android4.4\frameworks\base\packages\SystemUI\src\com\android\systemui\recent\RecentsActivity.java
此函数是打开最近应用点击空闲地方跳转
public void dismissAndGoHome() {
if (mRecentsPanel != null) {
Intent homeIntent = new Intent(Intent.ACTION_MAIN, null);
homeIntent.addCategory(Intent.CATEGORY_HOME);
homeIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
| Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
startActivityAsUser(homeIntent, new UserHandle(UserHandle.USER_CURRENT));//这里是跳转到系统最高Launch 里面
}
}
//记录最近应用在这里面
android4.4\frameworks\base\packages\SystemUI\src\com\android\systemui\recent\RecentTasksLoader.java
protected Void doInBackground(Void... params) {
// We load in two stages: first, we update progress with just the first screenful
// of items. Then, we update with the rest of the items
final int origPri = Process.getThreadPriority(Process.myTid());
Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
final PackageManager pm = mContext.getPackageManager();
final ActivityManager am = (ActivityManager)
mContext.getSystemService(Context.ACTIVITY_SERVICE);
final List<ActivityManager.RecentTaskInfo> recentTasks =
am.getRecentTasks(MAX_TASKS, ActivityManager.RECENT_IGNORE_UNAVAILABLE);
int numTasks = recentTasks.size();
ActivityInfo homeInfo = new Intent(Intent.ACTION_MAIN)
.addCategory(Intent.CATEGORY_HOME).resolveActivityInfo(pm, 0);
boolean firstScreenful = true;
ArrayList<TaskDescription> tasks = new ArrayList<TaskDescription>();
// skip the first task - assume it‘s either the home screen or the current activity.
final int first = 0;
for (int i = first, index = 0; i < numTasks && (index < MAX_TASKS); ++i) {
if (isCancelled()) {
break;
}
final ActivityManager.RecentTaskInfo recentInfo = recentTasks.get(i);
Intent intent = new Intent(recentInfo.baseIntent);
if (recentInfo.origActivity != null) {
intent.setComponent(recentInfo.origActivity);
}
//关键代码
// Don‘t load the current home activity.
if (isCurrentHomeActivity(intent.getComponent(), homeInfo)) {//这里是屏蔽了系统最高launch 不记录在最近应用的栈中
continue;
}
// Don‘t load ourselves
if (intent.getComponent().getPackageName().equals(mContext.getPackageName())) {
continue;
}
TaskDescription item = createTaskDescription(recentInfo.id,
recentInfo.persistentId, recentInfo.baseIntent,
recentInfo.origActivity, recentInfo.description);
if (item != null) {
while (true) {
try {
tasksWaitingForThumbnails.put(item);
break;
} catch (InterruptedException e) {
}
}
tasks.add(item);
if (firstScreenful && tasks.size() == mNumTasksInFirstScreenful) {
publishProgress(tasks);
tasks = new ArrayList<TaskDescription>();
firstScreenful = false;
//break;
}
++index;
}
}
if (!isCancelled()) {
publishProgress(tasks);
if (firstScreenful) {
// always should publish two updates
publishProgress(new ArrayList<TaskDescription>());
}
}
while (true) {
try {
tasksWaitingForThumbnails.put(new TaskDescription());
break;
} catch (InterruptedException e) {
}
}
Process.setThreadPriority(origPri);
return null;
}
};
mTaskLoader.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
loadThumbnailsAndIconsInBackground(tasksWaitingForThumbnails);
}