Index: gtk2_ardour/editing.h
===================================================================
--- gtk2_ardour/editing.h	(revision 1640)
+++ gtk2_ardour/editing.h	(working copy)
@@ -15,6 +15,17 @@
 #define DISPLAYCONTROL(a) /*empty*/
 #define IMPORTMODE(a) /*empty*/
 
+// compile time switch 
+#define OSC_CANVAS
+
+#ifdef OSC_CANVAS
+#  include <lo/lo.h>
+#  define OSC_CANVAS_HOST Config->get_osc_notify_host()
+#  define OSC_CANVAS_PORT Config->get_osc_notify_port()
+#  define OSC_CANVAS_CMDC Config->get_osc_notify_cmd_canvas()
+#  define OSC_CANVAS_TX Config->get_osc_notify_mode()
+#endif
+
 namespace Editing {
 
 // SNAPTYPE
Index: gtk2_ardour/editor_canvas.cc
===================================================================
--- gtk2_ardour/editor_canvas.cc	(revision 1640)
+++ gtk2_ardour/editor_canvas.cc	(working copy)
@@ -724,5 +724,13 @@
 	update_fixed_rulers ();
 
 	tempo_map_changed (Change (0), !_dragging_hscrollbar);
+#ifdef OSC_CANVAS
+	if (OSC_CANVAS_TX) {
+		//printf("DEBUG: hscroll! %lu %lu\n",(unsigned long) leftmost_frame,(unsigned long) rightmost_frame);
+		lo_address a= lo_address_new (OSC_CANVAS_HOST, OSC_CANVAS_PORT);
+		lo_send(a, OSC_CANVAS_CMDC, "ii", (unsigned long) leftmost_frame, (unsigned long) rightmost_frame);
+		lo_address_free(a);
+	}
+#endif
 }
 
Index: gtk2_ardour/editor.cc
===================================================================
--- gtk2_ardour/editor.cc	(revision 1640)
+++ gtk2_ardour/editor.cc	(working copy)
@@ -3669,6 +3669,16 @@
 		}
 	}
 
+#ifdef OSC_CANVAS
+	if (OSC_CANVAS_TX) {
+		nframes_t leftmost_frame = (nframes_t) floor (horizontal_adjustment.get_value() * frames_per_unit);
+		nframes_t rightmost_frame = leftmost_frame + current_page_frames ();
+		//printf("DEBUG: zoom:   %lu %lu\n",(unsigned long) my_leftmost_frame,(unsigned long) my_rightmost_frame);
+		lo_address a= lo_address_new (OSC_CANVAS_HOST, OSC_CANVAS_PORT);
+		lo_send(a, OSC_CANVAS_CMDC, "ii", (unsigned long) leftmost_frame, (unsigned long) rightmost_frame);
+		lo_address_free(a);
+	}
+#endif
 	return 0;
 }
 
Index: gtk2_ardour/ardour_ui.h
===================================================================
--- gtk2_ardour/ardour_ui.h	(revision 1640)
+++ gtk2_ardour/ardour_ui.h	(working copy)
@@ -657,6 +657,7 @@
 	void toggle_send_mtc ();
 
 	void toggle_use_osc ();
+	void toggle_osc_notify_mode ();
 
 	void set_input_auto_connect (ARDOUR::AutoConnectOption);
 	void set_output_auto_connect (ARDOUR::AutoConnectOption);
Index: gtk2_ardour/ardour.menus
===================================================================
--- gtk2_ardour/ardour.menus	(revision 1640)
+++ gtk2_ardour/ardour.menus	(working copy)
@@ -343,6 +343,7 @@
                <menuitem action='UseMMC'/>
                <separator/>
                <menuitem action='UseOSC'/>
+               <menuitem action='SendOSC'/>
                <menuitem action='StopPluginsWithTransport'/>
                <menuitem action='DoNotRunPluginsWhileRecording'/>
                <menuitem action='LatchedRecordEnable'/>
Index: gtk2_ardour/ardour_ui_ed.cc
===================================================================
--- gtk2_ardour/ardour_ui_ed.cc	(revision 1640)
+++ gtk2_ardour/ardour_ui_ed.cc	(working copy)
@@ -396,6 +396,7 @@
 	act = ActionManager::register_toggle_action (option_actions, X_("UseMIDIcontrol"), _("Use MIDI control"), mem_fun (*this, &ARDOUR_UI::toggle_use_midi_control));
 	ActionManager::session_sensitive_actions.push_back (act);
 
+	act = ActionManager::register_toggle_action (option_actions, X_("SendOSC"), _("Send OSC"), mem_fun (*this, &ARDOUR_UI::toggle_osc_notify_mode));
 	act = ActionManager::register_toggle_action (option_actions, X_("UseOSC"), _("Use OSC"), mem_fun (*this, &ARDOUR_UI::toggle_use_osc));
 #ifndef HAVE_LIBLO
 	act->set_sensitive (false);
Index: gtk2_ardour/ardour_ui_options.cc
===================================================================
--- gtk2_ardour/ardour_ui_options.cc	(revision 1640)
+++ gtk2_ardour/ardour_ui_options.cc	(working copy)
@@ -64,6 +64,12 @@
 }
 
 void
+ARDOUR_UI::toggle_osc_notify_mode ()
+{
+	ActionManager::toggle_config_state ("options", "SendOSC", &Configuration::set_osc_notify_mode, &Configuration::get_osc_notify_mode);
+}
+
+void
 ARDOUR_UI::toggle_use_osc ()
 {
 	ActionManager::toggle_config_state ("options", "UseOSC", &Configuration::set_use_osc, &Configuration::get_use_osc);
@@ -851,6 +857,11 @@
 
 		ActionManager::map_some_state ("options", "SendMMC", &Configuration::get_send_mmc);
 
+	} else if (PARAM_IS ("osc-notify-mode")) {
+
+		// TODO: realloc static OSC address here
+		ActionManager::map_some_state ("options", "SendOSC", &Configuration::get_osc_notify_mode);
+
 	} else if (PARAM_IS ("use-osc")) {
 
 #ifdef HAVE_LIBLO
Index: libs/ardour/ardour/configuration_vars.h
===================================================================
--- libs/ardour/ardour/configuration_vars.h	(revision 1640)
+++ libs/ardour/ardour/configuration_vars.h	(working copy)
@@ -40,6 +40,13 @@
 CONFIG_VARIABLE (uint32_t, osc_port, "osc-port", 3819)
 CONFIG_VARIABLE (bool, use_osc, "use-osc", false)
 
+/* OSC - notify */
+
+CONFIG_VARIABLE (bool, osc_notify_mode, "osc-notify-mode", false)
+CONFIG_VARIABLE (char*, osc_notify_port, "osc-notify-port", "5280")
+CONFIG_VARIABLE (char*, osc_notify_host, "osc-notify-host", "localhost")
+CONFIG_VARIABLE (char*, osc_notify_cmd_canvas, "osc-notify-cmd-canvas", "/ardour2/info/canvas")
+
 /* crossfades */
 
 CONFIG_VARIABLE (CrossfadeModel, xfade_model, "xfade-model", FullCrossfade)