Chip 2002 September/Chip_2002-09_cd1.bin/zkuste/vbasic/Data/Utils/XZipComp.exe/XceedCompression.Cab/F112873_MemoryCompressDlg.cpp

C/C++ Source or Header | 2001-05-11 | 16.9 KB | 553 lines

// Xceed Streaming Compression Library - Memory Compress sample
// Copyright (c) 2001 Xceed Software Inc.
//
// [MemoryCompressDlg.cpp]
//
// This form module contains the main form's code. It demonstrates how to
// compress a chunk of memory data using different kinds of compression formats,
// and decompress a compressed memory data. It specifically uses:
//  - The Compress and Decompress method.
//  - The CompressionFormat property.
//
// This file is part of the Xceed Streaming Compression Library sample applications.
// The source code in this file is only intended as a supplement to Xceed
// Streaming Compression Library's documentation, and is provided "as is", without
// warranty of any kind, either expressed or implied.

#include "stdafx.h"
#include "MemoryCompress.h"
#include "MemoryCompressDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
    CAboutDlg();

// Dialog Data
    //{{AFX_DATA(CAboutDlg)
    enum { IDD = IDD_ABOUTBOX };
    //}}AFX_DATA

    // ClassWizard generated virtual function overrides
    //{{AFX_VIRTUAL(CAboutDlg)
    protected:
    virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
    //}}AFX_VIRTUAL

// Implementation
protected:
    //{{AFX_MSG(CAboutDlg)
    //}}AFX_MSG
    DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
    //{{AFX_DATA_INIT(CAboutDlg)
    //}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    //{{AFX_DATA_MAP(CAboutDlg)
    //}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
    //{{AFX_MSG_MAP(CAboutDlg)
        // No message handlers
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMemoryCompressDlg dialog

CMemoryCompressDlg::CMemoryCompressDlg(CWnd* pParent /*=NULL*/)
    : CDialog(CMemoryCompressDlg::IDD, pParent)
{
    //{{AFX_DATA_INIT(CMemoryCompressDlg)
    m_lCompressionFormat = -1;
    m_sCompressedSize = _T("");
    m_sOriginalSize = _T("");
    m_sDecompressed = _T("");
    m_sToCompress = _T("");
    //}}AFX_DATA_INIT
    // Note that LoadIcon does not require a subsequent DestroyIcon in Win32
    m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMemoryCompressDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    //{{AFX_DATA_MAP(CMemoryCompressDlg)
    DDX_Control(pDX, IDC_CBO_COMPRESSIONFORMAT, m_cboCompressionFormat);
    DDX_CBIndex(pDX, IDC_CBO_COMPRESSIONFORMAT, m_lCompressionFormat);
    DDX_Text(pDX, IDC_LBL_COMPRESSEDSIZE, m_sCompressedSize);
    DDX_Text(pDX, IDC_LBL_ORIGINALSIZE, m_sOriginalSize);
    DDX_Text(pDX, IDC_TXT_DECOMPRESSED, m_sDecompressed);
    DDX_Text(pDX, IDC_TXT_TOCOMPRESS, m_sToCompress);
    //}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CMemoryCompressDlg, CDialog)
    //{{AFX_MSG_MAP(CMemoryCompressDlg)
    ON_WM_SYSCOMMAND()
    ON_WM_PAINT()
    ON_WM_QUERYDRAGICON()
    ON_EN_CHANGE(IDC_TXT_TOCOMPRESS, OnChangeTxtTocompress)
    ON_BN_CLICKED(IDC_CMD_COMPRESS, OnCmdCompress)
    ON_BN_CLICKED(IDC_CMD_DECOMPRESS, OnCmdDecompress)
    ON_BN_CLICKED(IDQUIT, OnQuit)
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMemoryCompressDlg message handlers

BOOL CMemoryCompressDlg::OnInitDialog()
{
  //
  // Set default values for the text to compress
  //
  m_sToCompress = "This is a little test to show you how the memory compression works.\r\n"
                  "And it is very easy to use.\r\n"
                  "And there is some repeating \r\n"
                  "repeating repeating repeating repeating repeating repeating repeating text.";

  CDialog::OnInitDialog();

    // Add "About..." menu item to system menu.

    // IDM_ABOUTBOX must be in the system command range.
    ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
    ASSERT(IDM_ABOUTBOX < 0xF000);

    CMenu* pSysMenu = GetSystemMenu(FALSE);
    if (pSysMenu != NULL)
    {
        CString strAboutMenu;
        strAboutMenu.LoadString(IDS_ABOUTBOX);
        if (!strAboutMenu.IsEmpty())
        {
            pSysMenu->AppendMenu(MF_SEPARATOR);
            pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
        }
    }

    // Set the icon for this dialog.  The framework does this automatically
    //  when the application's main window is not a dialog
    SetIcon(m_hIcon, TRUE);            // Set big icon
    SetIcon(m_hIcon, FALSE);        // Set small icon

  //----------------------------------------------------------------------------------
  // Initialize the size labels and fill the 2 combo boxes
  //----------------------------------------------------------------------------------

  // Fill the combo boxes
    m_cboCompressionFormat.AddString( "BZip2" );
    m_cboCompressionFormat.AddString( "GZip" );
    m_cboCompressionFormat.AddString( "Standard" );
    m_cboCompressionFormat.AddString( "Zip3" );
    m_cboCompressionFormat.AddString( "ZLib" );
    m_cboCompressionFormat.AddString( "BurrowsWheeler" );
    m_cboCompressionFormat.AddString( "Deflate" );
    m_cboCompressionFormat.AddString( "Store" );

  m_cboCompressionFormat.SetItemData( 0, cfBZip2 );
  m_cboCompressionFormat.SetItemData( 1, cfGZip );
  m_cboCompressionFormat.SetItemData( 2, cfStandard );
  m_cboCompressionFormat.SetItemData( 3, cfZip3 );
  m_cboCompressionFormat.SetItemData( 4, cfZLib );
  m_cboCompressionFormat.SetItemData( 5, cfBWT );
  m_cboCompressionFormat.SetItemData( 5, cfDeflate );
  m_cboCompressionFormat.SetItemData( 5, cfStore );

  m_cboCompressionFormat.SetCurSel( cfBZip2 );

  OnChangeTxtTocompress();

    return TRUE;  // return TRUE  unless you set the focus to a control
}

void CMemoryCompressDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
    if ((nID & 0xFFF0) == IDM_ABOUTBOX)
    {
        CAboutDlg dlgAbout;
        dlgAbout.DoModal();
    }
    else
    {
        CDialog::OnSysCommand(nID, lParam);
    }
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CMemoryCompressDlg::OnPaint()
{
    if (IsIconic())
    {
        CPaintDC dc(this); // device context for painting

        SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

        // Center icon in client rectangle
        int cxIcon = GetSystemMetrics(SM_CXICON);
        int cyIcon = GetSystemMetrics(SM_CYICON);
        CRect rect;
        GetClientRect(&rect);
        int x = (rect.Width() - cxIcon + 1) / 2;
        int y = (rect.Height() - cyIcon + 1) / 2;

        // Draw the icon
        dc.DrawIcon(x, y, m_hIcon);
    }
    else
    {
        CDialog::OnPaint();
    }
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CMemoryCompressDlg::OnQueryDragIcon()
{
    return (HCURSOR) m_hIcon;
}

//====================================================================================
//
// EVENTS - triggered by the form and its controls
//
//====================================================================================

void CMemoryCompressDlg::OnChangeTxtTocompress()
{
  if( UpdateData( TRUE ) )
  {
    m_sOriginalSize.Format( "%d", m_sToCompress.GetLength() );
    UpdateData( FALSE );
  }
}

//------------------------------------------------------------------------------------
// Do the compression of the text
//------------------------------------------------------------------------------------
void CMemoryCompressDlg::OnCmdCompress()
{
  if( UpdateData( TRUE ) )
  {
    CWaitCursor xWaitCursor;

    COleException* pExcept = new COleException;
    DXceedStreamingCompression xCompressor;
    COleVariant vaToCompress;

    try
    {
      // Create an instance of the XceedStreamingCompression class.
      if( !xCompressor.CreateDispatch( "Xceed.StreamingCompression", pExcept ) )
      {
        throw pExcept;
      }

      // Create and prepare the compression format (BZip2, GZip, ZLib, ...)
      // This function can throw an exception that will be caught here.
      PrepareCompressionFormat( xCompressor );

      // Store in the variant to compress the content of the text box
      // as an ANSI String. We could have used a BSTR representation
      // of the string but it would have unnecessarily doubled the string
      // size, and slightly affect the compression ratio. The Variant will
      // report containing a VT_BSTR, but the actual data and size will
      // reflect the Ansi string format.
      vaToCompress.SetString( m_sToCompress, VT_BSTRT );

      // Compress the string in a single call (bEndOfData is TRUE).
      m_vaCompressed = xCompressor.Compress( vaToCompress, TRUE );

      // We assign an value of 0 as a default compressed size.
      m_sCompressedSize = "0";

      // We check that the compressed variant is really a byte array. For instance,
      // it won't be if there was no characters to compress (empty string).
      if( m_vaCompressed.vt == ( VT_ARRAY | VT_UI1 ) )
      {
        LONG lHigh;
        LONG lLow;

        // We extracts the upper bound and the lower bound of the
        // byte array.
        SafeArrayGetUBound( m_vaCompressed.parray, 1, &lHigh );
        SafeArrayGetLBound( m_vaCompressed.parray, 1, &lLow );

        // We display the compressed size
        m_sCompressedSize.Format( "%d", lHigh - lLow + 1 );
      }

      // Update mainly the compressed size label
      UpdateData( FALSE );
    }
    catch( COleDispatchException* pEx )
    {
      pEx->ReportError();
      pEx->Delete();
    }
    catch( COleException* pEx )
    {
      pEx->ReportError();
      pEx->Delete();
    }
    catch( CException* pEx )
    {
      pEx->ReportError();
      pEx->Delete();
    }

    pExcept->Delete();
  }
}

//------------------------------------------------------------------------------------
// Do the decompression of the compressed byte array
//------------------------------------------------------------------------------------
void CMemoryCompressDlg::OnCmdDecompress()
{
  // If the user did not performed a compression first, refuse to Decompress
  if( m_vaCompressed.vt == VT_EMPTY )
    return;

  if( UpdateData( TRUE ) )
  {
    CWaitCursor xWaitCursor;

    COleException* pExcept = new COleException;
    DXceedStreamingCompression xCompressor;
    COleVariant vaDecompressed;

    try
    {
      // Create an instance of the Xceed Streaming Compression
      if( !xCompressor.CreateDispatch( "Xceed.StreamingCompression", pExcept ) )
      {
        throw pExcept;
      }

      // Create and prepare the compression format (BZip2, GZip, ZLib, ...)
      // This function can throw an exception that will be caught here.
      PrepareCompressionFormat( xCompressor );

      // Decompress the compressed byte array in a single call
      // (bEndOfData is TRUE).
      vaDecompressed = xCompressor.Decompress( m_vaCompressed, TRUE );

      // We assign an empty string as a default decompressed value.
      m_sDecompressed = "";

      // We check that the decompressed variant is really a byte array.
      if( vaDecompressed.vt == ( VT_ARRAY | VT_UI1 ) )
      {
        LONG lHigh;
        LONG lLow;

        // We extracts the upper bound and the lower bound of the
        // byte array.
        SafeArrayGetUBound( vaDecompressed.parray, 1, &lHigh );
        SafeArrayGetLBound( vaDecompressed.parray, 1, &lLow );

        // This pointer will contain the address of the byte array
        char* pszDecompressed = NULL;

        // We get a pointer on the actual data in the safe array.
        SafeArrayAccessData( vaDecompressed.parray, ( void** )&pszDecompressed );

        // We display the decompressed string by assigning this Ansi string
        // to the CString member, using the constructor accepting a char* and a size.
        m_sDecompressed = CString( pszDecompressed, lHigh - lLow + 1 );

        // We release the lock on the safe array
        SafeArrayUnaccessData( vaDecompressed.parray );
      }

      // Let's say we want to check format-specific properties. In this sample, when
      // compressing using the GZip format, we add a comment. Let's get it back!
      switch( m_lCompressionFormat )
      {
        case cfGZip:
        {
          DXceedGZipCompressionFormat xGZip = xCompressor.GetCompressionFormat();

          m_sDecompressed += "\r\nThe comment is: ";
          m_sDecompressed += xGZip.GetComment();
          break;
        }
      }

      // Update mainly the decompressed text box
      UpdateData( FALSE );
    }
    catch( COleDispatchException* pEx )
    {
      pEx->ReportError();
      pEx->Delete();
    }
    catch( COleException* pEx )
    {
      pEx->ReportError();
      pEx->Delete();
    }
    catch( CException* pEx )
    {
      pEx->ReportError();
      pEx->Delete();
    }

    pExcept->Delete();
  }
}

//------------------------------------------------------------------------------------
// Quit the sample application
//------------------------------------------------------------------------------------
void CMemoryCompressDlg::OnQuit()
{
  EndDialog( IDOK );
}

//====================================================================================
//
// FUNCTIONS
//
//====================================================================================

//------------------------------------------------------------------------------------
// Prepare the compression format according to the user selection
//------------------------------------------------------------------------------------
void CMemoryCompressDlg::PrepareCompressionFormat( DXceedStreamingCompression& xCompressor )
{
  // To simplify the matter here, we use a generic compression format object data type
  // (xGenericOleDispatch is of type COleDispatchDriver)

  // If you need to set some properties on your compression format object, you'll need
  // to use the specific data type you create. This is demonstrated with the cfGZip case.
  COleDispatchDriver xGenericOleDispatch;

  if( UpdateData( TRUE ) )
  {
    COleException* pEx = new COleException;

    switch( m_lCompressionFormat )
    {
      case cfBZip2 :
      {
        if( !xGenericOleDispatch.CreateDispatch( "Xceed.BZip2CompressionFormat", pEx ) )
        {
          throw pEx;
        }
        break;
      }

      case cfGZip :
      {
        // Let's say we want to set some properties on our format object. We use
        // a specific DXceedGZipCompressionFormat variable instead of the generic one.
        DXceedGZipCompressionFormat xGZip;

        if( !xGZip.CreateDispatch( "Xceed.GZipCompressionFormat", pEx ) )
        {
          throw pEx;
        }

        xGZip.SetComment( "This is my comment" );

        // We make sure xGenericOleDispatch does point to this format object instance!
        // Simply transfert the responsability of this IDispatch interface reference.
        xGenericOleDispatch.AttachDispatch( xGZip.DetachDispatch() );
        break;
      }

      case cfStandard :
      {
        if( !xGenericOleDispatch.CreateDispatch( "Xceed.StandardCompressionFormat", pEx ) )
        {
          throw pEx;
        }
        break;
      }

      case cfZip3 :
      {
        if( !xGenericOleDispatch.CreateDispatch( "Xceed.Zip3CompressionFormat", pEx ) )
        {
          throw pEx;
        }
        break;
      }

      case cfZLib :
      {
        if( !xGenericOleDispatch.CreateDispatch( "Xceed.ZLibCompressionFormat", pEx ) )
        {
          throw pEx;
        }
        break;
      }

      // The next three items are not compression formats. They are compression
      // methods. They still can be assigned to the CompressionFormat property of the
      // XceedStreamingCompression object. In these cases, the resulting compressed
      // streams will have no formating (no header, footer, checksum, ...)
      case cfBWT :
      {
        if( !xGenericOleDispatch.CreateDispatch( "Xceed.BWTCompression", pEx ) )
        {
          throw pEx;
        }
        break;
      }

      case cfDeflate :
      {
        if( !xGenericOleDispatch.CreateDispatch( "Xceed.DeflateCompression", pEx ) )
        {
          throw pEx;
        }
        break;
      }

      case cfStore :
      {
        // Using Store as the compression format will produce an output
        // compressed stream identical to the original text!
        if( !xGenericOleDispatch.CreateDispatch( "Xceed.StoreCompression", pEx ) )
        {
          throw pEx;
        }
        break;
      }
    }

    if( xGenericOleDispatch.m_lpDispatch )
    {
      // Simply set the CompressionFormat property of our main XceedStreamingCompression instance
      xCompressor.SetRefCompressionFormat( xGenericOleDispatch.m_lpDispatch );
    }

    pEx->Delete();
  }
}