1、找到ActivityManagerService.java

在..\rk3229_5.1_box\frameworks\base\services\core\java\com\android\server\am目录找到ActivityManagerService.java文件。在文件里找到startHomeActivityLocked函数里的setDefaultLauncher。

 boolean startHomeActivityLocked(int userId, String reason) {setDefaultLauncher(userId);if (mFactoryTest == FactoryTest.FACTORY_TEST_LOW_LEVEL&& mTopAction == null) {// We are running in factory test mode, but unable to find// the factory test app, so just sit around displaying the// error message and don't try to start anything.return false;}Intent intent = getHomeIntent();ActivityInfo aInfo =resolveActivityInfo(intent, STOCK_PM_FLAGS, userId);if (aInfo != null) {intent.setComponent(new ComponentName(aInfo.applicationInfo.packageName, aInfo.name));// Don't do this if the home app is currently being// instrumented.aInfo = new ActivityInfo(aInfo);aInfo.applicationInfo = getAppInfoForUser(aInfo.applicationInfo, userId);ProcessRecord app = getProcessRecordLocked(aInfo.processName,aInfo.applicationInfo.uid, true);if (app == null || app.instrumentationClass == null) {intent.setFlags(intent.getFlags() | Intent.FLAG_ACTIVITY_NEW_TASK);mStackSupervisor.startHomeActivity(intent, aInfo, reason);}}return true;}

2、设置开机默认桌面包名

在setDefaultLauncher设置开机默认桌面launch的包名。我开发的固件，所要启动的包名如下：

         String  packageName = SystemProperties.get("persist.sys.yz.defpackage", "com.zhai.ads");
         String  className = SystemProperties.get("persist.sys.yz.defclass", "com.zhai.touchhome.Loading");

    private void setDefaultLauncher(int userId){// get default component//String  packageName = SystemProperties.get("persist.sys.yz.defpackage", "com.zhaisoft.app.hesiling");// String  className = SystemProperties.get("persist.sys.yz.defclass", "com.zhaisoft.app.hesiling.activity.MainActivity");String  packageName = SystemProperties.get("persist.sys.yz.defpackage", "com.zhai.ads");String  className = SystemProperties.get("persist.sys.yz.defclass", "com.zhai.touchhome.Loading");Slog.i(TAG, "default packageName = " + packageName + ", default className = " + className);if(!packageName.equals("no") && !className.equals("no")){boolean firstLaunch = SystemProperties.getBoolean("persist.sys.sw.firstLaunch", true);Slog.d(TAG, "firstLaunch = " + firstLaunch);if(firstLaunch){mFirstLaunch = true;// do this only for the first bootSystemProperties.set("persist.sys.sw.firstLaunch", "false");}Slog.d(TAG, "mFirstLaunch = " + mFirstLaunch);// if(mFirstLaunch){IPackageManager pm = ActivityThread.getPackageManager();//clear the current preferred launcherArrayList<IntentFilter> intentList = new ArrayList<IntentFilter>();ArrayList<ComponentName> cnList = new ArrayList<ComponentName>();mContext.getPackageManager().getPreferredActivities(intentList, cnList, null);IntentFilter dhIF;for(int i = 0; i < cnList.size(); i++){dhIF = intentList.get(i);if(dhIF.hasAction(Intent.ACTION_MAIN) &&dhIF.hasCategory(Intent.CATEGORY_HOME)){mContext.getPackageManager().clearPackagePreferredActivities(cnList.get(i).getPackageName());}}// get all Launcher activitiesIntent intent = new Intent(Intent.ACTION_MAIN);intent.addCategory(Intent.CATEGORY_HOME);List<ResolveInfo> list = new ArrayList<ResolveInfo>();try{list = pm.queryIntentActivities(intent,intent.resolveTypeIfNeeded(mContext.getContentResolver()),PackageManager.MATCH_DEFAULT_ONLY, userId);}catch (RemoteException e) {throw new RuntimeException("Package manager has died", e);}// get all components and the best matchIntentFilter filter = new IntentFilter();filter.addAction(Intent.ACTION_MAIN);filter.addCategory(Intent.CATEGORY_HOME);filter.addCategory(Intent.CATEGORY_DEFAULT);final int N = list.size();ComponentName[] set = new ComponentName[N];int bestMatch = 0;for (int i = 0; i < N; i++){ResolveInfo r = list.get(i);set[i] = new ComponentName(r.activityInfo.packageName,r.activityInfo.name);if (r.match > bestMatch) bestMatch = r.match;}// add the default launcher as the preferred launcherComponentName launcher = new ComponentName(packageName, className);try{pm.addPreferredActivity(filter, bestMatch, set, launcher, userId);} catch (RemoteException e) {throw new RuntimeException("Package manager has died", e);}//}}}

3、寻找HomeSettings.java

在..\rk3229_5.1_box\packages\apps\Settings\src\com\android\settings里寻找HomeSettings.java文件。在makeCurrentHome里第二次设置自己需要的桌面。主要是客户有两个桌面，需要频繁切换。

    void makeCurrentHome(HomeAppPreference newHome) {if (mCurrentHome != null) {mCurrentHome.setChecked(false);}newHome.setChecked(true);mCurrentHome = newHome;mPm.replacePreferredActivity(mHomeFilter, IntentFilter.MATCH_CATEGORY_EMPTY,mHomeComponentSet, newHome.activityName);//huangxing add System.out.println("huangxing----activityName== " + newHome.activityName);//ComponentName chatActivity =new ComponentName();String launcherInfo  = newHome.activityName.toString();System.out.println("huangxing----launcherInfo== " + launcherInfo);if(launcherInfo.indexOf("com.android.launcher3") != -1){SystemProperties.set("persist.sys.yz.defpackage", "com.android.launcher3");SystemProperties.set("persist.sys.yz.defclass", "com.android.launcher3.Launcher");System.out.println("huangxing---launcher3-----");}else if(launcherInfo.indexOf("com.zhai.ads") != -1){SystemProperties.set("persist.sys.yz.defpackage", "com.zhai.ads");SystemProperties.set("persist.sys.yz.defclass", "com.zhai.touchhome.Loading");System.out.println("huangxing---com.zhai.ads-----");}else {//wjz addSystem.out.println("huangxing---heshiling launcher-----");SystemProperties.set("persist.sys.yz.defpackage", "com.zhaisoft.app.hesiling");SystemProperties.set("persist.sys.yz.defclass", "com.zhaisoft.app.hesiling.activity.MainActivity");//SystemProperties.set("persist.sys.yz.defpackage", "com.zhai.ads");//SystemProperties.set("persist.sys.yz.defclass", "com.zhai.touchhome.Loading");}getActivity().setResult(Activity.RESULT_OK);}

4、在System.prop的文件里，设置默认launcher

为了客户定制更加灵活，后来在System.prop里设置了默认launcher的参数。通过脚本配置，进行一站式编译。