I launched my app in the Qt Creator debugger, then closed the app. The debug panes didn't hide automatically. Then I waited a bit until the status bar said "Debugger finished." but even then they did not hide automatically.
My window looks like this:
Maybe this is a missing feature and I need to close them myself? Any ideas?
Edit: Now I see that even closing them manually is not a full solution, as:
Hmm, all this is making me feel like I'm doing something fundamentally wrong... this is basic stuff I'm asking about.
I figured it out. I just needed to switch from "Debug mode" to "Edit mode" via the leftmost dark vertical button bar. That hides the debug panes and bars. And vice versa - switching to the "Debug mode" button shows the debug stuff.
Confusing when I'm used to Visual Studio, but workable I guess.