Revisit your spec file. Look at what dependencies you have listed. Now look at the wxWidgets tar file (it is readable with your file browser). Compare what you find out there to what is in your spec.
Next, have a look at their website. Search it for info. You should be able to expand your understanding of wxWidgets enough to make more adjustments, I believe.
A question -- Are you using KDE4 as your packaging DE? If not, you probably should. Maybe Gnome.
Re coding: There are some good tools in the repos. For C++, QT Designer is available and Qt Creator, which may be a good one for you. These are KDE IDEs. There are GTK (gimp tool kit -- Gnome, XFCE and LXDE) tools available, also, like Glade Interface Designer. There are more. I won't try to give you an exhaustive list. PM me, if you want to discuss this further. I'll help where I can.