What could set TimelineMax.duration() == 0 ?

[cerulean 3 Likes (Newbie)]

I've solved this, but I have no idea how, and I'm trying to understand what happened.

 

I have TImelineMax's set up in a class.  One of them is this, super-simple -- I use it to have a person 'escaping' or not escaping -- if they are escaping, they move off screen, if you click, the timeline is reversed and they come back.  Instantiations of this class are being moved in z-space forwards, in a timelinemax which contains repeat = -1 tweenmaxes (as per Carl's great help) -- when the person disappears off screen in the distance I reset this timeline to get them not escaping anymore. I was using gotoAndStop(0) but now am using seek(0), pause() -- the reset can happen while the timeline is moving forwards, or reverse.

_escapeString = Math.random() > .5 ? "+="  + ESCAPE_DISTANCE : "-=" + ESCAPE_DISTANCE;
			_escapeTimeline = new TimelineMax({paused:true,onStart:tlStart,onComplete:tlComplete,onReverseComplete:tlReverseComplete,ease:Linear.easeNone});
			
			_escapeTimeline.add(new TweenMax(this,ESCAPE_TIME,{x:_escapeString,ease:Linear.easeNone}));

As I said, I solved it, somehow -- but as I don't like unknown unknowns, my question is:

 

apart from kills(), is there anything else that would make the duration() of a timeline == 0, and the progress() == NaN ? That's what was happening.  But the timeline itself existed, i.e. != null.  

[Carl 10,824 Likes (Superhero)]

Not really sure. the duration should only be 0 if the timeline has no tweens inside or if all the child elements have no duration also.