implement entire project in nodes

Project items are now represented directly in nodes opening up more versatility and possibilities. This is the first iteration of this and will be buggy. Need to test thoroughly.

app/widget/timebased/timebasedwidget.cpp

@@ -68,12 +68,12 @@ const int64_t &TimeBasedWidget::GetTimestamp() const
   return ruler_->GetTime();
 }
 
-ViewerOutput *TimeBasedWidget::GetConnectedNode() const
+Sequence *TimeBasedWidget::GetConnectedNode() const
 {
   return viewer_node_;
 }
 
-void TimeBasedWidget::ConnectViewerNode(ViewerOutput *node)
+void TimeBasedWidget::ConnectViewerNode(Sequence *node)
 {
   if (viewer_node_ == node) {
     return;
@@ -244,12 +244,12 @@ void TimeBasedWidget::resizeEvent(QResizeEvent *event)
 
 TimelinePoints *TimeBasedWidget::ConnectTimelinePoints()
 {
-  return static_cast<Sequence*>(viewer_node_->parent());
+  return viewer_node_->timeline_points();
 }
 
 Project *TimeBasedWidget::GetTimelinePointsProject()
 {
-  return static_cast<Sequence*>(viewer_node_->parent())->project();
+  return viewer_node_->project();
 }
 
 TimelinePoints *TimeBasedWidget::GetConnectedTimelinePoints() const
@@ -323,7 +323,10 @@ void TimeBasedWidget::ZoomOut()
 
 void TimeBasedWidget::GoToPrevCut()
 {
-  if (!GetConnectedNode()) {
+  // Cuts are only possible in sequences
+  Sequence* sequence = dynamic_cast<Sequence*>(viewer_node_);
+
+  if (!sequence) {
     return;
   }
 
@@ -333,7 +336,7 @@ void TimeBasedWidget::GoToPrevCut()
 
   int64_t closest_cut = 0;
 
-  foreach (Track* track, viewer_node_->GetTracks()) {
+  foreach (Track* track, sequence->GetTracks()) {
     int64_t this_track_closest_cut = 0;
 
     foreach (Block* block, track->Blocks()) {
@@ -354,13 +357,16 @@ void TimeBasedWidget::GoToPrevCut()
 
 void TimeBasedWidget::GoToNextCut()
 {
-  if (!GetConnectedNode()) {
+  // Cuts are only possible in sequences
+  Sequence* sequence = dynamic_cast<Sequence*>(viewer_node_);
+
+  if (!sequence) {
     return;
   }
 
   int64_t closest_cut = INT64_MAX;
 
-  foreach (Track* track, GetConnectedNode()->GetTracks()) {
+  foreach (Track* track, sequence->GetTracks()) {
     int64_t this_track_closest_cut = Timecode::time_to_timestamp(track->track_length(), timebase());
 
     if (this_track_closest_cut <= GetTimestamp()) {
@@ -573,7 +579,7 @@ void TimeBasedWidget::SetMarker()
   }
 
   if (ok) {
-    Core::instance()->undo_stack()->push(new MarkerAddCommand(static_cast<Sequence*>(GetConnectedNode()->parent())->project(),
+    Core::instance()->undo_stack()->push(new MarkerAddCommand(GetConnectedNode()->project(),
                                                               points_->markers(), TimeRange(GetTime(), GetTime()), marker_name));
   }
 }