add canvas rulers event dispatch and reinstate scrolling behaviour

gtk2_ardour/editor.h

@@ -1413,6 +1413,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	bool canvas_automation_track_event(GdkEvent* event, ArdourCanvas::Item*, AutomationTimeAxisView*);
 	bool canvas_note_event (GdkEvent* event, ArdourCanvas::Item *);
 
+	bool canvas_ruler_event (GdkEvent* event, ArdourCanvas::Item *, ItemType);
 	bool canvas_tempo_bar_event (GdkEvent* event, ArdourCanvas::Item*);
 	bool canvas_meter_bar_event (GdkEvent* event, ArdourCanvas::Item*);
 	bool canvas_marker_bar_event (GdkEvent* event, ArdourCanvas::Item*);

gtk2_ardour/editor_canvas_events.cc

@@ -162,6 +162,10 @@ Editor::track_canvas_scroll (GdkEventScroll* ev)
 bool
 Editor::canvas_scroll_event (GdkEventScroll *event)
 {
+	if (h_scroll_group->covers (Duple (event->x, event->y))) {
+		return canvas_ruler_event ((GdkEvent*) event, timecode_ruler, TimecodeRulerItem);
+	}
+
 	_track_canvas->grab_focus();
 	return track_canvas_scroll (event);
 }
@@ -979,6 +983,59 @@ Editor::canvas_meter_marker_event (GdkEvent *event, ArdourCanvas::Item* item, Me
 	return typed_event (item, event, MeterMarkerItem);
 }
 
+bool
+Editor::canvas_ruler_event (GdkEvent *event, ArdourCanvas::Item* item, ItemType type)
+{
+	framepos_t xdelta;
+	bool handled = false;
+
+	if (event->type == GDK_SCROLL) {
+		
+		/* scroll events in the rulers are handled a little differently from
+		   scrolling elsewhere in the canvas.
+		*/
+
+		switch (event->scroll.direction) {
+		case GDK_SCROLL_UP:
+			temporal_zoom_step (false);
+			handled = true;
+			break;
+			
+		case GDK_SCROLL_DOWN:
+			temporal_zoom_step (true);
+			handled = true;
+			break;
+			
+		case GDK_SCROLL_LEFT:
+			xdelta = (current_page_samples() / 2);
+			if (leftmost_frame > xdelta) {
+				reset_x_origin (leftmost_frame - xdelta);
+			} else {
+				reset_x_origin (0);
+			}
+			handled = true;
+			break;
+			
+		case GDK_SCROLL_RIGHT:
+			xdelta = (current_page_samples() / 2);
+			if (max_framepos - xdelta > leftmost_frame) {
+				reset_x_origin (leftmost_frame + xdelta);
+			} else {
+				reset_x_origin (max_framepos - current_page_samples());
+			}
+			handled = true;
+			break;
+			
+		default:
+			/* what? */
+			break;
+		}
+		return handled;
+	}
+
+	return typed_event (item, event, type);
+}
+
 bool
 Editor::canvas_tempo_bar_event (GdkEvent *event, ArdourCanvas::Item* item)
 {

gtk2_ardour/editor_items.h

@@ -56,7 +56,11 @@ enum ItemType {
 	StartCrossFadeItem,
 	EndCrossFadeItem,
 	CrossfadeViewItem,
-
+	TimecodeRulerItem,
+	MinsecRulerItem,
+	BBTRulerItem,
+	SamplesRulerItem,
+	
 	/* don't remove this */
 
 	NoItem

gtk2_ardour/editor_rulers.cc

@@ -164,10 +164,12 @@ Editor::initialize_rulers ()
 	lab_children.push_back (Element(mark_label, PACK_SHRINK, PACK_START));
 	lab_children.push_back (Element(videotl_label, PACK_SHRINK, PACK_START));
 
-	// timecode_ruler->Event.connect (...);
-	// samples_ruler->Event.connect (...);
-	// bbt_ruler->Event.connect (...);
-	// minsec_ruler->Event.connect (...);
+	/* 1 event handler to bind them all ... */
+
+	timecode_ruler->Event.connect (sigc::bind (sigc::mem_fun (*this, &Editor::canvas_ruler_event), timecode_ruler, TimecodeRulerItem));
+	minsec_ruler->Event.connect (sigc::bind (sigc::mem_fun (*this, &Editor::canvas_ruler_event), minsec_ruler, MinsecRulerItem));
+	bbt_ruler->Event.connect (sigc::bind (sigc::mem_fun (*this, &Editor::canvas_ruler_event), bbt_ruler, BBTRulerItem));
+	samples_ruler->Event.connect (sigc::bind (sigc::mem_fun (*this, &Editor::canvas_ruler_event), samples_ruler, SamplesRulerItem));
 	
 	visible_timebars = 0; /*this will be changed below */
 }

gtk2_ardour/enums.cc

@@ -167,5 +167,9 @@ setup_gtk_ardour_enums ()
 	REGISTER_ENUM (StartCrossFadeItem);
 	REGISTER_ENUM (EndCrossFadeItem);
 	REGISTER_ENUM (CrossfadeViewItem);
+	REGISTER_ENUM (TimecodeRulerItem);
+	REGISTER_ENUM (MinsecRulerItem);
+	REGISTER_ENUM (BBTRulerItem);
+	REGISTER_ENUM (SamplesRulerItem);
 	REGISTER (item_type);
 }