How to implement a resizable property sheet class that contains a menu bar in Visual C++ 6.0 (300606)

MORE INFORMATION

The following instructions show you how to add a new property sheet class to an existing MFC project and customize the sheet by handling resize requests and by providing a menu for the sheet. These steps demonstrate how to write a base class, CMyPropertySheet, that can be used to provide this functionality. This new class would be a drop-in replacement for MFC's CPropertySheet and would provide the additional functionality described in the "Summary" section.

1. To any MFC based project add a new property sheet by using the component gallery. Accept all the defaults. To do so, from the Project menu, click Add to project, and then click Component and Controls. In the dialog box double-click the "Components" folder and then select Property Sheet.
2. In order to enable resizable borders you must override DoModal() and provide a callback function that will set the appropriate styles for the property sheet. Therefore, you must provide the following two functions (in both the header file and the source file for the CMyPropertySheet class.):
   • The static property sheet callback function, XmnPropSheetCallback():

     // This function must be a STATIC member function. 
     //Callback to allow us set the default window styles 
     //    for the property sheet
     int CALLBACK CMyPropertySheet::XmnPropSheetCallback(HWND hWnd, UINT message, LPARAM lParam)
     {
        extern int CALLBACK AfxPropSheetCallback(HWND, UINT message, LPARAM lParam);
        // XMN: Call MFC's callback
        int nRes = AfxPropSheetCallback(hWnd, message, lParam);
     
        switch (message)
        {
        case PSCB_PRECREATE:
           // Set our own window styles
           ((LPDLGTEMPLATE)lParam)->style |= (DS_3DLOOK | DS_SETFONT
              | WS_THICKFRAME | WS_SYSMENU | WS_POPUP | WS_VISIBLE | WS_CAPTION);
           break;
        }
        return nRes;
     }
      
     						

   • The DoModal() override:

     // Overriding DoModal() allows us to hook our callback into
     //    the prop sheet creation
     int CMyPropertySheet::DoModal() 
     {
        // Hook into property sheet creation code
        AFX_OLDPROPSHEETHEADER* psh = GetPropSheetHeader();
        psh->dwFlags |= PSH_USECALLBACK;
        psh->pfnCallback = XmnPropSheetCallback;
        return CPropertySheet::DoModal();
     }
     						

3. At this point you have a property sheet that you can drag to resize by using the mouse. In order to add a menu, you must provide an override for OnInitDialog(). From the View menu, click Class Wizard, and then select the project and the property sheet class from the Class Wizard dialog box. Next, select the OnInitDialog entry from the Messages drop-down list. The following code fragment provides an override for OnInitDialog():

   BOOL CMyPropertySheet::OnInitDialog() 
   {
      BOOL bResult = CPropertySheet::OnInitDialog();
       
      // Add a new menu
      CMenu *pMenu = new CMenu; pMenu->LoadMenu(IDR_PS_MENU);
      SetMenu(pMenu);
   
      // Adjust propsheet size to account for the new menu
      CRect r;  GetWindowRect(&r);
      r.bottom += GetSystemMetrics(SM_CYMENU);
      MoveWindow(r);
   
      return bResult;
   }
   					

4. You should provide a resize policy. The most straightforward way to do so is to resize the embedded tab control according to the resize request and move the buttons present on the sheet. To do so:
   
   
   1. Add the following data members to the CMyPropertySheet class:

      protected:
         BOOL   m_bNeedInit;
         CRect  m_rCrt;
         int    m_nMinCX;
         int    m_nMinCY;
      							

   2. Initialize these new data members and set m_bNeedInit to TRUE in the CMyPropertySheet constructor:

      CMyPropertySheet::CMyPropertySheet(CWnd* pWndParent)
      	 : CPropertySheet(IDS_PROPSHT_CAPTION, pWndParent) 	 
      	 , m_bNeedInit(TRUE)
      	 , m_nMinCX(0)
      	 , m_nMinCY(0)
      
      {
         AddPage(&m_Page1);
         AddPage(&m_Page2);
      
      }
      							

   3. Add the following lines to the end of OnInitDialog():

      BOOL CMyPropertySheet::OnInitDialog() 
      {
         // ...
         // Init m_nMinCX/Y
         m_nMinCX = r.Width();
         m_nMinCY = r.Height();
         // After this point we allow resize code to kick in
         m_bNeedInit = FALSE;
         GetClientRect(&m_rCrt);
      
         return bResult;
      }
      							

   4. Provide a handler for the WM_SIZE event. From the View menu, click Class Wizard, and then select the project and the property sheet class from the Class Wizard dialog box. Next, select the WM_SIZE entry from the Messages drop-down list. The following is the message handler implementation:

      // Handle WM_SIZE events by resizing the tab control and by 
      //    moving all the buttons on the property sheet.
      void CMyPropertySheet::OnSize(UINT nType, int cx, int cy) 
      {
         CRect r1; 
         CPropertySheet::OnSize(nType, cx, cy);
      
         if (m_bNeedInit)
            return;
      
         CTabCtrl *pTab = GetTabControl();
         ASSERT(NULL != pTab && IsWindow(pTab->m_hWnd));
          
         int dx = cx - m_rCrt.Width();
         int dy = cy - m_rCrt.Height();
         GetClientRect(&m_rCrt);
      
         HDWP hDWP = ::BeginDeferWindowPos(5);
      
         pTab->GetClientRect(&r1); 
         r1.right += dx; r1.bottom += dy;
         ::DeferWindowPos(hDWP, pTab->m_hWnd, NULL,
                          0, 0, r1.Width(), r1.Height(),
                          SWP_NOACTIVATE|SWP_NOMOVE|SWP_NOZORDER);
      
         // Move all buttons with the lower right sides
         for (CWnd *pChild = GetWindow(GW_CHILD);
              pChild != NULL;
              pChild = pChild->GetWindow(GW_HWNDNEXT))
         {
            if (pChild->SendMessage(WM_GETDLGCODE) & DLGC_BUTTON)
            {
               pChild->GetWindowRect(&r1); ScreenToClient(&r1); 
               r1.top += dy; r1.bottom += dy; r1.left+= dx; r1.right += dx;
               ::DeferWindowPos(hDWP, pChild->m_hWnd, NULL,
                                r1.left, r1.top, 0, 0,
                                SWP_NOACTIVATE|SWP_NOSIZE|SWP_NOZORDER);
            }
            // Resize everything else...
            else
            {
               pChild->GetClientRect(&r1); 
      	 r1.right += dx; r1.bottom += dy;
      	 ::DeferWindowPos(hDWP, pChild->m_hWnd, NULL, 0, 0, r1.Width(), r1.Height(),SWP_NOACTIVATE|SWP_NOMOVE|SWP_NOZORDER);
            }
      
         }
      
         ::EndDeferWindowPos(hDWP);
      }
      							

   5. Lastly, you must provide a handler for the WM_GETMINMAXINFO message. From the View menu, click Class Wizard, and then select the project and the property sheet class from the Class Wizard dialog box. Next, select WM_GETMINMAXINFO from the Messages drop-down list. The following is the WM_GETMINMAXINFO handler implementation:

      void CMyPropertySheet::OnGetMinMaxInfo(MINMAXINFO FAR* lpMMI) 
      {
         CPropertySheet::OnGetMinMaxInfo(lpMMI);
         lpMMI->ptMinTrackSize.x = m_nMinCX;
         lpMMI->ptMinTrackSize.y = m_nMinCY;
      }