Our new class extends CustomClipper<Path> and overrides two methods. shouldReclip method tells framework when Clipper should be rerendered. We will set this to always return true for simplicity. In the production app, we might want to add actual logic here. getClip method returns a Path object which describes what area of a widget should remain visible. After defining bottom left apex 60 pixels above the bottom right apex, we end up with a figure we needed.

Now we just need to use our clipper with ClipPath widget.