Transitioned TimelineBody drawing code to use the TimelineLayoutHelper

src/gui/widgets/timeline/timeline-body.cpp

@@ -287,26 +287,46 @@ TimelineBody::draw_tracks(Cairo::RefPtr<Cairo::Context> cr)
   REQUIRE(timelineWidget->sequence);
   
   // Prepare
+  TimelineLayoutHelper &layout_helper = timelineWidget->layoutHelper;
+  const TimelineLayoutHelper::TrackTree &layout_tree =
+    layout_helper.get_layout_tree();
   const Allocation allocation = get_allocation();
   
   // Save the view matrix
   Cairo::Matrix view_matrix;
   cr->get_matrix(view_matrix);
   
-  // Translate the view by the scroll distance
-  cr->translate(0, -get_vertical_offset());
+  // Iterate drawing each track
+  TimelineLayoutHelper::TrackTree::pre_order_iterator iterator;
+  for(iterator = ++layout_tree.begin(); // ++ so we skip the sequence root
+    iterator != layout_tree.end();
+    iterator++)
+    {
+      const shared_ptr<model::Track> model_track(*iterator);
+      const shared_ptr<timeline::Track> timeline_track =
+        timelineWidget->lookup_timeline_track(*iterator);
         
-  // Interate drawing each track
-  BOOST_FOREACH( shared_ptr<model::Track> model_track,
-    timelineWidget->sequence->get_child_tracks() )
-    draw_track_recursive(cr, model_track, allocation.get_width());
+      optional<Gdk::Rectangle> rect =
+        layout_helper.get_track_header_rect(timeline_track);
+      
+      // Is this track visible?
+      if(rect)
+        {
+          // Translate to the top of the track
+          cr->set_matrix(view_matrix);
+          cr->translate(0, rect->get_y());
+          
+          // Draw the track
+          draw_track(cr, model_track, allocation.get_width());
+        } 
+    }
   
   // Restore the view matrix  
   cr->set_matrix(view_matrix);
 }
 
 void
-TimelineBody::draw_track_recursive(Cairo::RefPtr<Cairo::Context> cr,
+TimelineBody::draw_track(Cairo::RefPtr<Cairo::Context> cr,
   shared_ptr<model::Track> model_track, const int view_width) const
 {
   REQUIRE(cr);
@@ -329,14 +349,6 @@ TimelineBody::draw_track_recursive(Cairo::RefPtr<Cairo::Context> cr,
   cr->save();
   timeline_track->draw_track(cr, &timelineWidget->get_view_window());
   cr->restore();
-  
-  // Shift for the next track
-  cr->translate(0, height  + TimelineWidget::TrackPadding);
-  
-  // Recurse drawing into children
-  BOOST_FOREACH( shared_ptr<model::Track> child,
-    model_track->get_child_tracks() )
-    draw_track_recursive(cr, child, view_width);
 }
 
 void

src/gui/widgets/timeline/timeline-body.hpp

@@ -118,7 +118,7 @@ private:
    */
   void draw_tracks(Cairo::RefPtr<Cairo::Context> cr);
   
-  void draw_track_recursive(Cairo::RefPtr<Cairo::Context> cr,
+  void draw_track(Cairo::RefPtr<Cairo::Context> cr,
     boost::shared_ptr<model::Track> track, const int view_width) const;
   
   /**

src/gui/widgets/timeline/timeline-layout-helper.cpp

@@ -107,6 +107,22 @@ TimelineLayoutHelper::header_from_point(const Gdk::Point &point)
   return shared_ptr<timeline::Track>();
 }
 
+boost::weak_ptr<timeline::Track>
+TimelineLayoutHelper::track_from_y(const int y)
+{
+  std::pair<weak_ptr<timeline::Track>, Gdk::Rectangle> pair; 
+  BOOST_FOREACH( pair, headerBoxes )
+    {
+      // Hit test the rectangle
+      const Gdk::Rectangle &rect = pair.second;
+      if(y >= rect.get_y() && y < rect.get_y() + rect.get_height())
+        return pair.first;
+    }
+
+  // No track was found - return an empty pointer
+  return shared_ptr<timeline::Track>();
+}
+
 int
 TimelineLayoutHelper::get_total_height() const
 {

src/gui/widgets/timeline/timeline-layout-helper.hpp

@@ -72,6 +72,8 @@ public:
   boost::weak_ptr<timeline::Track> header_from_point(
     const Gdk::Point &point);
     
+  boost::weak_ptr<timeline::Track> track_from_y(const int y);
+    
   int get_total_height() const;
   
 protected: