Consider xwayland viewport scaling when determining SSD controls
This MR is another, less hack-ish, attempt at fixing #1592 (closed). I still prefer !1661 (merged) though, due to it not introducing X11 SSD specific code to Wayland classes and not doing unnecessary calculations.
It introduces a (badly named) function to do event to buffer coordinate transformation in MetaWaylandSurface
and then exposes it via an (equally badly named) function in MetaWindow
. This is done to avoid any explicit Wayland code in the X11 specific SSD code. The transformation can not be done any earlier than in the SSD code that determines the control element, because opening context menus requires the original cursor position.
If we want to go with this variant, I'm open to suggestions for better names for these functions.