src/msw/ole/droptgt.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/msw/ole/droptgt.cpp
   3 // Purpose:     wxDropTarget implementation
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // Declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #if defined(__BORLANDC__)
  24     #pragma hdrstop
  25 #endif
  26
  27 #if wxUSE_OLE && wxUSE_DRAG_AND_DROP
  28
  29 #ifndef WX_PRECOMP
  30     #include "wx/msw/wrapwin.h"
  31     #include "wx/log.h"
  32 #endif
  33
  34 #include "wx/msw/private.h"
  35
  36 #ifdef __WXWINCE__
  37     #include <winreg.h>
  38     #include <ole2.h>
  39 #endif
  40
  41 #ifdef __WIN32__
  42     #if !defined(__GNUWIN32__) || wxUSE_NORLANDER_HEADERS
  43         #include <shlobj.h>            // for DROPFILES structure
  44     #endif
  45 #else
  46     #include <shellapi.h>
  47 #endif
  48
  49 #include "wx/dnd.h"
  50
  51 #include "wx/msw/ole/oleutils.h"
  52
  53 #include <initguid.h>
  54
  55 // Some (very) old SDKs don't define IDropTargetHelper, so define our own
  56 // version of it here.
  57 struct wxIDropTargetHelper : public IUnknown
  58 {
  59     virtual HRESULT STDMETHODCALLTYPE DragEnter(HWND hwndTarget,
  60                                                 IDataObject *pDataObject,
  61                                                 POINT *ppt,
  62                                                 DWORD dwEffect) = 0;
  63     virtual HRESULT STDMETHODCALLTYPE DragLeave() = 0;
  64     virtual HRESULT STDMETHODCALLTYPE DragOver(POINT *ppt, DWORD dwEffect) = 0;
  65     virtual HRESULT STDMETHODCALLTYPE Drop(IDataObject *pDataObject,
  66                                            POINT *ppt,
  67                                            DWORD dwEffect) = 0;
  68     virtual HRESULT STDMETHODCALLTYPE Show(BOOL fShow) = 0;
  69 };
  70
  71 namespace
  72 {
  73     DEFINE_GUID(wxIID_IDropTargetHelper,
  74                 0x4657278B,0x411B,0x11D2,0x83,0x9A,0x00,0xC0,0x4F,0xD9,0x18,0xD0);
  75 }
  76
  77 // ----------------------------------------------------------------------------
  78 // IDropTarget interface: forward all interesting things to wxDropTarget
  79 // (the name is unfortunate, but wx_I_DropTarget is not at all the same thing
  80 //  as wxDropTarget which is 'public' class, while this one is private)
  81 // ----------------------------------------------------------------------------
  82
  83 class wxIDropTarget : public IDropTarget
  84 {
  85 public:
  86     wxIDropTarget(wxDropTarget *p);
  87     virtual ~wxIDropTarget();
  88
  89     // accessors for wxDropTarget
  90     HWND GetHWND() const { return m_hwnd; }
  91     void SetHwnd(HWND hwnd) { m_hwnd = hwnd; }
  92
  93     // IDropTarget methods
  94     STDMETHODIMP DragEnter(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
  95     STDMETHODIMP DragOver(DWORD, POINTL, LPDWORD);
  96     STDMETHODIMP DragLeave();
  97     STDMETHODIMP Drop(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
  98
  99     DECLARE_IUNKNOWN_METHODS;
 100
 101 protected:
 102     IDataObject  *m_pIDataObject; // !NULL between DragEnter and DragLeave/Drop
 103     wxDropTarget *m_pTarget;      // the real target (we're just a proxy)
 104
 105     HWND          m_hwnd;         // window we're associated with
 106
 107     // get default drop effect for given keyboard flags
 108     static DWORD GetDropEffect(DWORD flags, wxDragResult defaultAction, DWORD pdwEffect);
 109
 110     wxDECLARE_NO_COPY_CLASS(wxIDropTarget);
 111 };
 112
 113 // ----------------------------------------------------------------------------
 114 // private functions
 115 // ----------------------------------------------------------------------------
 116
 117 static wxDragResult ConvertDragEffectToResult(DWORD dwEffect);
 118 static DWORD ConvertDragResultToEffect(wxDragResult result);
 119
 120 // ============================================================================
 121 // wxIDropTarget implementation
 122 // ============================================================================
 123
 124 // Name    : static wxIDropTarget::GetDropEffect
 125 // Purpose : determine the drop operation from keyboard/mouse state.
 126 // Returns : DWORD combined from DROPEFFECT_xxx constants
 127 // Params  : [in] DWORD flags                 kbd & mouse flags as passed to
 128 //                                            IDropTarget methods
 129 //           [in] wxDragResult defaultAction  the default action of the drop target
 130 //           [in] DWORD pdwEffect             the supported actions of the drop
 131 //                                            source passed to IDropTarget methods
 132 // Notes   : We do "move" normally and "copy" if <Ctrl> is pressed,
 133 //           which is the standard behaviour (currently there is no
 134 //           way to redefine it)
 135 DWORD wxIDropTarget::GetDropEffect(DWORD flags,
 136                                    wxDragResult defaultAction,
 137                                    DWORD pdwEffect)
 138 {
 139     DWORD effectiveAction;
 140     if ( defaultAction == wxDragCopy )
 141         effectiveAction = flags & MK_SHIFT ? DROPEFFECT_MOVE : DROPEFFECT_COPY;
 142     else
 143         effectiveAction = flags & MK_CONTROL ? DROPEFFECT_COPY : DROPEFFECT_MOVE;
 144
 145     if ( !(effectiveAction & pdwEffect) )
 146     {
 147         // the action is not supported by drag source, fall back to something
 148         // that it does support
 149         if ( pdwEffect & DROPEFFECT_MOVE )
 150             effectiveAction = DROPEFFECT_MOVE;
 151         else if ( pdwEffect & DROPEFFECT_COPY )
 152             effectiveAction = DROPEFFECT_COPY;
 153         else if ( pdwEffect & DROPEFFECT_LINK )
 154             effectiveAction = DROPEFFECT_LINK;
 155         else
 156             effectiveAction = DROPEFFECT_NONE;
 157     }
 158
 159     return effectiveAction;
 160 }
 161
 162 wxIDropTarget::wxIDropTarget(wxDropTarget *pTarget)
 163 {
 164   m_pTarget      = pTarget;
 165   m_pIDataObject = NULL;
 166 }
 167
 168 wxIDropTarget::~wxIDropTarget()
 169 {
 170 }
 171
 172 BEGIN_IID_TABLE(wxIDropTarget)
 173   ADD_IID(Unknown)
 174   ADD_IID(DropTarget)
 175 END_IID_TABLE;
 176
 177 IMPLEMENT_IUNKNOWN_METHODS(wxIDropTarget)
 178
 179 // Name    : wxIDropTarget::DragEnter
 180 // Purpose : Called when the mouse enters the window (dragging something)
 181 // Returns : S_OK
 182 // Params  : [in]    IDataObject *pIDataSource : source data
 183 //           [in]    DWORD        grfKeyState  : kbd & mouse state
 184 //           [in]    POINTL       pt           : mouse coordinates
 185 //           [in/out]DWORD       *pdwEffect    : effect flag
 186 //                                               In:  Supported effects
 187 //                                               Out: Resulting effect
 188 // Notes   :
 189 STDMETHODIMP wxIDropTarget::DragEnter(IDataObject *pIDataSource,
 190                                       DWORD        grfKeyState,
 191                                       POINTL       pt,
 192                                       DWORD       *pdwEffect)
 193 {
 194     wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragEnter"));
 195
 196     wxASSERT_MSG( m_pIDataObject == NULL,
 197                   wxT("drop target must have data object") );
 198
 199     // show the list of formats supported by the source data object for the
 200     // debugging purposes, this is quite useful sometimes - please don't remove
 201 #if 0
 202     IEnumFORMATETC *penumFmt;
 203     if ( SUCCEEDED(pIDataSource->EnumFormatEtc(DATADIR_GET, &penumFmt)) )
 204     {
 205         FORMATETC fmt;
 206         while ( penumFmt->Next(1, &fmt, NULL) == S_OK )
 207         {
 208             wxLogDebug(wxT("Drop source supports format %s"),
 209                        wxDataObject::GetFormatName(fmt.cfFormat));
 210         }
 211
 212         penumFmt->Release();
 213     }
 214     else
 215     {
 216         wxLogLastError(wxT("IDataObject::EnumFormatEtc"));
 217     }
 218 #endif // 0
 219
 220     // for use in OnEnter and OnDrag calls
 221     m_pTarget->MSWSetDataSource(pIDataSource);
 222
 223     // get hold of the data object
 224     m_pIDataObject = pIDataSource;
 225     m_pIDataObject->AddRef();
 226
 227     if ( !m_pTarget->MSWIsAcceptedData(pIDataSource) ) {
 228         // we don't accept this kind of data
 229         *pdwEffect = DROPEFFECT_NONE;
 230     }
 231     else
 232     {
 233         // we need client coordinates to pass to wxWin functions
 234         if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 235         {
 236             wxLogLastError(wxT("ScreenToClient"));
 237         }
 238
 239         // give some visual feedback
 240         *pdwEffect = ConvertDragResultToEffect(
 241             m_pTarget->OnEnter(pt.x, pt.y, ConvertDragEffectToResult(
 242                 GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect))
 243                         )
 244                      );
 245     }
 246
 247     // update drag image
 248     const wxDragResult res = ConvertDragEffectToResult(*pdwEffect);
 249     m_pTarget->MSWUpdateDragImageOnEnter(pt.x, pt.y, res);
 250     m_pTarget->MSWUpdateDragImageOnDragOver(pt.x, pt.y, res);
 251
 252     return S_OK;
 253 }
 254
 255
 256
 257 // Name    : wxIDropTarget::DragOver
 258 // Purpose : Indicates that the mouse was moved inside the window represented
 259 //           by this drop target.
 260 // Returns : S_OK
 261 // Params  : [in]    DWORD   grfKeyState     kbd & mouse state
 262 //           [in]    POINTL  pt              mouse coordinates
 263 //           [in/out]LPDWORD pdwEffect       current effect flag
 264 // Notes   : We're called on every WM_MOUSEMOVE, so this function should be
 265 //           very efficient.
 266 STDMETHODIMP wxIDropTarget::DragOver(DWORD   grfKeyState,
 267                                      POINTL  pt,
 268                                      LPDWORD pdwEffect)
 269 {
 270     // there are too many of them... wxLogDebug("IDropTarget::DragOver");
 271
 272     wxDragResult result;
 273     if ( m_pIDataObject ) {
 274         result = ConvertDragEffectToResult(
 275             GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect));
 276     }
 277     else {
 278         // can't accept data anyhow normally
 279         result = wxDragNone;
 280     }
 281
 282     if ( result != wxDragNone ) {
 283         // we need client coordinates to pass to wxWin functions
 284         if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 285         {
 286             wxLogLastError(wxT("ScreenToClient"));
 287         }
 288
 289         *pdwEffect = ConvertDragResultToEffect(
 290                         m_pTarget->OnDragOver(pt.x, pt.y, result)
 291                      );
 292     }
 293     else {
 294         *pdwEffect = DROPEFFECT_NONE;
 295     }
 296
 297     // update drag image
 298     m_pTarget->MSWUpdateDragImageOnDragOver(pt.x, pt.y,
 299                                             ConvertDragEffectToResult(*pdwEffect));
 300
 301     return S_OK;
 302 }
 303
 304 // Name    : wxIDropTarget::DragLeave
 305 // Purpose : Informs the drop target that the operation has left its window.
 306 // Returns : S_OK
 307 // Notes   : good place to do any clean-up
 308 STDMETHODIMP wxIDropTarget::DragLeave()
 309 {
 310   wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragLeave"));
 311
 312   // remove the UI feedback
 313   m_pTarget->OnLeave();
 314
 315   // release the held object
 316   RELEASE_AND_NULL(m_pIDataObject);
 317
 318   // update drag image
 319   m_pTarget->MSWUpdateDragImageOnLeave();
 320
 321   return S_OK;
 322 }
 323
 324 // Name    : wxIDropTarget::Drop
 325 // Purpose : Instructs the drop target to paste data that was just now
 326 //           dropped on it.
 327 // Returns : S_OK
 328 // Params  : [in]    IDataObject *pIDataSource     the data to paste
 329 //           [in]    DWORD        grfKeyState      kbd & mouse state
 330 //           [in]    POINTL       pt               where the drop occurred?
 331 //           [in/out]DWORD       *pdwEffect        operation effect
 332 // Notes   :
 333 STDMETHODIMP wxIDropTarget::Drop(IDataObject *pIDataSource,
 334                                  DWORD        grfKeyState,
 335                                  POINTL       pt,
 336                                  DWORD       *pdwEffect)
 337 {
 338     wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::Drop"));
 339
 340     // TODO I don't know why there is this parameter, but so far I assume
 341     //      that it's the same we've already got in DragEnter
 342     wxASSERT( m_pIDataObject == pIDataSource );
 343
 344     // we need client coordinates to pass to wxWin functions
 345     if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 346     {
 347         wxLogLastError(wxT("ScreenToClient"));
 348     }
 349
 350     // first ask the drop target if it wants data
 351     if ( m_pTarget->OnDrop(pt.x, pt.y) ) {
 352         // it does, so give it the data source
 353         m_pTarget->MSWSetDataSource(pIDataSource);
 354
 355         // and now it has the data
 356         wxDragResult rc = ConvertDragEffectToResult(
 357             GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect));
 358         rc = m_pTarget->OnData(pt.x, pt.y, rc);
 359         if ( wxIsDragResultOk(rc) ) {
 360             // operation succeeded
 361             *pdwEffect = ConvertDragResultToEffect(rc);
 362         }
 363         else {
 364             *pdwEffect = DROPEFFECT_NONE;
 365         }
 366     }
 367     else {
 368         // OnDrop() returned false, no need to copy data
 369         *pdwEffect = DROPEFFECT_NONE;
 370     }
 371
 372     // release the held object
 373     RELEASE_AND_NULL(m_pIDataObject);
 374
 375     // update drag image
 376     m_pTarget->MSWUpdateDragImageOnData(pt.x, pt.y,
 377                                         ConvertDragEffectToResult(*pdwEffect));
 378
 379     return S_OK;
 380 }
 381
 382 // ============================================================================
 383 // wxDropTarget implementation
 384 // ============================================================================
 385
 386 // ----------------------------------------------------------------------------
 387 // ctor/dtor
 388 // ----------------------------------------------------------------------------
 389
 390 wxDropTarget::wxDropTarget(wxDataObject *dataObj)
 391             : wxDropTargetBase(dataObj),
 392               m_dropTargetHelper(NULL)
 393 {
 394     // create an IDropTarget implementation which will notify us about d&d
 395     // operations.
 396     m_pIDropTarget = new wxIDropTarget(this);
 397     m_pIDropTarget->AddRef();
 398 }
 399
 400 wxDropTarget::~wxDropTarget()
 401 {
 402     ReleaseInterface(m_pIDropTarget);
 403 }
 404
 405 // ----------------------------------------------------------------------------
 406 // [un]register drop handler
 407 // ----------------------------------------------------------------------------
 408
 409 bool wxDropTarget::Register(WXHWND hwnd)
 410 {
 411     // FIXME
 412     // RegisterDragDrop not available on Windows CE >= 400?
 413     // Or maybe we can dynamically load them from ceshell.dll
 414     // or similar.
 415 #if defined(__WXWINCE__) && _WIN32_WCE >= 400
 416     wxUnusedVar(hwnd);
 417     return false;
 418 #else
 419     HRESULT hr;
 420
 421     // May exist in later WinCE versions
 422 #ifndef __WXWINCE__
 423     hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE);
 424     if ( FAILED(hr) ) {
 425         wxLogApiError(wxT("CoLockObjectExternal"), hr);
 426         return false;
 427     }
 428 #endif
 429
 430     hr = ::RegisterDragDrop((HWND) hwnd, m_pIDropTarget);
 431     if ( FAILED(hr) ) {
 432     // May exist in later WinCE versions
 433 #ifndef __WXWINCE__
 434         ::CoLockObjectExternal(m_pIDropTarget, FALSE, FALSE);
 435 #endif
 436         wxLogApiError(wxT("RegisterDragDrop"), hr);
 437         return false;
 438     }
 439
 440     // we will need the window handle for coords transformation later
 441     m_pIDropTarget->SetHwnd((HWND)hwnd);
 442
 443     MSWInitDragImageSupport();
 444
 445     return true;
 446 #endif
 447 }
 448
 449 void wxDropTarget::Revoke(WXHWND hwnd)
 450 {
 451 #if defined(__WXWINCE__) && _WIN32_WCE >= 400
 452     // Not available, see note above
 453     wxUnusedVar(hwnd);
 454 #else
 455     HRESULT hr = ::RevokeDragDrop((HWND) hwnd);
 456
 457     if ( FAILED(hr) ) {
 458         wxLogApiError(wxT("RevokeDragDrop"), hr);
 459     }
 460
 461     // May exist in later WinCE versions
 462 #ifndef __WXWINCE__
 463     ::CoLockObjectExternal(m_pIDropTarget, FALSE, TRUE);
 464 #endif
 465
 466     MSWEndDragImageSupport();
 467
 468     // remove window reference
 469     m_pIDropTarget->SetHwnd(0);
 470 #endif
 471 }
 472
 473 // ----------------------------------------------------------------------------
 474 // base class pure virtuals
 475 // ----------------------------------------------------------------------------
 476
 477 // OnDrop() is called only if we previously returned true from
 478 // IsAcceptedData(), so no need to check anything here
 479 bool wxDropTarget::OnDrop(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y))
 480 {
 481     return true;
 482 }
 483
 484 // copy the data from the data source to the target data object
 485 bool wxDropTarget::GetData()
 486 {
 487     wxDataFormat format = MSWGetSupportedFormat(m_pIDataSource);
 488     if ( format == wxDF_INVALID ) {
 489         return false;
 490     }
 491
 492     STGMEDIUM stm;
 493     FORMATETC fmtMemory;
 494     fmtMemory.cfFormat  = format;
 495     fmtMemory.ptd       = NULL;
 496     fmtMemory.dwAspect  = DVASPECT_CONTENT;
 497     fmtMemory.lindex    = -1;
 498     fmtMemory.tymed     = TYMED_HGLOBAL;  // TODO to add other media
 499
 500     bool rc = false;
 501
 502     HRESULT hr = m_pIDataSource->GetData(&fmtMemory, &stm);
 503     if ( SUCCEEDED(hr) ) {
 504         IDataObject *dataObject = m_dataObject->GetInterface();
 505
 506         hr = dataObject->SetData(&fmtMemory, &stm, TRUE);
 507         if ( SUCCEEDED(hr) ) {
 508             rc = true;
 509         }
 510         else {
 511             wxLogApiError(wxT("IDataObject::SetData()"), hr);
 512         }
 513     }
 514     else {
 515         wxLogApiError(wxT("IDataObject::GetData()"), hr);
 516     }
 517
 518     return rc;
 519 }
 520
 521 // ----------------------------------------------------------------------------
 522 // callbacks used by wxIDropTarget
 523 // ----------------------------------------------------------------------------
 524
 525 // we need a data source, so wxIDropTarget gives it to us using this function
 526 void wxDropTarget::MSWSetDataSource(IDataObject *pIDataSource)
 527 {
 528     m_pIDataSource = pIDataSource;
 529 }
 530
 531 // determine if we accept data of this type
 532 bool wxDropTarget::MSWIsAcceptedData(IDataObject *pIDataSource) const
 533 {
 534     return MSWGetSupportedFormat(pIDataSource) != wxDF_INVALID;
 535 }
 536
 537 // ----------------------------------------------------------------------------
 538 // helper functions
 539 // ----------------------------------------------------------------------------
 540
 541 wxDataFormat wxDropTarget::GetMatchingPair()
 542 {
 543     return MSWGetSupportedFormat( m_pIDataSource );
 544 }
 545
 546 wxDataFormat wxDropTarget::MSWGetSupportedFormat(IDataObject *pIDataSource) const
 547 {
 548     // this strucutre describes a data of any type (first field will be
 549     // changing) being passed through global memory block.
 550     static FORMATETC s_fmtMemory = {
 551         0,
 552         NULL,
 553         DVASPECT_CONTENT,
 554         -1,
 555         TYMED_HGLOBAL       // TODO is it worth supporting other tymeds here?
 556     };
 557
 558     // get the list of supported formats
 559     size_t nFormats = m_dataObject->GetFormatCount(wxDataObject::Set);
 560     wxDataFormat format;
 561     wxDataFormat *formats;
 562     formats = nFormats == 1 ? &format :  new wxDataFormat[nFormats];
 563
 564     m_dataObject->GetAllFormats(formats, wxDataObject::Set);
 565
 566     // cycle through all supported formats
 567     size_t n;
 568     for ( n = 0; n < nFormats; n++ ) {
 569         s_fmtMemory.cfFormat = formats[n];
 570
 571         // NB: don't use SUCCEEDED macro here: QueryGetData returns S_FALSE
 572         //     for file drag and drop (format == CF_HDROP)
 573         if ( pIDataSource->QueryGetData(&s_fmtMemory) == S_OK ) {
 574             format = formats[n];
 575
 576             break;
 577         }
 578     }
 579
 580     if ( formats != &format ) {
 581         // free memory if we allocated it
 582         delete [] formats;
 583     }
 584
 585     return n < nFormats ? format : wxFormatInvalid;
 586 }
 587
 588 // ----------------------------------------------------------------------------
 589 // drag image functions
 590 // ----------------------------------------------------------------------------
 591
 592 void
 593 wxDropTarget::MSWEndDragImageSupport()
 594 {
 595     // release drop target helper
 596     if ( m_dropTargetHelper != NULL )
 597     {
 598         m_dropTargetHelper->Release();
 599         m_dropTargetHelper = NULL;
 600     }
 601 }
 602
 603 void
 604 wxDropTarget::MSWInitDragImageSupport()
 605 {
 606     // Use the default drop target helper to show shell drag images
 607     CoCreateInstance(CLSID_DragDropHelper, NULL, CLSCTX_INPROC_SERVER,
 608                      wxIID_IDropTargetHelper, (LPVOID*)&m_dropTargetHelper);
 609 }
 610
 611 void
 612 wxDropTarget::MSWUpdateDragImageOnData(wxCoord x,
 613                                        wxCoord y,
 614                                        wxDragResult dragResult)
 615 {
 616     // call corresponding event on drop target helper
 617     if ( m_dropTargetHelper != NULL )
 618     {
 619         POINT pt = {x, y};
 620         DWORD dwEffect = ConvertDragResultToEffect(dragResult);
 621         m_dropTargetHelper->Drop(m_pIDataSource, &pt, dwEffect);
 622     }
 623 }
 624
 625 void
 626 wxDropTarget::MSWUpdateDragImageOnDragOver(wxCoord x,
 627                                            wxCoord y,
 628                                            wxDragResult dragResult)
 629 {
 630     // call corresponding event on drop target helper
 631     if ( m_dropTargetHelper != NULL )
 632     {
 633         POINT pt = {x, y};
 634         DWORD dwEffect = ConvertDragResultToEffect(dragResult);
 635         m_dropTargetHelper->DragOver(&pt, dwEffect);
 636     }
 637 }
 638
 639 void
 640 wxDropTarget::MSWUpdateDragImageOnEnter(wxCoord x,
 641                                         wxCoord y,
 642                                         wxDragResult dragResult)
 643 {
 644     // call corresponding event on drop target helper
 645     if ( m_dropTargetHelper != NULL )
 646     {
 647         POINT pt = {x, y};
 648         DWORD dwEffect = ConvertDragResultToEffect(dragResult);
 649         m_dropTargetHelper->DragEnter(m_pIDropTarget->GetHWND(), m_pIDataSource, &pt, dwEffect);
 650     }
 651 }
 652
 653 void
 654 wxDropTarget::MSWUpdateDragImageOnLeave()
 655 {
 656     // call corresponding event on drop target helper
 657     if ( m_dropTargetHelper != NULL )
 658     {
 659         m_dropTargetHelper->DragLeave();
 660     }
 661 }
 662
 663 // ----------------------------------------------------------------------------
 664 // private functions
 665 // ----------------------------------------------------------------------------
 666
 667 static wxDragResult ConvertDragEffectToResult(DWORD dwEffect)
 668 {
 669     switch ( dwEffect ) {
 670         case DROPEFFECT_COPY:
 671             return wxDragCopy;
 672
 673         case DROPEFFECT_LINK:
 674             return wxDragLink;
 675
 676         case DROPEFFECT_MOVE:
 677             return wxDragMove;
 678
 679         default:
 680             wxFAIL_MSG(wxT("invalid value in ConvertDragEffectToResult"));
 681             // fall through
 682
 683         case DROPEFFECT_NONE:
 684             return wxDragNone;
 685     }
 686 }
 687
 688 static DWORD ConvertDragResultToEffect(wxDragResult result)
 689 {
 690     switch ( result ) {
 691         case wxDragCopy:
 692             return DROPEFFECT_COPY;
 693
 694         case wxDragLink:
 695             return DROPEFFECT_LINK;
 696
 697         case wxDragMove:
 698             return DROPEFFECT_MOVE;
 699
 700         default:
 701             wxFAIL_MSG(wxT("invalid value in ConvertDragResultToEffect"));
 702             // fall through
 703
 704         case wxDragNone:
 705             return DROPEFFECT_NONE;
 706     }
 707 }
 708
 709 #endif // wxUSE_OLE && wxUSE_DRAG_AND_DROP