android 系统存在多个Launcher时，设置开机自动进入默认的Launcher

开机完成并解锁后，如果android系统存在多个Launcher，系统会弹出一个选择框让用户选择进入某个Launcher。如果用户不想选择，而是想直接进入某一个默认的Launcher，要怎么修改？

注意：此修改方法对Google Now Launcher(GoogleHome.apk)无效，因为此APP启动Activity的<intent-filter>中无<category android:name="android.intent.category.HOME" />这个选项。



下面以设置Google Launcher2作为默认启动的Launcher为例，

其package name 为 com.android.launcher

launcher activity name 为 com.android.launcher2.Launcher

1、请在PackageManagerService.java中的systemReady函数的最后中增加以下代码。

if(isFirstBoot())

{

//ADD BEGIN

String examplePackageName = "com.android.launcher"; //请修改为需要设置的 package name

String exampleActivityName = "com.android.launcher2.Launcher"; //请修改为需要设置的 launcher activity name

Intent intent=new Intent(Intent.ACTION_MAIN);

intent.addCategory(Intent.CATEGORY_HOME);

final int callingUserId = UserHandle.getCallingUserId();



List<ResolveInfo> resolveInfoList = queryIntentActivities(intent,null, PackageManager.GET_META_DATA,callingUserId);

if(resolveInfoList != null){

int size = resolveInfoList.size();

for(int j=0;j<size;){

final ResolveInfo r = resolveInfoList.get(j);

if(!r.activityInfo.packageName.equals(examplePackageName)){

resolveInfoList.remove(j);

size -= 1;

}else

{

j++;

}

}

ComponentName[] set = new ComponentName[size];

ComponentName defaultLauncher=new ComponentName(examplePackageName, exampleActivityName);

int defaultMatch=0;

for(int i=0;i<size;i++){

final ResolveInfo resolveInfo = resolveInfoList.get(i);

Log.d(TAG, resolveInfo.toString());

set[i] = new ComponentName(resolveInfo.activityInfo.packageName,resolveInfo.activityInfo.name);

if(defaultLauncher.getClassName().equals(resolveInfo.activityInfo.name)){

defaultMatch = resolveInfo.match;

}

}

Slog.e(TAG,"defaultMatch="+Integer.toHexString(defaultMatch));

IntentFilter filter=new IntentFilter();

filter.addAction(Intent.ACTION_MAIN);

filter.addCategory(Intent.CATEGORY_HOME);

filter.addCategory(Intent.CATEGORY_DEFAULT);



addPreferredActivity2(filter, defaultMatch, set, defaultLauncher);

}

//ADD END

}

2.在PackageManagerService.java中增加addPreferredActivity2函数。

public void addPreferredActivity2(IntentFilter filter, int match,

ComponentName[] set, ComponentName activity) {

Log.d("debug_default","addPreferredActivity2 is called.");

// writer

synchronized (mPackages) {

Slog.i(TAG, "Adding preferred activity " + activity + ":");

filter.dump(new LogPrinter(Log.INFO, TAG), " ");

mSettings.editPreferredActivitiesLPw(0).addFilter(

new PreferredActivity(filter, match, set, activity, true));

scheduleWriteSettingsLocked();

}

}

3.修改PackageManagerService.java的函数findPreferredActivity



（1） 对原来的removeMatches 增加判断条件，在launcher时不remove

if(!(intent.getAction() != null && intent.getAction().equals(intent.ACTION_MAIN) && intent.getCategories()!=null && intent.getCategories().contains(intent.CATEGORY_HOME))) { //ADD

Slog.d(TAG,"launcher");

}else {

if (removeMatches) {

pir.removeFilter(pa);

if (DEBUG_PREFERRED) {

Slog.v(TAG, "Removing match " + pa.mPref.mComponent);

}

break;

}

}

（2）

if (always && !pa.mPref.sameSet(query, priority)) {

Slog.i(TAG, "Result set changed, dropping preferred activity for "

+ intent + " type " + resolvedType);

if (DEBUG_PREFERRED) {

Slog.v(TAG, "Removing preferred activity since set changed "

+ pa.mPref.mComponent);

}

pir.removeFilter(pa);

// Re-add the filter as a "last chosen" entry (!always)

PreferredActivity lastChosen = new PreferredActivity(

pa, pa.mPref.mMatch, null, pa.mPref.mComponent, false);

pir.addFilter(lastChosen);

mSettings.writePackageRestrictionsLPr(userId);

return null;

}

上面这段修改为下面的内容：

if (always && !pa.mPref.sameSet(query, priority)) {



if(!(intent.getAction() != null && intent.getAction().equals(intent.ACTION_MAIN) && intent.getCategories()!=null &&



intent.getCategories().contains(intent.CATEGORY_HOME))) { //ADD

Slog.i(TAG, "Result set changed, dropping preferred activity for "

+ intent + " type " + resolvedType);

if (DEBUG_PREFERRED) {

Slog.v(TAG, "Removing preferred activity since set changed "

+ pa.mPref.mComponent);

}

pir.removeFilter(pa);



// Re-add the filter as a "last chosen" entry (!always)

PreferredActivity lastChosen = new PreferredActivity(

pa, pa.mPref.mMatch, null, pa.mPref.mComponent, false);

pir.addFilter(lastChosen);

mSettings.writePackageRestrictionsLPr(userId);

return null;

}

}

Slog.i(TAG,"Result set not change, not drop preferred activity for special intent: "+intent);//ADD

// Yay! Either the set matched or we're looking for the last chosen

JB系列findPreferredActivity略有调整，见下面：

修改 packageManagerService.java (framework/base/services/java/com/android/server/pm/)的findPreferredActivity方法，将此方法比较靠后的一段代码：

if (!pa.mPref.sameSet(query, priority)) {

Slog.i(TAG, "Result set changed, dropping preferred activity for " + intent + " type " + resolvedType);

pir.removeFilter(pa);

return null;

}



修改为：

if (!pa.mPref.sameSet(query, priority)) {

if(!(intent.getAction() != null && intent.getAction().equals(intent.ACTION_MAIN) && intent.getCategories()!=null &&

intent.getCategories().contains(intent.CATEGORY_HOME))) { //ADD

Slog.i(TAG, "Result set changed, dropping preferred activity for "+ intent + " type " + resolvedType);

pir.removeFilter(pa);

return null;

} //ADD

Slog.i(TAG,"Result set not change, not drop preferred activity for special intent: "+intent);//ADD

}



如果用户在设置->应用程序->管理应用程序->所有应用程序列表，找到之前设置的默认Launcher，并取消了默认值，系统会重新弹出launcher选择框。