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