Question

I don’t see how Qt does the low level graphics work, in order to create its own custom GUI look/feel for each platform. Does it utilize each of the platforms APIs or something? I ask because I am really wondering how I could go about creating my own framework in order to make a custom GUI application with a unique graphical look.

Answer 1

“How does QT only use C++ to make custom GUIs for some many platforms?”

“Does it utilize each of the platforms APIs … ?”

You answered your own question. It makes a common library for developers to write their applications with. The application developers write their application only once, not caring about platform specifics. Then, the library author puts out different versions of the library for each platform, which handles all the specific UI calls. This is called encapsulation:

http://en.wikipedia.org/wiki/Information_hiding#Encapsulation

If you were to write your own such library, you would need to figure out what is common between all of the platforms you target, or figure out what high-level concepts your application would need, and create that abstraction. Then, implement that abstraction for each of the platforms you wanted to support.

Edit:

Also see Juliano’s comment. This seems like it might be closer to what you want to do, rather than the question you asked. I’d not re-do the work that Trolltech or the WxWidgets team or the Gtk guys or the Mono people did, if I could possibly avoid it.