wm_setfocusonprevchild.c

MCB2300_ucgui_LCD320240.rar LPC2368的uc/gui的移植

/*
*********************************************************************************************************
*   											 uC/GUI
*   					 Universal graphic software for embedded applications
*
*   					(c) Copyright 2002, Micrium Inc., Weston, FL
*   					(c) Copyright 2002, SEGGER Microcontroller Systeme GmbH
*
*   		   礐/GUI is protected by international copyright laws. Knowledge of the
*   		   source code may not be used to write a similar product. This file may
*   		   only be used in accordance with a license and should not be redistributed
*   		   in any way. We appreciate your understanding and fairness.
*
----------------------------------------------------------------------
File		: WM_SetFocusOnPrevChild.c
Purpose 	: Implementation of WM_SetFocusOnPrevChild
----------------------------------------------------------------------
*/

#include "WM_Intern.h"

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

/*********************************************************************
*
*   	Static code
*
**********************************************************************
*/
/*********************************************************************
*
*   	_GetPrevChild
*
* Purpose:
*   Returns a handle to the previous child of a window.
*
* Parameters:
*   hParent:  Handle of parent window.
*   hChild:   Handle of child to begin our search to its previous sibling.
*
* Return value:
*   Handle to previous child if we found one.
*   0 if window has no other children.
*/
static WM_HWIN _GetPrevChild(WM_HWIN hChild)
{
	WM_HWIN hObj = 0;
	if (hChild)
	{
		hObj = WM__GetPrevSibling(hChild);
	}
	if (!hObj)
	{
		hObj = WM__GetLastSibling(hChild);
	}
	if (hObj != hChild)
	{
		return hObj;
	}
	return 0;
}

/*********************************************************************
*
*   	_SetFocusOnPrevChild
*
* Purpose:
*   Sets the focus on previous focussable child of a window.
*
* Return value:
*   Handle of focussed child, if we found an other focussable child
*   as the current. Otherwise the return value is zero.
*/
static WM_HWIN _SetFocusOnPrevChild(WM_HWIN hParent)
{
	WM_HWIN hChild, hWin;
	hChild = WM__GetFocussedChild(hParent);
	hChild = _GetPrevChild(hChild);
	hWin = hChild;
	while ((WM_IsFocussable(hWin) == 0) && hWin)
	{
		hWin = _GetPrevChild(hWin);
		if (hWin == hChild)
		{
			break;
		}
	}
	if (WM_SetFocus(hWin) == 0)
	{
		return hWin;
	}
	return 0;
}

/*********************************************************************
*
*   	Public code
*
**********************************************************************
*/
/*********************************************************************
*
*   	WM_SetFocusOnPrevChild
*/
WM_HWIN WM_SetFocusOnPrevChild(WM_HWIN hParent)
{
	WM_HWIN r = 0;
	if (hParent)
	{
		WM_LOCK();
		r = _SetFocusOnPrevChild(hParent);
		WM_UNLOCK();
	}
	return r;
}

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

/*************************** End of file ****************************/