Sel -= pObj->PageSize;
      } else if (x <= Pos.x1_Thumb) {      /* Thumb area */
        if (Pos.xSizeMoveable > 0) {
          x = x - Pos.ThumbSize/2 - Pos.x1_LeftArrow-1;
          Sel = GUI__DivideRound(Range * x, Pos.xSizeMoveable);
        }
      } else if (x < Pos.x0_RightArrow) {  /* right area (page right) */
        Sel += pObj->PageSize;
      } else  if (x <= Pos.x1_RightArrow) {
        Sel++;
      }
      /* WM_SetFocus(hObj); */
      WM_SetCapture(hObj, 1);
      SCROLLBAR_SetValue(hObj, Sel);
      if ((pObj->Widget.State & SCROLLBAR_STATE_PRESSED) == 0){   
        _ScrollbarPressed(hObj, pObj);
      }
    } else {
      /* React only if button was pressed before ... avoid problems with moving / hiding windows above (such as dropdown) */
      if (pObj->Widget.State & SCROLLBAR_STATE_PRESSED) {   
        _ScrollbarReleased(hObj, pObj);
      }
    }
  }
}

/*********************************************************************
*
*       _OnKey
*/
static void  _OnKey(SCROLLBAR_Handle hObj, WM_MESSAGE*pMsg) {
  const WM_KEY_INFO* pKeyInfo;
  int Key;
  pKeyInfo = (const WM_KEY_INFO*)(pMsg->Data.p);
  Key = pKeyInfo->Key;
  if (pKeyInfo->PressedCnt > 0) {
    switch (Key) {
      case GUI_KEY_RIGHT:
      case GUI_KEY_DOWN:
        SCROLLBAR_Inc(hObj);
        break;                    /* Send to parent by not doing anything */
      case GUI_KEY_LEFT:
      case GUI_KEY_UP:
        SCROLLBAR_Dec(hObj);
        break;                    /* Send to parent by not doing anything */
      default:
        return;
    }
  }
}

/*********************************************************************
*
*       _OnSetScrollState 
*/
static void _OnSetScrollState(SCROLLBAR_Handle hObj, SCROLLBAR_Obj* pObj, const WM_SCROLL_STATE* pState) {
  if (  (pState->NumItems != pObj->NumItems)
      || (pObj->PageSize   != pState->PageSize)
      || (pObj->v          != pState->v))
  {
    pObj->NumItems = pState->NumItems;
    pObj->PageSize = pState->PageSize;
    pObj->v        = pState->v;
    WM_InvalidateWindow(hObj);
  }
}

/*********************************************************************
*
*       SCROLLBAR__InvalidatePartner
*/
void SCROLLBAR__InvalidatePartner(SCROLLBAR_Handle hObj) {     /* Invalidate the partner, since it is also affected */
  WM_InvalidateWindow(WM_GetScrollPartner(hObj));
  WM_SendMessageNoPara(WM_GetParent(hObj), WM_NOTIFY_CLIENTCHANGE);   /* Client area may have changed */
}

/*********************************************************************
*
*       _SCROLLBAR_Callback
*/
static void _SCROLLBAR_Callback (WM_MESSAGE *pMsg) {
  SCROLLBAR_Handle hObj;
  SCROLLBAR_Obj* pObj;
  hObj = pMsg->hWin;
  pObj = SCROLLBAR_H2P(hObj);
  /* Let widget handle the standard messages */
  if (WIDGET_HandleActive(hObj, pMsg) == 0) {
    return;
  }
  switch (pMsg->MsgId) {
  case WM_DELETE:
    SCROLLBAR__InvalidatePartner(hObj);
    break;
  case WM_PAINT:
    GUI_DEBUG_LOG("SCROLLBAR: _Callback(WM_PAINT)\n");
    _Paint(pObj);
    return;
  case WM_TOUCH:
    _OnTouch(hObj, pObj, pMsg);
    break;
  case WM_KEY:
    _OnKey(hObj, pMsg);
    break;
  case WM_SET_SCROLL_STATE:
    _OnSetScrollState(hObj, pObj, (const WM_SCROLL_STATE*)pMsg->Data.p);
    break;
  case WM_GET_SCROLL_STATE:
    ((WM_SCROLL_STATE*)pMsg->Data.p)->NumItems = pObj->NumItems;
    ((WM_SCROLL_STATE*)pMsg->Data.p)->PageSize = pObj->PageSize;
    ((WM_SCROLL_STATE*)pMsg->Data.p)->v        = pObj->v;
    break;
  }
  WM_DefaultProc(pMsg);
}

/*********************************************************************
*
*       Exported routines:  Create
*
**********************************************************************
*/

/* Note: the parameters to a create function may vary.
         Some widgets may have multiple create functions */

/*********************************************************************
*
*       SCROLLBAR_CreateEx
*/
SCROLLBAR_Handle SCROLLBAR_CreateEx(int x0, int y0, int xsize, int ysize, WM_HWIN hParent,
                                    int WinFlags, int ExFlags, int Id)
{
  SCROLLBAR_Handle hObj;
  WM_LOCK();
  /* Set defaults if necessary */
  if ((xsize == 0) && (ysize == 0)) {
    GUI_RECT Rect;
    WM_GetInsideRectEx(hParent, &Rect);
    if (ExFlags & SCROLLBAR_CF_VERTICAL) {
      xsize = SCROLLBAR__DefaultWidth;
      x0    = Rect.x1 + 1 - xsize;
      y0    = Rect.y0;
      ysize = Rect.y1 - Rect.y0 + 1;
    } else {
      ysize = SCROLLBAR__DefaultWidth;
      y0    = Rect.y1 + 1 - ysize;
      x0    = Rect.x0;
      xsize = Rect.x1 - Rect.x0 + 1;
    }
  }
  /* Create the window */
  hObj = WM_CreateWindowAsChild(x0, y0, xsize, ysize, hParent, WinFlags, _SCROLLBAR_Callback,
                                sizeof(SCROLLBAR_Obj) - sizeof(WM_Obj));
  if (hObj) {
    SCROLLBAR_Obj* pObj = SCROLLBAR_H2P(hObj);
    U16 InitState;
    /* Handle SpecialFlags */
    InitState = 0;
    if (ExFlags & SCROLLBAR_CF_VERTICAL) {
      InitState |= WIDGET_CF_VERTICAL;
    }
    if (ExFlags & SCROLLBAR_CF_FOCUSSABLE) {
      InitState |= WIDGET_STATE_FOCUSSABLE;
    }
    if ((Id != GUI_ID_HSCROLL) && (Id != GUI_ID_VSCROLL)) {
      InitState |= WIDGET_STATE_FOCUSSABLE;
    }
    /* init widget specific variables */
    WIDGET__Init(&pObj->Widget, Id, InitState);
    /* init member variables */
    SCROLLBAR_INIT_ID(pObj);
    pObj->aBkColor[0]   = SCROLLBAR__aDefaultBkColor[0];
    pObj->aBkColor[1]   = SCROLLBAR__aDefaultBkColor[1];
    pObj->aColor[0]     = SCROLLBAR__aDefaultColor[0];
    pObj->aColor[1]     = SCROLLBAR__aDefaultColor[1];
    pObj->NumItems      = 100;
    pObj->PageSize      =  10;
    pObj->v             =   0;
    SCROLLBAR__InvalidatePartner(hObj);
  } else {
    GUI_DEBUG_ERROROUT_IF(hObj==0, "SCROLLBAR_Create failed")
  }
  WM_UNLOCK();
  return hObj;
}

/*********************************************************************
*
*       Exported routines:  Various methods
*
**********************************************************************
*/
/*********************************************************************
*
*       SCROLLBAR_Dec
*/
void SCROLLBAR_Dec(SCROLLBAR_Handle hObj) {
  SCROLLBAR_AddValue(hObj, -1);
}

/*********************************************************************
*
*       SCROLLBAR_Inc
*/
void SCROLLBAR_Inc(SCROLLBAR_Handle hObj) {
  SCROLLBAR_AddValue(hObj,  1);
}

/*********************************************************************
*
*       SCROLLBAR_AddValue
*/
void SCROLLBAR_AddValue(SCROLLBAR_Handle hObj, int Add) {
  SCROLLBAR_Obj* pObj;
  if (hObj) {
    WM_LOCK();
    pObj = SCROLLBAR_H2P(hObj);
    SCROLLBAR_SetValue(hObj, pObj->v + Add);
    WM_UNLOCK();
  }
}

/*********************************************************************
*
*       SCROLLBAR_SetValue
*/
void SCROLLBAR_SetValue(SCROLLBAR_Handle hObj, int v) {
  SCROLLBAR_Obj* pObj;
  int Max;
  if (hObj) {
    WM_LOCK();
    pObj = SCROLLBAR_H2P(hObj);
    Max = pObj->NumItems - pObj->PageSize;
    if (Max < 0)
      Max =0;
    /* Put in min/max range */
    if (v < 0) {
      v = 0;
    }
    if (v > Max) {
      v = Max;
    }
    if (pObj->v != v) {
      pObj->v = v;
      WM_InvalidateWindow(hObj);
      WM_NotifyParent(hObj, WM_NOTIFICATION_VALUE_CHANGED);
    }
    WM_UNLOCK();
  }
}

/*********************************************************************
*
*       SCROLLBAR_SetNumItems
*/
void SCROLLBAR_SetNumItems(SCROLLBAR_Handle hObj, int NumItems) {
  SCROLLBAR_Obj* pObj;
  if (hObj) {
    WM_LOCK();
    pObj = SCROLLBAR_H2P(hObj);
    if (pObj->NumItems != NumItems) {
      pObj->NumItems = NumItems;
      WM_InvalidateWindow(hObj);
    }
    WM_UNLOCK();
  }
}

/*********************************************************************
*
*       SCROLLBAR_SetPageSize
*/
void SCROLLBAR_SetPageSize(SCROLLBAR_Handle hObj, int PageSize) {
  SCROLLBAR_Obj* pObj;
  if (hObj) {
    WM_LOCK();
    pObj = SCROLLBAR_H2P(hObj);
    if (pObj->PageSize != PageSize) {
      pObj->PageSize = PageSize;
      WM_InvalidateWindow(hObj);
    }
    WM_UNLOCK();
  }
}

/*********************************************************************
*
*       SCROLLBAR_SetState
*/
void  SCROLLBAR_SetState   (SCROLLBAR_Handle hObj, const WM_SCROLL_STATE* pState) {
  if (hObj) {
    SCROLLBAR_SetPageSize(hObj, pState->PageSize);
    SCROLLBAR_SetNumItems(hObj, pState->NumItems);
    SCROLLBAR_SetValue   (hObj, pState->v);
  }
}


#else /* avoid empty object files */

void SCROLLBAR_C(void);
void SCROLLBAR_C(void){}

#endif  /* #if GUI_WINSUPPORT */