Hello Ralph.

It looks great but you should add some basic usage howto. It is obvious that you know how to use it, you created it, but other people do not.

The first time I used it it was very frustrating because I only created circle handlers, and said: This is sh*t!! Then I close the window and looked back at the sample image and saw square pointers, so I said: There must be some key that creates square pointers. After trying again I discover it creates square handlers by default.

This is the typical engineer mindset, after having spent years doing something they consider obvious what it is not.

Read "The Design of everyday things" for more design concepts if you are interested.