Carousel: add ability to disable scrolling animation

[pixelzoom]

In function-builder, I need to programmatically scroll the carousel in order to determine the location of each item in the carousel in the global coordinate frame. Because of the animation that takes place when you call Carousel.scrollToItem or scrollToItemIndex, I was getting the incorrect result. So this is one situation in which disabling animation is useful, and it seems like a generally useful feature.

[pixelzoom]

Feature implemented. Assigning to @jonathanolson to review, since we discussed this briefly today. Rather than adding an animationEnabled flag to scrollToItem and scrollToItem, I added option animationEnabled and setter/getter for animationEnabled field. This allows you to enable/disable animation not only for the scroll functions, but for the Carousel in general.

[jonathanolson]

Looks good, although one question (unlikely to come up in practice):

I saw scrollTween && scrollTween.stop() was only run if animation was enabled. If the client:

1. Sets animationEnabled to true
2. Calls scrollToItem to kick off animation (to item A)
   and before the animation completes:
3. Sets animationEnabled to false
4. Calls scrollToItem to something on another page (item B)

Presumably the last scrollToItem wouldn't interrupt the tween, so would the tween cause the scroll to end up at item A while the index is at item B?

[pixelzoom]

Good point. Should probably call scrollTween && scrollTween.stop() regardless of whether animationEnabled.

[pixelzoom]

Done. @jonathanolson anything else?

[jonathanolson]

Nope, thanks!

[pixelzoom]

Reopening. There's a bug in this feature, it only works for horizontal carousels.

[pixelzoom]

Fixed and closing.

[pixelzoom]

Reopening.

To reset a carousel without scrolling, the client has to currently do something like this:

var saveAnimationEnabled = myCarousel.animationEnabled;
myCarousel.animationEnabled = false;
myCarousel.reset();
myCarousel.animationEnabled = saveAnimationEnabled;

In Function Builder, I have 3 carousels to reset, so this gets quite ugly. What I'd really like to do is tell reset to temporarily disable animation, and let it handle saving and restoring the animation state, e.g.:

myCarousel.reset( { animationEnabled: false } );

[pixelzoom]

Done, closing. If anyone wants to review, go for it.

[veillette]

I assigned this commit to the wrong ticket