Hide screen in 'Recent Apps List', but all

Question

I mainly want to blank the screen in the recent apps list due to sensitive data being shown. For this, the solution is to use:

getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);

but this also disallows screenshots, which is a problem.

Is there a way to show a blank screen (or a predefined image) in the recent apps list, while still allowing screenshots?

Answer 1

I have tried this method and it's working. For making the screen blank in recent list and still allowing screen you can set the flag in onPause() and clear the flag in onResume().

@Override
protected void onPause() {
  super.onPause();
  getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE,WindowManager.LayoutParams.FLAG_SECURE);
}

@Override
protected void onResume() {
    super.onResume()
    getWindow().clearFlags(WindowManager.LayoutParams.FLAG_SECURE);     
}

Answer 2

After doing some research I have found this to be impossible at this point.

The onCreateThumbnail seems to be the function you're looking for. Unfortunately this function seems to be unimplemented or at least not working.

As Ped7g pointed out: The onCreateThumbnail is "won't fix" since 2014.

It's also flagged deprecated for removal in the Android onCreateThumbnail reference page

This functionality will most likely never work.

Answer 3

If your Activity is showing sensitive data, for the security reason is better to don't allow user to make screenshots. If you are worry even about recent app screen, why you are not worry about screenshots on the same time? I think, that Android OS SecureFlag is designed to protect your data, and screenshots ability, just negates it's purpose.
If you anyway, want this ability, you can try to move all your sensitive data to separate activity with this flag. In that case, you will protect your sensitive data, and in other app's activities will have ability to make screenshots.

Answer 4

I think what you need is:

android:excludeFromRecents="true"

put that in your android manifest inside your <activity>(activity you want to exclude from recents)</activity>