c++编程调整停靠的Qt QDockWidget的大小?

I've just started working on a new C++/Qt project. It's going to be an MDI-based IDE with docked widgets for things like the file tree, object browser, compiler output, etc. One thing is bugging me so far though: I can't figure out how to programmatically make a I've just started working on a new C++/Qt proje