Some advice on how to structure this program?

[yogeshgokul]

Thanks for the help... I have put all my source classes into a static library and when I compile it it produces a load of .o files and a .a file named libXXXX.a

Relax, this is usual. After all you are making a big change in your project so errors are normal.

But I am having trouble linking it to my GUI program....? I have tried editing the .pro file but I can't seem to get it to work? Where does the libXXXXX.a file need to reside? Do I need the XXXXX.o files as well?

Yes you need to have lib files. Otherwise GUI will provide you errors.

BTW... I am using QtCreator... is there an easier way to link it using the IDE?

I dont think so, .pro files are very powerful. You should configure them instead of changing the IDE settings. Then it will be easy for you to port your project to other operating systems.

I would suggest, to create a test static lib and a test GUI who uses that test lib. Then it will be easy change your actual project.

All the best.