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L_DispContainerGetActionCallBack

Summary

Gets the current action callback function along with the user data, which were set using L_DispContainerSetActionCallBack.

Syntax

#include "ltivw.h"

L_LTIVW_API L_INT L_DispContainerGetActionCallBack(hCellWnd, ppfnCallBack, ppUserData)

Parameters

L_HWND hCellWnd

A handle to the window that represents the Medical Viewer Cell.

DISPCONTAINERACTIONCALLBACK * ppfnCallBack

Pointer to a pointer to a callback function to be updated with the last action callback function set using L_DispContainerSetActionCallBack.

LPVOID * ppUserData

Void pointer to be updated with the value of user defined data associated with the tag callback. If you are not interested in the user-defined data, pass NULL for this parameter.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Required DLLs and Libraries

LTIVW
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Example

This function will add one cell and apply a custom action and tag on it.

// This structure will be the user data to sent for both action and tag callback. 
typedef struct tagFIRSTCELLDATA 
{ 
   L_INT       nValue; 
   L_INT       nOldX; 
   L_INT       nBrightness; 
} 
FIRSTCELLDATA,  * pFIRSTCELLDATA; 
 
 
// Tag call back will write the brightness value of the top left corner of the cell. 
L_INT  EXT_CALLBACK TagCallBack(HWND hCellWnd, 
                                L_INT    nCellIndex, 
                                HDC      hDC, 
                                RECT *   lpRect, 
                                L_VOID * pUserData) 
{ 
   UNREFERENCED_PARAMETER(hCellWnd); 
  pFIRSTCELLDATA pFirstCellData = (pFIRSTCELLDATA)pUserData; 
  if (nCellIndex == 0) 
   { 
      L_TCHAR a[10] = TEXT("\0"); 
      static LOGFONT lf; 
      HFONT hFont, hOldFont; 
      lf.lfHeight = lpRect->bottom - lpRect->top ; 
      lf.lfItalic = TRUE; 
      wsprintf(lf.lfFaceName, TEXT("Times new Roman\0")); 
      SetTextAlign(hDC, TA_LEFT | TA_TOP); 
      SetTextColor(hDC, RGB(255, 255, 255)); 
      hFont = CreateFontIndirect(&lf); 
      hOldFont = SelectFont(hDC, hFont); 
      if (pUserData != NULL) 
         wsprintf(a, TEXT("B = %d"), pFirstCellData->nValue); 
      TextOut(hDC, lpRect->left, lpRect->top, a, lstrlen(a)); 
      SelectFont(hDC, hOldFont); 
      DeleteFont(hFont); 
   } 
   return TRUE; 
} 
 
// This callback is called every time the user clicks on the left mouse button. 
// This will modifies the brightness value as the user drags the mouse cursor to the left or to the right 
// this function applies the brightness effect only on the first cell. 
L_INT EXT_CALLBACK ActionCallBack(HBITMAPLIST  * phBitmapList, 
                                  L_UINT         uCount, 
                                  L_INT          nAction, 
                                  L_UINT         uMessage, 
                                  L_UINT         wParam, 
                                  POINT   *      ptMousePos, 
                                  L_VOID  *      pUserData) 
{ 
   pFIRSTCELLDATA pFirstCellData = (pFIRSTCELLDATA)pUserData; 
   L_INT          nI; 
   L_INT          nCount; 
   BITMAPHANDLE   Bitmap; 
   HWND           hWnd;  
 
   UNREFERENCED_PARAMETER(wParam); 
   UNREFERENCED_PARAMETER(nAction); 
   UNREFERENCED_PARAMETER(uCount); 
 
   switch(uMessage) 
   { 
 
   case WM_LBUTTONDOWN: 
      pFirstCellData->nOldX = ptMousePos->x; 
      break; 
   case WM_MOUSEMOVE: 
      L_GetBitmapListCount(phBitmapList[0], (L_UINT *)&nCount); 
 
      pFirstCellData->nValue = pFirstCellData->nBrightness + ptMousePos->x - pFirstCellData->nOldX; 
      pFirstCellData->nValue = max(-1000, min(1000, pFirstCellData->nValue)); 
 
      for (nI = 0; nI < nCount; nI++) 
      { 
         L_GetBitmapListItem (phBitmapList[0], nI, &Bitmap, sizeof(BITMAPHANDLE)); 
         L_SetPaintContrast (&Bitmap, pFirstCellData->nValue); 
         L_SetBitmapListItem (phBitmapList[0], nI, &Bitmap); 
      } 
 
      // redraw the cell. 
      hWnd = L_DispContainerGetCellWindowHandle(hCon, 0, 0); 
      InvalidateRect(hWnd, NULL, FALSE); 
      break; 
 
   case WM_LBUTTONUP: 
      pFirstCellData->nBrightness = pFirstCellData->nValue; 
 
      break; 
   } 
   return TRUE; 
} 
 
 
#define CONTAINER_ACTION_BRIGHTNESS 101 
DISPCONTAINERACTIONCALLBACK pOldActionCallBack; 
DISPCONTAINERTAGCALLBACK    pOldTagCallBack; 
 
L_INT DispContainerGetActionCallBackExample(HDISPCONTAINER hCon) 
{ 
   L_INT                   nCellIndex; 
   pFIRSTCELLDATA          pFirstCellData; 
   L_INT                   nCount; 
   L_INT                   nRet; 
   HBITMAPLIST             hBitmapList; 
   DISPOWNERACTIONPROPS    OwnerActionProp; 
 
   if (hCon == NULL) 
      return ERROR_NO_MEMORY ; 
 
   // removes all the cells and starts over again. 
   nCount = L_DispContainerGetCellCount (hCon, 0); 
   if (nCount) 
   { 
      nRet = L_DispContainerRemoveCell(hCon, -1, 0); 
      if(nRet != SUCCESS) 
         return nRet; 
   } 
 
   // load a bitmap list. 
   nRet = L_LoadBitmapList (MAKE_IMAGE_PATH(TEXT("Image2.cmp")), &hBitmapList, 0, ORDER_BGRORGRAY, NULL, NULL); 
 
   // if the image is corrupted, not found, or not supported, the program will destroy the container and terminate 
   if (nRet != SUCCESS) 
   { 
      L_DispContainerDestroy (hCon, 0); 
      return nRet; 
   } 
 
   HWND hConWnd = L_DispContainerGetWindowHandle(hCon, 0); 
   HWND hCellWnd = L_DispContainerCreateCell(hConWnd, 0); 
 
   // Insert a new cell at the end of the container cell queue. 
   nCellIndex = L_DispContainerInsertCell (hCon, hCellWnd, -1, 0); 
 
   // Attach the loaded bitmaplist to the newly inserted cell. 
   nRet = L_DispContainerSetCellBitmapList (hCellWnd, 
                                           hBitmapList, 
                                           TRUE, 
                                           0); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   // Get the old action and tag callback. 
   // We assumed here that there is neither old user data exist for the tag nor for the action. 
   nRet = L_DispContainerGetTagCallBack(hCellWnd, &pOldTagCallBack, NULL); 
   if(nRet != SUCCESS) 
      return nRet; 
   nRet = L_DispContainerGetActionCallBack (hCellWnd, &pOldActionCallBack, NULL); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   // Add some tags to the cell 
   nRet = L_DispContainerSetCellTag(hCellWnd, 0, DISPWIN_ALIGN_TOPLEFT, DISPWIN_TYPE_OWNERDRAW, NULL, 0); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   // add the custom action to the container. 
   nRet = L_DispContainerAddAction(hCellWnd, CONTAINER_ACTION_BRIGHTNESS, 0); 
   if(nRet != SUCCESS) 
      return nRet; 
   nRet = L_DispContainerSetAction (hCellWnd, CONTAINER_ACTION_BRIGHTNESS, CONTAINER_MOUSE_BUTTON_LEFT, DCACTION_ACTIVEONLY); 
   if(nRet != SUCCESS) 
      return nRet; 
   OwnerActionProp.DispContainerActionProps.bCircularMouseMove = FALSE; 
   OwnerActionProp.DispContainerActionProps.hCursor = NULL; 
   OwnerActionProp.DispContainerActionProps.nChange = 100; 
   OwnerActionProp.DispContainerActionProps.uStructSize = sizeof(DISPOWNERACTIONPROPS); 
 
   nRet = L_DispContainerSetActionProperties(hCellWnd, CONTAINER_ACTION_BRIGHTNESS, 0, &OwnerActionProp, 0); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   pFirstCellData = (pFIRSTCELLDATA)GlobalAllocPtr(GHND, sizeof(FIRSTCELLDATA)); 
   pFirstCellData->nBrightness = 0; 
 
   // Sets the new callback functions for the action and for the tag. 
   nRet = L_DispContainerSetActionCallBack(hCellWnd, ActionCallBack, (L_VOID  *)pFirstCellData); 
   if(nRet != SUCCESS) 
      return nRet; 
   nRet = L_DispContainerSetTagCallBack(hCellWnd, TagCallBack, (L_VOID * )pFirstCellData); 
   if(nRet != SUCCESS) 
      return nRet; 
   return SUCCESS; 
}