[ Version ( since = "2.12" ) ]
public void set_opacity (double opacity)

Set this to render as partially transparent, with opacity 0 being fully transparent and 1 fully opaque.

(Values of the opacity parameter are clamped to the [0,1] range.)

For toplevel windows this depends on support from the windowing system that may not always be there. For instance, On X11, this works only on X screens with a compositing manager running. On Wayland, there is no per-window opacity value that the compositor would apply. Instead, use `gdk_window_set_opaque_region (window, NULL)` to tell the compositor that the entire window is (potentially) non-opaque, and draw your content with alpha, or use gtk_widget_set_opacity to set an overall opacity for your widgets.

For child windows this function only works for non-native windows.

For setting up per-pixel alpha topelevels, see get_rgba_visual, and for non-toplevels, see set_composited.

Support for non-toplevel windows was added in 3.8.



a top-level or non-native Window