polygon UIView to fire an event

I need something like that:

An image map (I think it will have to be done with an UIView of some sort开发者_如何学Go) which is an image (a special map) with some areas (polygons) which should call an event when touched... How to make a poligon-"overlay" for images which fire an event?

The image map mentioned above and an UITableView in a UIScrollView - but I think this shouldn't be that hard...? Should look like this afterwards.

-------------------------- UIScrollView top
 +-----------------------+
 +    polygon UIView     +
 +-----------------------+
 +-----------------------+
 +      UITableView      +
 +-----------------------+
-------------------------- UIScrollView bottom

Thanks in advance for your answers!

I'd create a subclass of UIView (e.g. DOMImageMapView), with a list of CGPathRef or UIBezierPath instances associated with it.

In DOMImageMapView's drawRect: implementation, you would draw the image, and then iterate through each path instance and fill it using CGContextFillPath() or -[UIBezierPath fill].

For hit tests, you would implement touchesEnded:withEvent: (or similar), and test each path via CGPathContainsPoint() or -[UIBezierPath containsPoint:]. If one of the paths returns YES, call a delegate method like imageMapView:didSelectArea:.

Your UITableViewController (or UIViewController with a UITableView in it) would create the DOMImageMapView and set itself as the delegate. When an area is tapped, the controller will receive the callback and can handle the event appropriately.