How to write a QML effect for KWin, KDE's window manager (blog.vladzahorodnii.com)
Since the dawn of the times, the only way to implement any effect that has fancy user interface used to be in C++. It would be rather an understatement to say that the C++ API is difficult to use or get it right so there are no glitches. On the other hand, it would be really nice to be able to implement dashboard-like effects...