Popup over incoming-call screen
Solution 1:
If you want to keep the Call activity still clickable, but not have any controls on your overlay, you can do this by calling
getWindow().addFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL);
In the onCreate() method of the activity that is shown over the call.
The layout parameters useable together with this are:
android:windowBackground="@android:color/transparent"
android:windowIsTranslucent="true"
android:windowAnimationStyle="@android:style/Animation.Translucent"