xdg_positioner constraint adjustment

[ehopperdietzel]

Hi again,

I noticed that no xdg_positioner constraint adjustment flags are used. This prevents compositors from properly repositioning popups, for example, when they end up outside of the screen boundaries.

I understand that enabling some flags could make it challenging to handle configure events or calculate other positioner parameters. However, adding slide_x and slide_y should be enough and it shouldn't require any additional changes, though I'm not sure, maybe that could mess up your internal X coordinate system.

[ehopperdietzel]

XDG Positioner rules initially seemed very complex to me. Here is an explanation with graphical examples if you're interested. By the way, all compositors implementing Xwayland seem to add at least the flip and slide flags, I'm not sure about the resize flag.