Using ATL to Automate an MFC Application

1. Lets start first to make the application visible. Add a property 'Visible' as a VARIANT_BOOL. The code should look like this:

   //-----------------------------------------------
   // get & put_Visible
   //-----------------------------------------------
   //
   STDMETHODIMP
   CAutoATLApp::get_Visible(VARIANT_BOOL *pVal)
   {
    METHOD_PROLOGUE_ATL
   
    CWnd* pMainWnd = AfxGetMainWnd();
    ASSERT(pMainWnd);
    *pVal = pMainWnd->IsWindowVisible();
   
    return S_OK;
   }
   
   STDMETHODIMP
   CAutoATLApp::put_Visible(VARIANT_BOOL newVal)
   {
    METHOD_PROLOGUE_ATL
   
    CWnd* pMainWnd = AfxGetMainWnd();
    ASSERT(pMainWnd);
    pMainWnd->ShowWindow(SW_SHOW);
    pMainWnd->UpdateWindow();
   
    return S_OK;
   }
   

2. When i document i created by a client no frame or views are created. To be able to do so we must override CreateNewDocument in CMultiDocTemplate. CreateNewDocument is called from OpenDocumentFile to create a new document. But the document already exists. CrateNewDocument should therefor be altered NOT to create a document. Create a new class that inherites from CMultiDocTemplate and override CreateNewDocument and add a member variable CDocument* m_pDocument. CreateNewDocument should look like this:

   CDocument*
   CAnotherMultiDocTemplate::CreateNewDocument()
   {
    // default implementation constructs one from CRuntimeClass
    if (m_pDocClass == NULL)
    {
     TRACE0("Error: you must override "
            "CDocTemplate::CreateNewDocument.\n");
     ASSERT(FALSE);
     return NULL;
    }
   
   //-----------------------------------------------
   //	BdL; Document has already been created!
   //
   //	CDocument* pDocument = 
   //	   (CDocument*)m_pDocClass->CreateObject();
   //-----------------------------------------------
    if (m_pDocument == NULL)
    {
     TRACE1("Warning: Dynamic create of document "
            "type %hs failed.\n",
     m_pDocClass->m_lpszClassName);
     return NULL;
    }
   
    ASSERT_KINDOF(CDocument, m_pDocument);
    AddDocument(m_pDocument);
    return m_pDocument;
   }
   

   To make your life a bit more easy, add the header file (AnotherMultiDocTemplate.h) of the new class to stdafx.h

3. Alter in InitInstance of the application the DocumentTemplate:

   // CMultiDocTemplate* pDocTemplate;		
   // pDocTemplate = new CMultiDocTemplate(
   to
   CAnotherMultiDocTemplate* pDocTemplate;
   pDocTemplate = new CAnotherMultiDocTemplate(
   

4. Add FinalConstruct and FinalRelease to CAutoATLDoc. FinalConstruct will continue to create Frame and View. FinalRelease will the necessary cleanup.

   Add the following lines to CAutoAtlDoc.h

   HRESULT	FinalConstruct();
   void	FinalRelease();
   

   Add the following lines to CAutoAtlDoc.cpp

   HRESULT
   CAutoATLDoc::FinalConstruct()
   {
    METHOD_PROLOGUE_ATL
   
    CAutoATLApp* pApp = (CAutoATLApp*)AfxGetApp();
    ASSERT_VALID(pApp);
   
    // Find document template
    POSITION pos = pApp->GetFirstDocTemplatePosition();
    CAnotherMultiDocTemplate* pDocClass = 
     (CAnotherMultiDocTemplate*)pApp->GetNextDocTemplate(pos);
   
    ASSERT_VALID(pDocClass);
   
    // Create view and frame
    pDocClass->m_pDocument = this;
    pDocClass->OpenDocumentFile(NULL, true);
   
    return S_OK;
   }
   
   void
   CAutoATLDoc::FinalRelease()
   {
    // Do will still have a View connected?
    // (The frame will no longer exist if the document
    // has been closed manually, because the OnClose
    // message is passed BEFORE deleting the document)
    POSITION pos = GetFirstViewPosition();
    if (pos != NULL) {
     // Prevent the document from deleting itself already.
     m_bAutoDelete = false;
     OnCloseDocument();
     m_bAutoDelete = true;
    }
   }
   

5. In the application override OnFileOpen, OnFileNew and OpenDocumentFile. Normally OnFileOpen and OnFileNew create a document AND the frame and view. Now the frame and view are now created in the FinalConstruct of CAutoAtlDoc.

   //-----------------------------------------------
   // 
   //-----------------------------------------------
   //
   void
   CAutoATLApp::OnFileNew() 
   {
    // Dynamically create a new CFuchiaDocument.
    // The document will continue to create itself
    // in the constructor.
    IMPLEMENT_CREATE_DOCUMENT;
   }
   
   void
   CAutoATLApp::OnFileOpen() 
   {
    // prompt the user (with all document templates)
    CString _lpszPathName;
    if (!DoPromptFileName(_lpszPathName, 
                          AFX_IDS_OPENFILE,
                          OFN_HIDEREADONLY | OFN_FILEMUSTEXIST,
                          TRUE, NULL))
     return; // open cancelled
   
    OpenDocumentFile(_lpszPathName);
   }
   
   CDocument*
   CAutoATLApp::OpenDocumentFile(LPCTSTR lpszFileName) 
   {
    // Dynamically create a new CFuchiaDocument.
    // The document will continue to create itself
    // in the constructor.
    IMPLEMENT_CREATE_DOCUMENT;
   
    // Open an existing document
    CWaitCursor wait;
    if ( !pDoc->OnOpenDocument( lpszFileName ) )
    {
     // Unable to open the document.
     TRACE( "Unable to open the document \
     in %s at %d.\n", THIS_FILE, __LINE__ );
     // We must delete the document instance.
     pDoc->Release();
     return NULL;
    }
   
    // Set the document file path and name.
    pDoc->SetPathName(lpszFileName);
    return pDoc;
   }
   

6. IMPLEMENT_CREATE_DOCUMENT is a macro you can put on top in the document header file.

   //-----------------------------------------------
   // Call this MACRO when you need to create a new Document.
   // The document will construct itself further inside
   // FinalConstruct.
   #define IMPLEMENT_CREATE_DOCUMENT \
    CComObject* pDoc; \
    HRESULT hr = CComObject::CreateInstance(&pDoc); \
    ASSERT(SUCCEEDED(hr)); \
    pDoc->InternalAddRef();
   //-----------------------------------------------
   

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