Home made MDI windows list in Window menu

Why we need it.

Windows list is a part of standard MDI windows interface. There are some bug(s) admitted by Microsoft. See MS KB article Q125435 for example. It is (almost) impossible to modify it. It is much easier to reproduce Windows menu behavior. This project can serve as a start point for window menu modification. Add something to menu items, graphics for example, or create a different MoreWindows dialog. To include invisible MDIChilds to activate them from a menu etc.

How to do this thing.

First of all this example based on MFC application generated by AppWizard. Modifications are mostly made in MainFrm.cpp,.h module, using wizards when possible.

1. Remove standard windows list.

2. Using ClassWizard add message handlers for new menu IDs.

void CMainFrame::OnWindowsTileHorz() 
{
 // TODO: Add your command handler code here
 MDITile(MDITILE_HORIZONTAL);
}

3. Add a protected member function to return CMenu object for Window menu to CMainFrame

CMenu* CMainFrame::GetWindowMenu()
{
// MENU_POSITION is not reliable because it's different for different views
		
	CMenu* pWindowMenu = NULL;
	CMenu* pTopMenu = GetMenu();
	CString strMenu;
	for (int iPos = pTopMenu->GetMenuItemCount()-1; iPos >= 0; iPos--)
	{
		pTopMenu->GetMenuString( iPos, strMenu, MF_BYPOSITION );
		if (strMenu == "&Window")
		{
			pWindowMenu = pTopMenu->GetSubMenu(iPos);
			break;
		}
	}
	ASSERT(pWindowMenu != NULL);
	return pWindowMenu;
}

4. Add new ID to resource.h manually

#define ID_WINDOWS_FIRST                32001
#define ID_WINDOWS_2                    32002
#define ID_WINDOWS_3                    32003
#define ID_WINDOWS_4                    32004
#define ID_WINDOWS_5                    32005
#define ID_WINDOWS_6                    32006
#define ID_WINDOWS_7                    32007
#define ID_WINDOWS_8                    32008
#define ID_WINDOWS_LAST                 32009
#define ID_WINDOWS_MORE                 32010

5. Add a protected member function looping through all visible MDI childs in CMainFrame to add them to Window menu.

void CMainFrame::UpdateWindowMenu()
{
	CMenu* pWindowMenu = GetWindowMenu();

	//Remove all entries after separator
	for (	int i = pWindowMenu->GetMenuItemCount()- 1 ; i > NUM_FIXED_ITEMS - 1;
			pWindowMenu->DeleteMenu(i--, MF_BYPOSITION) );

	//m_hWndMDIClient - undocumented

	CWnd* pWnd = CWnd::FromHandle(m_hWndMDIClient)->GetWindow(GW_CHILD);

	CString strTitle;
	i = 0;
	char buff[3];

	while(pWnd)
	{
		if(pWnd)
			if(pWnd->IsWindowVisible())
			{
			    if (i == NUM_WINDOWS_ITEMS)    //Critical number ow windows (9) reached
				{
					pWindowMenu->AppendMenu( MF_STRING,  ID_WINDOWS_MORE, "&Windows...");
					return;
				}
				pWnd->GetWindowText(strTitle);
				strTitle = CString("&") + itoa(i + 1,buff,10) + " " + strTitle;
				pWindowMenu->AppendMenu( MF_STRING,  ID_WINDOWS_FIRST + i++,strTitle);
			}
		pWnd = pWnd->GetWindow(GW_HWNDNEXT);
	}

}

void CMainFrame::OnUpdateWindowsCascade(CCmdUI* pCmdUI) 
{
	// TODO: Add your command update UI handler code here
	//It is a challenge to find a better place to call it from
	UpdateWindowMenu();
}

7. Add a member function to activate a particular MDI child

void CMainFrame::ActivateFrameFromMenu(int nItem)
{
	CWnd* pWnd = CWnd::FromHandle(m_hWndMDIClient)->GetWindow(GW_CHILD);
	int i = ID_WINDOWS_FIRST;
	BOOL bMaximized;

	while(pWnd)
	{
		if(pWnd)
			if(pWnd->IsWindowVisible())
				if ( i++ == nItem)
				{
					MDIGetActive( &bMaximized );
					if (!bMaximized)
						MDIRestore(pWnd);
					MDIActivate(pWnd);
					return;
				}
		pWnd = pWnd->GetWindow(GW_HWNDNEXT);
	}
}

6. Add message handler for all new menu items.

BOOL CMainFrame::OnCmdMsg(UINT nID, int nCode, void* pExtra, AFX_CMDHANDLERINFO* pHandlerInfo) 
{
	// If pHandlerInfo is NULL, then handle the message
	if (pHandlerInfo == NULL)
	{
		// Filter the commands sent to Window menu
		if (nID >= ID_WINDOWS_FIRST && nID <= ID_WINDOWS_LAST)
		{
			if (nCode == CN_COMMAND)
				// Handle WM_COMMAND message
				ActivateFrameFromMenu(nID);
			else 
				if (nCode == CN_UPDATE_COMMAND_UI)
					// Update UI element state
				DoUpdateWindowMenu(nID, (CCmdUI*)pExtra);
			return TRUE;
		}
				
	}

	// If we didn't process the command, call the base class
	// version of OnCmdMsg so the message-map can handle the message
	
	return CMDIFrameWnd::OnCmdMsg(nID, nCode, pExtra, pHandlerInfo);

}

void CMainFrame::DoUpdateWindowMenu(int nID, CCmdUI* pCCmdUI)
{
	pCCmdUI->Enable(TRUE);
	if (nID == ID_WINDOWS_FIRST)
		pCCmdUI->SetCheck();
}

7. Add a windows list dialog.

((CMainFrame*) AfxGetMainWnd())->FillWinList(&m_lbWinList);

void CMainFrame::FillWinList(CListBox* pListBox)
{
	CWnd* pWnd = m_wndMdiClient.GetWindow(GW_CHILD);
	CString strTitle;
	while(pWnd)
	{
		if(pWnd)
			if(pWnd->IsWindowVisible())
			{
				pWnd->GetWindowText(strTitle);
				pListBox->AddString(strTitle);
			}
		pWnd = pWnd->GetWindow(GW_HWNDNEXT);
	}
	pListBox->SetCurSel(0);
}

void CWinList::OnOK() 
{
	// TODO: Add extra validation here
	EndDialog(m_lbWinList.GetCurSel() + ID_WINDOWS_FIRST);
	//CDialog::OnOK(); Do not call default implementation
}

8. Handle ID_WINDOWS_MORE command

void CMainFrame::OnWindowsMore()
{
	int nItem = CWinList().DoModal();
	if (nItem != IDCANCEL) 
		ActivateFrameFromMenu(nItem);
}

9. Build. Run. Enjoy!

Download demo project - 21 KB

Last Updated: January 15, 1999