Handler methods should be able to specify their scope

[c-jo]

And example can be found in !Hyper. Clicking on a button in the toolbar will also cause the "mouse clicked" handler in the main window to be invoked, which causes unrequired behaviour. While the handler can check the IDs match, this is easy to forget to do and adds to extra code. The handlers should be able to say if they should match the self, parent or ancestor.