private void OnPositionChanged(SpatialManip sender, Vector2f oldValue)
 {
   UpdateSelectedSpatial();
 }
 private void OnAngleChanged(SpatialManip sender, float oldValue)
 {
   UpdateSelectedSpatial();
 }
 private void OnShapeManipChanged(ShapesView sender, SpatialManip oldValue)
 {
   if(oldValue != null)
   {
     oldValue.PositionChanged -= this.OnPositionChanged;
     oldValue.AngleChanged -= this.OnAngleChanged;
   }
   
   if(sender.SelectedManip != null)
   {
     sender.SelectedManip.PositionChanged += this.OnPositionChanged;
     sender.SelectedManip.AngleChanged += this.OnAngleChanged;
   }
   
   UpdateSelectedSpatial();
 }