graesslin added a comment.
I also cannot imagine this to work due to the fact how X11 works. There is just no mapping from window to screen. No window can know on which screen it is. Not even KWin knows that as the window manager (screen is not a constant property, but evaluated every time it is accessed, it's based on the distance to closest screen). Especially for overlapping windows it's very difficult to try to get to which screen it belongs. It gets even more complicated when things like panning and overlapping screens get into it. So I wouldn't trust this thing in Qt to work due to the pain we have in KWin especially with these problems. REPOSITORY R104 KScreen REVISION DETAIL https://phabricator.kde.org/D12405 To: fvogt, #plasma Cc: graesslin, davidedmundson, plasma-devel, ragreen, Pitel, ZrenBot, lesliezhai, ali-mohamed, jensreuterberg, abetts, sebas, apol, mart