MapView get dislayed region on e.g. zoom

Hi,

Let’s say I have a MapView. Now the user zooms out… How do I get the region that’s being displayed?

Use case: on zoom out, I want to fetch extra locations to add markers (pretty basic). I can imagine getting the regions periodically via a timer, or a zoom event or, … 

What’s the way to do this?

Thanks,

Maarten