add Gtkmm2ext::detach_menu() that was needed by my previous commit

git-svn-id: svn://localhost/ardour2/branches/3.0@6471 d708f5d6-7413-0410-9779-e7cbd77b26cf

2 files changed, 15 insertions, 0 deletions

diff --git a/libs/gtkmm2ext/gtkmm2ext/utils.h b/libs/gtkmm2ext/gtkmm2ext/utils.h
index 7f986e738c..d6d5a9498c 100644
--- a/libs/gtkmm2ext/gtkmm2ext/utils.h
+++ b/libs/gtkmm2ext/gtkmm2ext/utils.h
@@ -31,6 +31,7 @@ namespace Gtk {
 	class Widget;
 	class Window;
 	class Paned;
+	class Menu;
 }
 
 namespace Gtkmm2ext {
@@ -69,6 +70,7 @@ namespace Gtkmm2ext {
 	void set_decoration (Gtk::Window* win, Gdk::WMDecoration decor);
 	void set_treeview_header_as_default_label(Gtk::TreeViewColumn *c);
 	Glib::RefPtr<Gdk::Drawable> get_bogus_drawable();
+	void detach_menu (Gtk::Menu&);
 };
 
 #endif /*  __gtkmm2ext_utils_h__ */
diff --git a/libs/gtkmm2ext/utils.cc b/libs/gtkmm2ext/utils.cc
index 3a021bbe7b..400899cb67 100644
--- a/libs/gtkmm2ext/utils.cc
+++ b/libs/gtkmm2ext/utils.cc
@@ -135,3 +135,16 @@ void Gtkmm2ext::set_treeview_header_as_default_label(Gtk::TreeViewColumn* c)
 	gtk_tree_view_column_set_widget( c->gobj(), GTK_WIDGET(0) );
 }
 
+void
+Gtkmm2ext::detach_menu (Gtk::Menu& menu)
+{
+	/* its possible for a Gtk::Menu to have no gobj() because it has
+	   not yet been instantiated. Catch this and provide a safe
+	   detach method.
+	*/
+	if (menu.gobj()) {
+		if (menu.get_attach_widget()) {
+			menu.detach ();
+		}
+	}
+}