1///////////////////////////////////////////////////////////////////////////////
2// Name:        src/msw/ole/dropsrc.cpp
3// Purpose:     implementation of wxIDropSource and wxDropSource
4// Author:      Vadim Zeitlin
5// Modified by:
6// Created:     10.05.98
7// RCS-ID:      $Id: dropsrc.cpp 38920 2006-04-26 08:21:31Z ABX $
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/window.h"
31    #include "wx/log.h"
32#endif
33
34#include "wx/dnd.h"
35
36#include "wx/msw/private.h"
37
38// for some compilers, the entire ole2.h must be included, not only oleauto.h
39#if wxUSE_NORLANDER_HEADERS || defined(__WATCOMC__) || defined(__WXWINCE__)
40    #include <ole2.h>
41#endif
42
43#include <oleauto.h>
44
45#include "wx/msw/ole/oleutils.h"
46
47// ----------------------------------------------------------------------------
48// wxIDropSource implementation of IDropSource interface
49// ----------------------------------------------------------------------------
50
51class wxIDropSource : public IDropSource
52{
53public:
54  wxIDropSource(wxDropSource *pDropSource);
55  virtual ~wxIDropSource() { }
56
57  // IDropSource
58  STDMETHODIMP QueryContinueDrag(BOOL fEscapePressed, DWORD grfKeyState);
59  STDMETHODIMP GiveFeedback(DWORD dwEffect);
60
61    DECLARE_IUNKNOWN_METHODS;
62
63private:
64  DWORD         m_grfInitKeyState;  // button which started the d&d operation
65  wxDropSource *m_pDropSource;      // pointer to C++ class we belong to
66
67  DECLARE_NO_COPY_CLASS(wxIDropSource)
68};
69
70// ============================================================================
71// Implementation
72// ============================================================================
73
74// ----------------------------------------------------------------------------
75// wxIDropSource implementation
76// ----------------------------------------------------------------------------
77BEGIN_IID_TABLE(wxIDropSource)
78  ADD_IID(Unknown)
79  ADD_IID(DropSource)
80END_IID_TABLE;
81
82IMPLEMENT_IUNKNOWN_METHODS(wxIDropSource)
83
84wxIDropSource::wxIDropSource(wxDropSource *pDropSource)
85{
86  wxASSERT( pDropSource != NULL );
87
88  m_pDropSource = pDropSource;
89  m_grfInitKeyState = 0;
90}
91
92// Name    : wxIDropSource::QueryContinueDrag
93// Purpose : decide if drag operation must be continued or not
94// Returns : HRESULT: S_OK              if we should continue
95//                    DRAGDROP_S_DROP   to drop right now
96//                    DRAGDROP_S_CANCEL to cancel everything
97// Params  : [in] BOOL  fEscapePressed  <Esc> pressed since last call?
98//           [in] DWORD grfKeyState     mask containing state of kbd keys
99// Notes   : as there is no reasonably simple portable way to implement this
100//           function, we currently don't give the possibility to override the
101//           default behaviour implemented here
102STDMETHODIMP wxIDropSource::QueryContinueDrag(BOOL fEscapePressed,
103                                              DWORD grfKeyState)
104{
105  if ( fEscapePressed )
106    return DRAGDROP_S_CANCEL;
107
108  // initialize ourself with the drag begin button
109  if ( m_grfInitKeyState == 0 ) {
110    m_grfInitKeyState = grfKeyState & (MK_LBUTTON | MK_RBUTTON | MK_MBUTTON);
111  }
112
113  if ( !(grfKeyState & m_grfInitKeyState) ) {
114    // button which started d&d released, go!
115    return DRAGDROP_S_DROP;
116  }
117
118  return S_OK;
119}
120
121// Name    : wxIDropSource::GiveFeedback
122// Purpose : give UI feedback according to current state of operation
123// Returns : STDMETHODIMP
124// Params  : [in] DWORD dwEffect - what would happen if we dropped now
125// Notes   : default implementation is ok in more than 99% of cases
126STDMETHODIMP wxIDropSource::GiveFeedback(DWORD dwEffect)
127{
128  wxDragResult effect;
129  if ( dwEffect & DROPEFFECT_COPY )
130    effect = wxDragCopy;
131  else if ( dwEffect & DROPEFFECT_MOVE )
132    effect = wxDragMove;
133  else
134    effect = wxDragNone;
135
136  if ( m_pDropSource->GiveFeedback(effect) )
137    return S_OK;
138
139  return DRAGDROP_S_USEDEFAULTCURSORS;
140}
141
142// ----------------------------------------------------------------------------
143// wxDropSource implementation
144// ----------------------------------------------------------------------------
145
146// ctors
147
148// common part of all ctors
149void wxDropSource::Init()
150{
151    m_pIDropSource = new wxIDropSource(this);
152    m_pIDropSource->AddRef();
153}
154
155wxDropSource::wxDropSource(wxWindow* WXUNUSED(win),
156                           const wxCursor &cursorCopy,
157                           const wxCursor &cursorMove,
158                           const wxCursor &cursorStop)
159            : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
160{
161    Init();
162}
163
164wxDropSource::wxDropSource(wxDataObject& data,
165                           wxWindow* WXUNUSED(win),
166                           const wxCursor &cursorCopy,
167                           const wxCursor &cursorMove,
168                           const wxCursor &cursorStop)
169            : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
170{
171    Init();
172    SetData(data);
173}
174
175wxDropSource::~wxDropSource()
176{
177    m_pIDropSource->Release();
178}
179
180// Name    : DoDragDrop
181// Purpose : start drag and drop operation
182// Returns : wxDragResult - the code of performed operation
183// Params  : [in] int flags: specifies if moving is allowe (or only copying)
184// Notes   : you must call SetData() before if you had used def ctor
185wxDragResult wxDropSource::DoDragDrop(int flags)
186{
187  wxCHECK_MSG( m_data != NULL, wxDragNone, wxT("No data in wxDropSource!") );
188
189  DWORD dwEffect;
190  HRESULT hr = ::DoDragDrop(m_data->GetInterface(),
191                            m_pIDropSource,
192                            (flags & wxDrag_AllowMove)
193                                ? DROPEFFECT_COPY | DROPEFFECT_MOVE
194                                : DROPEFFECT_COPY,
195                            &dwEffect);
196
197  if ( hr == DRAGDROP_S_CANCEL ) {
198    return wxDragCancel;
199  }
200  else if ( hr == DRAGDROP_S_DROP ) {
201    if ( dwEffect & DROPEFFECT_COPY ) {
202      return wxDragCopy;
203    }
204    else if ( dwEffect & DROPEFFECT_MOVE ) {
205      // consistency check: normally, we shouldn't get "move" at all
206      // here if we don't allow it, but in practice it does happen quite often
207      return (flags & wxDrag_AllowMove) ? wxDragMove : wxDragCopy;
208    }
209    else {
210      // not copy or move
211      return wxDragNone;
212    }
213  }
214  else {
215    if ( FAILED(hr) ) {
216      wxLogApiError(wxT("DoDragDrop"), hr);
217      wxLogError(wxT("Drag & drop operation failed."));
218    }
219    else {
220      wxLogDebug(wxT("Unexpected success return code %08lx from DoDragDrop."),
221                 hr);
222    }
223
224    return wxDragError;
225  }
226}
227
228// Name    : wxDropSource::GiveFeedback
229// Purpose : visually inform the user about d&d operation state
230// Returns : bool: true if we do all ourselves or false for default feedback
231// Params  : [in] DragResult effect - what would happen if we dropped now
232// Notes   : here we just leave this stuff for default implementation
233bool wxDropSource::GiveFeedback(wxDragResult effect)
234{
235    const wxCursor& cursor = GetCursor(effect);
236    if ( cursor.Ok() )
237    {
238        ::SetCursor((HCURSOR)cursor.GetHCURSOR());
239
240        return true;
241    }
242    else
243    {
244        return false;
245    }
246}
247
248#endif  // wxUSE_OLE && wxUSE_DRAG_AND_DROP
249