Adding a Customozied ‘More Windows…’ Dialog to an MDI Application

To add a customized windows dialog to the windows
menu, you just have to take only two following steps in the
mainframe class…

• Override InitPopupMenu and replace it with the following code :

#define DEFAULT_NUMBER_OF_MDIS 9

void CMainFrame::OnInitMenuPopup(CMenu* pPopupMenu,
                                 UINT nIndex,
                                 BOOL bSysMenu )
{
 CMDIFrameWnd::OnInitMenuPopup(pPopupMenu, nIndex, bSysMenu);

 // If the number of active windows is zero, the window submenu 
 // probably does'nt esists. If you have the window submenu present
 // even in zero child windows, remove this code.

 int nCount = 0;
 CWnd * pWnd = GetWindow (GW_CHILD);
 ASSERT (pWnd);
 pWnd = pWnd->GetWindow (GW_CHILD);
 while (pWnd)
 {
  nCount++;
  pWnd = pWnd->GetWindow (GW_HWNDNEXT);
 }

 // The count is zero. exit.
 if ( nCount == 0 )
  return;

 // If it's a system menu, we don't need to handle that...
 if ( !bSysMenu )
 {
  // The default handler places the "more windows" command in the 
  // submenu which contains IDs between AFX_IDM_FIRST_MDICHILD and 
  // AFX_IDM_LAST_MDICHILD, so check the popup for occurence of
  // AFX_IDM_FIRST_MDICHILD.

  int nLength = pPopupMenu->GetMenuItemCount();
  for ( int i = 0; i < nLength; i++ )
  {
   if ( pPopupMenu->GetMenuItemID( i ) == AFX_IDM_FIRST_MDICHILD )
   {
    // Found. If the last item is already the "more windows"
    // command than remove it.
    if ( pPopupMenu->GetMenuItemID( nLength - 1 ) ==
    AFX_IDM_FIRST_MDICHILD + DEFAULT_NUMBER_OF_MDIS )
    {
     pPopupMenu->DeleteMenu( nLength - 1, MF_BYPOSITION );
    }

    // Add our own window command.
    // Note : The ID must be - ( AFX_IDM_FIRST_MDICHILD +  
    // ( total number of entries in window list supported ) ). 
    // This saves us to make any default handler for the  
    // command, as the default procedure itself 
    // handles the command and sends it to the mainframe class.
    pPopupMenu->AppendMenu(MF_ENABLED|MF_STRING,
                           AFX_IDM_FIRST_MDICHILD + DEFAULT_NUMBER_OF_MDIS,
                           "&Windows..." );

    // Done the processing.
    return;
   }
  }
 }
}

• Override OnCommand and replace it with the following code:

BOOL CMainFrame::OnCommand(WPARAM wParam, LPARAM lParam)
{
 // If the command is "more windows" command call our 
 // own customized dialog
 if ( wParam == AFX_IDM_FIRST_MDICHILD + 9 )
 {
  // Replace CWindowDlg with your own class
  CWindowDlg dlgWindowDlg;
  dlgWindowDlg.DoModal();

  // OK. We handled the command so return true, 
  // as we don't want the default handler to 
  // handle this command too.
  return TRUE;
 }

 return CMDIFrameWnd::OnCommand(wParam, lParam);
}

Downloads

Download demo project – 22 Kb