Sets a widget's window. This function should only be used in a widget's GtkWidget::realize implementation. The %window passed is usually either new window created with gdk_window_new(), or the window of its parent widget as returned by gtk_widget_get_parent_window(). Widgets must indicate whether they will create their own GdkWindow by calling gtk_widget_set_has_window(). This is usually done in the widget's init() function. <note><para>This function does not add any reference to @window.</para></note>