Creating a system overlay window (always on top)

Question

I\'m trying to create an always-op-top button/clickable-image which stays on top of all the windows all the time.

The proof of concept is

• here - Smar

Answer 1

Starting with Android 4.x, Android team fixed a potential security problem by adding a new function adjustWindowParamsLw() in which it will add FLAG_NOT_FOCUSABLE, FLAG_NOT_TOUCHABLE and remove FLAG_WATCH_OUTSIDE_TOUCH flags for TYPE_SYSTEM_OVERLAY windows.

That is, a TYPE_SYSTEM_OVERLAY window won't receive any touch event on ICS platform and, of course, to use TYPE_SYSTEM_OVERLAY is not a workable solution for ICS and future devices.