Open most recent file (2)

The article Open most recent file by Adam Solesby discussed how to open the most recently used file using the MRU list.
This article develops the idea to starting a MDI application with many recent files opened.

With MDI application it is sometimes useful to start a session with more documents opened or perhaps only documents that were active at the end of our last session.
MRU list treats all recent files equally and doesn’t check whether they were opened or closed when we left.
There is a way around if we manage the MRU list by ourselves.

First, we should declare some variables and constants:

int nStartMode;             // remember the starting mode 
int nMaxFiles;              // number of recent active files to remember
BOOL bCleanMRU;             // shall we manage the MRU list ourselves?
CRecentFileList* pMRU;      // global pointer to MRU list. 
#define NO_DOCUMENT   1     // don't open new document at all
#define LAST_DOCUMENT 2     // open one or more last documents
#define MAX_MRUFILES 10     // Number of most recent documents 

We can allow the user to select various starting modes: to open application with an empty document, with documents that were active when we left our last session, or without any document window.
The user could also define maximal number of recent active files to be opened.

nStartMode = LAST_DOCUMENT;
nMaxFiles = MAX_MRUFILES;
bCleanMRU = TRUE;

Now add the following code to your application’s InitInstance(), after the call to ParseCommandLine():

CMyApp::InitInstance()
{
    .
    .
    .
    // Parse command line for standard shell commands, DDE, file open
    CCommandLineInfo cmdInfo;
    ParseCommandLine(cmdInfo);

    //===START OF MODIFICATION BLOCK=========================
    if (cmdInfo.m_strFileName.IsEmpty())
    {
        // If a file is not specified on the command line
        // and we don't want to start with an empty document
        // we will not use shell command to open a document
        if(nStartMode==NO_DOCUMENT || nStartMode==LAST_DOCUMENT)
            cmdInfo.m_nShellCommand = CCommandLineInfo::FileNothing;
    }

    // Dispatch commands specified on the command line
    if (!ProcessShellCommand(cmdInfo))
        return FALSE;

    // The main window has been initialized, so show and update it.
    pMainFrame->ShowWindow(m_nCmdShow);
    pMainFrame->UpdateWindow();

    pMRU=m_pRecentFileList;  // remember the pointer to MRU. 

    // Open documents with our new function
    if(cmdInfo.m_strFileName.IsEmpty() && (nStartMode == LAST_DOCUMENT))
        OpenRecentFiles(nMaxFiles);
    //===END OF MODIFICATION BLOCK =========================

    return TRUE;
}

And here is the procedure (called from the InitInstance() above) that will open all the documents from the MRU list.
Put it into the main application class. With the parameter you can limit the number of documents.

void CMyApp::OpenRecentFiles(int n)
{
    for(int i=0;(i < m_pRecentFileList->GetSize() && i < n);i++)
    {
        CString strFileName(m_pRecentFileList->m_arrNames[i]);
        if(strFileName.IsEmpty())
            return;
        OpenDocumentFile(strFileName);
    }
}

To close the session leaving only the active documents on the MRU list we need to modify it.
Put this code at the end of CMainFrame::OnClose().

void CMainFrame::OnClose()
{
    .
    .
    //===START OF MODIFICATION BLOCK=========================
    if(bCleanMRU)  // option to save only the active files
    {
        // clear list
        for(int i=0;i < pMRU->m_nSize;i++)
        pMRU->Remove(0);

        // fill list with active files paths
        POSITION pos = AfxGetApp()->GetFirstDocTemplatePosition();
        if(pos!=NULL)
        {
            CDocTemplate* pTempl = AfxGetApp()->GetNextDocTemplate(pos);
            POSITION pos=pTempl->GetFirstDocPosition();
            while(pos!=NULL)
            {
                CDocument* pDoc = pTempl->GetNextDoc(pos);
                if(pDoc)
                    pMRU->Add((LPCTSTR)pDoc->GetPathName());
            }
        }
    }
    //===END OF MODIFICATION BLOCK=========================
    CMDIFrameWnd::OnClose();
}