[ptx]

> Most cross platform GUI frameworks are object orientated even if the underlying graphical APIs are procedural. For example, win 32 API is procedural.

Well, win32 is kind of object-oriented, in a way, even though it doesn't always map cleanly to OOP languages.

Windows are basically objects whose methods you call through SendMessage. There is even inheritance by replacing the window procedure and delegating to the parent procedure. There is polymorphism in that many kinds of windows support the same messages (e.g. WM_PAINT) and can decide how to handle them.