Lock application with knock code using always on top Activity

Question

I am new in Android. I am developing a kind of app locker. I want to start a fullscreen always on top Activity that listens to onTouchEvent(), when the user starts a locked app. I want to make user to get rid of that Activity only if he/she enters a knock code as password. I have used following code to lock buttons by making Activity always on top (Source: Creating a system overlay window (always on top)). But onTouchEvent() does not receives any touches for knock code. I have searched a lot and tried a lot of codes. But always one solution destroys other parts like current problem!

final WindowManager.LayoutParams params = new WindowManager.LayoutParams(
                 WindowManager.LayoutParams.FLAG_FULLSCREEN,
                 WindowManager.LayoutParams.FLAG_FULLSCREEN,
                 WindowManager.LayoutParams.TYPE_SYSTEM_ALERT ,
                 WindowManager.LayoutParams.FLAG_FULLSCREEN,
                 PixelFormat.TRANSPARENT);

                 WindowManager wm = (WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE);

                 ViewGroup mTopView = (ViewGroup) getLayoutInflater().inflate(R.layout.activity_color, null);
                 getWindow().setAttributes(params);
                 wm.addView(mTopView, params);

score 0 · Accepted Answer · answered Oct 03 '16 at 22:06

onTouchEvent() does not work because we have an overlay on top of everything. So when we touch screen, we touch ViewGroup. So we need to trigger onTouchEvent() when user touches ViewGroup. We can trigger it like this:

mTopView.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View arg0, MotionEvent event) 
            {  
                   // do something ...
            }
});

Lock application with knock code using always on top Activity

1 Answers1