la enumeración GOL_OBJ_TYPE la encuentro en GOL.h
typedef enum
{
OBJ_BUTTON, // Type defined for Button Object.
OBJ_WINDOW, // Type defined for Window Object.
OBJ_CHECKBOX, // Type defined for Check Box Object.
OBJ_RADIOBUTTON, // Type defined for Radio Button Object.
OBJ_EDITBOX, // Type defined for Edit Box Object.
OBJ_LISTBOX, // Type defined for List Box Object.
OBJ_SLIDER, // Type defined for Slider and/or Scroll Bar Object.
OBJ_PROGRESSBAR, // Type defined for Progress Object.
OBJ_STATICTEXT, // Type defined for Static Text Object.
OBJ_PICTURE, // Type defined for Picture or Bitmap Object.
OBJ_GROUPBOX, // Type defined for Group Box Object.
OBJ_CUSTOM, // Type defined for Custom Object.
OBJ_ROUNDDIAL, // Type defined for Dial Object.
OBJ_METER, // Type defined for Meter Object.
OBJ_GRID, // Type defined for Grid Object.
OBJ_CHART, // Type defined for Chart Object.
OBJ_TEXTENTRY, // Type defined for Text-Entry Object.
OBJ_DIGITALMETER, // Type defined for DIGITALMETER Object.
OBJ_ANALOGCLOCK, // Type defined for ANALOGCLOCK Object.
OBJ_UNKNOWN // Type is undefined and not supported by the library.
} GOL_OBJ_TYPE;
y esta seria una TERCERA pregunta, como es que se relaciona enum con struct?