mrucombo.cpp

一个完整的源代码统计器

//////////////////////////////////////////////////////////////////////////
//
// Function:    SetMRUValueFormat()
//
// Description:
//  Sets the format to be used for writing MRU items to the registry or
//  the app's INI file.
//
// Input:
//  szValueFormat: [in] The format to use.
//
// Returns:
//  TRUE if the format is acceptable (i.e., contains "%d"), FALSE if not.
//
//////////////////////////////////////////////////////////////////////////

BOOL CMRUComboBox::SetMRUValueFormat ( LPCTSTR szValueFormat )
{
BOOL bRetVal = FALSE;

                                        // The key name can't be a null string.
    ASSERT ( NULL != szValueFormat );


                                        // Check that the format strings 
                                        // contains "%d"
    if ( NULL == _tcsstr ( szValueFormat, _T("%d") ) )
        {
        TRACE0("CMRUComboBox -- SetMRUValueFormat() returning FALSE - argument didn't contain \"%d\"\n");
        return FALSE;
        }
    else
        {
        try
            {
                                        // Save the format string and set the
                                        // changed flag.
            m_cstrRegValueFormat = szValueFormat;
            m_bParamsChanged = TRUE;
            bRetVal = TRUE;
            }
        catch ( CMemoryException )
            {
            TRACE0("CMRUComboBox -- Memory exception in CMRUComboBox::SetMRUValueFormat()!\n");
            throw;
            }
        }

    return bRetVal;
}


//////////////////////////////////////////////////////////////////////////
//
// Function:    GetMRUValueFormat
//
// Description:
//  Returns the current registry value format string.
//
// Input:
//  Nothing.
//
// Returns:
//  The format string.
//
//////////////////////////////////////////////////////////////////////////

const CString& CMRUComboBox::GetMRUValueFormat() const
{
    return m_cstrRegValueFormat;
}


//////////////////////////////////////////////////////////////////////////
//
// Function:    SetMaxMRUSize()
//
// Description:
//  Sets the max number of entries that the MRU can hold.
//
// Input:
//  nMaxSize: [in] The new MRU size.
//
// Returns:
//  The previous MRU size, or 0 if there was no previous MRU allocated, or
//  -1 on error.
//
// Notes:
//  This function always reallocates a CRecentFileList so that the size
//  change (and registry string changes, if any) takes place immediately.
//
//////////////////////////////////////////////////////////////////////////

int CMRUComboBox::SetMaxMRUSize ( int nMaxSize )
{
int nRetVal = m_nMaxMRUSize;

                                        // New size needs to be a positive
                                        // number.
    ASSERT ( nMaxSize >= 1 );

    if ( nMaxSize <= 0 )
        return -1;


    m_nMaxMRUSize = nMaxSize;

    if ( NULL == m_pMRU )
        {
        nRetVal = 0;                    // no previous size
        }

    if ( !AllocNewMRU() )
        {
        nRetVal = -1;                   // error!!
        TRACE0("CMRUComboBox -- SetMaxMRUSize() failed - couldn't allocate new CRecentFileList.\n");
        }

    return nRetVal;
}


//////////////////////////////////////////////////////////////////////////
//
// Function:    GetMaxMRUSize
//
// Description:
//  Returns the current max MRU size.
//
// Input:
//  Nothing.
//
// Returns:
//  The current max size.
//
//////////////////////////////////////////////////////////////////////////

int CMRUComboBox::GetMaxMRUSize() const
{
    return m_nMaxMRUSize;
}


//////////////////////////////////////////////////////////////////////////
//
// Function:    SetAutoSaveOnDestroy()
//
// Description:
//  Sets whether the CMRUComboBox will automatically save the MRU when
//  the object is destroyed.
//
// Input:
//  bAutoSave: [in] Flag: enable auto-saving?
//
// Returns:
//  The previous value of this setting.
//
//////////////////////////////////////////////////////////////////////////

BOOL CMRUComboBox::SetAutoSaveOnDestroy ( BOOL bAutoSave )
{
BOOL bRetVal = m_bSaveOnDestroy;

    m_bSaveOnDestroy = bAutoSave;

    return bRetVal;
}


//////////////////////////////////////////////////////////////////////////
//
// Function:    SetAutoSaveAfterAdd()
//
// Description:
//  Sets whether the CMRUComboBox will automatically save the MRU after
//  an item is added successfully.
//
// Input:
//  bAutoSave: [in] Flag: enable auto-saving?
//
// Returns:
//  The previous value of this setting.
//
//////////////////////////////////////////////////////////////////////////

BOOL CMRUComboBox::SetAutoSaveAfterAdd ( BOOL bAutoSave )
{
BOOL bRetVal = m_bSaveAfterAdd;

    m_bSaveAfterAdd = bAutoSave;

    return bRetVal;
}


//////////////////////////////////////////////////////////////////////////
//
// Function:    SetAutoRefreshAfterAdd()
//
// Description:
//  Sets whether the CMRUComboBox will automatically refresh the combobox
//  control after an item is added successfully.
//
// Input:
//  bAutoSave: [in] Flag: enable auto-refresh?
//
// Returns:
//  The previous value of this setting.
//
//////////////////////////////////////////////////////////////////////////

BOOL CMRUComboBox::SetAutoRefreshAfterAdd ( BOOL bAutoSave )
{
BOOL bRetVal = m_bRefreshAfterAdd;

    m_bRefreshAfterAdd = bAutoSave;

    return bRetVal;
}


/////////////////////////////////////////////////////////////////////////////
// CMRUComboBox misc. functions


//////////////////////////////////////////////////////////////////////////
//
// Function:    VerifyMRUParams()
//
// Description:
//  Checks the registry and size parameters and makes sure they're valid
//  for CRecentFileList.
//
// Input:
//  Nothing. (uses member variables)
//
// Returns:
//  TRUE if the params are OK, FALSE if not.
//
//////////////////////////////////////////////////////////////////////////

BOOL CMRUComboBox::VerifyMRUParams() const
{
BOOL bRetVal = TRUE;

                                        // 1. The registry key string must be
                                        //    non-empty.
    if ( m_cstrRegKey.IsEmpty() || 0 == m_cstrRegKey.GetLength() )
        {
        TRACE0("CMRUComboBox -- VerifyMRUParams() - registry key name not set.\n");
        bRetVal = FALSE;
        }

                                        // 2. The reg value must be non-empty
                                        //    and contain "%d"
    if ( m_cstrRegValueFormat.IsEmpty() || 
         0 == m_cstrRegValueFormat.GetLength() )
        {
        TRACE0("CMRUComboBox -- VerifyMRUParams() - registry value format not set.\n");
        bRetVal = FALSE;
        }
    else if ( -1 == m_cstrRegValueFormat.Find ( _T("%d") ) )
        {
        TRACE0("CMRUComboBox -- VerifyMRUParams() - registry value format doesn't contain \"%d\"\n");
        bRetVal = FALSE;
        }

                                        // 3. The Max MRU size must be > 0.
    if ( m_nMaxMRUSize <= 0 )
        {
        TRACE0("CMRUComboBox -- VerifyMRUParams() - max MRU size is set to <= 0\n");
        bRetVal = FALSE;
        }


    return bRetVal;
}


//////////////////////////////////////////////////////////////////////////
//
// Function:    AllocNewMRU()
//
// Description:
//  Allocates a new CRecentFileList, and copies the contents of the previous
//  MRU (if any) to the new one.
//
// Input:
//  Nothing.
//
// Returns:
//  TRUE if successful, FALSE if not.
//
//////////////////////////////////////////////////////////////////////////

BOOL CMRUComboBox::AllocNewMRU()
{
CString* acstrOldList = NULL;
int      nItemsToCopy;
int      i;

                                        // Make sure the MRU params are OK.
    if ( !VerifyMRUParams() )
        {
        TRACE0("CMRUComboBox -- AllocNewMRU() returning FALSE - MRU list params invalid or not set.\n");
        return FALSE;
        }


    try
        {
                                        // Figuring out how many strings to
                                        // copy: The lesser of the new MRU 
                                        // size and the previous MRU's size.
                                        // Of course, if there was no previous
                                        // MRU, then nothing will be copied.
        nItemsToCopy = m_nMaxMRUSize;

        if ( NULL != m_pMRU )
            {
            nItemsToCopy = __min ( m_nMaxMRUSize, m_pMRU->GetSize() );

                                        // Save the contents of the old MRU list.
            acstrOldList = new CString [ nItemsToCopy ];

            for ( i = 0; i < nItemsToCopy; i++ )
                {
                acstrOldList[i] = (*m_pMRU)[i];
                }

                                        // Nuke the old CRecentFileList object...
            delete m_pMRU;
            }

                                        // and make a new one!
        m_pMRU = new CRecentFileList ( 1, m_cstrRegKey,
                                       m_cstrRegValueFormat, m_nMaxMRUSize );

        // Copy the MRU strings if there was a previous MRU.  We add
        // the strings in reverse numerical order so they end up in the same
        // order as they were in the old MRU.

        if ( NULL != acstrOldList )
            {
            for ( i = nItemsToCopy - 1; i >= 0; i-- )
                {
                m_pMRU->Add ( acstrOldList[i] );
                }

            delete [] acstrOldList;
            }
        }
    catch ( CMemoryException )
        {
        TRACE0("CMRUComboBox -- Memory exception in AllocNewMRU()!\n");
        
        if ( NULL != m_pMRU )
            {
            delete m_pMRU;
            }

        throw;
        }

                                        // Reset the changed flag.
    m_bParamsChanged = FALSE;

    return TRUE;
}