Question

In my app I have an array of points which have been added by the user and I want to be able to create a filled shape from these points.

I also want to be able to get any taps within the shape (not the rectangular frame of the shape but the actual shape itself). Also, if the tap is not within the shape (but possibly still within the shape’s frame), I want the tap to be ‘passed down’ to a shape underneath if there is one.

In a sense, I am trying to create an irregularly shaped UIButton from an array of points.

Answer 1

1. Create a subclass of UIView.
2. In it, create a UIBezierPath property from the points array (moveToPoint: and addLineToPoint:).
3. In drawRect:, use the bezier path to draw the shape (call fill or stroke or both).
4. For hit testing, override pointInside:withEvent: and return the correct value based on the return value of -[UIBezierPath containsPoint:].

Make sure to convert correctly between the view’s and path’s coordinate systems if they differ from each other.