Provide a base class for all OnceUX event handlers.
Identifies OnceUX event types used and emitted within the OnceUX plugin.
Deals with PROGRESS events by capturing the current segment and handling any uncompleted seek operations.
Provide a class to send an event corresponding to a <Impression> element.
Provide a class to send out a tracking beacon as part of processing for the <Tracking> elements encountered in an ad break.