wm_setfocusonnextchild.c

uCGUI

/*************************************************************************************************************
                                                   uC/GUI
                                               嵌入式通用图形软件
File        : WM_SetFocusOnNextChild.c
Purpose     : Implementation of WM_SetFocusOnNextChild
************************************************************************************************************/

#include "WM_Intern.H"

#if GUI_WINSUPPORT    /* If 0, WM will not generate any code */

/*************************************************************************************************************
*       static code
************************************************************************************************************/
static WM_HWIN _SetFocusOnNextChild(WM_HWIN hParent) {     /* Set the focus to the first child */
  WM_Obj* pParent = WM_HANDLE2PTR(hParent);
  WM_Obj* pi;
  WM_HWIN hChild  = WM_GetFocussedChild(hParent);
  WM_HWIN hi = hChild;
  if (pParent->hFirstChild == 0) {
    return 0;                                     /* "Parent" does not have a child ... */
  }
  do {
    if (hi == 0) {
      hi = pParent->hFirstChild;
    } else {
      pi = WM_HANDLE2PTR(hi);
      hi = pi->hNext;
    }
    if (hi == hChild) {
      break;                                      /* We have completed a round -- No other child to focus --- give up ! */
    }
    if (WM_SetFocus(hi)) {
      break;
    }
  } while (1);
  return hi;
}

/*************************************************************************************************************
*       Public code
************************************************************************************************************/

/*************************************************************************************************************
*       WM_SetFocusOnNextChild
*/


WM_HWIN WM_SetFocusOnNextChild(WM_HWIN hParent) {     /* Set the focus to the first child */
  WM_HWIN r;
  WM_LOCK();
    r = _SetFocusOnNextChild(hParent);
  WM_UNLOCK();
  return r;
}


#else
  void WM_SetFocusOnNextChild_C(void) {} /* avoid empty object files */
#endif