On Fri Oct 17 21:10:22 2025 +0000, Rémi Bernon wrote:
Fwiw I could approve this if you think it helps winewayland, but I'm not completely sure this is the right thing to do. I don't see anything like that on the X11 side, and from reading about it a bit it seems to me that WS_EX_TRANSPARENT has some specific behavior that we should be implementing instead of magically delegating to the compositor. There are some details about it that we would possibly miss by doing that.
This is implemented in wineserver based on the `is_window_transparent` function. It's not implemented in winex11.drv, but we could do so by setting the window's ShapeInput region to empty. That would allow us to click through to non-Wine windows.
Xalia uses this on Windows: https://github.com/madewokherd/xalia/blob/main/xalia/Sdl/Win32LayeredBox.cs#...
and ShapeInput on X11: https://github.com/madewokherd/xalia/blob/main/xalia/Sdl/XShapeBox.cs#L134
I have tested both approaches.