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: droptgt.cpp 54398 2008-06-28 01:40:42Z VZ $
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
SetHwnd(HWND hwnd)66 void SetHwnd(HWND hwnd) { m_hwnd = hwnd; }
67
68 // IDropTarget methods
69 STDMETHODIMP DragEnter(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
70 STDMETHODIMP DragOver(DWORD, POINTL, LPDWORD);
71 STDMETHODIMP DragLeave();
72 STDMETHODIMP Drop(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
73
74 DECLARE_IUNKNOWN_METHODS;
75
76 protected:
77 IDataObject *m_pIDataObject; // !NULL between DragEnter and DragLeave/Drop
78 wxDropTarget *m_pTarget; // the real target (we're just a proxy)
79
80 HWND m_hwnd; // window we're associated with
81
82 // get default drop effect for given keyboard flags
83 static DWORD GetDropEffect(DWORD flags, wxDragResult defaultAction, DWORD pdwEffect);
84
85 DECLARE_NO_COPY_CLASS(wxIDropTarget)
86 };
87
88 // ----------------------------------------------------------------------------
89 // private functions
90 // ----------------------------------------------------------------------------
91
92 static wxDragResult ConvertDragEffectToResult(DWORD dwEffect);
93 static DWORD ConvertDragResultToEffect(wxDragResult result);
94
95 // ============================================================================
96 // wxIDropTarget implementation
97 // ============================================================================
98
99 // Name : static wxIDropTarget::GetDropEffect
100 // Purpose : determine the drop operation from keyboard/mouse state.
101 // Returns : DWORD combined from DROPEFFECT_xxx constants
102 // Params : [in] DWORD flags kbd & mouse flags as passed to
103 // IDropTarget methods
104 // Notes : We do "move" normally and "copy" if <Ctrl> is pressed,
105 // which is the standard behaviour (currently there is no
106 // way to redefine it)
GetDropEffect(DWORD flags,wxDragResult defaultAction,DWORD pdwEffect)107 DWORD wxIDropTarget::GetDropEffect(DWORD flags,
108 wxDragResult defaultAction,
109 DWORD pdwEffect)
110 {
111 DWORD effectiveAction;
112 if ( defaultAction == wxDragCopy )
113 effectiveAction = flags & MK_SHIFT ? DROPEFFECT_MOVE : DROPEFFECT_COPY;
114 else
115 effectiveAction = flags & MK_CONTROL ? DROPEFFECT_COPY : DROPEFFECT_MOVE;
116
117 if ( !(effectiveAction & pdwEffect) )
118 {
119 // the action is not supported by drag source, fall back to something
120 // that it does support
121 if ( pdwEffect & DROPEFFECT_MOVE )
122 effectiveAction = DROPEFFECT_MOVE;
123 else if ( pdwEffect & DROPEFFECT_COPY )
124 effectiveAction = DROPEFFECT_COPY;
125 else if ( pdwEffect & DROPEFFECT_LINK )
126 effectiveAction = DROPEFFECT_LINK;
127 else
128 effectiveAction = DROPEFFECT_NONE;
129 }
130
131 return effectiveAction;
132 }
133
wxIDropTarget(wxDropTarget * pTarget)134 wxIDropTarget::wxIDropTarget(wxDropTarget *pTarget)
135 {
136 m_pTarget = pTarget;
137 m_pIDataObject = NULL;
138 }
139
~wxIDropTarget()140 wxIDropTarget::~wxIDropTarget()
141 {
142 }
143
144 BEGIN_IID_TABLE(wxIDropTarget)
145 ADD_IID(Unknown)
146 ADD_IID(DropTarget)
147 END_IID_TABLE;
148
IMPLEMENT_IUNKNOWN_METHODS(wxIDropTarget)149 IMPLEMENT_IUNKNOWN_METHODS(wxIDropTarget)
150
151 // Name : wxIDropTarget::DragEnter
152 // Purpose : Called when the mouse enters the window (dragging something)
153 // Returns : S_OK
154 // Params : [in] IDataObject *pIDataSource : source data
155 // [in] DWORD grfKeyState : kbd & mouse state
156 // [in] POINTL pt : mouse coordinates
157 // [out]DWORD *pdwEffect : effect flag
158 // Notes :
159 STDMETHODIMP wxIDropTarget::DragEnter(IDataObject *pIDataSource,
160 DWORD grfKeyState,
161 POINTL pt,
162 DWORD *pdwEffect)
163 {
164 wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragEnter"));
165
166 wxASSERT_MSG( m_pIDataObject == NULL,
167 _T("drop target must have data object") );
168
169 // show the list of formats supported by the source data object for the
170 // debugging purposes, this is quite useful sometimes - please don't remove
171 #if 0
172 IEnumFORMATETC *penumFmt;
173 if ( SUCCEEDED(pIDataSource->EnumFormatEtc(DATADIR_GET, &penumFmt)) )
174 {
175 FORMATETC fmt;
176 while ( penumFmt->Next(1, &fmt, NULL) == S_OK )
177 {
178 wxLogDebug(_T("Drop source supports format %s"),
179 wxDataObject::GetFormatName(fmt.cfFormat));
180 }
181
182 penumFmt->Release();
183 }
184 else
185 {
186 wxLogLastError(_T("IDataObject::EnumFormatEtc"));
187 }
188 #endif // 0
189
190 if ( !m_pTarget->IsAcceptedData(pIDataSource) ) {
191 // we don't accept this kind of data
192 *pdwEffect = DROPEFFECT_NONE;
193
194 return S_OK;
195 }
196
197 // get hold of the data object
198 m_pIDataObject = pIDataSource;
199 m_pIDataObject->AddRef();
200
201 // we need client coordinates to pass to wxWin functions
202 if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
203 {
204 wxLogLastError(wxT("ScreenToClient"));
205 }
206
207 // give some visual feedback
208 *pdwEffect = ConvertDragResultToEffect(
209 m_pTarget->OnEnter(pt.x, pt.y, ConvertDragEffectToResult(
210 GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect))
211 )
212 );
213
214 return S_OK;
215 }
216
217 // Name : wxIDropTarget::DragOver
218 // Purpose : Indicates that the mouse was moved inside the window represented
219 // by this drop target.
220 // Returns : S_OK
221 // Params : [in] DWORD grfKeyState kbd & mouse state
222 // [in] POINTL pt mouse coordinates
223 // [out]LPDWORD pdwEffect effect flag
224 // Notes : We're called on every WM_MOUSEMOVE, so this function should be
225 // very efficient.
DragOver(DWORD grfKeyState,POINTL pt,LPDWORD pdwEffect)226 STDMETHODIMP wxIDropTarget::DragOver(DWORD grfKeyState,
227 POINTL pt,
228 LPDWORD pdwEffect)
229 {
230 // there are too many of them... wxLogDebug("IDropTarget::DragOver");
231
232 wxDragResult result;
233 if ( m_pIDataObject ) {
234 result = ConvertDragEffectToResult(
235 GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect));
236 }
237 else {
238 // can't accept data anyhow normally
239 result = wxDragNone;
240 }
241
242 if ( result != wxDragNone ) {
243 // we need client coordinates to pass to wxWin functions
244 if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
245 {
246 wxLogLastError(wxT("ScreenToClient"));
247 }
248
249 *pdwEffect = ConvertDragResultToEffect(
250 m_pTarget->OnDragOver(pt.x, pt.y, result)
251 );
252 }
253 else {
254 *pdwEffect = DROPEFFECT_NONE;
255 }
256
257 return S_OK;
258 }
259
260 // Name : wxIDropTarget::DragLeave
261 // Purpose : Informs the drop target that the operation has left its window.
262 // Returns : S_OK
263 // Notes : good place to do any clean-up
DragLeave()264 STDMETHODIMP wxIDropTarget::DragLeave()
265 {
266 wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragLeave"));
267
268 // remove the UI feedback
269 m_pTarget->OnLeave();
270
271 // release the held object
272 RELEASE_AND_NULL(m_pIDataObject);
273
274 return S_OK;
275 }
276
277 // Name : wxIDropTarget::Drop
278 // Purpose : Instructs the drop target to paste data that was just now
279 // dropped on it.
280 // Returns : S_OK
281 // Params : [in] IDataObject *pIDataSource the data to paste
282 // [in] DWORD grfKeyState kbd & mouse state
283 // [in] POINTL pt where the drop occurred?
284 // [ouy]DWORD *pdwEffect operation effect
285 // Notes :
Drop(IDataObject * pIDataSource,DWORD grfKeyState,POINTL pt,DWORD * pdwEffect)286 STDMETHODIMP wxIDropTarget::Drop(IDataObject *pIDataSource,
287 DWORD grfKeyState,
288 POINTL pt,
289 DWORD *pdwEffect)
290 {
291 wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::Drop"));
292
293 // TODO I don't know why there is this parameter, but so far I assume
294 // that it's the same we've already got in DragEnter
295 wxASSERT( m_pIDataObject == pIDataSource );
296
297 // we need client coordinates to pass to wxWin functions
298 if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
299 {
300 wxLogLastError(wxT("ScreenToClient"));
301 }
302
303 // first ask the drop target if it wants data
304 if ( m_pTarget->OnDrop(pt.x, pt.y) ) {
305 // it does, so give it the data source
306 m_pTarget->SetDataSource(pIDataSource);
307
308 // and now it has the data
309 wxDragResult rc = ConvertDragEffectToResult(
310 GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction(), *pdwEffect));
311 rc = m_pTarget->OnData(pt.x, pt.y, rc);
312 if ( wxIsDragResultOk(rc) ) {
313 // operation succeeded
314 *pdwEffect = ConvertDragResultToEffect(rc);
315 }
316 else {
317 *pdwEffect = DROPEFFECT_NONE;
318 }
319 }
320 else {
321 // OnDrop() returned false, no need to copy data
322 *pdwEffect = DROPEFFECT_NONE;
323 }
324
325 // release the held object
326 RELEASE_AND_NULL(m_pIDataObject);
327
328 return S_OK;
329 }
330
331 // ============================================================================
332 // wxDropTarget implementation
333 // ============================================================================
334
335 // ----------------------------------------------------------------------------
336 // ctor/dtor
337 // ----------------------------------------------------------------------------
338
wxDropTarget(wxDataObject * dataObj)339 wxDropTarget::wxDropTarget(wxDataObject *dataObj)
340 : wxDropTargetBase(dataObj)
341 {
342 // create an IDropTarget implementation which will notify us about d&d
343 // operations.
344 m_pIDropTarget = new wxIDropTarget(this);
345 m_pIDropTarget->AddRef();
346 }
347
~wxDropTarget()348 wxDropTarget::~wxDropTarget()
349 {
350 ReleaseInterface(m_pIDropTarget);
351 }
352
353 // ----------------------------------------------------------------------------
354 // [un]register drop handler
355 // ----------------------------------------------------------------------------
356
Register(WXHWND hwnd)357 bool wxDropTarget::Register(WXHWND hwnd)
358 {
359 // FIXME
360 // RegisterDragDrop not available on Windows CE >= 400?
361 // Or maybe we can dynamically load them from ceshell.dll
362 // or similar.
363 #if defined(__WXWINCE__) && _WIN32_WCE >= 400
364 wxUnusedVar(hwnd);
365 return false;
366 #else
367 HRESULT hr;
368
369 // May exist in later WinCE versions
370 #ifndef __WXWINCE__
371 hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE);
372 if ( FAILED(hr) ) {
373 wxLogApiError(wxT("CoLockObjectExternal"), hr);
374 return false;
375 }
376 #endif
377
378 hr = ::RegisterDragDrop((HWND) hwnd, m_pIDropTarget);
379 if ( FAILED(hr) ) {
380 // May exist in later WinCE versions
381 #ifndef __WXWINCE__
382 ::CoLockObjectExternal(m_pIDropTarget, FALSE, FALSE);
383 #endif
384 wxLogApiError(wxT("RegisterDragDrop"), hr);
385 return false;
386 }
387
388 // we will need the window handle for coords transformation later
389 m_pIDropTarget->SetHwnd((HWND)hwnd);
390
391 return true;
392 #endif
393 }
394
Revoke(WXHWND hwnd)395 void wxDropTarget::Revoke(WXHWND hwnd)
396 {
397 #if defined(__WXWINCE__) && _WIN32_WCE >= 400
398 // Not available, see note above
399 wxUnusedVar(hwnd);
400 #else
401 HRESULT hr = ::RevokeDragDrop((HWND) hwnd);
402
403 if ( FAILED(hr) ) {
404 wxLogApiError(wxT("RevokeDragDrop"), hr);
405 }
406
407 // May exist in later WinCE versions
408 #ifndef __WXWINCE__
409 ::CoLockObjectExternal(m_pIDropTarget, FALSE, TRUE);
410 #endif
411
412 m_pIDropTarget->SetHwnd(0);
413 #endif
414 }
415
416 // ----------------------------------------------------------------------------
417 // base class pure virtuals
418 // ----------------------------------------------------------------------------
419
420 // OnDrop() is called only if we previously returned true from
421 // IsAcceptedData(), so no need to check anything here
OnDrop(wxCoord WXUNUSED (x),wxCoord WXUNUSED (y))422 bool wxDropTarget::OnDrop(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y))
423 {
424 return true;
425 }
426
427 // copy the data from the data source to the target data object
GetData()428 bool wxDropTarget::GetData()
429 {
430 wxDataFormat format = GetSupportedFormat(m_pIDataSource);
431 if ( format == wxDF_INVALID ) {
432 // this is strange because IsAcceptedData() succeeded previously!
433 wxFAIL_MSG(wxT("strange - did supported formats list change?"));
434
435 return false;
436 }
437
438 STGMEDIUM stm;
439 FORMATETC fmtMemory;
440 fmtMemory.cfFormat = format;
441 fmtMemory.ptd = NULL;
442 fmtMemory.dwAspect = DVASPECT_CONTENT;
443 fmtMemory.lindex = -1;
444 fmtMemory.tymed = TYMED_HGLOBAL; // TODO to add other media
445
446 bool rc = false;
447
448 HRESULT hr = m_pIDataSource->GetData(&fmtMemory, &stm);
449 if ( SUCCEEDED(hr) ) {
450 IDataObject *dataObject = m_dataObject->GetInterface();
451
452 hr = dataObject->SetData(&fmtMemory, &stm, TRUE);
453 if ( SUCCEEDED(hr) ) {
454 rc = true;
455 }
456 else {
457 wxLogApiError(wxT("IDataObject::SetData()"), hr);
458 }
459 }
460 else {
461 wxLogApiError(wxT("IDataObject::GetData()"), hr);
462 }
463
464 return rc;
465 }
466
467 // ----------------------------------------------------------------------------
468 // callbacks used by wxIDropTarget
469 // ----------------------------------------------------------------------------
470
471 // we need a data source, so wxIDropTarget gives it to us using this function
SetDataSource(IDataObject * pIDataSource)472 void wxDropTarget::SetDataSource(IDataObject *pIDataSource)
473 {
474 m_pIDataSource = pIDataSource;
475 }
476
477 // determine if we accept data of this type
IsAcceptedData(IDataObject * pIDataSource) const478 bool wxDropTarget::IsAcceptedData(IDataObject *pIDataSource) const
479 {
480 return GetSupportedFormat(pIDataSource) != wxDF_INVALID;
481 }
482
483 // ----------------------------------------------------------------------------
484 // helper functions
485 // ----------------------------------------------------------------------------
486
GetSupportedFormat(IDataObject * pIDataSource) const487 wxDataFormat wxDropTarget::GetSupportedFormat(IDataObject *pIDataSource) const
488 {
489 // this strucutre describes a data of any type (first field will be
490 // changing) being passed through global memory block.
491 static FORMATETC s_fmtMemory = {
492 0,
493 NULL,
494 DVASPECT_CONTENT,
495 -1,
496 TYMED_HGLOBAL // TODO is it worth supporting other tymeds here?
497 };
498
499 // get the list of supported formats
500 size_t nFormats = m_dataObject->GetFormatCount(wxDataObject::Set);
501 wxDataFormat format;
502 wxDataFormat *formats;
503 formats = nFormats == 1 ? &format : new wxDataFormat[nFormats];
504
505 m_dataObject->GetAllFormats(formats, wxDataObject::Set);
506
507 // cycle through all supported formats
508 size_t n;
509 for ( n = 0; n < nFormats; n++ ) {
510 s_fmtMemory.cfFormat = formats[n];
511
512 // NB: don't use SUCCEEDED macro here: QueryGetData returns S_FALSE
513 // for file drag and drop (format == CF_HDROP)
514 if ( pIDataSource->QueryGetData(&s_fmtMemory) == S_OK ) {
515 format = formats[n];
516
517 break;
518 }
519 }
520
521 if ( formats != &format ) {
522 // free memory if we allocated it
523 delete [] formats;
524 }
525
526 return n < nFormats ? format : wxFormatInvalid;
527 }
528
529 // ----------------------------------------------------------------------------
530 // private functions
531 // ----------------------------------------------------------------------------
532
ConvertDragEffectToResult(DWORD dwEffect)533 static wxDragResult ConvertDragEffectToResult(DWORD dwEffect)
534 {
535 switch ( dwEffect ) {
536 case DROPEFFECT_COPY:
537 return wxDragCopy;
538
539 case DROPEFFECT_LINK:
540 return wxDragLink;
541
542 case DROPEFFECT_MOVE:
543 return wxDragMove;
544
545 default:
546 wxFAIL_MSG(wxT("invalid value in ConvertDragEffectToResult"));
547 // fall through
548
549 case DROPEFFECT_NONE:
550 return wxDragNone;
551 }
552 }
553
ConvertDragResultToEffect(wxDragResult result)554 static DWORD ConvertDragResultToEffect(wxDragResult result)
555 {
556 switch ( result ) {
557 case wxDragCopy:
558 return DROPEFFECT_COPY;
559
560 case wxDragLink:
561 return DROPEFFECT_LINK;
562
563 case wxDragMove:
564 return DROPEFFECT_MOVE;
565
566 default:
567 wxFAIL_MSG(wxT("invalid value in ConvertDragResultToEffect"));
568 // fall through
569
570 case wxDragNone:
571 return DROPEFFECT_NONE;
572 }
573 }
574
575 #endif // wxUSE_OLE && wxUSE_DRAG_AND_DROP
576