dataobj.cpp

很牛的GUI源码wxWidgets-2.8.0.zip 可在多种平台下运行.

///////////////////////////////////////////////////////////////////////////////
// Name:        msw/ole/dataobj.cpp
// Purpose:     implementation of wx[I]DataObject class
// Author:      Vadim Zeitlin
// Modified by:
// Created:     10.05.98
// RCS-ID:      $Id: dataobj.cpp,v 1.98 2006/11/12 15:54:06 JS Exp $
// Copyright:   (c) 1998 Vadim Zeitlin <[e-mail]>
// Licence:     wxWindows licence
///////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#if defined(__BORLANDC__)
    #pragma hdrstop
#endif

#ifndef WX_PRECOMP
    #include "wx/intl.h"
    #include "wx/log.h"
    #include "wx/utils.h"
#endif

#include "wx/dataobj.h"

#if wxUSE_OLE && defined(__WIN32__) && !defined(__GNUWIN32_OLD__)

#include "wx/msw/private.h"         // includes <windows.h>

#ifdef __WXWINCE__
#include <winreg.h>
#endif

// for some compilers, the entire ole2.h must be included, not only oleauto.h
#if wxUSE_NORLANDER_HEADERS || defined(__WATCOMC__) || defined(__WXWINCE__)
  #include <ole2.h>
#endif

#include <oleauto.h>
#include <shlobj.h>

#include "wx/msw/ole/oleutils.h"

#include "wx/msw/dib.h"

#ifndef CFSTR_SHELLURL
#define CFSTR_SHELLURL _T("UniformResourceLocator")
#endif

// ----------------------------------------------------------------------------
// functions
// ----------------------------------------------------------------------------

#ifdef __WXDEBUG__
    static const wxChar *GetTymedName(DWORD tymed);
#else // !Debug
    #define GetTymedName(tymed) wxEmptyString
#endif // Debug/!Debug

// ----------------------------------------------------------------------------
// wxIEnumFORMATETC interface implementation
// ----------------------------------------------------------------------------

class wxIEnumFORMATETC : public IEnumFORMATETC
{
public:
    wxIEnumFORMATETC(const wxDataFormat* formats, ULONG nCount);
    virtual ~wxIEnumFORMATETC() { delete [] m_formats; }

    // IEnumFORMATETC
    STDMETHODIMP Next(ULONG celt, FORMATETC *rgelt, ULONG *pceltFetched);
    STDMETHODIMP Skip(ULONG celt);
    STDMETHODIMP Reset();
    STDMETHODIMP Clone(IEnumFORMATETC **ppenum);

    DECLARE_IUNKNOWN_METHODS;

private:
    CLIPFORMAT *m_formats;  // formats we can provide data in
    ULONG       m_nCount,   // number of formats we support
                m_nCurrent; // current enum position

    DECLARE_NO_COPY_CLASS(wxIEnumFORMATETC)
};

// ----------------------------------------------------------------------------
// wxIDataObject implementation of IDataObject interface
// ----------------------------------------------------------------------------

class wxIDataObject : public IDataObject
{
public:
    wxIDataObject(wxDataObject *pDataObject);
    virtual ~wxIDataObject();

    // normally, wxDataObject controls our lifetime (i.e. we're deleted when it
    // is), but in some cases, the situation is reversed, that is we delete it
    // when this object is deleted - setting this flag enables such logic
    void SetDeleteFlag() { m_mustDelete = true; }

    // IDataObject
    STDMETHODIMP GetData(FORMATETC *pformatetcIn, STGMEDIUM *pmedium);
    STDMETHODIMP GetDataHere(FORMATETC *pformatetc, STGMEDIUM *pmedium);
    STDMETHODIMP QueryGetData(FORMATETC *pformatetc);
    STDMETHODIMP GetCanonicalFormatEtc(FORMATETC *In, FORMATETC *pOut);
    STDMETHODIMP SetData(FORMATETC *pfetc, STGMEDIUM *pmedium, BOOL fRelease);
    STDMETHODIMP EnumFormatEtc(DWORD dwDirection, IEnumFORMATETC **ppenumFEtc);
    STDMETHODIMP DAdvise(FORMATETC *pfetc, DWORD ad, IAdviseSink *p, DWORD *pdw);
    STDMETHODIMP DUnadvise(DWORD dwConnection);
    STDMETHODIMP EnumDAdvise(IEnumSTATDATA **ppenumAdvise);

    DECLARE_IUNKNOWN_METHODS;

private:
    wxDataObject *m_pDataObject;      // pointer to C++ class we belong to

    bool m_mustDelete;

    DECLARE_NO_COPY_CLASS(wxIDataObject)
};

// ============================================================================
// implementation
// ============================================================================

// ----------------------------------------------------------------------------
// wxDataFormat
// ----------------------------------------------------------------------------

void wxDataFormat::SetId(const wxChar *format)
{
    m_format = (wxDataFormat::NativeFormat)::RegisterClipboardFormat(format);
    if ( !m_format )
    {
        wxLogError(_("Couldn't register clipboard format '%s'."), format);
    }
}

wxString wxDataFormat::GetId() const
{
    static const int max = 256;

    wxString s;

    wxCHECK_MSG( !IsStandard(), s,
                 wxT("name of predefined format cannot be retrieved") );

    int len = ::GetClipboardFormatName(m_format, wxStringBuffer(s, max), max);

    if ( !len )
    {
        wxLogError(_("The clipboard format '%d' doesn't exist."), m_format);
    }

    return s;
}

// ----------------------------------------------------------------------------
// wxIEnumFORMATETC
// ----------------------------------------------------------------------------

BEGIN_IID_TABLE(wxIEnumFORMATETC)
    ADD_IID(Unknown)
    ADD_IID(EnumFORMATETC)
END_IID_TABLE;

IMPLEMENT_IUNKNOWN_METHODS(wxIEnumFORMATETC)

wxIEnumFORMATETC::wxIEnumFORMATETC(const wxDataFormat *formats, ULONG nCount)
{
    m_nCurrent = 0;
    m_nCount = nCount;
    m_formats = new CLIPFORMAT[nCount];
    for ( ULONG n = 0; n < nCount; n++ ) {
        m_formats[n] = formats[n].GetFormatId();
    }
}

STDMETHODIMP wxIEnumFORMATETC::Next(ULONG      celt,
                                    FORMATETC *rgelt,
                                    ULONG     *pceltFetched)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIEnumFORMATETC::Next"));

    ULONG numFetched = 0;
    while (m_nCurrent < m_nCount && numFetched < celt) {
        FORMATETC format;
        format.cfFormat = m_formats[m_nCurrent++];
        format.ptd      = NULL;
        format.dwAspect = DVASPECT_CONTENT;
        format.lindex   = -1;
        format.tymed    = TYMED_HGLOBAL;

        *rgelt++ = format;
        numFetched++;
    }

    if (pceltFetched)
        *pceltFetched = numFetched;

    return numFetched == celt ? S_OK : S_FALSE;
}

STDMETHODIMP wxIEnumFORMATETC::Skip(ULONG celt)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIEnumFORMATETC::Skip"));

    m_nCurrent += celt;
    if ( m_nCurrent < m_nCount )
        return S_OK;

    // no, can't skip this many elements
    m_nCurrent -= celt;

    return S_FALSE;
}

STDMETHODIMP wxIEnumFORMATETC::Reset()
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIEnumFORMATETC::Reset"));

    m_nCurrent = 0;

    return S_OK;
}

STDMETHODIMP wxIEnumFORMATETC::Clone(IEnumFORMATETC **ppenum)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIEnumFORMATETC::Clone"));

    // unfortunately, we can't reuse the code in ctor - types are different
    wxIEnumFORMATETC *pNew = new wxIEnumFORMATETC(NULL, 0);
    pNew->m_nCount = m_nCount;
    pNew->m_formats = new CLIPFORMAT[m_nCount];
    for ( ULONG n = 0; n < m_nCount; n++ ) {
        pNew->m_formats[n] = m_formats[n];
    }
    pNew->AddRef();
    *ppenum = pNew;

    return S_OK;
}

// ----------------------------------------------------------------------------
// wxIDataObject
// ----------------------------------------------------------------------------

BEGIN_IID_TABLE(wxIDataObject)
    ADD_IID(Unknown)
    ADD_IID(DataObject)
END_IID_TABLE;

IMPLEMENT_IUNKNOWN_METHODS(wxIDataObject)

wxIDataObject::wxIDataObject(wxDataObject *pDataObject)
{
    m_pDataObject = pDataObject;
    m_mustDelete = false;
}

wxIDataObject::~wxIDataObject()
{
    if ( m_mustDelete )
    {
        delete m_pDataObject;
    }
}

// get data functions
STDMETHODIMP wxIDataObject::GetData(FORMATETC *pformatetcIn, STGMEDIUM *pmedium)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIDataObject::GetData"));

    // is data is in our format?
    HRESULT hr = QueryGetData(pformatetcIn);
    if ( FAILED(hr) )
        return hr;

    // for the bitmaps and metafiles we use the handles instead of global memory
    // to pass the data
    wxDataFormat format = (wxDataFormat::NativeFormat)pformatetcIn->cfFormat;

    switch ( format )
    {
        case wxDF_BITMAP:
            pmedium->tymed = TYMED_GDI;
            break;

        case wxDF_ENHMETAFILE:
            pmedium->tymed = TYMED_ENHMF;
            break;

#ifndef __WXWINCE__
        case wxDF_METAFILE:
            pmedium->hGlobal = GlobalAlloc(GMEM_MOVEABLE | GMEM_SHARE,
                                           sizeof(METAFILEPICT));
            if ( !pmedium->hGlobal ) {
                wxLogLastError(wxT("GlobalAlloc"));
                return E_OUTOFMEMORY;
            }
            pmedium->tymed = TYMED_MFPICT;
            break;
#endif
        default:
            // alloc memory
            size_t size = m_pDataObject->GetDataSize(format);
            if ( !size ) {
                // it probably means that the method is just not implemented
                wxLogDebug(wxT("Invalid data size - can't be 0"));

                return DV_E_FORMATETC;
            }

            // we may need extra space for the buffer size
            size += m_pDataObject->GetBufferOffset( format );

            HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE | GMEM_SHARE, size);
            if ( hGlobal == NULL ) {
                wxLogLastError(wxT("GlobalAlloc"));
                return E_OUTOFMEMORY;
            }

            // copy data
            pmedium->tymed   = TYMED_HGLOBAL;
            pmedium->hGlobal = hGlobal;
    }

    pmedium->pUnkForRelease = NULL;

    // do copy the data
    hr = GetDataHere(pformatetcIn, pmedium);
    if ( FAILED(hr) ) {
        // free resources we allocated
        if ( pmedium->tymed & (TYMED_HGLOBAL | TYMED_MFPICT) ) {
            GlobalFree(pmedium->hGlobal);
        }

        return hr;
    }

    return S_OK;
}

STDMETHODIMP wxIDataObject::GetDataHere(FORMATETC *pformatetc,
                                        STGMEDIUM *pmedium)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIDataObject::GetDataHere"));

    // put data in caller provided medium
    switch ( pmedium->tymed )
    {
        case TYMED_GDI:
            if ( !m_pDataObject->GetDataHere(wxDF_BITMAP, &pmedium->hBitmap) )
                return E_UNEXPECTED;
            break;

        case TYMED_ENHMF:
            if ( !m_pDataObject->GetDataHere(wxDF_ENHMETAFILE,
                                             &pmedium->hEnhMetaFile) )
                return E_UNEXPECTED;
            break;

        case TYMED_MFPICT:
            // fall through - we pass METAFILEPICT through HGLOBAL

        case TYMED_HGLOBAL:
            {
                // copy data
                HGLOBAL hGlobal = pmedium->hGlobal;
                void *pBuf = GlobalLock(hGlobal);
                if ( pBuf == NULL ) {
                    wxLogLastError(wxT("GlobalLock"));
                    return E_OUTOFMEMORY;
                }

                wxDataFormat format = pformatetc->cfFormat;

                // possibly put the size in the beginning of the buffer
                pBuf = m_pDataObject->SetSizeInBuffer
                                      (
                                        pBuf,
                                        ::GlobalSize(hGlobal),
                                        format
                                      );

                if ( !m_pDataObject->GetDataHere(format, pBuf) )
                    return E_UNEXPECTED;

                GlobalUnlock(hGlobal);
            }
            break;

        default:
            return DV_E_TYMED;
    }

    return S_OK;
}


// set data functions
STDMETHODIMP wxIDataObject::SetData(FORMATETC *pformatetc,
                                    STGMEDIUM *pmedium,
                                    BOOL       fRelease)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIDataObject::SetData"));

    switch ( pmedium->tymed )
    {
        case TYMED_GDI:
            m_pDataObject->SetData(wxDF_BITMAP, 0, &pmedium->hBitmap);
            break;

        case TYMED_ENHMF:
            m_pDataObject->SetData(wxDF_ENHMETAFILE, 0, &pmedium->hEnhMetaFile);
            break;

        case TYMED_MFPICT:
            // fall through - we pass METAFILEPICT through HGLOBAL
        case TYMED_HGLOBAL:
            {
                wxDataFormat format = pformatetc->cfFormat;

                // this is quite weird, but for file drag and drop, explorer
                // calls our SetData() with the formats we do *not* support!
                //
                // as we can't fix this bug in explorer (it's a bug because it
                // should only use formats returned by EnumFormatEtc), do the
                // check here
                if ( !m_pDataObject->IsSupported(format, wxDataObject::Set) ) {
                    // go away!
                    return DV_E_FORMATETC;