reworked and vastly improved snapping subsystem

app/widget/nodeparamview/nodeparamview.cpp

@@ -29,6 +29,7 @@
 #include "common/timecodefunctions.h"
 #include "node/output/viewer/viewer.h"
 #include "widget/nodeview/nodeviewundo.h"
+#include "widget/timeruler/timeruler.h"
 
 namespace olive {
 
@@ -117,6 +118,7 @@ NodeParamView::NodeParamView(bool create_keyframe_view, QWidget *parent) :
     // Create keyframe view
     keyframe_view_ = new KeyframeView();
     keyframe_view_->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    keyframe_view_->SetSnapService(this);
     ConnectTimelineView(keyframe_view_);
     keyframe_area_layout->addWidget(keyframe_view_);
 

app/widget/nodeparamview/nodeparamview.h

@@ -88,6 +88,16 @@ protected:
 
   virtual void ConnectedNodeChangeEvent(ViewerOutput* n) override;
 
+  virtual const QVector<KeyframeViewInputConnection*> *GetSnapKeyframes() const override
+  {
+    return keyframe_view_ ? &keyframe_view_->GetKeyframeTracks() : nullptr;
+  }
+
+  virtual const std::vector<NodeKeyframe*> *GetSnapIgnoreKeyframes() const override
+  {
+    return keyframe_view_ ? &keyframe_view_->GetSelectedKeyframes() : nullptr;
+  }
+
 private:
   void UpdateItemTime(const rational &time);