This article will cover the events of RadTransitionControl.
RadTransitionControl exposes TransitionStatusChanged event which is fired anytime there is a change in the content and the transition animation. The TransitionStatusChangedEventArgs exposes a Status property which is of enum TransitionStatus. The property value could be one of the Started, Interrupted or Completed members.
Started indicates that the transition has been idle and new transition is triggered.
Interrupted indicates new transition start before the old one has completed.
Completed means the transition completes and the RadTransitionControl is now idle.
To check if new content is available and has started a transition you should take care to handle both cases of Started and Interrupted. They both indicate a new transition has started the difference is whether the RadTransitionControl has been playing other transition or not.
If you want to do some UI related logic like disabling buttons while a transition is in progress you could use the Started and Interrupted to set the buttons to disabled and Completed to reset them back to enabled.
For this purpose also a read-only dependency property IsTransitionIdle is available so you could bind IsEnabled of the buttons to IsTransitionIdle.