How to detect DOM changes from Ember component

I've written a dropdown component, it calculates its own height to fit the page on afterRender.

The dropdown consists of outer DIV (div1) and internal DIV (div2). The height of the div1 depends on div2 height and gets document height if div1 greater then document height (cut dropdown, to prevent transgress of page).

But sometimes div2 body changes, and height of div1 should be recalculated.

How can I detect div2 DOM changes? Maybe Ember has an event that fires every time when template rerenders.

PS: Except onDomChange event (it's wrong, i guess)