gdk:display-is-composited (display)

display -- a gdk:display object

Whether surfaces with RGBA visuals supports an alpha channel.

Returns whether surfaces can reasonably be expected to have their alpha channel drawn correctly on the screen.

Check the value of the gdk:display-is-rgba function for whether the display supports an alpha channel. On X11 this function returns whether a compositing manager is compositing on display. On modern displays, this value is always true.