Index: gtk2_ardour/editing.h
===================================================================
--- gtk2_ardour/editing.h	(revision 1640)
+++ gtk2_ardour/editing.h	(working copy)
@@ -15,6 +15,19 @@
 #define DISPLAYCONTROL(a) /*empty*/
 #define IMPORTMODE(a) /*empty*/
 
+// compile time switch 
+#define OSC_CANVAS
+
+#ifdef OSC_CANVAS
+#  include <lo/lo.h>
+// this is a placeholder for OSC config chars..
+#  define OSC_CANVAS_HOST "localhost"
+#  define OSC_CANVAS_PORT "5280"
+#  define OSC_CANVAS_CMDC "/ardour2/info/canvas"
+// ..and a boolean or int to en/disable during runtime
+#  define OSC_CANVAS_TX 1
+#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
+	//printf("DEBUG: hscroll! %lu %lu\n",(long unsigned) leftmost_frame,(long unsigned) rightmost_frame);
+	if (OSC_CANVAS_TX) {
+		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
+  	nframes_t my_leftmost_frame = (nframes_t) floor (horizontal_adjustment.get_value() * frames_per_unit);
+	nframes_t my_rightmost_frame = leftmost_frame + current_page_frames ();
+	//printf("DEBUG: zoom:   %lu %lu\n",(long unsigned) my_leftmost_frame,(long unsigned) my_rightmost_frame);
+	if (OSC_CANVAS_TX) {
+		lo_address a= lo_address_new (OSC_CANVAS_HOST, OSC_CANVAS_PORT);
+		lo_send(a, OSC_CANVAS_CMDC, "ii", (unsigned long) my_leftmost_frame, (unsigned long) my_rightmost_frame);
+		lo_address_free(a);
+	}
+#endif
 	return 0;
 }