Finding an item (matching any member of TV_ITEM)

HTREEITEM CTreeCtrlEx::FindNextItem(TV_ITEM* pItem, HTREEITEM hItem)
{
   ASSERT(::IsWindow(m_hWnd));
   
   TV_ITEM hNextItem;

   //Clear Item data
   ZeroMemory(&hNextItem, sizeof(hNextItem));
      
   //The mask is used to retrieve the data to compare
   hNextItem.mask = pItem->mask;
   hNextItem.hItem = (hItem) ? GetNextItem(hItem) : GetRootItem();
   
   //Prepare to compare pszText
   //Testing pItem->pszText protects the code from a client setting the
   //TVIF_TEXT bit but passing in a NULL pointer.
   if((pItem->mask & TVIF_TEXT) && pItem->pszText)
   {
      hNextItem.cchTextMax = strlen(pItem->pszText);

      if(hNextItem.cchTextMax)
         hNextItem.pszText = new char[++hNextItem.cchTextMax];
   }

   while(hNextItem.hItem)
   {
      if(Compare(pItem, hNextItem))
      {         
         //Copy all the information into pItem and return
         memcpy(pItem, &hNextItem, sizeof(TV_ITEM));

         //Free resources
         if(hNextItem.pszText)
            delete hNextItem.pszText;
         
         return pItem->hItem;
      }

      //The mask is used to retrieve the data to compare and must be
      //reset before calling Compare
      hNextItem.mask = pItem->mask;
      hNextItem.hItem = GetNextItem(hNextItem.hItem);
   }   
   
   //Set hItem in pItem
   pItem->hItem = NULL;

   //Free resources
   if(hNextItem.pszText)
      delete hNextItem.pszText;
   
   return NULL;
}

BOOL CTreeCtrlEx::Compare(TV_ITEM* pItem, TV_ITEM& tvTempItem)
{
   //This call uses the .mask setting to just retrieve the values
   //that the client wants to compare.
   //Get all the data passed in by pItem
   GetItem(&tvTempItem);

   //Reset the mask so I can keep track of the matching attributes
   tvTempItem.mask = 0;

   if((pItem->mask & TVIF_STATE) && 
      (pItem->state == tvTempItem.state))
      tvTempItem.mask |= TVIF_STATE;

   if((pItem->mask & TVIF_IMAGE) && 
      (pItem->iImage == tvTempItem.iImage))
      tvTempItem.mask |= TVIF_IMAGE;

   if((pItem->mask & TVIF_PARAM) && 
      (pItem->lParam == tvTempItem.lParam))
      tvTempItem.mask |= TVIF_PARAM;

   if((pItem->mask & TVIF_TEXT) &&
      pItem->pszText && tvTempItem.pszText && //Don't compare if either is NULL
      !strcmp(pItem->pszText, tvTempItem.pszText))
      tvTempItem.mask |= TVIF_TEXT;

   if((pItem->mask & TVIF_CHILDREN) && 
      (pItem->cChildren == tvTempItem.cChildren))
      tvTempItem.mask |= TVIF_CHILDREN;

   if((pItem->mask & TVIF_SELECTEDIMAGE) && 
      (pItem->iSelectedImage == tvTempItem.iSelectedImage))
      tvTempItem.mask |= TVIF_SELECTEDIMAGE;
   
   //If by this point these two values are the same.
   //tvTempItem.hItem is the desired item
   return (pItem->mask == tvTempItem.mask);
}

Date Last Updated: April 24, 1999