void gtk_widget_set_app_paintable ( GtkWidget* widget, gboolean app_paintable )
Sets whether the application intends to draw on the widget in
This is a hint to the widget and does not affect the behavior of
the GTK+ core; many widgets ignore this flag entirely. For widgets
that do pay attention to the flag, such as
the effect is to suppress default themed drawing of the widget’s
background. (Children of the widget will still be drawn.) The application
is then entirely responsible for drawing the widget background.
Note that the background is still drawn when the widget is mapped.