Tired of coding Gtk+ w/ other text editors or IDEs?
Ever tried Eclipse? Yes, it's open-source, free and easy-to-use, of course.
It worths a try, believe me ! 
Follow my instructions step-by-step below:
1. Use your Linux system to install Eclipse first, make sure you're running under Gnome.
note: make sure you install Eclipse CDT (C/C++ Development Tools) and Gtk+ 2.0 Development Headers and Libraries.
2. Launch Eclipse then create a new empty C project.
3. Under menu Project, choose Properties. Locate C/C++ General => Paths and Symbols
4. Under tab Include => choose GNU C then click button Add, a dialog pops up. Here you place the path of include folders need for Gtk+ headers.
- In order to find out headers need for Gtk+, use pkg-config tools, I mentioned in previous post. Check it out.
5. Locate C/C++ Build => Settings, under tab Tools Settings, select GNU C Linker => Libraries, then add libraries into text 'Libraries (-l)'. Again, use pkg-config tools to check required libraries for Gtk+.
6. Finally, add a new source C/C++ file and rock! 
Have fun!@