src/msw/ole/droptgt.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        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 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  21 #pragma implementation "droptgt.h"
  22 #endif
  23
  24 // For compilers that support precompilation, includes "wx.h".
  25 #include "wx/wxprec.h"
  26
  27 #if defined(__BORLANDC__)
  28 #pragma hdrstop
  29 #endif
  30
  31 #include "wx/setup.h"
  32
  33 #if wxUSE_OLE && wxUSE_DRAG_AND_DROP
  34
  35 #include "wx/msw/private.h"
  36 #include "wx/log.h"
  37
  38 #ifdef __WXWINCE__
  39     #include <winreg.h>
  40     #include <ole2.h>
  41 #endif
  42
  43 #ifdef __WIN32__
  44     #if !defined(__GNUWIN32__) || wxUSE_NORLANDER_HEADERS
  45         #if wxCHECK_W32API_VERSION( 1, 0 )
  46             #include "wx/msw/wrapwin.h"
  47         #endif
  48         #include <shlobj.h>            // for DROPFILES structure
  49     #endif
  50 #else
  51     #include <shellapi.h>
  52 #endif
  53
  54 #include "wx/dnd.h"
  55
  56 #include "wx/msw/ole/oleutils.h"
  57
  58 // ----------------------------------------------------------------------------
  59 // IDropTarget interface: forward all interesting things to wxDropTarget
  60 // (the name is unfortunate, but wx_I_DropTarget is not at all the same thing
  61 //  as wxDropTarget which is 'public' class, while this one is private)
  62 // ----------------------------------------------------------------------------
  63
  64 class wxIDropTarget : public IDropTarget
  65 {
  66 public:
  67     wxIDropTarget(wxDropTarget *p);
  68     virtual ~wxIDropTarget();
  69
  70     // accessors for wxDropTarget
  71     void SetHwnd(HWND hwnd) { m_hwnd = hwnd; }
  72
  73     // IDropTarget methods
  74     STDMETHODIMP DragEnter(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
  75     STDMETHODIMP DragOver(DWORD, POINTL, LPDWORD);
  76     STDMETHODIMP DragLeave();
  77     STDMETHODIMP Drop(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
  78
  79     DECLARE_IUNKNOWN_METHODS;
  80
  81 protected:
  82     IDataObject  *m_pIDataObject; // !NULL between DragEnter and DragLeave/Drop
  83     wxDropTarget *m_pTarget;      // the real target (we're just a proxy)
  84
  85     HWND          m_hwnd;         // window we're associated with
  86
  87     // get default drop effect for given keyboard flags
  88     static inline DWORD GetDropEffect(DWORD flags, wxDragResult defaultAction);
  89
  90     DECLARE_NO_COPY_CLASS(wxIDropTarget)
  91 };
  92
  93 // ----------------------------------------------------------------------------
  94 // private functions
  95 // ----------------------------------------------------------------------------
  96
  97 static wxDragResult ConvertDragEffectToResult(DWORD dwEffect);
  98 static DWORD ConvertDragResultToEffect(wxDragResult result);
  99
 100 // ============================================================================
 101 // wxIDropTarget implementation
 102 // ============================================================================
 103
 104 // Name    : static wxIDropTarget::GetDropEffect
 105 // Purpose : determine the drop operation from keyboard/mouse state.
 106 // Returns : DWORD combined from DROPEFFECT_xxx constants
 107 // Params  : [in] DWORD flags       kbd & mouse flags as passed to
 108 //                                  IDropTarget methods
 109 // Notes   : We do "move" normally and "copy" if <Ctrl> is pressed,
 110 //           which is the standard behaviour (currently there is no
 111 //           way to redefine it)
 112 DWORD wxIDropTarget::GetDropEffect(DWORD flags, wxDragResult defaultAction)
 113 {
 114   if (defaultAction == wxDragCopy)
 115     return flags & MK_SHIFT ? DROPEFFECT_MOVE : DROPEFFECT_COPY;
 116   return flags & MK_CONTROL ? DROPEFFECT_COPY : DROPEFFECT_MOVE;
 117 }
 118
 119 wxIDropTarget::wxIDropTarget(wxDropTarget *pTarget)
 120 {
 121   m_pTarget      = pTarget;
 122   m_pIDataObject = NULL;
 123 }
 124
 125 wxIDropTarget::~wxIDropTarget()
 126 {
 127 }
 128
 129 BEGIN_IID_TABLE(wxIDropTarget)
 130   ADD_IID(Unknown)
 131   ADD_IID(DropTarget)
 132 END_IID_TABLE;
 133
 134 IMPLEMENT_IUNKNOWN_METHODS(wxIDropTarget)
 135
 136 // Name    : wxIDropTarget::DragEnter
 137 // Purpose : Called when the mouse enters the window (dragging something)
 138 // Returns : S_OK
 139 // Params  : [in] IDataObject *pIDataSource : source data
 140 //           [in] DWORD        grfKeyState  : kbd & mouse state
 141 //           [in] POINTL       pt           : mouse coordinates
 142 //           [out]DWORD       *pdwEffect    : effect flag
 143 // Notes   :
 144 STDMETHODIMP wxIDropTarget::DragEnter(IDataObject *pIDataSource,
 145                                       DWORD        grfKeyState,
 146                                       POINTL       pt,
 147                                       DWORD       *pdwEffect)
 148 {
 149     wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragEnter"));
 150
 151     wxASSERT_MSG( m_pIDataObject == NULL,
 152                   _T("drop target must have data object") );
 153
 154     // show the list of formats supported by the source data object for the
 155     // debugging purposes, this is quite useful sometimes - please don't remove
 156 #if 0
 157     IEnumFORMATETC *penumFmt;
 158     if ( SUCCEEDED(pIDataSource->EnumFormatEtc(DATADIR_GET, &penumFmt)) )
 159     {
 160         FORMATETC fmt;
 161         while ( penumFmt->Next(1, &fmt, NULL) == S_OK )
 162         {
 163             wxLogDebug(_T("Drop source supports format %s"),
 164                        wxDataObject::GetFormatName(fmt.cfFormat));
 165         }
 166
 167         penumFmt->Release();
 168     }
 169     else
 170     {
 171         wxLogLastError(_T("IDataObject::EnumFormatEtc"));
 172     }
 173 #endif // 0
 174
 175     if ( !m_pTarget->IsAcceptedData(pIDataSource) ) {
 176         // we don't accept this kind of data
 177         *pdwEffect = DROPEFFECT_NONE;
 178
 179         return S_OK;
 180     }
 181
 182     // get hold of the data object
 183     m_pIDataObject = pIDataSource;
 184     m_pIDataObject->AddRef();
 185
 186     // we need client coordinates to pass to wxWin functions
 187     if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 188     {
 189         wxLogLastError(wxT("ScreenToClient"));
 190     }
 191
 192     // give some visual feedback
 193     *pdwEffect = ConvertDragResultToEffect(
 194         m_pTarget->OnEnter(pt.x, pt.y, ConvertDragEffectToResult(
 195             GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()))
 196                     )
 197                  );
 198
 199     return S_OK;
 200 }
 201
 202 // Name    : wxIDropTarget::DragOver
 203 // Purpose : Indicates that the mouse was moved inside the window represented
 204 //           by this drop target.
 205 // Returns : S_OK
 206 // Params  : [in] DWORD   grfKeyState     kbd & mouse state
 207 //           [in] POINTL  pt              mouse coordinates
 208 //           [out]LPDWORD pdwEffect       effect flag
 209 // Notes   : We're called on every WM_MOUSEMOVE, so this function should be
 210 //           very efficient.
 211 STDMETHODIMP wxIDropTarget::DragOver(DWORD   grfKeyState,
 212                                      POINTL  pt,
 213                                      LPDWORD pdwEffect)
 214 {
 215     // there are too many of them... wxLogDebug("IDropTarget::DragOver");
 216
 217     wxDragResult result;
 218     if ( m_pIDataObject ) {
 219         result = ConvertDragEffectToResult(
 220             GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()));
 221     }
 222     else {
 223         // can't accept data anyhow normally
 224         result = wxDragNone;
 225     }
 226
 227     // we need client coordinates to pass to wxWin functions
 228     if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 229     {
 230         wxLogLastError(wxT("ScreenToClient"));
 231     }
 232
 233     *pdwEffect = ConvertDragResultToEffect(
 234                     m_pTarget->OnDragOver(pt.x, pt.y, result)
 235                  );
 236
 237     return S_OK;
 238 }
 239
 240 // Name    : wxIDropTarget::DragLeave
 241 // Purpose : Informs the drop target that the operation has left its window.
 242 // Returns : S_OK
 243 // Notes   : good place to do any clean-up
 244 STDMETHODIMP wxIDropTarget::DragLeave()
 245 {
 246   wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragLeave"));
 247
 248   // remove the UI feedback
 249   m_pTarget->OnLeave();
 250
 251   // release the held object
 252   RELEASE_AND_NULL(m_pIDataObject);
 253
 254   return S_OK;
 255 }
 256
 257 // Name    : wxIDropTarget::Drop
 258 // Purpose : Instructs the drop target to paste data that was just now
 259 //           dropped on it.
 260 // Returns : S_OK
 261 // Params  : [in] IDataObject *pIDataSource     the data to paste
 262 //           [in] DWORD        grfKeyState      kbd & mouse state
 263 //           [in] POINTL       pt               where the drop occurred?
 264 //           [ouy]DWORD       *pdwEffect        operation effect
 265 // Notes   :
 266 STDMETHODIMP wxIDropTarget::Drop(IDataObject *pIDataSource,
 267                                  DWORD        grfKeyState,
 268                                  POINTL       pt,
 269                                  DWORD       *pdwEffect)
 270 {
 271     wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::Drop"));
 272
 273     // TODO I don't know why there is this parameter, but so far I assume
 274     //      that it's the same we've already got in DragEnter
 275     wxASSERT( m_pIDataObject == pIDataSource );
 276
 277     // by default, nothing happens
 278     *pdwEffect = DROPEFFECT_NONE;
 279
 280     // we need client coordinates to pass to wxWin functions
 281     if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
 282     {
 283         wxLogLastError(wxT("ScreenToClient"));
 284     }
 285
 286     // first ask the drop target if it wants data
 287     if ( m_pTarget->OnDrop(pt.x, pt.y) ) {
 288         // it does, so give it the data source
 289         m_pTarget->SetDataSource(pIDataSource);
 290
 291         // and now it has the data
 292         wxDragResult rc = ConvertDragEffectToResult(
 293             GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()));
 294         rc = m_pTarget->OnData(pt.x, pt.y, rc);
 295         if ( wxIsDragResultOk(rc) ) {
 296             // operation succeeded
 297             *pdwEffect = ConvertDragResultToEffect(rc);
 298         }
 299         //else: *pdwEffect is already DROPEFFECT_NONE
 300     }
 301     //else: OnDrop() returned false, no need to copy data
 302
 303     // release the held object
 304     RELEASE_AND_NULL(m_pIDataObject);
 305
 306     return S_OK;
 307 }
 308
 309 // ============================================================================
 310 // wxDropTarget implementation
 311 // ============================================================================
 312
 313 // ----------------------------------------------------------------------------
 314 // ctor/dtor
 315 // ----------------------------------------------------------------------------
 316
 317 wxDropTarget::wxDropTarget(wxDataObject *dataObj)
 318             : wxDropTargetBase(dataObj)
 319 {
 320     // create an IDropTarget implementation which will notify us about d&d
 321     // operations.
 322     m_pIDropTarget = new wxIDropTarget(this);
 323     m_pIDropTarget->AddRef();
 324 }
 325
 326 wxDropTarget::~wxDropTarget()
 327 {
 328     ReleaseInterface(m_pIDropTarget);
 329 }
 330
 331 // ----------------------------------------------------------------------------
 332 // [un]register drop handler
 333 // ----------------------------------------------------------------------------
 334
 335 bool wxDropTarget::Register(WXHWND hwnd)
 336 {
 337     // FIXME
 338     // RegisterDragDrop not available on Windows CE >= 400?
 339     // Or maybe we can dynamically load them from ceshell.dll
 340     // or similar.
 341 #if defined(__WXWINCE__) && _WIN32_WCE >= 400
 342     wxUnusedVar(hwnd);
 343     return false;
 344 #else
 345     HRESULT hr;
 346
 347     // May exist in later WinCE versions
 348 #ifndef __WXWINCE__
 349     hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE);
 350     if ( FAILED(hr) ) {
 351         wxLogApiError(wxT("CoLockObjectExternal"), hr);
 352         return false;
 353     }
 354 #endif
 355
 356     hr = ::RegisterDragDrop((HWND) hwnd, m_pIDropTarget);
 357     if ( FAILED(hr) ) {
 358     // May exist in later WinCE versions
 359 #ifndef __WXWINCE__
 360         ::CoLockObjectExternal(m_pIDropTarget, FALSE, FALSE);
 361 #endif
 362         wxLogApiError(wxT("RegisterDragDrop"), hr);
 363         return false;
 364     }
 365
 366     // we will need the window handle for coords transformation later
 367     m_pIDropTarget->SetHwnd((HWND)hwnd);
 368
 369     return true;
 370 #endif
 371 }
 372
 373 void wxDropTarget::Revoke(WXHWND hwnd)
 374 {
 375 #if defined(__WXWINCE__) && _WIN32_WCE >= 400
 376     // Not available, see note above
 377     wxUnusedVar(hwnd);
 378 #else
 379     HRESULT hr = ::RevokeDragDrop((HWND) hwnd);
 380
 381     if ( FAILED(hr) ) {
 382         wxLogApiError(wxT("RevokeDragDrop"), hr);
 383     }
 384
 385     // May exist in later WinCE versions
 386 #ifndef __WXWINCE__
 387     ::CoLockObjectExternal(m_pIDropTarget, FALSE, TRUE);
 388 #endif
 389
 390     m_pIDropTarget->SetHwnd(0);
 391 #endif
 392 }
 393
 394 // ----------------------------------------------------------------------------
 395 // base class pure virtuals
 396 // ----------------------------------------------------------------------------
 397
 398 // OnDrop() is called only if we previously returned true from
 399 // IsAcceptedData(), so no need to check anything here
 400 bool wxDropTarget::OnDrop(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y))
 401 {
 402     return true;
 403 }
 404
 405 // copy the data from the data source to the target data object
 406 bool wxDropTarget::GetData()
 407 {
 408     wxDataFormat format = GetSupportedFormat(m_pIDataSource);
 409     if ( format == wxDF_INVALID ) {
 410         // this is strange because IsAcceptedData() succeeded previously!
 411         wxFAIL_MSG(wxT("strange - did supported formats list change?"));
 412
 413         return false;
 414     }
 415
 416     STGMEDIUM stm;
 417     FORMATETC fmtMemory;
 418     fmtMemory.cfFormat  = format;
 419     fmtMemory.ptd       = NULL;
 420     fmtMemory.dwAspect  = DVASPECT_CONTENT;
 421     fmtMemory.lindex    = -1;
 422     fmtMemory.tymed     = TYMED_HGLOBAL;  // TODO to add other media
 423
 424     bool rc = false;
 425
 426     HRESULT hr = m_pIDataSource->GetData(&fmtMemory, &stm);
 427     if ( SUCCEEDED(hr) ) {
 428         IDataObject *dataObject = m_dataObject->GetInterface();
 429
 430         hr = dataObject->SetData(&fmtMemory, &stm, TRUE);
 431         if ( SUCCEEDED(hr) ) {
 432             rc = true;
 433         }
 434         else {
 435             wxLogApiError(wxT("IDataObject::SetData()"), hr);
 436         }
 437     }
 438     else {
 439         wxLogApiError(wxT("IDataObject::GetData()"), hr);
 440     }
 441
 442     return rc;
 443 }
 444
 445 // ----------------------------------------------------------------------------
 446 // callbacks used by wxIDropTarget
 447 // ----------------------------------------------------------------------------
 448
 449 // we need a data source, so wxIDropTarget gives it to us using this function
 450 void wxDropTarget::SetDataSource(IDataObject *pIDataSource)
 451 {
 452     m_pIDataSource = pIDataSource;
 453 }
 454
 455 // determine if we accept data of this type
 456 bool wxDropTarget::IsAcceptedData(IDataObject *pIDataSource) const
 457 {
 458     return GetSupportedFormat(pIDataSource) != wxDF_INVALID;
 459 }
 460
 461 // ----------------------------------------------------------------------------
 462 // helper functions
 463 // ----------------------------------------------------------------------------
 464
 465 wxDataFormat wxDropTarget::GetSupportedFormat(IDataObject *pIDataSource) const
 466 {
 467     // this strucutre describes a data of any type (first field will be
 468     // changing) being passed through global memory block.
 469     static FORMATETC s_fmtMemory = {
 470         0,
 471         NULL,
 472         DVASPECT_CONTENT,
 473         -1,
 474         TYMED_HGLOBAL       // TODO is it worth supporting other tymeds here?
 475     };
 476
 477     // get the list of supported formats
 478     size_t nFormats = m_dataObject->GetFormatCount(wxDataObject::Set);
 479     wxDataFormat format;
 480     wxDataFormat *formats;
 481     formats = nFormats == 1 ? &format :  new wxDataFormat[nFormats];
 482
 483     m_dataObject->GetAllFormats(formats, wxDataObject::Set);
 484
 485     // cycle through all supported formats
 486     size_t n;
 487     for ( n = 0; n < nFormats; n++ ) {
 488         s_fmtMemory.cfFormat = formats[n];
 489
 490         // NB: don't use SUCCEEDED macro here: QueryGetData returns S_FALSE
 491         //     for file drag and drop (format == CF_HDROP)
 492         if ( pIDataSource->QueryGetData(&s_fmtMemory) == S_OK ) {
 493             format = formats[n];
 494
 495             break;
 496         }
 497     }
 498
 499     if ( formats != &format ) {
 500         // free memory if we allocated it
 501         delete [] formats;
 502     }
 503
 504     return n < nFormats ? format : wxFormatInvalid;
 505 }
 506
 507 // ----------------------------------------------------------------------------
 508 // private functions
 509 // ----------------------------------------------------------------------------
 510
 511 static wxDragResult ConvertDragEffectToResult(DWORD dwEffect)
 512 {
 513     switch ( dwEffect ) {
 514         case DROPEFFECT_COPY:
 515             return wxDragCopy;
 516
 517         case DROPEFFECT_LINK:
 518             return wxDragLink;
 519
 520         case DROPEFFECT_MOVE:
 521             return wxDragMove;
 522
 523         default:
 524             wxFAIL_MSG(wxT("invalid value in ConvertDragEffectToResult"));
 525             // fall through
 526
 527         case DROPEFFECT_NONE:
 528             return wxDragNone;
 529     }
 530 }
 531
 532 static DWORD ConvertDragResultToEffect(wxDragResult result)
 533 {
 534     switch ( result ) {
 535         case wxDragCopy:
 536             return DROPEFFECT_COPY;
 537
 538         case wxDragLink:
 539             return DROPEFFECT_LINK;
 540
 541         case wxDragMove:
 542             return DROPEFFECT_MOVE;
 543
 544         default:
 545             wxFAIL_MSG(wxT("invalid value in ConvertDragResultToEffect"));
 546             // fall through
 547
 548         case wxDragNone:
 549             return DROPEFFECT_NONE;
 550     }
 551 }
 552
 553 #endif
 554  // wxUSE_DRAG_AND_DROP