public void set_opacity (double opacity)
Request the this to be rendered partially transparent, with opacity 0 being fully transparent and 1 fully opaque.
(Opacity values are clamped to the [0,1] range.). This works on both toplevel widget, and child widgets, although there are some limitations:
For toplevel widgets this depends on the capabilities of the windowing system. On X11 this has any effect only on X screens with a compositing manager running. See is_composited. On Windows it should work always, although setting a window’s opacity after the window has been shown causes it to flicker once on Windows.
For child widgets it doesn’t work if any affected widget has a native window, or disables double buffering.
desired opacity, between 0 and 1