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(wxCLSID_DragDropHelper,
  74                 0x4657278A,0x411B,0x11D2,0x83,0x9A,0x00,0xC0,0x4F,0xD9,0x18,0xD0);
  75     DEFINE_GUID(wxIID_IDropTargetHelper,
  76                 0x4657278B,0x411B,0x11D2,0x83,0x9A,0x00,0xC0,0x4F,0xD9,0x18,0xD0);
  77 }
  78
  79 // ----------------------------------------------------------------------------
  80 // IDropTarget interface: forward all interesting things to wxDropTarget
  81 // (the name is unfortunate, but wx_I_DropTarget is not at all the same thing
  82 //  as wxDropTarget which is 'public' class, while this one is private)
  83 // ----------------------------------------------------------------------------
  84
  85 class wxIDropTarget : public IDropTarget
  86 {
  87 public:
  88     wxIDropTarget(wxDropTarget *p);
  89     virtual ~wxIDropTarget();
  90
  91     // accessors for wxDropTarget
  92     HWND GetHWND() const { return m_hwnd; }
  93     void SetHwnd(HWND hwnd) { m_hwnd = hwnd; }
  94
  95     // IDropTarget methods
  96     STDMETHODIMP DragEnter(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
  97     STDMETHODIMP DragOver(DWORD, POINTL, LPDWORD);
  98     STDMETHODIMP DragLeave();
  99     STDMETHODIMP Drop(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
 100
 101     DECLARE_IUNKNOWN_METHODS;
 102
 103 protected:
 104     IDataObject  *m_pIDataObject; // !NULL between DragEnter and DragLeave/Drop
 105     wxDropTarget *m_pTarget;      // the real target (we're just a proxy)
 106
 107     HWND          m_hwnd;         // window we're associated with
 108
 109     // get default drop effect for given keyboard flags
 110     static DWORD GetDropEffect(DWORD flags, wxDragResult defaultAction, DWORD pdwEffect);
 111
 112     wxDECLARE_NO_COPY_CLASS(wxIDropTarget);
 113 };
 114
 115 // ----------------------------------------------------------------------------
 116 // private functions
 117 // ----------------------------------------------------------------------------
 118
 119 static wxDragResult ConvertDragEffectToResult(DWORD dwEffect);
 120 static DWORD ConvertDragResultToEffect(wxDragResult result);
 121
 122 // ============================================================================
 123 // wxIDropTarget implementation
 124 // ============================================================================
 125
 126 // Name    : static wxIDropTarget::GetDropEffect
 127 // Purpose : determine the drop operation from keyboard/mouse state.
 128 // Returns : DWORD combined from DROPEFFECT_xxx constants
 129 // Params  : [in] DWORD flags                 kbd & mouse flags as passed to
 130 //                                            IDropTarget methods
 131 //           [in] wxDragResult defaultAction  the default action of the drop target
 132 //           [in] DWORD pdwEffect             the supported actions of the drop
 133 //                                            source passed to IDropTarget methods
 134 // Notes   : We do "move" normally and "copy" if <Ctrl> is pressed,
 135 //           which is the standard behaviour (currently there is no
 136 //           way to redefine it)
 137 DWORD wxIDropTarget::GetDropEffect(DWORD flags,
 138                                    wxDragResult defaultAction,
 139                                    DWORD pdwEffect)
 140 {
 141     DWORD effectiveAction;
 142     if ( defaultAction == wxDragCopy )
 143         effectiveAction = flags & MK_SHIFT ? DROPEFFECT_MOVE : DROPEFFECT_COPY;
 144     else
 145         effectiveAction = flags & MK_CONTROL ? DROPEFFECT_COPY : DROPEFFECT_MOVE;
 146
 147     if ( !(effectiveAction & pdwEffect) )
 148     {
 149         // the action is not supported by drag source, fall back to something
 150         // that it does support
 151         if ( pdwEffect & DROPEFFECT_MOVE )
 152             effectiveAction = DROPEFFECT_MOVE;
 153         else if ( pdwEffect & DROPEFFECT_COPY )
 154             effectiveAction = DROPEFFECT_COPY;
 155         else if ( pdwEffect & DROPEFFECT_LINK )
 156             effectiveAction = DROPEFFECT_LINK;
 157         else
 158             effectiveAction = DROPEFFECT_NONE;
 159     }
 160
 161     return effectiveAction;
 162 }
 163
 164 wxIDropTarget::wxIDropTarget(wxDropTarget *pTarget)
 165 {
 166   m_pTarget      = pTarget;
 167   m_pIDataObject = NULL;
 168 }
 169
 170 wxIDropTarget::~wxIDropTarget()
 171 {
 172 }
 173
 174 BEGIN_IID_TABLE(wxIDropTarget)
 175   ADD_IID(Unknown)
 176   ADD_IID(DropTarget)
 177 END_IID_TABLE;
 178
 179 IMPLEMENT_IUNKNOWN_METHODS(wxIDropTarget)
 180
 181 // Name    : wxIDropTarget::DragEnter
 182 // Purpose : Called when the mouse enters the window (dragging something)
 183 // Returns : S_OK
 184 // Params  : [in]    IDataObject *pIDataSource : source data
 185 //           [in]    DWORD        grfKeyState  : kbd & mouse state
 186 //           [in]    POINTL       pt           : mouse coordinates
 187 //           [in/out]DWORD       *pdwEffect    : effect flag
 188 //                                               In:  Supported effects
 189 //                                               Out: Resulting effect
 190 // Notes   :
 191 STDMETHODIMP wxIDropTarget::DragEnter(IDataObject *pIDataSource,
 192                                       DWORD        grfKeyState,
 193                                       POINTL       pt,
 194                                       DWORD       *pdwEffect)
 195 {
 196     wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragEnter"));
 197
 198     wxASSERT_MSG( m_pIDataObject == NULL,
 199                   wxT("drop target must have data object") );
 200
 201     // show the list of formats supported by the source data object for the
 202     // debugging purposes, this is quite useful sometimes - please don't remove
 203 #if 0
 204     IEnumFORMATETC *penumFmt;
 205     if ( SUCCEEDED(pIDataSource->EnumFormatEtc(DATADIR_GET, &penumFmt)) )
 206     {
 207         FORMATETC fmt;
 208         while ( penumFmt->Next(1, &fmt, NULL) == S_OK )
 209         {
 210             wxLogDebug(wxT("Drop source supports format %s"),
 211                        wxDataObject::GetFormatName(fmt.cfFormat));
 212         }
 213
 214         penumFmt->Release();
 215     }
 216     else
 217     {
 218         wxLogLastError(wxT("IDataObject::EnumFormatEtc"));
 219     }
 220 #endif // 0
 221
 222     // for use in OnEnter and OnDrag calls
 223     m_pTarget->MSWSetDataSource(pIDataSource);
 224
 225     // get hold of the data object
 226     m_pIDataObject = pIDataSource;
 227     m_pIDataObject->AddRef();
 228
 229     if ( !m_pTarget->MSWIsAcceptedData(pIDataSource) ) {
 230         // we don't accept this kind of data
 231         *pdwEffect = DROPEFFECT_NONE;
 232     }
 233     else
 234     {
 235         // we need client coordinates to pass to wxWin functions
 236         if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 237         {
 238             wxLogLastError(wxT("ScreenToClient"));
 239         }
 240
 241         // give some visual feedback
 242         *pdwEffect = ConvertDragResultToEffect(
 243             m_pTarget->OnEnter(pt.x, pt.y, ConvertDragEffectToResult(
 244                 GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect))
 245                         )
 246                      );
 247     }
 248
 249     // update drag image
 250     const wxDragResult res = ConvertDragEffectToResult(*pdwEffect);
 251     m_pTarget->MSWUpdateDragImageOnEnter(pt.x, pt.y, res);
 252     m_pTarget->MSWUpdateDragImageOnDragOver(pt.x, pt.y, res);
 253
 254     return S_OK;
 255 }
 256
 257
 258
 259 // Name    : wxIDropTarget::DragOver
 260 // Purpose : Indicates that the mouse was moved inside the window represented
 261 //           by this drop target.
 262 // Returns : S_OK
 263 // Params  : [in]    DWORD   grfKeyState     kbd & mouse state
 264 //           [in]    POINTL  pt              mouse coordinates
 265 //           [in/out]LPDWORD pdwEffect       current effect flag
 266 // Notes   : We're called on every WM_MOUSEMOVE, so this function should be
 267 //           very efficient.
 268 STDMETHODIMP wxIDropTarget::DragOver(DWORD   grfKeyState,
 269                                      POINTL  pt,
 270                                      LPDWORD pdwEffect)
 271 {
 272     // there are too many of them... wxLogDebug("IDropTarget::DragOver");
 273
 274     wxDragResult result;
 275     if ( m_pIDataObject ) {
 276         result = ConvertDragEffectToResult(
 277             GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect));
 278     }
 279     else {
 280         // can't accept data anyhow normally
 281         result = wxDragNone;
 282     }
 283
 284     if ( result != wxDragNone ) {
 285         // we need client coordinates to pass to wxWin functions
 286         if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 287         {
 288             wxLogLastError(wxT("ScreenToClient"));
 289         }
 290
 291         *pdwEffect = ConvertDragResultToEffect(
 292                         m_pTarget->OnDragOver(pt.x, pt.y, result)
 293                      );
 294     }
 295     else {
 296         *pdwEffect = DROPEFFECT_NONE;
 297     }
 298
 299     // update drag image
 300     m_pTarget->MSWUpdateDragImageOnDragOver(pt.x, pt.y,
 301                                             ConvertDragEffectToResult(*pdwEffect));
 302
 303     return S_OK;
 304 }
 305
 306 // Name    : wxIDropTarget::DragLeave
 307 // Purpose : Informs the drop target that the operation has left its window.
 308 // Returns : S_OK
 309 // Notes   : good place to do any clean-up
 310 STDMETHODIMP wxIDropTarget::DragLeave()
 311 {
 312   wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragLeave"));
 313
 314   // remove the UI feedback
 315   m_pTarget->OnLeave();
 316
 317   // release the held object
 318   RELEASE_AND_NULL(m_pIDataObject);
 319
 320   // update drag image
 321   m_pTarget->MSWUpdateDragImageOnLeave();
 322
 323   return S_OK;
 324 }
 325
 326 // Name    : wxIDropTarget::Drop
 327 // Purpose : Instructs the drop target to paste data that was just now
 328 //           dropped on it.
 329 // Returns : S_OK
 330 // Params  : [in]    IDataObject *pIDataSource     the data to paste
 331 //           [in]    DWORD        grfKeyState      kbd & mouse state
 332 //           [in]    POINTL       pt               where the drop occurred?
 333 //           [in/out]DWORD       *pdwEffect        operation effect
 334 // Notes   :
 335 STDMETHODIMP wxIDropTarget::Drop(IDataObject *pIDataSource,
 336                                  DWORD        grfKeyState,
 337                                  POINTL       pt,
 338                                  DWORD       *pdwEffect)
 339 {
 340     wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::Drop"));
 341
 342     // TODO I don't know why there is this parameter, but so far I assume
 343     //      that it's the same we've already got in DragEnter
 344     wxASSERT( m_pIDataObject == pIDataSource );
 345
 346     // we need client coordinates to pass to wxWin functions
 347     if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 348     {
 349         wxLogLastError(wxT("ScreenToClient"));
 350     }
 351
 352     // first ask the drop target if it wants data
 353     if ( m_pTarget->OnDrop(pt.x, pt.y) ) {
 354         // it does, so give it the data source
 355         m_pTarget->MSWSetDataSource(pIDataSource);
 356
 357         // and now it has the data
 358         wxDragResult rc = ConvertDragEffectToResult(
 359             GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect));
 360         rc = m_pTarget->OnData(pt.x, pt.y, rc);
 361         if ( wxIsDragResultOk(rc) ) {
 362             // operation succeeded
 363             *pdwEffect = ConvertDragResultToEffect(rc);
 364         }
 365         else {
 366             *pdwEffect = DROPEFFECT_NONE;
 367         }
 368     }
 369     else {
 370         // OnDrop() returned false, no need to copy data
 371         *pdwEffect = DROPEFFECT_NONE;
 372     }
 373
 374     // release the held object
 375     RELEASE_AND_NULL(m_pIDataObject);
 376
 377     // update drag image
 378     m_pTarget->MSWUpdateDragImageOnData(pt.x, pt.y,
 379                                         ConvertDragEffectToResult(*pdwEffect));
 380
 381     return S_OK;
 382 }
 383
 384 // ============================================================================
 385 // wxDropTarget implementation
 386 // ============================================================================
 387
 388 // ----------------------------------------------------------------------------
 389 // ctor/dtor
 390 // ----------------------------------------------------------------------------
 391
 392 wxDropTarget::wxDropTarget(wxDataObject *dataObj)
 393             : wxDropTargetBase(dataObj),
 394               m_dropTargetHelper(NULL)
 395 {
 396     // create an IDropTarget implementation which will notify us about d&d
 397     // operations.
 398     m_pIDropTarget = new wxIDropTarget(this);
 399     m_pIDropTarget->AddRef();
 400 }
 401
 402 wxDropTarget::~wxDropTarget()
 403 {
 404     ReleaseInterface(m_pIDropTarget);
 405 }
 406
 407 // ----------------------------------------------------------------------------
 408 // [un]register drop handler
 409 // ----------------------------------------------------------------------------
 410
 411 bool wxDropTarget::Register(WXHWND hwnd)
 412 {
 413     // FIXME
 414     // RegisterDragDrop not available on Windows CE >= 400?
 415     // Or maybe we can dynamically load them from ceshell.dll
 416     // or similar.
 417 #if defined(__WXWINCE__) && _WIN32_WCE >= 400
 418     wxUnusedVar(hwnd);
 419     return false;
 420 #else
 421     HRESULT hr;
 422
 423     // May exist in later WinCE versions
 424 #ifndef __WXWINCE__
 425     hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE);
 426     if ( FAILED(hr) ) {
 427         wxLogApiError(wxT("CoLockObjectExternal"), hr);
 428         return false;
 429     }
 430 #endif
 431
 432     hr = ::RegisterDragDrop((HWND) hwnd, m_pIDropTarget);
 433     if ( FAILED(hr) ) {
 434     // May exist in later WinCE versions
 435 #ifndef __WXWINCE__
 436         ::CoLockObjectExternal(m_pIDropTarget, FALSE, FALSE);
 437 #endif
 438         wxLogApiError(wxT("RegisterDragDrop"), hr);
 439         return false;
 440     }
 441
 442     // we will need the window handle for coords transformation later
 443     m_pIDropTarget->SetHwnd((HWND)hwnd);
 444
 445     MSWInitDragImageSupport();
 446
 447     return true;
 448 #endif
 449 }
 450
 451 void wxDropTarget::Revoke(WXHWND hwnd)
 452 {
 453 #if defined(__WXWINCE__) && _WIN32_WCE >= 400
 454     // Not available, see note above
 455     wxUnusedVar(hwnd);
 456 #else
 457     HRESULT hr = ::RevokeDragDrop((HWND) hwnd);
 458
 459     if ( FAILED(hr) ) {
 460         wxLogApiError(wxT("RevokeDragDrop"), hr);
 461     }
 462
 463     // May exist in later WinCE versions
 464 #ifndef __WXWINCE__
 465     ::CoLockObjectExternal(m_pIDropTarget, FALSE, TRUE);
 466 #endif
 467
 468     MSWEndDragImageSupport();
 469
 470     // remove window reference
 471     m_pIDropTarget->SetHwnd(0);
 472 #endif
 473 }
 474
 475 // ----------------------------------------------------------------------------
 476 // base class pure virtuals
 477 // ----------------------------------------------------------------------------
 478
 479 // OnDrop() is called only if we previously returned true from
 480 // IsAcceptedData(), so no need to check anything here
 481 bool wxDropTarget::OnDrop(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y))
 482 {
 483     return true;
 484 }
 485
 486 // copy the data from the data source to the target data object
 487 bool wxDropTarget::GetData()
 488 {
 489     wxDataFormat format = MSWGetSupportedFormat(m_pIDataSource);
 490     if ( format == wxDF_INVALID ) {
 491         return false;
 492     }
 493
 494     STGMEDIUM stm;
 495     FORMATETC fmtMemory;
 496     fmtMemory.cfFormat  = format;
 497     fmtMemory.ptd       = NULL;
 498     fmtMemory.dwAspect  = DVASPECT_CONTENT;
 499     fmtMemory.lindex    = -1;
 500     fmtMemory.tymed     = TYMED_HGLOBAL;  // TODO to add other media
 501
 502     bool rc = false;
 503
 504     HRESULT hr = m_pIDataSource->GetData(&fmtMemory, &stm);
 505     if ( SUCCEEDED(hr) ) {
 506         IDataObject *dataObject = m_dataObject->GetInterface();
 507
 508         hr = dataObject->SetData(&fmtMemory, &stm, TRUE);
 509         if ( SUCCEEDED(hr) ) {
 510             rc = true;
 511         }
 512         else {
 513             wxLogApiError(wxT("IDataObject::SetData()"), hr);
 514         }
 515     }
 516     else {
 517         wxLogApiError(wxT("IDataObject::GetData()"), hr);
 518     }
 519
 520     return rc;
 521 }
 522
 523 // ----------------------------------------------------------------------------
 524 // callbacks used by wxIDropTarget
 525 // ----------------------------------------------------------------------------
 526
 527 // we need a data source, so wxIDropTarget gives it to us using this function
 528 void wxDropTarget::MSWSetDataSource(IDataObject *pIDataSource)
 529 {
 530     m_pIDataSource = pIDataSource;
 531 }
 532
 533 // determine if we accept data of this type
 534 bool wxDropTarget::MSWIsAcceptedData(IDataObject *pIDataSource) const
 535 {
 536     return MSWGetSupportedFormat(pIDataSource) != wxDF_INVALID;
 537 }
 538
 539 // ----------------------------------------------------------------------------
 540 // helper functions
 541 // ----------------------------------------------------------------------------
 542
 543 wxDataFormat wxDropTarget::GetMatchingPair()
 544 {
 545     return MSWGetSupportedFormat( m_pIDataSource );
 546 }
 547
 548 wxDataFormat wxDropTarget::MSWGetSupportedFormat(IDataObject *pIDataSource) const
 549 {
 550     // this strucutre describes a data of any type (first field will be
 551     // changing) being passed through global memory block.
 552     static FORMATETC s_fmtMemory = {
 553         0,
 554         NULL,
 555         DVASPECT_CONTENT,
 556         -1,
 557         TYMED_HGLOBAL       // TODO is it worth supporting other tymeds here?
 558     };
 559
 560     // get the list of supported formats
 561     size_t nFormats = m_dataObject->GetFormatCount(wxDataObject::Set);
 562     wxDataFormat format;
 563     wxDataFormat *formats;
 564     formats = nFormats == 1 ? &format :  new wxDataFormat[nFormats];
 565
 566     m_dataObject->GetAllFormats(formats, wxDataObject::Set);
 567
 568     // cycle through all supported formats
 569     size_t n;
 570     for ( n = 0; n < nFormats; n++ ) {
 571         s_fmtMemory.cfFormat = formats[n];
 572
 573         // NB: don't use SUCCEEDED macro here: QueryGetData returns S_FALSE
 574         //     for file drag and drop (format == CF_HDROP)
 575         if ( pIDataSource->QueryGetData(&s_fmtMemory) == S_OK ) {
 576             format = formats[n];
 577
 578             break;
 579         }
 580     }
 581
 582     if ( formats != &format ) {
 583         // free memory if we allocated it
 584         delete [] formats;
 585     }
 586
 587     return n < nFormats ? format : wxFormatInvalid;
 588 }
 589
 590 // ----------------------------------------------------------------------------
 591 // drag image functions
 592 // ----------------------------------------------------------------------------
 593
 594 void
 595 wxDropTarget::MSWEndDragImageSupport()
 596 {
 597     // release drop target helper
 598     if ( m_dropTargetHelper != NULL )
 599     {
 600         m_dropTargetHelper->Release();
 601         m_dropTargetHelper = NULL;
 602     }
 603 }
 604
 605 void
 606 wxDropTarget::MSWInitDragImageSupport()
 607 {
 608     // Use the default drop target helper to show shell drag images
 609     CoCreateInstance(wxCLSID_DragDropHelper, NULL, CLSCTX_INPROC_SERVER,
 610                      wxIID_IDropTargetHelper, (LPVOID*)&m_dropTargetHelper);
 611 }
 612
 613 void
 614 wxDropTarget::MSWUpdateDragImageOnData(wxCoord x,
 615                                        wxCoord y,
 616                                        wxDragResult dragResult)
 617 {
 618     // call corresponding event on drop target helper
 619     if ( m_dropTargetHelper != NULL )
 620     {
 621         POINT pt = {x, y};
 622         DWORD dwEffect = ConvertDragResultToEffect(dragResult);
 623         m_dropTargetHelper->Drop(m_pIDataSource, &pt, dwEffect);
 624     }
 625 }
 626
 627 void
 628 wxDropTarget::MSWUpdateDragImageOnDragOver(wxCoord x,
 629                                            wxCoord y,
 630                                            wxDragResult dragResult)
 631 {
 632     // call corresponding event on drop target helper
 633     if ( m_dropTargetHelper != NULL )
 634     {
 635         POINT pt = {x, y};
 636         DWORD dwEffect = ConvertDragResultToEffect(dragResult);
 637         m_dropTargetHelper->DragOver(&pt, dwEffect);
 638     }
 639 }
 640
 641 void
 642 wxDropTarget::MSWUpdateDragImageOnEnter(wxCoord x,
 643                                         wxCoord y,
 644                                         wxDragResult dragResult)
 645 {
 646     // call corresponding event on drop target helper
 647     if ( m_dropTargetHelper != NULL )
 648     {
 649         POINT pt = {x, y};
 650         DWORD dwEffect = ConvertDragResultToEffect(dragResult);
 651         m_dropTargetHelper->DragEnter(m_pIDropTarget->GetHWND(), m_pIDataSource, &pt, dwEffect);
 652     }
 653 }
 654
 655 void
 656 wxDropTarget::MSWUpdateDragImageOnLeave()
 657 {
 658     // call corresponding event on drop target helper
 659     if ( m_dropTargetHelper != NULL )
 660     {
 661         m_dropTargetHelper->DragLeave();
 662     }
 663 }
 664
 665 // ----------------------------------------------------------------------------
 666 // private functions
 667 // ----------------------------------------------------------------------------
 668
 669 static wxDragResult ConvertDragEffectToResult(DWORD dwEffect)
 670 {
 671     switch ( dwEffect ) {
 672         case DROPEFFECT_COPY:
 673             return wxDragCopy;
 674
 675         case DROPEFFECT_LINK:
 676             return wxDragLink;
 677
 678         case DROPEFFECT_MOVE:
 679             return wxDragMove;
 680
 681         default:
 682             wxFAIL_MSG(wxT("invalid value in ConvertDragEffectToResult"));
 683             // fall through
 684
 685         case DROPEFFECT_NONE:
 686             return wxDragNone;
 687     }
 688 }
 689
 690 static DWORD ConvertDragResultToEffect(wxDragResult result)
 691 {
 692     switch ( result ) {
 693         case wxDragCopy:
 694             return DROPEFFECT_COPY;
 695
 696         case wxDragLink:
 697             return DROPEFFECT_LINK;
 698
 699         case wxDragMove:
 700             return DROPEFFECT_MOVE;
 701
 702         default:
 703             wxFAIL_MSG(wxT("invalid value in ConvertDragResultToEffect"));
 704             // fall through
 705
 706         case wxDragNone:
 707             return DROPEFFECT_NONE;
 708     }
 709 }
 710
 711 #endif // wxUSE_OLE && wxUSE_DRAG_AND_DROP