| 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 license |
| 10 | /////////////////////////////////////////////////////////////////////////////// |
| 11 | |
| 12 | // ============================================================================ |
| 13 | // Declarations |
| 14 | // ============================================================================ |
| 15 | |
| 16 | // ---------------------------------------------------------------------------- |
| 17 | // headers |
| 18 | // ---------------------------------------------------------------------------- |
| 19 | |
| 20 | #ifdef __GNUG__ |
| 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_DRAG_AND_DROP |
| 34 | |
| 35 | #include "wx/log.h" |
| 36 | |
| 37 | #ifdef __WIN32__ |
| 38 | #ifndef __GNUWIN32__ |
| 39 | #include <shlobj.h> // for DROPFILES structure |
| 40 | #endif |
| 41 | #else |
| 42 | #include <shellapi.h> |
| 43 | #endif |
| 44 | |
| 45 | #include "wx/dnd.h" |
| 46 | |
| 47 | #ifndef __WIN32__ |
| 48 | #include <ole2.h> |
| 49 | #include <olestd.h> |
| 50 | #endif |
| 51 | |
| 52 | #include "wx/msw/ole/oleutils.h" |
| 53 | |
| 54 | // ---------------------------------------------------------------------------- |
| 55 | // IDropTarget interface: forward all interesting things to wxDropTarget |
| 56 | // (the name is unfortunate, but wx_I_DropTarget is not at all the same thing |
| 57 | // as wxDropTarget which is 'public' class, while this one is private) |
| 58 | // ---------------------------------------------------------------------------- |
| 59 | |
| 60 | class wxIDropTarget : public IDropTarget |
| 61 | { |
| 62 | public: |
| 63 | wxIDropTarget(wxDropTarget *p); |
| 64 | ~wxIDropTarget(); |
| 65 | |
| 66 | // accessors for wxDropTarget |
| 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 inline DWORD GetDropEffect(DWORD flags); |
| 85 | }; |
| 86 | |
| 87 | // ---------------------------------------------------------------------------- |
| 88 | // private functions |
| 89 | // ---------------------------------------------------------------------------- |
| 90 | |
| 91 | static wxDragResult ConvertDragEffectToResult(DWORD dwEffect); |
| 92 | static DWORD ConvertDragResultToEffect(wxDragResult result); |
| 93 | |
| 94 | // ============================================================================ |
| 95 | // wxIDropTarget implementation |
| 96 | // ============================================================================ |
| 97 | |
| 98 | // Name : static wxIDropTarget::GetDropEffect |
| 99 | // Purpose : determine the drop operation from keyboard/mouse state. |
| 100 | // Returns : DWORD combined from DROPEFFECT_xxx constants |
| 101 | // Params : [in] DWORD flags kbd & mouse flags as passed to |
| 102 | // IDropTarget methods |
| 103 | // Notes : We do "move" normally and "copy" if <Ctrl> is pressed, |
| 104 | // which is the standard behaviour (currently there is no |
| 105 | // way to redefine it) |
| 106 | DWORD wxIDropTarget::GetDropEffect(DWORD flags) |
| 107 | { |
| 108 | return flags & MK_CONTROL ? DROPEFFECT_COPY : DROPEFFECT_MOVE; |
| 109 | } |
| 110 | |
| 111 | wxIDropTarget::wxIDropTarget(wxDropTarget *pTarget) |
| 112 | { |
| 113 | m_cRef = 0; |
| 114 | m_pTarget = pTarget; |
| 115 | m_pIDataObject = NULL; |
| 116 | } |
| 117 | |
| 118 | wxIDropTarget::~wxIDropTarget() |
| 119 | { |
| 120 | } |
| 121 | |
| 122 | BEGIN_IID_TABLE(wxIDropTarget) |
| 123 | ADD_IID(Unknown) |
| 124 | ADD_IID(DropTarget) |
| 125 | END_IID_TABLE; |
| 126 | |
| 127 | IMPLEMENT_IUNKNOWN_METHODS(wxIDropTarget) |
| 128 | |
| 129 | // Name : wxIDropTarget::DragEnter |
| 130 | // Purpose : Called when the mouse enters the window (dragging something) |
| 131 | // Returns : S_OK |
| 132 | // Params : [in] IDataObject *pIDataSource : source data |
| 133 | // [in] DWORD grfKeyState : kbd & mouse state |
| 134 | // [in] POINTL pt : mouse coordinates |
| 135 | // [out]DWORD *pdwEffect : effect flag |
| 136 | // Notes : |
| 137 | STDMETHODIMP wxIDropTarget::DragEnter(IDataObject *pIDataSource, |
| 138 | DWORD grfKeyState, |
| 139 | POINTL pt, |
| 140 | DWORD *pdwEffect) |
| 141 | { |
| 142 | wxLogDebug(wxT("IDropTarget::DragEnter")); |
| 143 | |
| 144 | wxASSERT( m_pIDataObject == NULL ); |
| 145 | |
| 146 | if ( !m_pTarget->IsAcceptedData(pIDataSource) ) { |
| 147 | // we don't accept this kind of data |
| 148 | *pdwEffect = DROPEFFECT_NONE; |
| 149 | |
| 150 | return S_OK; |
| 151 | } |
| 152 | |
| 153 | // get hold of the data object |
| 154 | m_pIDataObject = pIDataSource; |
| 155 | m_pIDataObject->AddRef(); |
| 156 | |
| 157 | // we need client coordinates to pass to wxWin functions |
| 158 | if ( !ScreenToClient(m_hwnd, (POINT *)&pt) ) |
| 159 | { |
| 160 | wxLogLastError("ScreenToClient"); |
| 161 | } |
| 162 | |
| 163 | // give some visual feedback |
| 164 | *pdwEffect = ConvertDragResultToEffect( |
| 165 | m_pTarget->OnEnter(pt.x, pt.y, |
| 166 | ConvertDragEffectToResult(GetDropEffect(grfKeyState)) |
| 167 | ) |
| 168 | ); |
| 169 | |
| 170 | return S_OK; |
| 171 | } |
| 172 | |
| 173 | // Name : wxIDropTarget::DragOver |
| 174 | // Purpose : Indicates that the mouse was moved inside the window represented |
| 175 | // by this drop target. |
| 176 | // Returns : S_OK |
| 177 | // Params : [in] DWORD grfKeyState kbd & mouse state |
| 178 | // [in] POINTL pt mouse coordinates |
| 179 | // [out]LPDWORD pdwEffect effect flag |
| 180 | // Notes : We're called on every WM_MOUSEMOVE, so this function should be |
| 181 | // very efficient. |
| 182 | STDMETHODIMP wxIDropTarget::DragOver(DWORD grfKeyState, |
| 183 | POINTL pt, |
| 184 | LPDWORD pdwEffect) |
| 185 | { |
| 186 | // there are too many of them... wxLogDebug("IDropTarget::DragOver"); |
| 187 | |
| 188 | wxDragResult result; |
| 189 | if ( m_pIDataObject ) { |
| 190 | result = ConvertDragEffectToResult(GetDropEffect(grfKeyState)); |
| 191 | } |
| 192 | else { |
| 193 | // can't accept data anyhow normally |
| 194 | result = wxDragNone; |
| 195 | } |
| 196 | |
| 197 | // we need client coordinates to pass to wxWin functions |
| 198 | if ( !ScreenToClient(m_hwnd, (POINT *)&pt) ) |
| 199 | { |
| 200 | wxLogLastError("ScreenToClient"); |
| 201 | } |
| 202 | |
| 203 | *pdwEffect = ConvertDragResultToEffect( |
| 204 | m_pTarget->OnDragOver(pt.x, pt.y, result) |
| 205 | ); |
| 206 | |
| 207 | return S_OK; |
| 208 | } |
| 209 | |
| 210 | // Name : wxIDropTarget::DragLeave |
| 211 | // Purpose : Informs the drop target that the operation has left its window. |
| 212 | // Returns : S_OK |
| 213 | // Notes : good place to do any clean-up |
| 214 | STDMETHODIMP wxIDropTarget::DragLeave() |
| 215 | { |
| 216 | wxLogDebug(wxT("IDropTarget::DragLeave")); |
| 217 | |
| 218 | // remove the UI feedback |
| 219 | m_pTarget->OnLeave(); |
| 220 | |
| 221 | // release the held object |
| 222 | RELEASE_AND_NULL(m_pIDataObject); |
| 223 | |
| 224 | return S_OK; |
| 225 | } |
| 226 | |
| 227 | // Name : wxIDropTarget::Drop |
| 228 | // Purpose : Instructs the drop target to paste data that was just now |
| 229 | // dropped on it. |
| 230 | // Returns : S_OK |
| 231 | // Params : [in] IDataObject *pIDataSource the data to paste |
| 232 | // [in] DWORD grfKeyState kbd & mouse state |
| 233 | // [in] POINTL pt where the drop occured? |
| 234 | // [ouy]DWORD *pdwEffect operation effect |
| 235 | // Notes : |
| 236 | STDMETHODIMP wxIDropTarget::Drop(IDataObject *pIDataSource, |
| 237 | DWORD grfKeyState, |
| 238 | POINTL pt, |
| 239 | DWORD *pdwEffect) |
| 240 | { |
| 241 | wxLogDebug(wxT("IDropTarget::Drop")); |
| 242 | |
| 243 | // TODO I don't know why there is this parameter, but so far I assume |
| 244 | // that it's the same we've already got in DragEnter |
| 245 | wxASSERT( m_pIDataObject == pIDataSource ); |
| 246 | |
| 247 | // by default, nothing happens |
| 248 | *pdwEffect = DROPEFFECT_NONE; |
| 249 | |
| 250 | // we need client coordinates to pass to wxWin functions |
| 251 | if ( !ScreenToClient(m_hwnd, (POINT *)&pt) ) |
| 252 | { |
| 253 | wxLogLastError("ScreenToClient"); |
| 254 | } |
| 255 | |
| 256 | // first ask the drop target if it wants data |
| 257 | if ( m_pTarget->OnDrop(pt.x, pt.y) ) { |
| 258 | // it does, so give it the data source |
| 259 | m_pTarget->SetDataSource(pIDataSource); |
| 260 | |
| 261 | // and now it has the data |
| 262 | wxDragResult rc = ConvertDragEffectToResult(GetDropEffect(grfKeyState)); |
| 263 | rc = m_pTarget->OnData(pt.x, pt.y, rc); |
| 264 | if ( wxIsDragResultOk(rc) ) { |
| 265 | // operation succeeded |
| 266 | *pdwEffect = ConvertDragResultToEffect(rc); |
| 267 | } |
| 268 | //else: *pdwEffect is already DROPEFFECT_NONE |
| 269 | } |
| 270 | //else: OnDrop() returned FALSE, no need to copy data |
| 271 | |
| 272 | // release the held object |
| 273 | RELEASE_AND_NULL(m_pIDataObject); |
| 274 | |
| 275 | return S_OK; |
| 276 | } |
| 277 | |
| 278 | // ============================================================================ |
| 279 | // wxDropTarget implementation |
| 280 | // ============================================================================ |
| 281 | |
| 282 | // ---------------------------------------------------------------------------- |
| 283 | // ctor/dtor |
| 284 | // ---------------------------------------------------------------------------- |
| 285 | |
| 286 | wxDropTarget::wxDropTarget(wxDataObject *dataObj) |
| 287 | : wxDropTargetBase(dataObj) |
| 288 | { |
| 289 | // create an IDropTarget implementation which will notify us about d&d |
| 290 | // operations. |
| 291 | m_pIDropTarget = new wxIDropTarget(this); |
| 292 | m_pIDropTarget->AddRef(); |
| 293 | } |
| 294 | |
| 295 | wxDropTarget::~wxDropTarget() |
| 296 | { |
| 297 | ReleaseInterface(m_pIDropTarget); |
| 298 | } |
| 299 | |
| 300 | // ---------------------------------------------------------------------------- |
| 301 | // [un]register drop handler |
| 302 | // ---------------------------------------------------------------------------- |
| 303 | |
| 304 | bool wxDropTarget::Register(WXHWND hwnd) |
| 305 | { |
| 306 | HRESULT hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE); |
| 307 | if ( FAILED(hr) ) { |
| 308 | wxLogApiError("CoLockObjectExternal", hr); |
| 309 | return FALSE; |
| 310 | } |
| 311 | |
| 312 | hr = ::RegisterDragDrop((HWND) hwnd, m_pIDropTarget); |
| 313 | if ( FAILED(hr) ) { |
| 314 | ::CoLockObjectExternal(m_pIDropTarget, FALSE, FALSE); |
| 315 | |
| 316 | wxLogApiError("RegisterDragDrop", hr); |
| 317 | return FALSE; |
| 318 | } |
| 319 | |
| 320 | // we will need the window handle for coords transformation later |
| 321 | m_pIDropTarget->SetHwnd((HWND)hwnd); |
| 322 | |
| 323 | return TRUE; |
| 324 | } |
| 325 | |
| 326 | void wxDropTarget::Revoke(WXHWND hwnd) |
| 327 | { |
| 328 | HRESULT hr = ::RevokeDragDrop((HWND) hwnd); |
| 329 | |
| 330 | if ( FAILED(hr) ) { |
| 331 | wxLogApiError("RevokeDragDrop", hr); |
| 332 | } |
| 333 | |
| 334 | ::CoLockObjectExternal(m_pIDropTarget, FALSE, TRUE); |
| 335 | |
| 336 | m_pIDropTarget->SetHwnd(0); |
| 337 | } |
| 338 | |
| 339 | // ---------------------------------------------------------------------------- |
| 340 | // base class pure virtuals |
| 341 | // ---------------------------------------------------------------------------- |
| 342 | |
| 343 | // OnDrop() is called only if we previously returned TRUE from |
| 344 | // IsAcceptedData(), so no need to check anything here |
| 345 | bool wxDropTarget::OnDrop(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y)) |
| 346 | { |
| 347 | return TRUE; |
| 348 | } |
| 349 | |
| 350 | // copy the data from the data source to the target data object |
| 351 | bool wxDropTarget::GetData() |
| 352 | { |
| 353 | wxDataFormat format = GetSupportedFormat(m_pIDataSource); |
| 354 | if ( format == wxDF_INVALID ) { |
| 355 | // this is strange because IsAcceptedData() succeeded previously! |
| 356 | wxFAIL_MSG(wxT("strange - did supported formats list change?")); |
| 357 | |
| 358 | return FALSE; |
| 359 | } |
| 360 | |
| 361 | STGMEDIUM stm; |
| 362 | FORMATETC fmtMemory; |
| 363 | fmtMemory.cfFormat = format; |
| 364 | fmtMemory.ptd = NULL; |
| 365 | fmtMemory.dwAspect = DVASPECT_CONTENT; |
| 366 | fmtMemory.lindex = -1; |
| 367 | fmtMemory.tymed = TYMED_HGLOBAL; // TODO to add other media |
| 368 | |
| 369 | bool rc = FALSE; |
| 370 | |
| 371 | HRESULT hr = m_pIDataSource->GetData(&fmtMemory, &stm); |
| 372 | if ( SUCCEEDED(hr) ) { |
| 373 | IDataObject *dataObject = m_dataObject->GetInterface(); |
| 374 | |
| 375 | hr = dataObject->SetData(&fmtMemory, &stm, TRUE); |
| 376 | if ( SUCCEEDED(hr) ) { |
| 377 | rc = TRUE; |
| 378 | } |
| 379 | else { |
| 380 | wxLogLastError("IDataObject::SetData()"); |
| 381 | } |
| 382 | } |
| 383 | else { |
| 384 | wxLogLastError("IDataObject::GetData()"); |
| 385 | } |
| 386 | |
| 387 | return rc; |
| 388 | } |
| 389 | |
| 390 | // ---------------------------------------------------------------------------- |
| 391 | // callbacks used by wxIDropTarget |
| 392 | // ---------------------------------------------------------------------------- |
| 393 | |
| 394 | // we need a data source, so wxIDropTarget gives it to us using this function |
| 395 | void wxDropTarget::SetDataSource(IDataObject *pIDataSource) |
| 396 | { |
| 397 | m_pIDataSource = pIDataSource; |
| 398 | } |
| 399 | |
| 400 | // determine if we accept data of this type |
| 401 | bool wxDropTarget::IsAcceptedData(IDataObject *pIDataSource) const |
| 402 | { |
| 403 | return GetSupportedFormat(pIDataSource) != wxDF_INVALID; |
| 404 | } |
| 405 | |
| 406 | // ---------------------------------------------------------------------------- |
| 407 | // helper functions |
| 408 | // ---------------------------------------------------------------------------- |
| 409 | |
| 410 | wxDataFormat wxDropTarget::GetSupportedFormat(IDataObject *pIDataSource) const |
| 411 | { |
| 412 | // this strucutre describes a data of any type (first field will be |
| 413 | // changing) being passed through global memory block. |
| 414 | static FORMATETC s_fmtMemory = { |
| 415 | 0, |
| 416 | NULL, |
| 417 | DVASPECT_CONTENT, |
| 418 | -1, |
| 419 | TYMED_HGLOBAL // TODO is it worth supporting other tymeds here? |
| 420 | }; |
| 421 | |
| 422 | // get the list of supported formats |
| 423 | size_t nFormats = m_dataObject->GetFormatCount(wxDataObject::Set); |
| 424 | wxDataFormat format, *formats; |
| 425 | formats = nFormats == 1 ? &format : new wxDataFormat[nFormats]; |
| 426 | |
| 427 | m_dataObject->GetAllFormats(formats, wxDataObject::Set); |
| 428 | |
| 429 | // cycle through all supported formats |
| 430 | size_t n; |
| 431 | for ( n = 0; n < nFormats; n++ ) { |
| 432 | s_fmtMemory.cfFormat = formats[n]; |
| 433 | |
| 434 | // NB: don't use SUCCEEDED macro here: QueryGetData returns S_FALSE |
| 435 | // for file drag and drop (format == CF_HDROP) |
| 436 | if ( pIDataSource->QueryGetData(&s_fmtMemory) == S_OK ) { |
| 437 | format = formats[n]; |
| 438 | |
| 439 | break; |
| 440 | } |
| 441 | } |
| 442 | |
| 443 | if ( formats != &format ) { |
| 444 | // free memory if we allocated it |
| 445 | delete [] formats; |
| 446 | } |
| 447 | |
| 448 | return n < nFormats ? format : wxFormatInvalid; |
| 449 | } |
| 450 | |
| 451 | // ---------------------------------------------------------------------------- |
| 452 | // private functions |
| 453 | // ---------------------------------------------------------------------------- |
| 454 | |
| 455 | static wxDragResult ConvertDragEffectToResult(DWORD dwEffect) |
| 456 | { |
| 457 | switch ( dwEffect ) { |
| 458 | case DROPEFFECT_COPY: |
| 459 | return wxDragCopy; |
| 460 | |
| 461 | case DROPEFFECT_MOVE: |
| 462 | return wxDragMove; |
| 463 | |
| 464 | default: |
| 465 | wxFAIL_MSG(wxT("invalid value in ConvertDragEffectToResult")); |
| 466 | // fall through |
| 467 | |
| 468 | case DROPEFFECT_NONE: |
| 469 | return wxDragNone; |
| 470 | } |
| 471 | } |
| 472 | |
| 473 | static DWORD ConvertDragResultToEffect(wxDragResult result) |
| 474 | { |
| 475 | switch ( result ) { |
| 476 | case wxDragCopy: |
| 477 | return DROPEFFECT_COPY; |
| 478 | |
| 479 | case wxDragMove: |
| 480 | return DROPEFFECT_MOVE; |
| 481 | |
| 482 | default: |
| 483 | wxFAIL_MSG(wxT("invalid value in ConvertDragResultToEffect")); |
| 484 | // fall through |
| 485 | |
| 486 | case wxDragNone: |
| 487 | return DROPEFFECT_NONE; |
| 488 | } |
| 489 | } |
| 490 | |
| 491 | #endif |
| 492 | // wxUSE_DRAG_AND_DROP |