project64/Source/Project64/UserInterface/WTLControls/ClistCtrl/DragDrop.h

787 lines
19 KiB
C++

#pragma once
#include <vector>
#include <shlobj.h>
using namespace std;
class CEnumFormatEtc : public IEnumFORMATETC
{
public:
CEnumFormatEtc( const vector < FORMATETC >& vFormatEtc )
{
m_nRefCount = 0;
m_nIndex = 0;
m_vFormatEtc = vFormatEtc;
}
protected:
vector < FORMATETC > m_vFormatEtc;
int m_nRefCount;
int m_nIndex;
public:
// IUnknown members
STDMETHOD(QueryInterface)( REFIID refiid, void FAR* FAR* ppvObject )
{
*ppvObject = ( refiid == IID_IUnknown || refiid == IID_IEnumFORMATETC ) ? this : NULL;
if ( *ppvObject != NULL )
( (LPUNKNOWN)*ppvObject )->AddRef();
return *ppvObject == NULL ? E_NOINTERFACE : S_OK;
}
STDMETHOD_(ULONG, AddRef)( void )
{
return ++m_nRefCount;
}
STDMETHOD_(ULONG, Release)( void )
{
int nRefCount = --m_nRefCount;
if ( nRefCount == 0 )
delete this;
return nRefCount;
}
// IEnumFORMATETC members
STDMETHOD(Next)( ULONG celt, LPFORMATETC lpFormatEtc, ULONG FAR *pceltFetched )
{
if ( pceltFetched != NULL )
*pceltFetched=0;
ULONG cReturn = celt;
if ( celt <= 0 || lpFormatEtc == NULL || m_nIndex >= (int)m_vFormatEtc.size() )
return S_FALSE;
if ( pceltFetched == NULL && celt != 1 ) // pceltFetched can be NULL only for 1 item request
return S_FALSE;
while ( m_nIndex < (int)m_vFormatEtc.size() && cReturn > 0 )
{
*lpFormatEtc++ = m_vFormatEtc[ m_nIndex++ ];
cReturn--;
}
if ( pceltFetched != NULL )
*pceltFetched = celt - cReturn;
return cReturn == 0 ? S_OK : S_FALSE;
}
STDMETHOD(Skip)( ULONG celt )
{
if ( ( m_nIndex + (int)celt ) >= (int)m_vFormatEtc.size() )
return S_FALSE;
m_nIndex += celt;
return S_OK;
}
STDMETHOD(Reset)( void )
{
m_nIndex = 0;
return S_OK;
}
STDMETHOD(Clone)( IEnumFORMATETC FAR * FAR* ppCloneEnumFormatEtc )
{
if ( ppCloneEnumFormatEtc == NULL )
return E_POINTER;
*ppCloneEnumFormatEtc = new CEnumFormatEtc( m_vFormatEtc );
( (CEnumFormatEtc*)*ppCloneEnumFormatEtc )->AddRef();
( (CEnumFormatEtc*)*ppCloneEnumFormatEtc )->m_nIndex = m_nIndex;
return S_OK;
}
};
class CDropSource : public IDropSource
{
public:
CDropSource()
{
m_nRefCount = 0;
}
protected:
int m_nRefCount;
public:
// IUnknown members
STDMETHOD(QueryInterface)( REFIID refiid, void FAR* FAR* ppvObject )
{
*ppvObject = ( refiid == IID_IUnknown || refiid == IID_IDropSource ) ? this : NULL;
if ( *ppvObject != NULL )
( (LPUNKNOWN)*ppvObject )->AddRef();
return *ppvObject == NULL ? E_NOINTERFACE : S_OK;
}
STDMETHOD_(ULONG, AddRef)( void )
{
return ++m_nRefCount;
}
STDMETHOD_(ULONG, Release)( void )
{
int nRefCount = --m_nRefCount;
if ( nRefCount == 0 )
delete this;
return nRefCount;
}
// IDropSource members
STDMETHOD(QueryContinueDrag)( BOOL bEscapePressed, DWORD dwKeyState )
{
if ( bEscapePressed )
return DRAGDROP_S_CANCEL;
if ( !( dwKeyState & ( MK_LBUTTON | MK_RBUTTON ) ) )
return DRAGDROP_S_DROP;
return S_OK;
}
STDMETHOD(GiveFeedback)( DWORD /*dwEffect*/ )
{
return DRAGDROP_S_USEDEFAULTCURSORS;
}
};
class CDataObject : public IDataObject
{
public:
CDataObject( CDropSource *pDropSource )
{
m_nRefCount = 0;
m_pDropSource = pDropSource;
m_bSwappedButtons = GetSystemMetrics( SM_SWAPBUTTON );
}
virtual ~CDataObject()
{
for ( vector < STGMEDIUM >::iterator posStgMedium = m_vStgMedium.begin(); posStgMedium != m_vStgMedium.end(); posStgMedium++ )
ReleaseStgMedium( &( *posStgMedium ) );
}
protected:
CDropSource *m_pDropSource;
int m_nRefCount;
BOOL m_bSwappedButtons;
vector < FORMATETC > m_vFormatEtc;
vector < STGMEDIUM > m_vStgMedium;
public:
// IUnknown members
STDMETHOD(QueryInterface)( REFIID refiid, void FAR* FAR* ppvObject )
{
*ppvObject = ( refiid == IID_IUnknown || refiid == IID_IDataObject ) ? this : NULL;
if ( *ppvObject != NULL )
( (LPUNKNOWN)*ppvObject )->AddRef();
return *ppvObject == NULL ? E_NOINTERFACE : S_OK;
}
STDMETHOD_(ULONG, AddRef)( void )
{
return ++m_nRefCount;
}
STDMETHOD_(ULONG, Release)( void )
{
int nRefCount = --m_nRefCount;
if ( nRefCount == 0 )
delete this;
return nRefCount;
}
// IDataObject members
STDMETHOD(GetData)( FORMATETC __RPC_FAR *pformatetcIn, STGMEDIUM __RPC_FAR *pmedium )
{
if ( pformatetcIn == NULL || pmedium == NULL )
return E_INVALIDARG;
ZeroMemory( pmedium, sizeof( STGMEDIUM ) );
for ( int nFormatEtc = 0; nFormatEtc < (int)m_vFormatEtc.size(); nFormatEtc++ )
{
if ( pformatetcIn->tymed & m_vFormatEtc[ nFormatEtc ].tymed &&
pformatetcIn->dwAspect == m_vFormatEtc[ nFormatEtc ].dwAspect &&
pformatetcIn->cfFormat == m_vFormatEtc[ nFormatEtc ].cfFormat )
{
if ( m_vStgMedium[ nFormatEtc ].tymed == TYMED_NULL )
return OnRenderData( m_vFormatEtc[ nFormatEtc ], pmedium, ( GetAsyncKeyState( m_bSwappedButtons ? VK_RBUTTON : VK_LBUTTON ) >= 0 ) ) ? S_OK : DV_E_FORMATETC;
CopyMedium( pmedium, m_vStgMedium[ nFormatEtc ], m_vFormatEtc[ nFormatEtc ] );
return S_OK;
}
}
return DV_E_FORMATETC;
}
STDMETHOD(GetDataHere)( FORMATETC __RPC_FAR * /*pformatetc*/, STGMEDIUM __RPC_FAR * /*pmedium*/ )
{
return E_NOTIMPL;
}
STDMETHOD(QueryGetData)( FORMATETC __RPC_FAR *pformatetc )
{
if ( pformatetc == NULL )
return E_INVALIDARG;
if ( !( pformatetc->dwAspect & DVASPECT_CONTENT ) )
return DV_E_DVASPECT;
HRESULT hResult = DV_E_TYMED;
for ( int nFormatEtc = 0; nFormatEtc < (int)m_vFormatEtc.size(); nFormatEtc++ )
{
if ( !( pformatetc->tymed & m_vFormatEtc[ nFormatEtc ].tymed ) )
{
hResult = DV_E_TYMED;
continue;
}
if ( pformatetc->cfFormat == m_vFormatEtc[ nFormatEtc ].cfFormat )
return S_OK;
hResult = DV_E_CLIPFORMAT;
}
return hResult;
}
STDMETHOD(GetCanonicalFormatEtc)( FORMATETC __RPC_FAR * /*pformatectIn*/, FORMATETC __RPC_FAR * pformatetcOut )
{
return pformatetcOut == NULL ? E_INVALIDARG : DATA_S_SAMEFORMATETC;
}
STDMETHOD(SetData)( FORMATETC __RPC_FAR *pformatetc, STGMEDIUM __RPC_FAR *pmedium, BOOL bRelease )
{
if ( pformatetc == NULL || pmedium == NULL )
return E_INVALIDARG;
m_vFormatEtc.push_back( *pformatetc );
STGMEDIUM StgMedium = *pmedium;
if ( !bRelease )
CopyMedium( &StgMedium, *pmedium, *pformatetc );
m_vStgMedium.push_back( StgMedium );
return S_OK;
}
STDMETHOD(EnumFormatEtc)( DWORD dwDirection, IEnumFORMATETC __RPC_FAR *__RPC_FAR *ppenumFormatEtc )
{
if ( ppenumFormatEtc == NULL )
return E_POINTER;
switch ( dwDirection )
{
case DATADIR_GET: *ppenumFormatEtc = new CEnumFormatEtc( m_vFormatEtc );
( (CEnumFormatEtc*)*ppenumFormatEtc )->AddRef();
return S_OK;
default: *ppenumFormatEtc = NULL;
return E_NOTIMPL;
}
}
STDMETHOD(DAdvise)( FORMATETC __RPC_FAR * /*pformatetc*/, DWORD /*advf*/, IAdviseSink __RPC_FAR * /*pAdvSink*/, DWORD __RPC_FAR * /*pdwConnection*/ )
{
return OLE_E_ADVISENOTSUPPORTED;
}
STDMETHOD(DUnadvise)( DWORD /*dwConnection*/ )
{
return E_NOTIMPL;
}
STDMETHOD(EnumDAdvise)( IEnumSTATDATA __RPC_FAR *__RPC_FAR * /*ppenumAdvise*/ )
{
return OLE_E_ADVISENOTSUPPORTED;
}
void CopyMedium( STGMEDIUM *pMedDest, STGMEDIUM& MedSrc, FORMATETC& FmtSrc )
{
switch( MedSrc.tymed )
{
case TYMED_HGLOBAL: pMedDest->hGlobal = (HGLOBAL)OleDuplicateData( MedSrc.hGlobal, FmtSrc.cfFormat, NULL );
break;
case TYMED_GDI: pMedDest->hBitmap = (HBITMAP)OleDuplicateData( MedSrc.hBitmap, FmtSrc.cfFormat, NULL );
break;
case TYMED_MFPICT: pMedDest->hMetaFilePict = (HMETAFILEPICT)OleDuplicateData( MedSrc.hMetaFilePict, FmtSrc.cfFormat, NULL );
break;
case TYMED_ENHMF: pMedDest->hEnhMetaFile = (HENHMETAFILE)OleDuplicateData( MedSrc.hEnhMetaFile, FmtSrc.cfFormat, NULL );
break;
case TYMED_FILE: pMedDest->lpszFileName = (LPOLESTR)OleDuplicateData( MedSrc.lpszFileName, FmtSrc.cfFormat, NULL );
break;
case TYMED_ISTREAM: pMedDest->pstm = MedSrc.pstm;
MedSrc.pstm->AddRef();
break;
case TYMED_ISTORAGE: pMedDest->pstg = MedSrc.pstg;
MedSrc.pstg->AddRef();
break;
}
pMedDest->tymed = MedSrc.tymed;
pMedDest->pUnkForRelease = NULL;
if ( MedSrc.pUnkForRelease != NULL )
{
pMedDest->pUnkForRelease = MedSrc.pUnkForRelease;
MedSrc.pUnkForRelease->AddRef();
}
}
virtual BOOL OnRenderData( FORMATETC& /*FormatEtc*/, STGMEDIUM * /*pStgMedium*/, BOOL /*bDropComplete*/ )
{
return FALSE;
}
};
class CDropTarget : public IDropTarget
{
public:
CDropTarget( HWND hTargetWnd )
{
m_hTargetWnd = hTargetWnd;
m_nRefCount = 0;
m_bAllowDrop = FALSE;
m_pDropTargetHelper = NULL;
ZeroMemory( &m_FormatEtc, sizeof( FORMATETC ) );
ZeroMemory( &m_StgMedium, sizeof( STGMEDIUM ) );
if ( FAILED( CoCreateInstance( CLSID_DragDropHelper, NULL, CLSCTX_INPROC_SERVER, IID_IDropTargetHelper, (LPVOID*)&m_pDropTargetHelper ) ) )
m_pDropTargetHelper = NULL;
}
virtual ~CDropTarget()
{
if ( m_pDropTargetHelper != NULL )
{
m_pDropTargetHelper->Release();
m_pDropTargetHelper = NULL;
}
}
protected:
HWND m_hTargetWnd;
int m_nRefCount;
struct IDropTargetHelper *m_pDropTargetHelper;
vector < FORMATETC > m_vFormatEtc;
BOOL m_bAllowDrop;
FORMATETC m_FormatEtc;
STGMEDIUM m_StgMedium;
public:
// IUnknown members
STDMETHOD(QueryInterface)( REFIID refiid, void FAR* FAR* ppvObject )
{
*ppvObject = ( refiid == IID_IUnknown || refiid == IID_IDropTarget ) ? this : NULL;
if ( *ppvObject != NULL )
( (LPUNKNOWN)*ppvObject )->AddRef();
return *ppvObject == NULL ? E_NOINTERFACE : S_OK;
}
STDMETHOD_(ULONG, AddRef)( void )
{
return ++m_nRefCount;
}
STDMETHOD_(ULONG, Release)( void )
{
int nRefCount = --m_nRefCount;
if ( nRefCount == 0 )
delete this;
return nRefCount;
}
STDMETHOD(DragEnter)( IDataObject __RPC_FAR *pDataObject, DWORD dwKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect )
{
if ( pDataObject == NULL )
return E_INVALIDARG;
if ( m_pDropTargetHelper != NULL )
m_pDropTargetHelper->DragEnter( m_hTargetWnd, pDataObject, (LPPOINT)&pt, *pdwEffect );
ZeroMemory( &m_FormatEtc, sizeof( FORMATETC ) );
if ( m_StgMedium.tymed != TYMED_NULL )
ReleaseStgMedium( &m_StgMedium );
ZeroMemory( &m_StgMedium, sizeof( STGMEDIUM ) );
for ( int nFormatEtc = 0; nFormatEtc < (int)m_vFormatEtc.size(); nFormatEtc++ )
{
STGMEDIUM StgMedium;
m_bAllowDrop = ( pDataObject->GetData( &m_vFormatEtc[ nFormatEtc ], &StgMedium ) == S_OK );
if ( m_bAllowDrop )
{
// store drag data for later use in DragOver
m_FormatEtc = m_vFormatEtc[ nFormatEtc ];
m_StgMedium = StgMedium;
// get client cursor position
CWindow hWnd( m_hTargetWnd );
CPoint point( pt.x, pt.y );
hWnd.ScreenToClient( &point );
*pdwEffect = OnDragEnter( m_FormatEtc, m_StgMedium, dwKeyState, point );
break;
}
}
QueryDrop( dwKeyState, pdwEffect );
return S_OK;
}
STDMETHOD(DragOver)( DWORD dwKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect )
{
if ( m_pDropTargetHelper )
m_pDropTargetHelper->DragOver( (LPPOINT)&pt, *pdwEffect );
if ( m_bAllowDrop && m_FormatEtc.cfFormat != CF_NULL && m_StgMedium.tymed != TYMED_NULL )
{
// get client cursor position
CWindow hWnd( m_hTargetWnd );
CPoint point( pt.x, pt.y );
hWnd.ScreenToClient( &point );
*pdwEffect = OnDragOver( m_FormatEtc, m_StgMedium, dwKeyState, point );
}
QueryDrop( dwKeyState, pdwEffect );
return S_OK;
}
STDMETHOD(DragLeave)( void )
{
if ( m_pDropTargetHelper )
m_pDropTargetHelper->DragLeave();
OnDragLeave();
m_bAllowDrop = FALSE;
ZeroMemory( &m_FormatEtc, sizeof( FORMATETC ) );
if ( m_StgMedium.tymed != TYMED_NULL )
ReleaseStgMedium( &m_StgMedium );
ZeroMemory( &m_StgMedium, sizeof( STGMEDIUM ) );
return S_OK;
}
STDMETHOD(Drop)( IDataObject __RPC_FAR *pDataObject, DWORD dwKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect )
{
if ( pDataObject == NULL )
return E_INVALIDARG;
if ( m_pDropTargetHelper )
m_pDropTargetHelper->Drop( pDataObject, (LPPOINT)&pt, *pdwEffect );
if ( m_bAllowDrop && m_FormatEtc.cfFormat != CF_NULL && QueryDrop( dwKeyState, pdwEffect ) )
{
STGMEDIUM StgMedium;
if ( pDataObject->GetData( &m_FormatEtc, &StgMedium ) == S_OK )
{
// get client cursor position
CWindow hWnd( m_hTargetWnd );
CPoint point( pt.x, pt.y );
hWnd.ScreenToClient( &point );
if ( !OnDrop( m_FormatEtc, StgMedium, *pdwEffect, point ) )
*pdwEffect = DROPEFFECT_NONE;
ReleaseStgMedium( &StgMedium );
}
}
m_bAllowDrop = FALSE;
ZeroMemory( &m_FormatEtc, sizeof( FORMATETC ) );
if ( m_StgMedium.tymed != TYMED_NULL )
ReleaseStgMedium( &m_StgMedium );
ZeroMemory( &m_StgMedium, sizeof( STGMEDIUM ) );
return S_OK;
}
void AddSupportedFormat( FORMATETC& FormatEtc )
{
m_vFormatEtc.push_back( FormatEtc );
}
void AddSupportedFormat( CLIPFORMAT cfFormat )
{
FORMATETC FormatEtc;
ZeroMemory( &FormatEtc, sizeof( FORMATETC ) );
FormatEtc.cfFormat = cfFormat;
FormatEtc.dwAspect = DVASPECT_CONTENT;
FormatEtc.lindex = -1;
FormatEtc.tymed = TYMED_HGLOBAL;
AddSupportedFormat( FormatEtc );
}
BOOL QueryDrop( DWORD dwKeyState, LPDWORD pdwEffect )
{
DWORD dwEffects = *pdwEffect;
if ( !m_bAllowDrop )
{
*pdwEffect = DROPEFFECT_NONE;
return FALSE;
}
*pdwEffect = ( dwKeyState & MK_CONTROL ) ? ( ( dwKeyState & MK_SHIFT ) ? DROPEFFECT_LINK : DROPEFFECT_COPY ) : ( ( dwKeyState & MK_SHIFT ) ? DROPEFFECT_MOVE : 0 );
if ( *pdwEffect == 0 )
{
if ( dwEffects & DROPEFFECT_COPY )
*pdwEffect = DROPEFFECT_COPY;
else if ( dwEffects & DROPEFFECT_MOVE )
*pdwEffect = DROPEFFECT_MOVE;
else if (dwEffects & DROPEFFECT_LINK )
*pdwEffect = DROPEFFECT_LINK;
else
*pdwEffect = DROPEFFECT_NONE;
}
else if ( !( *pdwEffect & dwEffects ) )
*pdwEffect = DROPEFFECT_NONE;
return ( *pdwEffect != DROPEFFECT_NONE );
}
virtual DWORD OnDragEnter( FORMATETC& /*FormatEtc*/, STGMEDIUM& /*StgMedium*/, DWORD /*dwKeyState*/, CPoint /*point*/ )
{
return FALSE;
}
virtual DWORD OnDragOver( FORMATETC& /*FormatEtc*/, STGMEDIUM& /*StgMedium*/, DWORD /*dwKeyState*/, CPoint /*point*/ )
{
return FALSE;
}
virtual BOOL OnDrop( FORMATETC& /*FormatEtc*/, STGMEDIUM& /*StgMedium*/, DWORD /*dwEffect*/, CPoint /*point*/ )
{
return FALSE;
}
virtual void OnDragLeave()
{
}
};
template < class T >
class CDropTargetT : public CDropTarget
{
public:
CDropTargetT( HWND hTargetWnd ) : CDropTarget( hTargetWnd )
{
m_pDelegate = NULL;
}
protected:
T *m_pDelegate;
public:
BOOL Register( T *pDelegate )
{
m_pDelegate = pDelegate;
return TRUE;
}
virtual DWORD OnDragEnter( FORMATETC& FormatEtc, STGMEDIUM& StgMedium, DWORD dwKeyState, CPoint point )
{
return m_pDelegate == NULL ? DROPEFFECT_NONE : m_pDelegate->OnDragEnter( FormatEtc, StgMedium, dwKeyState, point );
}
virtual DWORD OnDragOver( FORMATETC& FormatEtc, STGMEDIUM& StgMedium, DWORD dwKeyState, CPoint point )
{
return m_pDelegate == NULL ? DROPEFFECT_NONE : m_pDelegate->OnDragOver( FormatEtc, StgMedium, dwKeyState, point );
}
virtual BOOL OnDrop( FORMATETC& FormatEtc, STGMEDIUM& StgMedium, DWORD dwEffect, CPoint point )
{
return m_pDelegate == NULL ? FALSE : m_pDelegate->OnDrop( FormatEtc, StgMedium, dwEffect, point );
}
virtual void OnDragLeave()
{
if ( m_pDelegate != NULL )
m_pDelegate->OnDragLeave();
}
};
template < class T >
class CDataObjectT : public CDataObject
{
public:
CDataObjectT( CDropSource *pDropSource ) : CDataObject( pDropSource )
{
m_pDelegate = FALSE;
}
protected:
T *m_pDelegate;
public:
BOOL Register( T *pDelegate )
{
m_pDelegate = pDelegate;
return TRUE;
}
virtual BOOL OnRenderData( FORMATETC& FormatEtc, STGMEDIUM *pStgMedium, BOOL bDropComplete )
{
return m_pDelegate == NULL ? FALSE : m_pDelegate->OnRenderData( FormatEtc, pStgMedium, bDropComplete );
}
};
template < class T >
class CDragDrop
{
public:
CDragDrop()
{
m_pDropSource = NULL;
m_pDataObject = NULL;
m_pDropTarget = NULL;
m_hTargetWnd = NULL;
}
virtual ~CDragDrop()
{
if ( m_pDropSource != NULL )
m_pDropSource->Release();
if ( m_pDataObject != NULL )
m_pDataObject->Release();
}
protected:
CDropSource *m_pDropSource;
CDataObjectT< T > *m_pDataObject;
CDropTargetT< T > *m_pDropTarget;
HWND m_hTargetWnd;
public:
BOOL Register( T *pDelegate, BOOL bDropSource = TRUE )
{
m_hTargetWnd = pDelegate->m_hWnd;
// instantiate new drop target object
m_pDropTarget = new CDropTargetT< T >( m_hTargetWnd );
m_pDropTarget->Register( pDelegate );
// register drop target
if ( FAILED( RegisterDragDrop( m_hTargetWnd, m_pDropTarget ) ) )
{
delete m_pDropTarget;
m_pDropTarget = NULL;
return FALSE;
}
// is this a drop target only?
if ( !bDropSource )
return TRUE;
// instantiate new drop source object
m_pDropSource = new CDropSource;
m_pDropSource->AddRef();
m_pDataObject = new CDataObjectT< T >( m_pDropSource );
m_pDataObject->AddRef();
// register drop source delegate for data render
return m_pDataObject->Register( pDelegate );
}
BOOL Revoke()
{
m_pDropTarget = NULL;
return ( RevokeDragDrop( m_hTargetWnd ) == S_OK );
}
BOOL AddTargetFormat( CLIPFORMAT cfFormat )
{
if ( m_pDropTarget == NULL )
return FALSE;
m_pDropTarget->AddSupportedFormat( cfFormat );
return TRUE;
}
BOOL AddSourceFormat( CLIPFORMAT cfFormat )
{
if ( m_pDataObject == NULL )
return FALSE;
FORMATETC FormatEtc;
ZeroMemory( &FormatEtc, sizeof( FORMATETC ) );
FormatEtc.cfFormat = cfFormat;
FormatEtc.dwAspect = DVASPECT_CONTENT;
FormatEtc.lindex = -1;
FormatEtc.tymed = TYMED_HGLOBAL;
STGMEDIUM StgMedium;
ZeroMemory( &StgMedium, sizeof( STGMEDIUM ) );
return SUCCEEDED( m_pDataObject->SetData( &FormatEtc, &StgMedium, TRUE ) );
}
BOOL SetClipboard( FORMATETC& FormatEtc, STGMEDIUM& StgMedium )
{
if ( m_pDataObject == NULL )
return DROPEFFECT_NONE;
if ( FAILED( m_pDataObject->SetData( &FormatEtc, &StgMedium, TRUE ) ) )
return DROPEFFECT_NONE;
return ( OleSetClipboard( m_pDataObject ) == S_OK );
}
BOOL FlushClipboard()
{
return ( OleFlushClipboard() == S_OK );
}
DWORD DoDragDrop( SHDRAGIMAGE *pDragImage = NULL, DWORD dwValidEffects = DROPEFFECT_COPY | DROPEFFECT_MOVE | DROPEFFECT_LINK )
{
if ( m_pDataObject == NULL )
return DROPEFFECT_NONE;
IDragSourceHelper *pDragSourceHelper = NULL;
// instantiate drag source helper object
if ( pDragImage != NULL )
{
if ( FAILED( CoCreateInstance( CLSID_DragDropHelper, NULL, CLSCTX_INPROC_SERVER, IID_IDragSourceHelper, (LPVOID*)&pDragSourceHelper ) ) )
pDragSourceHelper = NULL;
if ( pDragSourceHelper != NULL )
pDragSourceHelper->InitializeFromBitmap( pDragImage, m_pDataObject );
}
DWORD dwEffects = DROPEFFECT_NONE;
dwEffects = ::DoDragDrop( m_pDataObject, m_pDropSource, dwValidEffects, &dwEffects ) == DRAGDROP_S_DROP ? DROPEFFECT_NONE : dwEffects;
// destroy drag source helper object
if ( pDragSourceHelper != NULL )
pDragSourceHelper->Release();
return dwEffects;
}
};