Masking of Android app content in "Recent Applications" view

[Shyan Ann Wang]

I am trying to implement a security feature where applications' content cannot be viewed in the "Recent Applications" view. In that view, the thumbnail will show a black screen instead of the cached content of that application. 

I tried the following solution from stackoverflow.com (http://stackoverflow.com/questions/9822076/how-do-i-prevent-android-taking-a-screenshot-when-my-app-goes-to-the-background):

public class FlagSecureTestActivity extends Activity {
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    getWindow().setFlags(LayoutParams.FLAG_SECURE,
                         LayoutParams.FLAG_SECURE);

    setContentView(R.layout.main);
  }
}

and it works. However, this solution prevents screenshots from being taken while the user is using the application, and I would like to allow this functionality.

Hoping to find a solution that allows masking of content, and screenshots to be taken as well! Thank you!