Ubuntu is redhat based, so I think I can help you, although I use fedora.
The best way to find stuff on your system is to start an xterm session.
Umbuntu has that "rootless" thing so do a sudo -i (I think) which should make the session root with root permission.
do a updatedb command. The drive will churn away for a few minutes while goes and find all the files and directories. when the prompt returns, type;
locate Qt
this will produce a massive list of Qt related places.
If you want to find the GUI execuatble, it lives in the bin directory.
so do a:
locate Qt | grep "/bin"
which should return the the path
I belive the executable for the GUI is Designer
Good luck.
I think it's unfortunate that someone like myself has to answer you rather than some of the more experienced "gurus" that should be luking here.
I have a Qt issue that I know someone with some REAL knowlege coulsd answer, but so far no one has.
I like codeblocks very much, but am disappointed by the lack of support this forum provides for REAL BUG issues.
Have you tried starting a Qt project in codeblocks on Ubuntu? You should have the same issues as I have had. It won't fly unless you do alot of modifications to the wizard script.
I got it to compile, but the xterm "run" output crashes.
So far...no help on this,yet it is a known issue.