Probably a bit of a straight forward one here but I was wondering what's the best way to add an event listener to a custom component to check for when it's selectedIndex gets re-set back to zero?
override selectedIndex setter or addEventListener(Event.CHANGE, );
It really depends on the component.
Assuming your component extends something that already has a selectedIndex implemented, it will probably also have a 'change' event which you can just listen to and check the new index.
Or if you really need an event where selectedIndex is set to 0; you could extend the setter method of the selectedIndex and fire off your own event if the selectedIndex is being set to 0.