src/Utils/DragDropImpl.cpp

   1 /**************************************************************************\r
   2    THIS CODE AND INFORMATION IS PROVIDED 'AS IS' WITHOUT WARRANTY OF\r
   3    ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO\r
   4    THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A\r
   5    PARTICULAR PURPOSE.\r
   6    Author: Leon Finker  1/2001\r
   7 **************************************************************************/\r
   8 // IDataObjectImpl.cpp: implementation of the CIDataObjectImpl class.\r
   9 //////////////////////////////////////////////////////////////////////\r
  10 #include <shlobj.h>\r
  11 #include <atlbase.h>\r
  12 #include "DragDropImpl.h"\r
  13 \r
  14 //////////////////////////////////////////////////////////////////////\r
  15 // CIDataObject Class\r
  16 //////////////////////////////////////////////////////////////////////\r
  17 \r
  18 CIDataObject::CIDataObject(CIDropSource* pDropSource):\r
  19 m_cRefCount(0), m_pDropSource(pDropSource)\r
  20 {\r
  21 }\r
  22 \r
  23 CIDataObject::~CIDataObject()\r
  24 {\r
  25         for(int i = 0; i < m_StgMedium.GetSize(); ++i)\r
  26         {\r
  27                 ReleaseStgMedium(m_StgMedium[i]);\r
  28                 delete m_StgMedium[i];\r
  29         }\r
  30         for(int j = 0; j < m_ArrFormatEtc.GetSize(); ++j)\r
  31                 delete m_ArrFormatEtc[j];\r
  32 }\r
  33 \r
  34 STDMETHODIMP CIDataObject::QueryInterface(/* [in] */ REFIID riid,\r
  35 /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject)\r
  36 {\r
  37         *ppvObject = NULL;\r
  38         if (IID_IUnknown==riid || IID_IDataObject==riid)\r
  39              *ppvObject=this;\r
  40         /*if(riid == IID_IAsyncOperation)\r
  41                 *ppvObject=(IAsyncOperation*)this;*/\r
  42     if (NULL!=*ppvObject)\r
  43     {\r
  44         ((LPUNKNOWN)*ppvObject)->AddRef();\r
  45         return S_OK;\r
  46     }\r
  47     return E_NOINTERFACE;\r
  48 }\r
  49 \r
  50 STDMETHODIMP_(ULONG) CIDataObject::AddRef( void)\r
  51 {\r
  52         return ++m_cRefCount;\r
  53 }\r
  54 \r
  55 STDMETHODIMP_(ULONG) CIDataObject::Release( void)\r
  56 {\r
  57    long nTemp;\r
  58    nTemp = --m_cRefCount;\r
  59    if(nTemp==0)\r
  60       delete this;\r
  61    return nTemp;\r
  62 }\r
  63 \r
  64 STDMETHODIMP CIDataObject::GetData( \r
  65     /* [unique][in] */ FORMATETC __RPC_FAR *pformatetcIn,\r
  66     /* [out] */ STGMEDIUM __RPC_FAR *pmedium)\r
  67 { \r
  68         if(pformatetcIn == NULL || pmedium == NULL)\r
  69                 return E_INVALIDARG;\r
  70         pmedium->hGlobal = NULL;\r
  71 \r
  72         ATLASSERT(m_StgMedium.GetSize() == m_ArrFormatEtc.GetSize());\r
  73         for(int i=0; i < m_ArrFormatEtc.GetSize(); ++i)\r
  74         {\r
  75                 if(pformatetcIn->tymed & m_ArrFormatEtc[i]->tymed &&\r
  76                    pformatetcIn->dwAspect == m_ArrFormatEtc[i]->dwAspect &&\r
  77                    pformatetcIn->cfFormat == m_ArrFormatEtc[i]->cfFormat)\r
  78                 {\r
  79                         CopyMedium(pmedium, m_StgMedium[i], m_ArrFormatEtc[i]);\r
  80                         return S_OK;\r
  81                 }\r
  82         }\r
  83         return DV_E_FORMATETC;\r
  84 }\r
  85 \r
  86 STDMETHODIMP CIDataObject::GetDataHere( \r
  87     /* [unique][in] */ FORMATETC __RPC_FAR * /*pformatetc*/,\r
  88     /* [out][in] */ STGMEDIUM __RPC_FAR * /*pmedium*/)\r
  89 {\r
  90         return E_NOTIMPL;\r
  91 }\r
  92 \r
  93 STDMETHODIMP CIDataObject::QueryGetData( \r
  94    /* [unique][in] */ FORMATETC __RPC_FAR *pformatetc)\r
  95 { \r
  96         if(pformatetc == NULL)\r
  97                 return E_INVALIDARG;\r
  98 \r
  99         //support others if needed DVASPECT_THUMBNAIL  //DVASPECT_ICON   //DVASPECT_DOCPRINT\r
 100         if (!(DVASPECT_CONTENT & pformatetc->dwAspect))\r
 101                 return (DV_E_DVASPECT);\r
 102         HRESULT  hr = DV_E_TYMED;\r
 103         for(int i = 0; i < m_ArrFormatEtc.GetSize(); ++i)\r
 104         {\r
 105            if(pformatetc->tymed & m_ArrFormatEtc[i]->tymed)\r
 106            {\r
 107                   if(pformatetc->cfFormat == m_ArrFormatEtc[i]->cfFormat)\r
 108                          return S_OK;\r
 109                   else\r
 110                          hr = DV_E_CLIPFORMAT;\r
 111            }\r
 112            else\r
 113                   hr = DV_E_TYMED;\r
 114         }\r
 115         return hr;\r
 116 }\r
 117 \r
 118 STDMETHODIMP CIDataObject::GetCanonicalFormatEtc( \r
 119     /* [unique][in] */ FORMATETC __RPC_FAR * /*pformatectIn*/,\r
 120     /* [out] */ FORMATETC __RPC_FAR *pformatetcOut)\r
 121 { \r
 122         if (pformatetcOut == NULL)\r
 123                 return E_INVALIDARG;\r
 124         return DATA_S_SAMEFORMATETC;\r
 125 }\r
 126 \r
 127 STDMETHODIMP CIDataObject::SetData( \r
 128     /* [unique][in] */ FORMATETC __RPC_FAR *pformatetc,\r
 129     /* [unique][in] */ STGMEDIUM __RPC_FAR *pmedium,\r
 130     /* [in] */ BOOL fRelease)\r
 131 { \r
 132         if(pformatetc == NULL || pmedium == NULL)\r
 133       return E_INVALIDARG;\r
 134 \r
 135         ATLASSERT(pformatetc->tymed == pmedium->tymed);\r
 136         FORMATETC* fetc=new FORMATETC;\r
 137         STGMEDIUM* pStgMed = new STGMEDIUM;\r
 138 \r
 139         if(fetc == NULL || pStgMed == NULL)\r
 140                 return E_OUTOFMEMORY;\r
 141 \r
 142         SecureZeroMemory(fetc,sizeof(FORMATETC));\r
 143         SecureZeroMemory(pStgMed,sizeof(STGMEDIUM));\r
 144 \r
 145         *fetc = *pformatetc;\r
 146         m_ArrFormatEtc.Add(fetc);\r
 147 \r
 148     if(fRelease)\r
 149       *pStgMed = *pmedium;\r
 150     else\r
 151     {\r
 152                 CopyMedium(pStgMed, pmedium, pformatetc);\r
 153         }\r
 154         m_StgMedium.Add(pStgMed);\r
 155 \r
 156     return S_OK;\r
 157 }\r
 158 void CIDataObject::CopyMedium(STGMEDIUM* pMedDest, STGMEDIUM* pMedSrc, FORMATETC* pFmtSrc)\r
 159 {\r
 160                 switch(pMedSrc->tymed)\r
 161                 {\r
 162                 case TYMED_HGLOBAL:\r
 163                         pMedDest->hGlobal = (HGLOBAL)OleDuplicateData(pMedSrc->hGlobal,pFmtSrc->cfFormat, NULL);\r
 164                         break;\r
 165                 case TYMED_GDI:\r
 166                         pMedDest->hBitmap = (HBITMAP)OleDuplicateData(pMedSrc->hBitmap,pFmtSrc->cfFormat, NULL);\r
 167                         break;\r
 168                 case TYMED_MFPICT:\r
 169                         pMedDest->hMetaFilePict = (HMETAFILEPICT)OleDuplicateData(pMedSrc->hMetaFilePict,pFmtSrc->cfFormat, NULL);\r
 170                         break;\r
 171                 case TYMED_ENHMF:\r
 172                         pMedDest->hEnhMetaFile = (HENHMETAFILE)OleDuplicateData(pMedSrc->hEnhMetaFile,pFmtSrc->cfFormat, NULL);\r
 173                         break;\r
 174                 case TYMED_FILE:\r
 175                         pMedSrc->lpszFileName = (LPOLESTR)OleDuplicateData(pMedSrc->lpszFileName,pFmtSrc->cfFormat, NULL);\r
 176                         break;\r
 177                 case TYMED_ISTREAM:\r
 178                         pMedDest->pstm = pMedSrc->pstm;\r
 179                         pMedSrc->pstm->AddRef();\r
 180                         break;\r
 181                 case TYMED_ISTORAGE:\r
 182                         pMedDest->pstg = pMedSrc->pstg;\r
 183                         pMedSrc->pstg->AddRef();\r
 184                         break;\r
 185                 case TYMED_NULL:\r
 186                 default:\r
 187                         break;\r
 188                 }\r
 189                 pMedDest->tymed = pMedSrc->tymed;\r
 190                 pMedDest->pUnkForRelease = NULL;\r
 191                 if(pMedSrc->pUnkForRelease != NULL)\r
 192                 {\r
 193                         pMedDest->pUnkForRelease = pMedSrc->pUnkForRelease;\r
 194                         pMedSrc->pUnkForRelease->AddRef();\r
 195                 }\r
 196 }\r
 197 STDMETHODIMP CIDataObject::EnumFormatEtc(\r
 198    /* [in] */ DWORD dwDirection,\r
 199    /* [out] */ IEnumFORMATETC __RPC_FAR *__RPC_FAR *ppenumFormatEtc)\r
 200 { \r
 201         if(ppenumFormatEtc == NULL)\r
 202       return E_POINTER;\r
 203 \r
 204         *ppenumFormatEtc=NULL;\r
 205         switch (dwDirection)\r
 206     {\r
 207       case DATADIR_GET:\r
 208          *ppenumFormatEtc= new CEnumFormatEtc(m_ArrFormatEtc);\r
 209                  if(*ppenumFormatEtc == NULL)\r
 210                          return E_OUTOFMEMORY;\r
 211          (*ppenumFormatEtc)->AddRef(); \r
 212          break;\r
 213       \r
 214           case DATADIR_SET:\r
 215       default:\r
 216                  return E_NOTIMPL;\r
 217          break;\r
 218     }\r
 219 \r
 220    return S_OK;\r
 221 }\r
 222 \r
 223 STDMETHODIMP CIDataObject::DAdvise( \r
 224    /* [in] */ FORMATETC __RPC_FAR * /*pformatetc*/,\r
 225    /* [in] */ DWORD /*advf*/,\r
 226    /* [unique][in] */ IAdviseSink __RPC_FAR * /*pAdvSink*/,\r
 227    /* [out] */ DWORD __RPC_FAR * /*pdwConnection*/)\r
 228 { \r
 229         return OLE_E_ADVISENOTSUPPORTED;\r
 230 }\r
 231 \r
 232 STDMETHODIMP CIDataObject::DUnadvise( \r
 233    /* [in] */ DWORD /*dwConnection*/)\r
 234 {\r
 235         return E_NOTIMPL;\r
 236 }\r
 237 \r
 238 HRESULT STDMETHODCALLTYPE CIDataObject::EnumDAdvise( \r
 239    /* [out] */ IEnumSTATDATA __RPC_FAR *__RPC_FAR * /*ppenumAdvise*/)\r
 240 {\r
 241         return OLE_E_ADVISENOTSUPPORTED;\r
 242 }\r
 243 \r
 244 //////////////////////////////////////////////////////////////////////\r
 245 // CIDropSource Class\r
 246 //////////////////////////////////////////////////////////////////////\r
 247 \r
 248 STDMETHODIMP CIDropSource::QueryInterface(/* [in] */ REFIID riid,\r
 249                                                                                  /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject)\r
 250 {\r
 251    *ppvObject = NULL;\r
 252    if (IID_IUnknown==riid || IID_IDropSource==riid)\r
 253        *ppvObject=this;\r
 254 \r
 255     if (*ppvObject != NULL)\r
 256     {\r
 257        ((LPUNKNOWN)*ppvObject)->AddRef();\r
 258         return S_OK;\r
 259     }\r
 260     return E_NOINTERFACE;\r
 261 }\r
 262 \r
 263 STDMETHODIMP_(ULONG) CIDropSource::AddRef( void)\r
 264 {\r
 265         return ++m_cRefCount;\r
 266 }\r
 267 \r
 268 STDMETHODIMP_(ULONG) CIDropSource::Release( void)\r
 269 {\r
 270    long nTemp;\r
 271    nTemp = --m_cRefCount;\r
 272    ATLASSERT(nTemp >= 0);\r
 273    if(nTemp==0)\r
 274       delete this;\r
 275    return nTemp;\r
 276 }\r
 277 \r
 278 STDMETHODIMP CIDropSource::QueryContinueDrag( \r
 279     /* [in] */ BOOL fEscapePressed,\r
 280     /* [in] */ DWORD grfKeyState)\r
 281 {\r
 282    if(fEscapePressed)\r
 283       return DRAGDROP_S_CANCEL;\r
 284    if(!(grfKeyState & (MK_LBUTTON|MK_RBUTTON)))\r
 285    {\r
 286           m_bDropped = true;\r
 287       return DRAGDROP_S_DROP;\r
 288    }\r
 289 \r
 290    return S_OK;\r
 291 \r
 292 }\r
 293 \r
 294 STDMETHODIMP CIDropSource::GiveFeedback(\r
 295     /* [in] */ DWORD /*dwEffect*/)\r
 296 {\r
 297         return DRAGDROP_S_USEDEFAULTCURSORS;\r
 298 }\r
 299 \r
 300 //////////////////////////////////////////////////////////////////////\r
 301 // CEnumFormatEtc Class\r
 302 //////////////////////////////////////////////////////////////////////\r
 303 \r
 304 CEnumFormatEtc::CEnumFormatEtc(const CSimpleArray<FORMATETC>& ArrFE):\r
 305 m_cRefCount(0),m_iCur(0)\r
 306 {\r
 307    ATLTRACE("CEnumFormatEtc::CEnumFormatEtc()\n");\r
 308    for(int i = 0; i < ArrFE.GetSize(); ++i)\r
 309                 m_pFmtEtc.Add(ArrFE[i]);\r
 310 }\r
 311 \r
 312 CEnumFormatEtc::CEnumFormatEtc(const CSimpleArray<FORMATETC*>& ArrFE):\r
 313 m_cRefCount(0),m_iCur(0)\r
 314 {\r
 315    for(int i = 0; i < ArrFE.GetSize(); ++i)\r
 316                 m_pFmtEtc.Add(*ArrFE[i]);\r
 317 }\r
 318 \r
 319 STDMETHODIMP  CEnumFormatEtc::QueryInterface(REFIID refiid, void FAR* FAR* ppv)\r
 320 {\r
 321    *ppv = NULL;\r
 322    if (IID_IUnknown==refiid || IID_IEnumFORMATETC==refiid)\r
 323              *ppv=this;\r
 324 \r
 325     if (*ppv != NULL)\r
 326     {\r
 327         ((LPUNKNOWN)*ppv)->AddRef();\r
 328         return S_OK;\r
 329     }\r
 330     return E_NOINTERFACE;\r
 331 }\r
 332 \r
 333 STDMETHODIMP_(ULONG) CEnumFormatEtc::AddRef(void)\r
 334 {\r
 335    return ++m_cRefCount;\r
 336 }\r
 337 \r
 338 STDMETHODIMP_(ULONG) CEnumFormatEtc::Release(void)\r
 339 {\r
 340    long nTemp = --m_cRefCount;\r
 341    ATLASSERT(nTemp >= 0);\r
 342    if(nTemp == 0)\r
 343      delete this;\r
 344 \r
 345    return nTemp; \r
 346 }\r
 347 \r
 348 STDMETHODIMP CEnumFormatEtc::Next( ULONG celt,LPFORMATETC lpFormatEtc, ULONG FAR *pceltFetched)\r
 349 {\r
 350    if(pceltFetched != NULL)\r
 351            *pceltFetched=0;\r
 352         \r
 353    ULONG cReturn = celt;\r
 354 \r
 355    if(celt <= 0 || lpFormatEtc == NULL || m_iCur >= m_pFmtEtc.GetSize())\r
 356       return S_FALSE;\r
 357 \r
 358    if(pceltFetched == NULL && celt != 1) // pceltFetched can be NULL only for 1 item request\r
 359       return S_FALSE;\r
 360 \r
 361         while (m_iCur < m_pFmtEtc.GetSize() && cReturn > 0)\r
 362         {\r
 363                 *lpFormatEtc++ = m_pFmtEtc[m_iCur++];\r
 364                 --cReturn;\r
 365         }\r
 366         if (pceltFetched != NULL)\r
 367                 *pceltFetched = celt - cReturn;\r
 368 \r
 369     return (cReturn == 0) ? S_OK : S_FALSE;\r
 370 }\r
 371    \r
 372 STDMETHODIMP CEnumFormatEtc::Skip(ULONG celt)\r
 373 {\r
 374         if((m_iCur + int(celt)) >= m_pFmtEtc.GetSize())\r
 375                 return S_FALSE;\r
 376         m_iCur += celt;\r
 377         return S_OK;\r
 378 }\r
 379 \r
 380 STDMETHODIMP CEnumFormatEtc::Reset(void)\r
 381 {\r
 382    m_iCur = 0;\r
 383    return S_OK;\r
 384 }\r
 385                \r
 386 STDMETHODIMP CEnumFormatEtc::Clone(IEnumFORMATETC FAR * FAR*ppCloneEnumFormatEtc)\r
 387 {\r
 388   if(ppCloneEnumFormatEtc == NULL)\r
 389       return E_POINTER;\r
 390       \r
 391   CEnumFormatEtc *newEnum = new CEnumFormatEtc(m_pFmtEtc);\r
 392   if(newEnum ==NULL)\r
 393                 return E_OUTOFMEMORY;   \r
 394   newEnum->AddRef();\r
 395   newEnum->m_iCur = m_iCur;\r
 396   *ppCloneEnumFormatEtc = newEnum;\r
 397   return S_OK;\r
 398 }\r
 399 \r
 400 //////////////////////////////////////////////////////////////////////\r
 401 // CIDropTarget Class\r
 402 //////////////////////////////////////////////////////////////////////\r
 403 CIDropTarget::CIDropTarget(HWND hTargetWnd): \r
 404         m_hTargetWnd(hTargetWnd),\r
 405         m_cRefCount(0), m_bAllowDrop(false),\r
 406         m_pDropTargetHelper(NULL), m_pSupportedFrmt(NULL)\r
 407 {\r
 408         if(FAILED(CoCreateInstance(CLSID_DragDropHelper,NULL,CLSCTX_INPROC_SERVER,\r
 409                      IID_IDropTargetHelper,(LPVOID*)&m_pDropTargetHelper)))\r
 410                 m_pDropTargetHelper = NULL;\r
 411 }\r
 412 \r
 413 CIDropTarget::~CIDropTarget()\r
 414 {\r
 415         if(m_pDropTargetHelper != NULL)\r
 416         {\r
 417                 m_pDropTargetHelper->Release();\r
 418                 m_pDropTargetHelper = NULL;\r
 419         }\r
 420 }\r
 421 \r
 422 HRESULT STDMETHODCALLTYPE CIDropTarget::QueryInterface( /* [in] */ REFIID riid,\r
 423                                                 /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject)\r
 424 {\r
 425    *ppvObject = NULL;\r
 426    if (IID_IUnknown==riid || IID_IDropTarget==riid)\r
 427                          *ppvObject=this;\r
 428 \r
 429         if (*ppvObject != NULL)\r
 430         {\r
 431                 ((LPUNKNOWN)*ppvObject)->AddRef();\r
 432                 return S_OK;\r
 433         }\r
 434         return E_NOINTERFACE;\r
 435 }\r
 436 \r
 437 ULONG STDMETHODCALLTYPE CIDropTarget::Release( void)\r
 438 {\r
 439    long nTemp;\r
 440    nTemp = --m_cRefCount;\r
 441    ATLASSERT(nTemp >= 0);\r
 442    if(nTemp==0)\r
 443           delete this;\r
 444    return nTemp;\r
 445 }\r
 446 \r
 447 bool CIDropTarget::QueryDrop(DWORD grfKeyState, LPDWORD pdwEffect)\r
 448 {  \r
 449         DWORD dwOKEffects = *pdwEffect; \r
 450 \r
 451         if(!m_bAllowDrop)\r
 452         {\r
 453            *pdwEffect = DROPEFFECT_NONE;\r
 454            return false;\r
 455         }\r
 456         //CTRL+SHIFT  -- DROPEFFECT_LINK\r
 457         //CTRL        -- DROPEFFECT_COPY\r
 458         //SHIFT       -- DROPEFFECT_MOVE\r
 459         //no modifier -- DROPEFFECT_MOVE or whatever is allowed by src\r
 460         *pdwEffect = (grfKeyState & MK_CONTROL) ?\r
 461                                  ( (grfKeyState & MK_SHIFT) ? DROPEFFECT_LINK : DROPEFFECT_COPY ):\r
 462                                  ( (grfKeyState & MK_SHIFT) ? DROPEFFECT_MOVE : 0 );\r
 463         if(*pdwEffect == 0) \r
 464         {\r
 465            // No modifier keys used by user while dragging. \r
 466            if (DROPEFFECT_MOVE & dwOKEffects)\r
 467                   *pdwEffect = DROPEFFECT_MOVE;\r
 468            else if (DROPEFFECT_COPY & dwOKEffects)\r
 469                   *pdwEffect = DROPEFFECT_COPY; \r
 470            else if (DROPEFFECT_LINK & dwOKEffects)\r
 471                   *pdwEffect = DROPEFFECT_LINK; \r
 472            else \r
 473            {\r
 474                   *pdwEffect = DROPEFFECT_NONE;\r
 475            }\r
 476         } \r
 477         else\r
 478         {\r
 479            // Check if the drag source application allows the drop effect desired by user.\r
 480            // The drag source specifies this in DoDragDrop\r
 481            if(!(*pdwEffect & dwOKEffects))\r
 482                   *pdwEffect = DROPEFFECT_NONE;\r
 483         }  \r
 484 \r
 485         return (DROPEFFECT_NONE == *pdwEffect)?false:true;\r
 486 }   \r
 487 \r
 488 HRESULT STDMETHODCALLTYPE CIDropTarget::DragEnter(\r
 489     /* [unique][in] */ IDataObject __RPC_FAR *pDataObj,\r
 490     /* [in] */ DWORD grfKeyState,\r
 491     /* [in] */ POINTL pt,\r
 492     /* [out][in] */ DWORD __RPC_FAR *pdwEffect)\r
 493 {\r
 494         if(pDataObj == NULL)\r
 495                 return E_INVALIDARG;\r
 496 \r
 497         if(m_pDropTargetHelper)\r
 498                 m_pDropTargetHelper->DragEnter(m_hTargetWnd, pDataObj, (LPPOINT)&pt, *pdwEffect);\r
 499         //IEnumFORMATETC* pEnum;\r
 500         //pDataObj->EnumFormatEtc(DATADIR_GET,&pEnum);\r
 501         //FORMATETC ftm;\r
 502         //for()\r
 503         //pEnum->Next(1,&ftm,0);\r
 504         //pEnum->Release();\r
 505         m_pSupportedFrmt = NULL;\r
 506         for(int i =0; i<m_formatetc.GetSize(); ++i)\r
 507         {\r
 508                 m_bAllowDrop = (pDataObj->QueryGetData(&m_formatetc[i]) == S_OK)?true:false;\r
 509                 if(m_bAllowDrop)\r
 510                 {\r
 511                         m_pSupportedFrmt = &m_formatetc[i];\r
 512                         break;\r
 513                 }\r
 514         }\r
 515 \r
 516         QueryDrop(grfKeyState, pdwEffect);\r
 517         return S_OK;\r
 518 }\r
 519 \r
 520 HRESULT STDMETHODCALLTYPE CIDropTarget::DragOver( \r
 521         /* [in] */ DWORD grfKeyState,\r
 522         /* [in] */ POINTL pt,\r
 523         /* [out][in] */ DWORD __RPC_FAR *pdwEffect)\r
 524 {\r
 525         if(m_pDropTargetHelper)\r
 526                 m_pDropTargetHelper->DragOver((LPPOINT)&pt, *pdwEffect);\r
 527         QueryDrop(grfKeyState, pdwEffect);\r
 528         return S_OK;\r
 529 }\r
 530 \r
 531 HRESULT STDMETHODCALLTYPE CIDropTarget::DragLeave( void)\r
 532 {\r
 533         if(m_pDropTargetHelper)\r
 534                 m_pDropTargetHelper->DragLeave();\r
 535         \r
 536         m_bAllowDrop = false;\r
 537         m_pSupportedFrmt = NULL;\r
 538         return S_OK;\r
 539 }\r
 540 \r
 541 HRESULT STDMETHODCALLTYPE CIDropTarget::Drop(\r
 542         /* [unique][in] */ IDataObject __RPC_FAR *pDataObj,\r
 543     /* [in] */ DWORD grfKeyState, /* [in] */ POINTL pt, \r
 544         /* [out][in] */ DWORD __RPC_FAR *pdwEffect)\r
 545 {\r
 546         if (pDataObj == NULL)\r
 547                 return E_INVALIDARG;    \r
 548 \r
 549         if(m_pDropTargetHelper)\r
 550                 m_pDropTargetHelper->Drop(pDataObj, (LPPOINT)&pt, *pdwEffect);\r
 551 \r
 552         if(QueryDrop(grfKeyState, pdwEffect))\r
 553         {\r
 554                 if(m_bAllowDrop && m_pSupportedFrmt != NULL)\r
 555                 {\r
 556                         STGMEDIUM medium;\r
 557                         if(pDataObj->GetData(m_pSupportedFrmt, &medium) == S_OK)\r
 558                         {\r
 559                                 if(OnDrop(m_pSupportedFrmt, medium, pdwEffect, pt)) //does derive class wants us to free medium?\r
 560                                         ReleaseStgMedium(&medium);\r
 561                         }\r
 562                 }\r
 563         }\r
 564         m_bAllowDrop=false;\r
 565         *pdwEffect = DROPEFFECT_NONE;\r
 566         m_pSupportedFrmt = NULL;\r
 567         return S_OK;\r
 568 }\r
 569 \r
 570 //////////////////////////////////////////////////////////////////////\r
 571 // CIDragSourceHelper Class\r
 572 //////////////////////////////////////////////////////////////////////\r