anchor.diff:    void zoomBy(double delta) {
       scale.setValues(scale.x + delta, scale.y + delta);
       _zoomDirty = true;
  +    Ranger.Application.instance.eventBus.fire(this);
  +
       _updateMatrix();
     }
     
  
positive.code:       scale.setValues(scaleFactor, scaleFactor);
  
        _zoomDirty = true;
        
        _updateMatrix();
    }
    
  
negative.code:  */
  class ZoomGroup extends Ranger.GroupNode with UTE.Tweenable {
    static const int TWEEN_SCALE = 1;
    static const int TRANSLATE_XY = 3;
  
    bool _zoomDirty = true;
    Vector2 scaleCenter = new Vector2.zero();
  