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