add a focus handling callback so that all button press events on CairoWidgets will...

[ardour.git] / libs / gtkmm2ext / gtkmm2ext / cairo_widget.h

diff --git a/libs/gtkmm2ext/gtkmm2ext/cairo_widget.h b/libs/gtkmm2ext/gtkmm2ext/cairo_widget.h
index 2e845b94eb3c590feb2da01ad763870fa59b3313..87002101bd7df99a14aadea0b030435e29aaa7b5 100644 (file)
--- a/libs/gtkmm2ext/gtkmm2ext/cairo_widget.h
+++ b/libs/gtkmm2ext/gtkmm2ext/cairo_widget.h
@@ -74,12 +74,30 @@ public:
 
        static void set_source_rgb_a( cairo_t* cr, Gdk::Color, float a=1.0 );
 
+       /* set_focus_handler() will cause all button-press events on any
+          CairoWidget to invoke this slot/functor/function/method/callback.
+          
+          We do this because in general, CairoWidgets do not grab
+          keyboard focus, but a button press on them should
+          clear focus from any active text entry.
+
+          This is global to all CairoWidgets and derived types.
+
+          However, derived types can override the behaviour by defining their
+          own on_button_press_event() handler which returns true under all
+          conditions (which will block this handler from being called). If 
+          they wish to invoke any existing focus handler from their own
+          button press handler, they can just use: focus_handler();
+       */
+       static void set_focus_handler (sigc::slot<void>);
+
 protected:
        /** Render the widget to the given Cairo context */
        virtual bool on_expose_event (GdkEventExpose *);
        void on_size_allocate (Gtk::Allocation &);
        void on_state_changed (Gtk::StateType);
        void on_style_changed (const Glib::RefPtr<Gtk::Style>&);
+       bool on_button_press_event (GdkEventButton*);
        Gdk::Color get_parent_bg ();
        
        /* this is an additional virtual "on_..." method. Glibmm does not
@@ -95,10 +113,13 @@ protected:
        static bool     _flat_buttons;
        bool            _grabbed;
 
+       static sigc::slot<void> focus_handler;
+
   private:
        Glib::SignalProxyProperty _name_proxy;
        sigc::connection _parent_style_change;
        Widget * _current_parent;
+       
 };
 
 #endif