angular-ui/bootstrap — pull request #2647 by NateRedding (2014-08-29 18:49:25+00:00)
Title: Add start and end events for collapse and expand transitions.

There are plenty of use cases where one would need to know when a collapse or accordion section is finished expanding/collapsing. This PR adds some simple start and end events that are emitted around the expand/collapse transistions. This will allow users of the collapse or accordion widgets to know when the animation is done so that they can take further action.