I opened a new window, I made it fullscreen and then set it to always on top with XSendEvent
on _NET_WM_STATE
to set _NET_WM_STATE_ABOVE
and then I XFlush
'ed. This makes the window appear on top of everything this is great.
Aside: I then draw the screenshot of the desktop to that window and overlay it with a 50% opacity black transparent layer.
So now the issue I am having is that placement is right and it is correct in that it is over the special UI (dock and menu bar) in that you cannot click it. But when I click in the window, the special UI just appears through. You cannot click on it, it is just appearing above my window.
Is there any window properties I can set to fix this issue?
Here is a screenshot showing before I click in the window:
Here is screenshot showing after i click in the window, the special ui appears through (while not clickable - which is good)
Replication
I can replicate this situation exactly on your system. Its a released firefox addon. Let me know please and we can chat using stackoverflow and i can walk you through to replicate.