Flex :: Creating A Dynamically Sized List Component

I need a List that resizes to exactly fit its content, unless that height exceeds its (dynamically sized) parent container. My requirements are as follows:

The component extends List, or at least acts similarly. variableRowHeight and wordWrap both equal to true. The height of the list cannot be less than minHeight (roughly 32px for scrollbar arrows). The height of the list cannot be greater than the height of the parent container .

Note that the parent container can be resized dynamically.

The height of the list should be updated as the size of both the contents and parent container changes.

Live updating would be preferable but not necessary.

There should be no scrollbars if the content height is less than the parent container height (sounds obvious, but I've had trouble with this too).

The trouble is that with variableRowHeight and wordWrap, it's very hard to know the size of the content at any given time. If the parent container's width is reduced, a line wrap may occur in the list which will change the height of the content. I know I can measure the height of the list content using measureHeightOfItems() + viewMetrics.top + viewMetrics.bottom, but when should I calculate that? What events should I listen for? And the thing I've had the most trouble with - when should I calculate it to set the size initially (i.e. just as the content has finished populating)?