wmsax.cpp

WDK 下的XPSDrv 中filter 例子之 watermark

/*++

Copyright (c) 2005 Microsoft Corporation

All rights reserved.

THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
PARTICULAR PURPOSE.

File Name:

   wmsax.cpp

Abstract:

   Watermark sax handler implementation. The watermark SAX handler is
   responsible for parsing the FixedPage mark-up for the page size and
   adding the inserting the watermark mark-up in appropriate place.

--*/

#include "precomp.h"
#include "debug.h"
#include "globals.h"
#include "xdstring.h"
#include "bstrops.h"
#include "wmsax.h"

/*++

Routine Name:

    CWMSaxHandler::CWMSaxHandler

Routine Description:

    Contructor for the watermark filters SAX handler.
    The constructor registers a writer for streaming out any markup and a watermark
    handler object for generating any new watermark markup and handling related resources

Arguments:

    pWriter    - Pointer to a write stream which receives markup
    pWatermark - Pointer to a watermark handler object

Return Value:

    None
    Throws CXDException(HRESULT) on an error

--*/
CWMSaxHandler::CWMSaxHandler(
    __in IPrintWriteStream* pWriter,
    __in CWatermark*        pWatermark
    ) :
    m_pWriter(pWriter),
    m_watermark(pWatermark),
    m_bOpenTag(FALSE)
{
    ASSERTMSG(m_pWriter != NULL, "NULL writer passed to watermark SAX handler.\n");
    ASSERTMSG(m_watermark != NULL, "NULL watermark passed to watermark SAX handler.\n");

    HRESULT hr = S_OK;
    if (FAILED(hr = CHECK_POINTER(m_pWriter, E_POINTER)) ||
        FAILED(hr = CHECK_POINTER(m_watermark, E_POINTER)))
    {
        throw CXDException(hr);
    }
}

/*++

Routine Name:

    CWMSaxHandler::~CWMSaxHandler

Routine Description:

    Default destructor for the watermark filter SAX handler

Arguments:

    None

Return Value:

    None

--*/
CWMSaxHandler::~CWMSaxHandler()
{
}

/*++

Routine Name:

    CWMSaxHandler::startElement

Routine Description:

    SAX handler method which handles each start element for the XML markup

Arguments:

    pwchQName   - Pointer to a string containing the element name
    cchQName    - Count of the number of characters in the element name
    pAttributes - Pointer to the attribute list for the supplied element

Return Value:

    HRESULT
    S_OK - On success
    E_*  - On error

--*/
HRESULT STDMETHODCALLTYPE
CWMSaxHandler::startElement(
    CONST wchar_t*,
    INT,
    CONST wchar_t*,
    INT,
    __in_ecount(cchQName) CONST wchar_t*  pwchQName,
    __in                  INT             cchQName,
    __in                  ISAXAttributes* pAttributes
    )
{
    HRESULT hr = S_OK;
    CStringXDW cstrOut;

    try
    {
        //
        // Check if we need to close an opened tag
        //
        if (m_bOpenTag)
        {
            cstrOut.Append(L">");
        }

        //
        // Store the opened element name so we can handle nested elements
        //
        m_bstrOpenElement = CComBSTR(cchQName, pwchQName);

        //
        // Write out element
        //
        cstrOut.Append(L"<");
        cstrOut.Append(m_bstrOpenElement);
    }
    catch (CXDException& e)
    {
        hr = e;
    }

    //
    // We opened a tag
    //
    m_bOpenTag = TRUE;

    //
    // If this is the fixed page we need the width and height retreived
    //
    BOOL bIsFixedPage = (m_bstrOpenElement == L"FixedPage");

    //
    // Find the number of attributes and enumerate over all of them
    //
    INT cAttributes = 0;
    if (SUCCEEDED(hr) &&
        SUCCEEDED(hr = pAttributes->getLength(&cAttributes)))
    {
        for (INT cIndex = 0; cIndex < cAttributes; cIndex++)
        {
            PCWSTR pszAttUri   = NULL;
            INT    cchAttUri   = 0;
            PCWSTR pszAttName  = NULL;
            INT    cchAttName  = 0;
            PCWSTR pszAttQName = NULL;
            INT    cchAttQName = 0;
            PCWSTR pszAttValue = NULL;
            INT    cchAttValue = 0;

            //
            // Get the attribute data ready to write out
            //
            if (SUCCEEDED(hr = pAttributes->getName(cIndex,
                                                    &pszAttUri,
                                                    &cchAttUri,
                                                    &pszAttName,
                                                    &cchAttName,
                                                    &pszAttQName,
                                                    &cchAttQName)))
            {
                if (SUCCEEDED(pAttributes->getValue(cIndex, &pszAttValue, &cchAttValue)))
                {
                    try
                    {
                        CComBSTR bstrAttName(cchAttQName, pszAttQName);
                        CComBSTR bstrAttValue(cchAttValue, pszAttValue);

                        //
                        // Delimit attributes with a space
                        //
                        cstrOut.Append(L" ");

                        //
                        // Reconstruct the attribute and write back to
                        // the fixed page
                        //
                        cstrOut.Append(bstrAttName);
                        cstrOut.Append(L"=\"");

                        //
                        // If this is a UnicodeString we may need to escape entities
                        //
                        if (bstrAttName == L"UnicodeString")
                        {
                            hr = EscapeEntity(&bstrAttValue);
                        }

                        cstrOut.Append(bstrAttValue);
                        cstrOut.Append(L"\"");
                    }
                    catch (CXDException& e)
                    {
                        hr = e;
                    }
                }
            }
        }
    }

    //
    // We output the mark-up here for underlaid watermarks
    //
    if (SUCCEEDED(hr) &&
        bIsFixedPage)
    {
        //
        // If this is the fixed page element make sure we close it in case the
        // page has no content.
        //
        try
        {
            cstrOut.Append(L">");
            m_bOpenTag = FALSE;
        }
        catch (CXDException& e)
        {
            hr = e;
        }

        if (SUCCEEDED(hr) &&
            SUCCEEDED(hr = CHECK_POINTER(m_watermark, E_PENDING)))
        {

            //
            // Create the watermark markup
            //
            if (SUCCEEDED(hr) &&
                SUCCEEDED(hr = m_watermark->CreateXMLElement()))
            {
                //
                // Check if the mark-up needs to inserted at the start of the
                // fixed page (underlay)
                //
                if (m_watermark->InsertStart())
                {
                    CComBSTR bstrWMText;
                    if (SUCCEEDED(hr = m_watermark->GetXML(&bstrWMText)))
                    {
                        //
                        // Insert the watermark mark-up
                        //
                        cstrOut.Append(bstrWMText);
                    }
                }
            }
        }
    }

    if (SUCCEEDED(hr))
    {
        hr = WriteToPrintStream(&cstrOut, m_pWriter);
    }

    ERR_ON_HR(hr);
    return hr;
}

/*++

Routine Name:

    CWMSaxHandler::endElement

Routine Description:

    SAX handler method which handles each end element for the XML markup

Arguments:

    pwchQName - Pointer to a string containing the element name
    cchQName  - Count of the number of characters in the element name

Return Value:

    HRESULT
    S_OK - On success
    E_*  - On error

--*/
HRESULT STDMETHODCALLTYPE
CWMSaxHandler::endElement(
    CONST wchar_t*,
    INT,
    CONST wchar_t*,
    INT,
    __in_ecount(cchQName) CONST wchar_t* pwchQName,
    __in                  INT            cchQName
    )
{
    HRESULT hr = S_OK;
    CStringXDW cstrClose;

    try
    {
        CComBSTR bstrElement(cchQName, pwchQName);

        if (bstrElement == L"FixedPage")
        {
            if (SUCCEEDED(hr = CHECK_POINTER(m_watermark, E_PENDING)) &&
                m_watermark->InsertEnd())
            {
                CComBSTR bstrWMText;
                if (SUCCEEDED(hr = m_watermark->GetXML(&bstrWMText)))
                {
                    cstrClose.Append(bstrWMText);
                }
            }
        }

        //
        // If this element matches the current open element, use shorthand to close
        // the tag
        //
        if (bstrElement == m_bstrOpenElement &&
            m_bOpenTag)
        {
            cstrClose.Append(L"/>");
        }
        else
        {
            //
            // Close the element
            //
            cstrClose.Append(L"</");
            cstrClose.Append(bstrElement);
            cstrClose.Append(L">");
        }
    }
    catch (CXDException& e)
    {
        hr = e;
    }

    if (SUCCEEDED(hr))
    {
        hr = WriteToPrintStream(&cstrClose, m_pWriter);
    }

    m_bOpenTag = FALSE;

    ERR_ON_HR(hr);
    return hr;
}


/*++

Routine Name:

    CWMSaxHandler::startDocument

Routine Description:

    SAX handler method which handles the start document call to ensure
    the xml version is correctly set

Arguments:

    None

Return Value:

    HRESULT
    S_OK - On success
    E_*  - On error

--*/
HRESULT STDMETHODCALLTYPE
CWMSaxHandler::startDocument(
    void
    )
{
    HRESULT hr = S_OK;

    try
    {
        if (SUCCEEDED(hr = CHECK_POINTER(m_pWriter, E_FAIL)))
        {
            CStringXDW cstrOut(L"<?xml version=\"1.0\" encoding=\"utf-8\"?>");
            hr = WriteToPrintStream(&cstrOut, m_pWriter);
        }
    }
    catch (CXDException& e)
    {
        hr = e;
    }

    ERR_ON_HR(hr);
    return hr;
}