What files can the developer edit safely and which files are overwritten?
Glade will not overwrite most of the files. It will recreate the build files if they don’t exist (and the corresponding project option is set.) The files which Glade overwrites are: interface.h, interface.c, support.h, and support.c. (Though you may have named them differently in your project, if you changed them in the Project Options dialog.) These files all have a warning at the top saying “DO NOT EDIT”. If you have added or updated any signal handlers, then these are appended to the callbacks.h and callbacks.c files. So any code you have already added for callbacks is completely safe! If you have renamed a handler function then it is up to you to remove the old version and copy any code to the new function.