from WIDGET.h:236
typedef struct
{
int EffectSize;
void (* pfDrawUp) (void);
void (* pfDrawUpRect) (const GUI_RECT * pRect);
void (* pfDrawDown) (void);
void (* pfDrawDownRect)(const GUI_RECT * pRect);
void (* pfDrawFlat) (void);
void (* pfDrawFlatRect)(const GUI_RECT * pRect);
} WIDGET_EFFECT;