学步园

作者：徐建祥（netpirate@gmail.com）

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

#strings.xml

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

#update_appwidget_info.xml

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

#update_appwidget.xml

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

#Globals.java

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

#UpdateService.java

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

#UpdateAppWidgetProvider.java

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

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！