Gtk.Widget.prototype.set_parent_window

function set_parent_window(parent_window:Gdk.Window):void {
    // Gjs wrapper for gtk_widget_set_parent_window()
}

Sets a non default parent window for widget.

For GtkWindow classes, setting a parent_window effects whether the window is a toplevel window or can be embedded into other widgets.

<note><para> For GtkWindow classes, this needs to be called before the window is realized. </para></note>