*   On traditional transparent windows, the transparent window is never drawn on its own,
*   so there is no need to restore the invalid rectangle.
*   However, with WM_SF_CONST_OUTLINE, the window itself may need to be redrawn because it
*   can be invalid. Modifying the invalid rectangle would lead to not updating the window
*   in the worst case.
*/

#if WM_SUPPORT_TRANSPARENCY
static int _Paint1Trans(WM_HWIN hWin, WM_Obj* pWin) {
  int xPrev, yPrev;
  WM_Obj* pAWin = WM_H2P(GUI_Context.hAWin);
  /* Check if we need to do any drawing */
  if (GUI_RectsIntersect(&pAWin->InvalidRect, &pWin->Rect)) {
    /* Save old values */
    xPrev = GUI_Context.xOff;
    yPrev = GUI_Context.yOff;
    /* Set values for the current (transparent) window, rather than the one below */
    GUI__IntersectRects(&pWin->InvalidRect, &pWin->Rect, &pAWin->InvalidRect);
    WM__hATransWindow = hWin;
    GUI_Context.xOff = pWin->Rect.x0;
    GUI_Context.yOff = pWin->Rect.y0;
    /* Do the actual drawing ... */
    _Paint1(hWin, pWin);
    /* Restore settings */
    WM__hATransWindow = 0;
    GUI_Context.xOff = xPrev;
    GUI_Context.yOff = yPrev;
    return 1;                       /* Some drawing took place */
  }
  return 0;                         /* No invalid area, so nothing was drawn */
}
#endif

/*********************************************************************
*
*       _PaintTransChildren
*
* Purpose:
*   Paint transparent children. This function is obviously required
*   only if there are transparent windows.
* Function:  Obvious
* Parameter: Obvious
* Returns:   ---
*/
#if WM_SUPPORT_TRANSPARENCY
static void _PaintTransChildren(WM_HWIN hWin, WM_Obj* pWin) {
  WM_HWIN hChild;
  WM_Obj* pChild;
  if (pWin->Status & WM_SF_ISVIS) {
    for (hChild = pWin->hFirstChild; hChild; hChild = pChild->hNext) {
      pChild = WM_H2P(hChild);
      if ((pChild->Status & (WM_SF_HASTRANS | WM_SF_ISVIS))   /* Transparent & visible ? */
		                ==  (WM_SF_HASTRANS | WM_SF_ISVIS)) {
        /* Set invalid area of the window to draw */
        if (GUI_RectsIntersect(&pChild->Rect, &pWin->InvalidRect)) {
          GUI_RECT InvalidRectPrev;
          InvalidRectPrev = pWin->InvalidRect;
          if(_Paint1Trans(hChild, pChild)) {
            #if GUI_SUPPORT_MEMDEV
              /* Within the paint event the application is alowed to deal with memory devices.
                 So the pointer(s) could be invalid after the last function call and needs
                 to be restored.
              */
              pChild = WM_H2P(hChild);
            #endif
            _PaintTransChildren(hChild, pChild);
            #if GUI_SUPPORT_MEMDEV
              /* Within the paint event the application is alowed to deal with memory devices.
                 So the pointer(s) could be invalid after the last function call and needs
                 to be restored.
              */
              pChild = WM_H2P(hChild);
              pWin   = WM_H2P(hWin);
            #endif
          }
          pWin->InvalidRect = InvalidRectPrev;
        }
      }
    }
  }
}
#endif

/*********************************************************************
*
*       _PaintTransTopSiblings
*
* Purpose:
*   Paint transparent top siblings. This function is obviously required
*   only if there are transparent windows.
* Function:  Obvious
* Parameter: Obvious
* Returns:   ---
*/
#if WM_SUPPORT_TRANSPARENCY
static void _PaintTransTopSiblings(WM_HWIN hWin, WM_Obj* pWin) {
  WM_HWIN hParent;
  WM_Obj* pParent;
  hParent = pWin->hParent;
  hWin = pWin->hNext;
  while (hParent) { /* Go hierarchy up to desktop window */
    for (; hWin; hWin = pWin->hNext) {
      pWin = WM_H2P(hWin);
      /* paint window if it is transparent & visible */
      if ((pWin->Status & (WM_SF_HASTRANS | WM_SF_ISVIS)) ==  (WM_SF_HASTRANS | WM_SF_ISVIS)) {
        _Paint1Trans(hWin, pWin);
        #if GUI_SUPPORT_MEMDEV
          /* Within the paint event the application is alowed to deal with memory devices.
             So the pointer(s) could be invalid after the last function call and needs
             to be restored.
          */
          pWin   = WM_H2P(hWin);
        #endif
      }
      /* paint transparent & visible children */
      _PaintTransChildren(hWin, pWin);
    }
    pParent = WM_H2P(hParent);
    hWin = pParent->hNext;
    hParent = pParent->hParent;
  }
}
#endif

/*********************************************************************
*
*       Callback for Paint message
*
* This callback is used by the window manger in conjunction with
* banding memory devices. A pointer to this routine is given to
* the banding memory device. This callback in turn will send the
* paint message to the window.
*
**********************************************************************
*/

/*********************************************************************
*
*       WM__PaintWinAndOverlays
*
* Purpose
*   Paint the given window and all overlaying windows
*   (transparent children and transparent top siblings)
*/
void WM__PaintWinAndOverlays(WM_PAINTINFO* pInfo) {
  WM_HWIN hWin;
  WM_Obj* pWin;
  hWin = pInfo->hWin;
  pWin = pInfo->pWin;
  if (!pWin) {
    pWin = WM_H2P(hWin);
  }
  #if WM_SUPPORT_TRANSPARENCY
    /* Transparent windows without const outline are drawn as part of the background and can be skipped. */
    if ((pWin->Status & (WM_SF_HASTRANS | WM_SF_CONST_OUTLINE)) != WM_SF_HASTRANS) {
  #endif
  _Paint1(hWin, pWin);    /* Draw the window itself */
  #if GUI_SUPPORT_MEMDEV
    /* Within the paint event the application is alowed to deal with memory devices.
       So the pointer(s) could be invalid after the last function call and needs
       to be restored.
    */
    pWin = WM_H2P(hWin);
  #endif
  #if WM_SUPPORT_TRANSPARENCY
    }
    if (WM__TransWindowCnt != 0) {
      _PaintTransChildren(hWin, pWin);             /* Draw all transparent children */
      #if GUI_SUPPORT_MEMDEV
        /* Within the paint event the application is alowed to deal with memory devices.
           So the pointer(s) could be invalid after the last function call and needs
           to be restored.
        */
        pWin = WM_H2P(hWin);
      #endif
      _PaintTransTopSiblings(hWin, pWin);    /* Draw all transparent top level siblings */
    }
  #endif
}

/*********************************************************************
*
*       _cbPaintMemDev
*
* Purpose:
*   This is the routine called by the banding memory device. It calls
*   the same _cbPaint Routine which is also used when drawing directly;
*   the only add. work done is adjustment of the invalid rectangle.
*   This way the invalid rectangle visible by the window callback function
*   is limited to the current band, allowing the callback to optimize
*   better.
*/
#if GUI_SUPPORT_MEMDEV
static void _cbPaintMemDev(void* p) {
  GUI_RECT Rect;
  WM_Obj* pWin = WM_H2P(GUI_Context.hAWin);
  Rect = pWin->InvalidRect;
  pWin->InvalidRect = GUI_Context.ClipRect;
  WM__PaintWinAndOverlays((WM_PAINTINFO*)p);
  pWin->InvalidRect = Rect;
}
#endif

/*********************************************************************
*
*       WM__Paint
  Returns:
    1: a window has been redrawn
    0: No window has been drawn  
*/
int WM__Paint(WM_HWIN hWin, WM_Obj* pWin) {
  int Ret = 0;
  if (pWin->Status & WM_SF_INVALID) {
    if (pWin->cb) {
      if (WM__ClipAtParentBorders(&pWin->InvalidRect, hWin)) {
        WM_PAINTINFO Info;
        Info.hWin = hWin;
        WM_SelectWindow(hWin);
        #if GUI_SUPPORT_MEMDEV
          Info.pWin = NULL; /* 'Invalidate' the window pointer, because it can 
                                become invalid through the creation of a memory device
                            */
          if (pWin->Status & WM_SF_MEMDEV) {
            int Flags;
            GUI_RECT r = pWin->InvalidRect;
            Flags = (pWin->Status & WM_SF_HASTRANS) ? GUI_MEMDEV_HASTRANS : GUI_MEMDEV_NOTRANS;
            /*
             * Currently we treat a desktop window as transparent, because per default it does not repaint itself.
             */
            if (pWin->hParent == 0) {
              Flags = GUI_MEMDEV_HASTRANS;
            }
            GUI_MEMDEV_Draw(&r, _cbPaintMemDev, &Info, 0, Flags);
          } else
        #endif
        {
          Info.pWin = pWin;
          WM__PaintWinAndOverlays(&Info);
          Ret = 1;    /* Something has been done */
        }
      }
    }
    /* We purposly clear the invalid flag after painting so we can still query the invalid rectangle while painting */
    pWin->Status &=  ~WM_SF_INVALID; /* Clear invalid flag */
    if (pWin->Status & WM_CF_MEMDEV_ON_REDRAW) {
      pWin->Status |= WM_CF_MEMDEV;
    }
    WM__NumInvalidWindows--;
  }
  return Ret;      /* Nothing done */
}

/*********************************************************************
*
*       _DrawNext
*/
static void _DrawNext(void) {
  int UpdateRem = 1;
  WM_HWIN iWin = (NextDrawWin == WM_HWIN_NULL) ? WM__FirstWin : NextDrawWin;
  GUI_CONTEXT ContextOld;
  GUI_SaveContext(&ContextOld);
  /* Make sure the next window to redraw is valid */
  for (; iWin && UpdateRem; ) {
    WM_Obj* pWin = WM_H2P(iWin);
    if (WM__Paint(iWin, pWin)) {
      UpdateRem--;  /* Only the given number of windows at a time ... */
    }
    iWin = pWin->hNextLin;
  }  
  NextDrawWin = iWin;   /* Remember the window */
  GUI_RestoreContext(&ContextOld);
}

/*********************************************************************
*
*       WM_Exec1
*/
int WM_Exec1(void) {
  /* Poll PID if necessary */
  if (WM_pfPollPID) {
    WM_pfPollPID();
  }
  if (WM_pfHandlePID) {
    if (WM_pfHandlePID())
      return 1;               /* We have done something ... */
  }
  if (WM_IsActive) {
    if (GUI_PollKeyMsg()) {
      return 1;               /* We have done something ... */
    }
  }
#ifdef WIN32
  if (WM_PollSimMsg()) {
    return 1;               /* We have done something ... */
  }
#endif
  if (WM_IsActive && WM__NumInvalidWindows) {
    WM_LOCK();
    _DrawNext();
    WM_UNLOCK();
    return 1;               /* We have done something ... */
  }
  return 0;                  /* There was nothing to do ... */
}

/*********************************************************************
*
*       WM_Exec
*/
int WM_Exec(void) {
  int r = 0;
  while (WM_Exec1()) {
    r = 1;                  /* We have done something */
  }
  return r;
}

/*********************************************************************
*
*       cbBackWin
*
* Purpose
*   Callback for background window
*
*/
static void cbBackWin( WM_MESSAGE* pMsg) {
  const WM_KEY_INFO* pKeyInfo;
  switch (pMsg->MsgId) {
  case WM_KEY:
    pKeyInfo = (const WM_KEY_INFO*)pMsg->Data.p;
    if (pKeyInfo->PressedCnt == 1) {
      GUI_StoreKey(pKeyInfo->Key);
    }
    break;
  case WM_PAINT:
    {
      int LayerIndex;
      #if GUI_NUM_LAYERS > 1
        LayerIndex = _DesktopHandle2Index(pMsg->hWin);
      #else
        LayerIndex = 0;
      #endif
      if (WM__aBkColor[LayerIndex] != GUI_INVALID_COLOR) {
        GUI_SetBkColor(WM__aBkColor[LayerIndex]);
        GUI_Clear();
      }
    }
  default:
    WM_DefaultProc(pMsg);
  }
}

/*********************************************************************
*
*       WM_Activate
*/
void WM_Activate(void) {
  WM_IsActive = 1;       /* Running */
}

/*********************************************************************
*
*       WM_Deactivate
*/
void WM_Deactivate(void) {
  WM_IsActive = 0;       /* No clipping performed by WM */
  WM_LOCK();
  LCD_SetClipRectMax();
  WM_UNLOCK();
}

/*********************************************************************
*
*       WM_DefaultProc
*
* Purpose
*   Default callback for windows
*   Any window should call this routine in the "default" part of the
*   its callback function for messages it does not handle itself.
*
*/
void WM_DefaultProc(WM_MESSAGE* pMsg) {
  WM_HWIN hWin = pMsg->hWin;
  const void *p = pMsg->Data.p;
  WM_Obj* pWin = WM_H2P(hWin);
  /* Exec message */
  switch (pMsg->MsgId) {
  case WM_GET_INSIDE_RECT:      /* return client window in absolute (screen) coordinates */
    WM__GetClientRectWin(pWin, (GUI_RECT*)p);
    break;
  case WM_GET_CLIENT_WINDOW:      /* return handle to client window. For most windows, there is no seperate client window, so it is the same handle */
    pMsg->Data.v = (int)hWin;
    return;                       /* Message handled */
  case WM_KEY:
    WM_SendToParent(hWin, pMsg);
    return;                       /* Message handled */
   case WM_GET_BKCOLOR:
    pMsg->Data.Color = GUI_INVALID_COLOR;
    return;                       /* Message handled */
  case WM_NOTIFY_ENABLE:
    WM_InvalidateWindow(hWin);    
    return;                       /* Message handled */
  }
  /* Message not handled. If it queries something, we return 0 to be on the safe side. */
  pMsg->Data.v = 0;
  pMsg->Data.p = 0;
}

/*********************************************************************
*
*       WM_Init
*/
void WM_Init(void) {
	if (!_IsInited) {
	  NextDrawWin = WM__FirstWin = WM_HWIN_NULL;
	  GUI_Context.WM__pUserClipRect = NULL;
	  WM__NumWindows = WM__NumInvalidWindows =0;
	  /* Make sure we have at least one window. This greatly simplifies the
		  drawing routines as they do not have to check if the window is valid.
	  */
    #if GUI_NUM_LAYERS == 1
      WM__ahDesktopWin[0] = WM_CreateWindow(0, 0, GUI_XMAX, GUI_YMAX, WM_CF_SHOW, cbBackWin, 0);
      WM__aBkColor[0] = GUI_INVALID_COLOR;
      WM_InvalidateWindow(WM__ahDesktopWin[0]); /* Required because a desktop window has no parent. */
    #else
    {
      int i;
      for (i = 0; i < GUI_NUM_LAYERS; i++) {
        WM__ahDesktopWin[i] = WM_CreateWindowAsChild(0, 0, GUI_XMAX, GUI_YMAX, WM_UNATTACHED, WM_CF_SHOW, cbBackWin, 0);
        WM__aBkColor[i] = GUI_INVALID_COLOR;
        WM_InvalidateWindow(WM__ahDesktopWin[i]); /* Required because a desktop window has no parent. */
      }
    }
    #endif
    /* Register the critical handles ... Note: This could be moved into the module setting the Window handle */
    WM__AddCriticalHandle(&WM__CHWinModal);
    WM__AddCriticalHandle(&WM__CHWinLast);
    #if GUI_SUPPORT_MOUSE
      WM__AddCriticalHandle(&WM__CHWinMouseOver);
    #endif

    WM_SelectWindow(WM__ahDesktopWin[0]);
	  WM_Activate();
    _IsInited =1;
	}
}


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

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