spine/spine — pull request #557 by larryzhao (2014-09-01 16:44:20+00:00)
Title: add a callback for controller to have a place to do sth after the elemen...

To add a callback for controllers to have a place to do sth after the element of the controller is actually shown.

Sometime I need to calculate the height/width of a element after a controller is activated, but through the callback of event `active` the elements of the controller to be activated is not actually shown yet. I think this pull request would fix this.