oslayer: Make wmctrl optional (for Wayland).

[daym]

Summary of changes

Make wmctrl optional (for Wayland--otherwise plover crashes on startup).

Closes

Pull Request Checklist

• Changes have tests
• News fragment added in news.d. See documentation for details

[mkrnr]

Thanks a lot for your PR!

Ruff is complaining right now. I'd suggest something like this:

from .display_server import DISPLAY_SERVER


def GetForegroundWindow():
    return None


def SetForegroundWindow(w):
    del w


if DISPLAY_SERVER == "x11":
    from .wmctrl_x11 import WmCtrl

    _wmctrl = WmCtrl()
    GetForegroundWindow = _wmctrl.get_foreground_window
    SetForegroundWindow = _wmctrl.set_foreground_window

[mkrnr]

Thanks again! 🙂