add back MIDI Learn for stereo panner

git-svn-id: svn://localhost/ardour2/branches/3.0@8394 d708f5d6-7413-0410-9779-e7cbd77b26cf

gtk2_ardour/stereo_panner.cc

@@ -67,6 +67,8 @@ StereoPanner::StereoPanner (boost::shared_ptr<PBD::Controllable> position, boost
         , detented (false)
         , drag_data_window (0)
         , drag_data_label (0)
+        , position_binder (position)
+        , width_binder (width)
 {
         if (!have_colors) {
                 set_colors ();
@@ -294,6 +296,19 @@ StereoPanner::on_button_press_event (GdkEventButton* ev)
         accumulated_delta = 0;
         detented = false;
 
+        /* Let the binding proxies get first crack at the press event
+         */
+
+        if (ev->y < 20) {
+                if (position_binder.button_press_handler (ev)) {
+                        return true;
+                }
+        } else {
+                if (width_binder.button_press_handler (ev)) {
+                        return true;
+                }
+        }
+        
         if (ev->button != 1) {
                 return false;
         }

gtk2_ardour/stereo_panner.h

@@ -25,6 +25,8 @@
 #include <gtkmm/drawingarea.h>
 #include <boost/shared_ptr.hpp>
 
+#include "gtkmm2ext/binding_proxy.h"
+
 namespace PBD {
         class Controllable;
 }
@@ -62,6 +64,9 @@ class StereoPanner : public Gtk::DrawingArea
         Gtk::Window* drag_data_window;
         Gtk::Label* drag_data_label;
 
+        BindingProxy position_binder;
+        BindingProxy width_binder;
+
         void value_change ();
         void set_drag_data ();
         void set_tooltip ();