Android : How much of the height of a View in a ListView is actually visible on screen?

When the user scrolls a ListView,I need to find out how much of the View is actually visible on the screen (i.e. how much of its height).

I have implemented AbsListView.OnScrollListener and through its callbacks I can find out the first visible item on the screen, but how can I find out how much of the View is actually visible?

Thanks.