void OnTranslationBegun(TranslationBeginInfo info)
 {
     if (translationBegun != null)
     {
         translationBegun.Invoke(info);
     }
 }
 void TranslationBegun(SliderHandleBase slider, TranslationBeginInfo info)
 {
     if (scalingBegun != null)
     {
         scalingBegun.Invoke();
     }
 }