Videoeditor with vis.js timeline module question

The following JSFiddle includes the question : https://jsfiddle.net/supereye/7j02Legx/14/

onMoving and onMove function needs to be implemented in a way that :

Each video element has following properties on the vis.js timeline:
• video_start : the starting timestamp of a video (the value is 0)
• video_end : the total length of the video (in seconds.milliseconds, e.g. 28.5)
• segment_start : distance timestamp in respect to video_start (e.g. 10.5)
• segment_end : end of segment timestamp in respect to video_start ( e.g. 20.9)
• (item.)start : pinpointing start moment of video element in vis.js timeline (JSDate)
• (item.)end : pinpointing ending moment of video element in vis.js timeline(JSDate)

Also some timeline properties :
• timeline_start : start moment of vis.js timeline (JS Date(1970, 0, 1, 0, 0, 0, 000))
• timeline_end : ending moment of vis.js timeline (JS Date(1970, 0, 1, 0, 1, 0, 000))

And the question goes …
How can you implement onMoving() and onMove() functions in a way that ? :
• Video element can not be stretched to left more than segment_start or timeline_start.
• Video element can not be stretched to right more than segment_end or timeline_end.
• Video element can not be moved to left more than segment_start or timeline_start.
• Video element can not be moved to right more than segment_end or timeline_end.
• When element stretched, segment_start and segment_end should be updated accordingly.
• None of the video elements overlaps in the case of stretching or moving elements.