Yeah, I like that too. Makes you think twice about re-implementing widgets because of the insane amount of functionality that is tied even to the simplest widgets and still invisible.

Think of how hard it would be to re-implement a dropdown, for instance: You would need to implement keyboard navigation (arrow keys), jump-to-entry (using the letter-keys), srolling with the mouse wheel, flipping through entries while the dropdown menu is closed and probably a thousand other things that I never used but some people do.