On Mon Aug 11 16:10:52 2025 +0000, Paul Gofman wrote:
FWIW even without multiple monitors a window can be larger than screen on Windows (and at least without fullscreen mode it is not getting resized or de-factor shrinked to the fullscreen size). Some games (one I remember offhand which was doing that at least back then is Halo Infinite) do that, make a window with decorations bigger than screen and position in a way so client area matches full screen size. It is probably not possible to match all the aspects of Windows behaviour for all the cases in the x11 interfacing limitations? IMO if we de facto have a choice between taskbar appearing on top (that is maybe correctable by user clicking the window?) and ending up with wrong window sizes maybe it is better to sacrifice the taskbar but keep sizes correct? And think or ask if it is possible to do something in KDE to support, maybe some property indicating fullscreen request without altering the size?
What if we decouple X11 window size from Win32 window size instead? X11 window would then show just the part of the Win32 window it covers. It would also help apps with custom decorations that expect a maximized window frame to stick out beyond the screen edges (e.g. apps using Codejock Toolkit Pro). I think Windows does something similar to prevent maximized window borders from showing up on adjacent monitors.