android Launcher AppWidget添加步骤介绍
作者：空间维度
大家好，本篇文章主要讲的是android Launcher AppWidget添加步骤介绍，感兴趣的同学赶快来看一看吧，对你有帮助的话记得收藏一下，方便下次浏览
一、AppWidget开机启动加载
Android系统启动，SystemServer创建AppWidgetService，并调用AppWidgetServiceImpl.onStart()方法，初始化相关管理器，注册四个广播接收器:
第一、注册有关软件包安装、删除、改变的广播，以便我们可以更新provider列表。;
// Register for broadcasts about package install, etc., so we can
// update the provider list.
IntentFilter packageFilter = new IntentFilter();
packageFilter.addAction(Intent.ACTION_PACKAGE_ADDED);
packageFilter.addAction(Intent.ACTION_PACKAGE_CHANGED);
packageFilter.addAction(Intent.ACTION_PACKAGE_REMOVED);
packageFilter.addDataScheme("package");
mContext.registerReceiverAsUser(mBroadcastReceiver, UserHandle.ALL,
packageFilter, null, null);
第二、当锁定状态发生变化时会播放一些事件:
IntentFilter offModeFilter = new IntentFilter();
offModeFilter.addAction(Intent.ACTION_MANAGED_PROFILE_AVAILABLE);
offModeFilter.addAction(Intent.ACTION_MANAGED_PROFILE_UNAVAILABLE);
mContext.registerReceiverAsUser(mBroadcastReceiver, UserHandle.ALL,
offModeFilter, null, null);
第三、暂停或解除暂停应用广播;
IntentFilter offModeFilter = new IntentFilter();
offModeFilter.addAction(Intent.ACTION_MANAGED_PROFILE_AVAILABLE);
offModeFilter.addAction(Intent.ACTION_MANAGED_PROFILE_UNAVAILABLE);
mContext.registerReceiverAsUser(mBroadcastReceiver, UserHandle.ALL,
offModeFilter, null, null);
第四、注册sdcard的安装与卸载的广播。
// Register for events related to sdcard installation.
IntentFilter sdFilter = new IntentFilter();
sdFilter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE);
sdFilter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE);
mContext.registerReceiverAsUser(mBroadcastReceiver, UserHandle.ALL,
sdFilter, null, null);
二、Launcher3启动添加
Launcher启动onCreate()方法初始化mAppWidgetManager, mAppWidgetHost对象，AppWidgetHost是launcher承载AppWidgetView的宿主
mAppWidgetHost.startListening，通过
public void onCreate() {
...
// 13 //得到AppWidget管理实例 ： AppWidgetManager , AppWidgetHost , AppWidgetHostView三个类的关系
mAppWidgetManager = AppWidgetManagerCompat.getInstance(this);
mAppWidgetHost = new LauncherAppWidgetHost(this);
// Host启动监听,监听LauncherProvider中的数据改变
mAppWidgetHost.startListening();
...
}
1、初始化AppWidgetHostd对象，创建用于回调的Callbacks服务类IAppWidgetHost.Stub, 绑定服务bindService，得到IAppWidgetService对象，进行launcher和AppWidgetService之间的调用
public AppWidgetHost(Context context, int hostId, InteractionHandler handler, Looper looper) {
mContextOpPackageName = context.getOpPackageName();
mHostId = hostId;
mInteractionHandler = handler;
mHandler = new UpdateHandler(looper);
mCallbacks = new Callbacks(mHandler);
mDisplayMetrics = context.getResources().getDisplayMetrics();
bindService(context);
}
2、在startListening 方法中 ，通过IAppWidgetService.startListening 方法解析Launcher中的AppWidget信息保存到系统服务成员变量中， 3、当添加AppWidget时，首页返回到Launcher中的onActivityResult中，在handleActivityResult中
addAppWidgetImpl(
appWidgetId, requestArgs, null,
requestArgs.getWidgetHandler(),
ON_ACTIVITY_RESULT_ANIMATION_DELAY);
创建添加小部件意图，之后返回到onActivityForResult,调用completeAddAppWidget，通过IAppWidgetService.getAppWidgetInfo,获取AppWidgetProviderInfo,保存到本地数据库中addItemToDatabase()，
@Thunk void completeAddAppWidget(int appWidgetId, ItemInfo itemInfo,
1070 AppWidgetHostView hostView, LauncherAppWidgetProviderInfo appWidgetInfo) {
1071
1072 if (appWidgetInfo == null) {
1073 appWidgetInfo = mAppWidgetManager.getLauncherAppWidgetInfo(appWidgetId);
1074 }
1075
1076 LauncherAppWidgetInfo launcherInfo;
1077 launcherInfo = new LauncherAppWidgetInfo(appWidgetId, appWidgetInfo.provider);
1078 launcherInfo.spanX = itemInfo.spanX;
1079 launcherInfo.spanY = itemInfo.spanY;
1080 launcherInfo.minSpanX = itemInfo.minSpanX;
1081 launcherInfo.minSpanY = itemInfo.minSpanY;
1082 launcherInfo.user = appWidgetInfo.getProfile();
1083
1084 getModelWriter().addItemToDatabase(launcherInfo,
1085 itemInfo.container, itemInfo.screenId, itemInfo.cellX, itemInfo.cellY);
1086
1087 if (hostView == null) {
1088 // Perform actual inflation because we're live
1089 hostView = mAppWidgetHost.createView(this, appWidgetId, appWidgetInfo);
1090 }
1091 hostView.setVisibility(View.VISIBLE);
1092 prepareAppWidget(hostView, launcherInfo);
1093 mWorkspace.addInScreen(hostView, launcherInfo);
1094 }
1095
1096 private void prepareAppWidget(AppWidgetHostView hostView, LauncherAppWidgetInfo item) {
1097 hostView.setTag(item);
// 计算AppWidget的显示大小位置
1098 item.onBindAppWidget(this, hostView);
1099 hostView.setFocusable(true);
1100 hostView.setOnFocusChangeListener(mFocusHandler);
1101 }
并创建AppWidgetHostView 对象，mAppWidgetHost.createView，返回RemoteView对象，IAppWidgetService。getAppWidgetViews（）
public final AppWidgetHostView createView(Context context, int appWidgetId,
AppWidgetProviderInfo appWidget) {
if (sService == null) {
return null;
}
AppWidgetHostView view = onCreateView(context, appWidgetId, appWidget);
view.setInteractionHandler(mInteractionHandler);
view.setAppWidget(appWidgetId, appWidget);
synchronized (mViews) {
mViews.put(appWidgetId, view);
}
RemoteViews views;
try {
views = sService.getAppWidgetViews(mContextOpPackageName, appWidgetId);
} catch (RemoteException e) {
throw new RuntimeException("system server dead?", e);
}
view.updateAppWidget(views);
return view;
}
调用AppWidgetHostView.updateAppWidget(views);更新View到launcher界面上mWorkspace.addInScreen(hostView, launcherInfo);
当AppWidgetProvider获得更新的广播，并执行onUpdate()，onUpdate()中创建了RemoteViews并通过AppWidgetManager.updateAppWidget()更新到AppWidgetService之后，AppWidgetService会通过注册的IAppWidgetHost的回调，执行AppWidgetHost的更新。
总结
到此这篇关于android Launcher AppWidget添加步骤介绍的文章就介绍到这了,更多相关android Launcher AppWidget内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！