[millstone]

I don't like UI frameworks that work the way you describe either! I think this is mainly C++-legacy living on in Java and .NET, where they pay a penalty for being static. OO UI frameworks in dynamic languages can be structured very differently.

In Cocoa, you don't have these silly class-specific interfaces ("ButtonClickListener" or whatever). Instead it uses target/action: you give the button an object, and the method name to call on the object. So it does allow you to bind any member of that "world of classes" as-is.

Next, you allow the target to be dynamically determined. For example, say you have a button representing the Copy to Clipboard. You can set its target object to a sentinel representing the keyboard focus. And the button can even use reflection, and disable itself if the focus doesn't support Copy.

In a functional world, functions are opaque: the only thing you can ultimately do with a function is call it. But in an OO world, functions are closer to objects: they have names, they can be inspected, they can be dynamically dispatched. This is part of what makes OO languages excel at UIs.