F2 means follow the character under the cursor. This should lead you to the right place, regardless of whether the code was provided by any included header file or not.
Your own projects will most likely not include the Qt source files, so you cannot directly jump to them (projects do not link to them, therefore they are not for the creator). Therefore, during editing, you cannot just go directly to the Qt source code. Of course, debugging will work (see the previous answer, buit rebuilding your own Qt is not really necessary).
You can open the projects.pro file found in Qt sources as an additional project in the creator. Then you can at least use the locator (Ctrl-K) to search for methods, etc.
Hope this helps ...
Tobias hunger
source share