There are a few errors across the project with the GLib/GTK boilerplate headers - relating to the macros for GObject pretty much:
IS_WINTC_XXX should be WINTC_IS_XXX (like GTK_IS_LABEL)
The class macros are incorrectly using the instance name and not class name (WINTC_XXX_CLASS(klass)) or the WINTC_XXX_GET_CLASS macro is wrong entirely
There are a few errors across the project with the GLib/GTK boilerplate headers - relating to the macros for GObject pretty much:
IS_WINTC_XXXshould beWINTC_IS_XXX(likeGTK_IS_LABEL)WINTC_XXX_CLASS(klass)) or theWINTC_XXX_GET_CLASSmacro is wrong entirelyG_BEGIN_DECLSandG_END_DECLS