a #GdkWindow.
Return: Either @style, or a newly-created #GtkStyle. If the style is newly created, the style parameter will be unref'ed, and the new style will have a reference count belonging to the caller.
Deprecated: Use gtk_widget_style_attach() instead
Attaches a style to a window; this process allocates the colors and creates the GC’s for the style - it specializes it to a particular visual. The process may involve the creation of a new style if the style has already been attached to a window with a different style and visual.
Since this function may return a new object, you have to use it in the following way: style = gtk_style_attach (style, window)