Question

I want to detect and count when Activity goes from background to foreground (when activity is visible, increase count).I tried to use flag in onPause() and onResume() like this:

void onPause(){
    flag = true;
}

void onResume(){
if(flag){
 //save to shared reference.  
   saveCount(getCount(count) + 1);
 flag = false;
}

}

It works when user press home key and relaunches the app, but when I transfer Activity then goes back, it still increases the count, because it calls onPause(). How to prevent that? Or is there anyway to count this?

Answer 1

Use this method to check wheter app is brought to background:

private boolean isApplicationBroughtToBackground(Context context) {
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    List<RunningTaskInfo> tasks = am.getRunningTasks(1);
    if (!tasks.isEmpty()) {
        ComponentName topActivity = tasks.get(0).topActivity;
        if (!topActivity.getPackageName().equals(context.getPackageName())) {
            return true;
        }
    }

    return false;
}

It requires the GET_TASKS permission:

<uses-permission android:name="android.permission.GET_TASKS" />