Android detect or block floating/overlaying apps

Question

Android enables apps to draw over other apps with android.permission.SYSTEM_ALERT_WINDOW and it's called a floating/overlaying app. For example Facebook Messenger has always visible chat bubbles at the edges of screen.

My question is: Is it possible to detect or block in Java code any app which draws over my app?

On newer versions you can ask fro screen recording permission, and compare what you draw and what is on the screen — Kirill Kulakov, Sep 14 '16 at 10:56
filterTouchesWhenObscured on view level set to true would also fix the issue — Bart Burg, Sep 03 '18 at 12:24
I've created a sample to show all ways to detect: https://stackoverflow.com/a/71719568/878126 — android developer, Apr 02 '22 at 17:11

score 15 · Answer 1 · edited Aug 30 '17 at 22:35

15

There is a View#onFilterTouchEventForSecurity() method you can override to detect if the motion event has the FLAG_WINDOW_IS_OBSCURED. This will let you know if something is drawn on top of your view.

@Override
public boolean onFilterTouchEventForSecurity(MotionEvent event) {
    if ((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_OBSCURED) == MotionEvent.FLAG_WINDOW_IS_OBSCURED){
        // show error message
        return false;
    }
    return super.onFilterTouchEventForSecurity(event);
}

If you just want to protect your app from tap jacking due to another app drawing over your app you can add setFilterTouchesWhenObscured to your views via XML or programmatically.

edited Aug 30 '17 at 22:35

Xavier Rubio Jansana

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answered Sep 08 '16 at 00:07

Don Cung

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thanks, will check and let you know if that's working – Andrii Bas Sep 09 '16 at 09:12
It doesn't work with facebook messenger bubble detection. But according to docs - it's the only way. #Android... – Andrii Kovalchuk Dec 09 '19 at 18:58
any full of code? why need add to view instead of activity? THanks – famfamfam Oct 18 '20 at 18:07
Here are all ways to detect it: https://stackoverflow.com/a/71719568/878126 – android developer Apr 02 '22 at 17:11

Android detect or block floating/overlaying apps

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