devicePixelRatioF() is not set in paint device

[paulmcauley]

I am the developer of the Klassy window decoration. On Wayland, my window decoration changes appearance depending on painter->device()->devicePixelRatioF() . I note that this is not happening with applet-window-buttons and devicePixelRatioF() seems to remain at 1.

I am not familiar with the applet-window-buttons implementation, but usually you initialise your pixmap size to qRound(size * devicePixelRatioF()), then you set your pixmap.setDevicePixelRatio(devicePixelRatioF()).