extern void calculateScrollBarMeasures(void );
extern void drawScrollLines(void );
extern void hideScrollBars(HDWindow * hdWindow);
extern void getScrollBarMinimumSize(int * width , int * height);
extern void linkScrollBars(void );
extern void makeScrollBarWindows(void );
extern void moveScroller(HDWindow * hdWindow);
extern void scrollDown(void );
extern void scrollDownPage(void );
extern void scrollScroller(XButtonEvent * event);
extern void scrollToFirstPage(void );
extern void scrollUp(void );
extern void scrollUpPage(void );
extern void showScrollBars(HDWindow * hdWindow);
#ifdef _SCROLLBAR_C
static int ch(int height);
static void changeWindowBackgroundPixmap(Window window , Pixmap pixmap);
static void drawScroller3DEffects(HDWindow * hdWindow , int x1 , int y1 , int x2 , int y2);
#endif