Improve scrolling performance for sessions containing hundreds of regions over many tracks by hiding offscreen tracks (scroll faster by making tracks larger, exposing fewer of them). Use distance from screen edges to drive autoscrolling distance. Avoid using canvas coordinates for displacement calculations where possible. Don't redisplay tempo in the colour handler.

git-svn-id: svn://localhost/ardour2/branches/2.0-ongoing@3853 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 17 insertions, 18 deletions

diff --git a/gtk2_ardour/time_axis_view.cc b/gtk2_ardour/time_axis_view.cc
index 0ca20e4670..88d585ddc2 100644
--- a/gtk2_ardour/time_axis_view.cc
+++ b/gtk2_ardour/time_axis_view.cc
@@ -222,29 +222,15 @@ TimeAxisView::show_at (double y, int& nth, VBox *parent)
 	order = nth;
 
 	if (y_position != y) {
-		/* the coordinates used here are in the system of the
-		   item's parent ...
-		*/
-		Group* pg;
-		double ix1, iy1, ix2, iy2;
-		canvas_display->get_bounds (ix1, iy1, ix2, iy2);
-		iy1 += editor.get_trackview_group_vertical_offset ();
-		pg = canvas_display->property_parent();
-		pg->i2w (ix1, iy1);
-		
-		if (iy1 < 0) {
-			iy1 = 0;
-		}
-		
-		canvas_display->move (0.0, y - iy1);
+		canvas_display->property_y () = y;
+		/* silly canvas */
+		canvas_display->move (0.0, 0.0);
 		y_position = y;
-
 	}
 
 	canvas_display->raise_to_top ();
 
 	if (_marked_for_display) {
-		canvas_display->show();
 		controls_frame.show ();
 		controls_ebox.show ();
 	}
@@ -266,6 +252,19 @@ TimeAxisView::show_at (double y, int& nth, VBox *parent)
 	return effective_height;
 }
 
+void
+TimeAxisView::clip_to_viewport ()
+{
+	if (_marked_for_display) {
+		if (y_position  +  effective_height < editor.get_trackview_group_vertical_offset () || y_position > editor.get_trackview_group_vertical_offset () + canvas_display->get_canvas()->get_height()) {
+			canvas_display->hide ();
+			return;
+		}
+		canvas_display->show ();
+	}
+	return;
+}
+
 bool
 TimeAxisView::controls_ebox_scroll (GdkEventScroll* ev)
 {
@@ -380,8 +379,8 @@ TimeAxisView::set_height(uint32_t h)
 	if (h == height) {
 		return;
 	}
-	controls_frame.property_height_request () = h;
 	height = h;
+	controls_frame.property_height_request () = h;
 
  	if (canvas_item_visible (selection_group)) {
 		/* resize the selection rect */