIDGET_COMPONENT_NAME, views); } } void notifyChange(UpdateService service, String what) { // } }

日志：

#init

12-15 19:23:09.479 D/ANYMOBILE-DEMO--UpdateAppWidgetProvider( 585): onReceive() android.appwidget.action.APPWIDGET_UPDATE

12-15 19:23:09.509 D/ANYMOBILE-DEMO--UpdateAppWidgetProvider( 585): onUpdate()

12-15 19:23:09.549 D/ANYMOBILE-DEMO--UpdateService( 585): onCreate()

12-15 19:23:09.579 D/ANYMOBILE-DEMO--UpdateService( 585): onStart()

#add widget

12-15 19:24:23.780 D/ANYMOBILE-DEMO--UpdateAppWidgetProvider( 585): onReceive() android.appwidget.action.APPWIDGET_UPDATE

12-15 19:24:23.780 D/ANYMOBILE-DEMO--UpdateAppWidgetProvider( 585): onUpdate()

12-15 19:24:23.850 D/ANYMOBILE-DEMO--UpdateService( 585): onStart()

#receive software event, reload and update widget

12-15 19:24:58.150 D/ANYMOBILE-DEMO--UpdateService( 585): onReceive() Activation

12-15 19:24:58.150 D/ANYMOBILE-DEMO--UpdateService( 585): doReload()

12-15 19:24:58.150 D/ANYMOBILE-DEMO--UpdateService( 585): notifyWidget()

12-15 19:24:58.200 D/ANYMOBILE-DEMO--UpdateService( 585): buildUpdate: layoutId = 2130903068; count = 11; id = 0

#click widget button, new start the bind service

12-15 19:25:49.260 D/ANYMOBILE-DEMO--UpdateService( 585): onStart()

12-15 19:24:58.150 D/ANYMOBILE-DEMO--UpdateService( 585): notifyWidget()

12-15 19:24:58.200 D/ANYMOBILE-DEMO--UpdateService( 585): buildUpdate: layoutId = 2130903068; count = 11; id = 0

OVER！