src/msw/ole/dropsrc.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        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:      $Id$
   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 #ifdef __GNUG__
  21   #pragma implementation "dropsrc.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 #ifndef WX_PRECOMP
  31 #include "wx/window.h"
  32 #endif
  33
  34 #include "wx/setup.h"
  35
  36 #if wxUSE_OLE && wxUSE_DRAG_AND_DROP
  37
  38 #include "wx/log.h"
  39 #include "wx/dnd.h"
  40
  41 #include <windows.h>
  42
  43 // for some compilers, the entire ole2.h must be included, not only oleauto.h
  44 #if wxUSE_NORLANDER_HEADERS || defined(__WATCOMC__)
  45     #include <ole2.h>
  46 #endif
  47
  48 #include <oleauto.h>
  49
  50 #include "wx/msw/ole/oleutils.h"
  51
  52 // ----------------------------------------------------------------------------
  53 // wxIDropSource implementation of IDropSource interface
  54 // ----------------------------------------------------------------------------
  55
  56 class wxIDropSource : public IDropSource
  57 {
  58 public:
  59   wxIDropSource(wxDropSource *pDropSource);
  60
  61   DECLARE_IUNKNOWN_METHODS;
  62
  63   // IDropSource
  64   STDMETHODIMP QueryContinueDrag(BOOL fEscapePressed, DWORD grfKeyState);
  65   STDMETHODIMP GiveFeedback(DWORD dwEffect);
  66
  67 private:
  68   DWORD         m_grfInitKeyState;  // button which started the d&d operation
  69   wxDropSource *m_pDropSource;      // pointer to C++ class we belong to
  70
  71     DECLARE_NO_COPY_CLASS(wxIDropSource)
  72 };
  73
  74 // ============================================================================
  75 // Implementation
  76 // ============================================================================
  77
  78 // ----------------------------------------------------------------------------
  79 // wxIDropSource implementation
  80 // ----------------------------------------------------------------------------
  81 BEGIN_IID_TABLE(wxIDropSource)
  82   ADD_IID(Unknown)
  83   ADD_IID(DropSource)
  84 END_IID_TABLE;
  85
  86 IMPLEMENT_IUNKNOWN_METHODS(wxIDropSource)
  87
  88 wxIDropSource::wxIDropSource(wxDropSource *pDropSource)
  89 {
  90   wxASSERT( pDropSource != NULL );
  91
  92   m_pDropSource = pDropSource;
  93   m_grfInitKeyState = 0;
  94 }
  95
  96 // Name    : wxIDropSource::QueryContinueDrag
  97 // Purpose : decide if drag operation must be continued or not
  98 // Returns : HRESULT: S_OK              if we should continue
  99 //                    DRAGDROP_S_DROP   to drop right now
 100 //                    DRAGDROP_S_CANCEL to cancel everything
 101 // Params  : [in] BOOL  fEscapePressed  <Esc> pressed since last call?
 102 //           [in] DWORD grfKeyState     mask containing state of kbd keys
 103 // Notes   : as there is no reasonably simple portable way to implement this
 104 //           function, we currently don't give the possibility to override the
 105 //           default behaviour implemented here
 106 STDMETHODIMP wxIDropSource::QueryContinueDrag(BOOL fEscapePressed,
 107                                               DWORD grfKeyState)
 108 {
 109   if ( fEscapePressed )
 110     return DRAGDROP_S_CANCEL;
 111
 112   // initialize ourself with the drag begin button
 113   if ( m_grfInitKeyState == 0 ) {
 114     m_grfInitKeyState = grfKeyState & (MK_LBUTTON | MK_RBUTTON | MK_MBUTTON);
 115   }
 116
 117   if ( !(grfKeyState & m_grfInitKeyState) ) {
 118     // button which started d&d released, go!
 119     return DRAGDROP_S_DROP;
 120   }
 121
 122   return S_OK;
 123 }
 124
 125 // Name    : wxIDropSource::GiveFeedback
 126 // Purpose : give UI feedback according to current state of operation
 127 // Returns : STDMETHODIMP
 128 // Params  : [in] DWORD dwEffect - what would happen if we dropped now
 129 // Notes   : default implementation is ok in more than 99% of cases
 130 STDMETHODIMP wxIDropSource::GiveFeedback(DWORD dwEffect)
 131 {
 132   wxDragResult effect;
 133   if ( dwEffect & DROPEFFECT_COPY )
 134     effect = wxDragCopy;
 135   else if ( dwEffect & DROPEFFECT_MOVE )
 136     effect = wxDragMove;
 137   else
 138     effect = wxDragNone;
 139
 140   if ( m_pDropSource->GiveFeedback(effect) )
 141     return S_OK;
 142
 143   return DRAGDROP_S_USEDEFAULTCURSORS;
 144 }
 145
 146 // ----------------------------------------------------------------------------
 147 // wxDropSource implementation
 148 // ----------------------------------------------------------------------------
 149
 150 // ctors
 151
 152 // common part of all ctors
 153 void wxDropSource::Init()
 154 {
 155     m_pIDropSource = new wxIDropSource(this);
 156     m_pIDropSource->AddRef();
 157 }
 158
 159 wxDropSource::wxDropSource(wxWindow* WXUNUSED(win),
 160                            const wxCursor &cursorCopy,
 161                            const wxCursor &cursorMove,
 162                            const wxCursor &cursorStop)
 163             : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
 164 {
 165     Init();
 166 }
 167
 168 wxDropSource::wxDropSource(wxDataObject& data,
 169                            wxWindow* WXUNUSED(win),
 170                            const wxCursor &cursorCopy,
 171                            const wxCursor &cursorMove,
 172                            const wxCursor &cursorStop)
 173             : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
 174 {
 175     Init();
 176     SetData(data);
 177 }
 178
 179 wxDropSource::~wxDropSource()
 180 {
 181     m_pIDropSource->Release();
 182 }
 183
 184 // Name    : DoDragDrop
 185 // Purpose : start drag and drop operation
 186 // Returns : wxDragResult - the code of performed operation
 187 // Params  : [in] int flags: specifies if moving is allowe (or only copying)
 188 // Notes   : you must call SetData() before if you had used def ctor
 189 wxDragResult wxDropSource::DoDragDrop(int flags)
 190 {
 191   wxCHECK_MSG( m_data != NULL, wxDragNone, wxT("No data in wxDropSource!") );
 192
 193   DWORD dwEffect;
 194   HRESULT hr = ::DoDragDrop(m_data->GetInterface(),
 195                             m_pIDropSource,
 196                             (flags & wxDrag_AllowMove)
 197                                 ? DROPEFFECT_COPY | DROPEFFECT_MOVE
 198                                 : DROPEFFECT_COPY,
 199                             &dwEffect);
 200
 201   if ( hr == DRAGDROP_S_CANCEL ) {
 202     return wxDragCancel;
 203   }
 204   else if ( hr == DRAGDROP_S_DROP ) {
 205     if ( dwEffect & DROPEFFECT_COPY ) {
 206       return wxDragCopy;
 207     }
 208     else if ( dwEffect & DROPEFFECT_MOVE ) {
 209       // consistency check: normally, we shouldn't get "move" at all
 210       // here if we don't allow it, but in practice it does happen quite often
 211       return (flags & wxDrag_AllowMove) ? wxDragMove : wxDragCopy;
 212     }
 213     else {
 214       // not copy or move
 215       return wxDragNone;
 216     }
 217   }
 218   else {
 219     if ( FAILED(hr) ) {
 220       wxLogApiError(wxT("DoDragDrop"), hr);
 221       wxLogError(wxT("Drag & drop operation failed."));
 222     }
 223     else {
 224       wxLogDebug(wxT("Unexpected success return code %08lx from DoDragDrop."),
 225                  hr);
 226     }
 227
 228     return wxDragError;
 229   }
 230 }
 231
 232 // Name    : wxDropSource::GiveFeedback
 233 // Purpose : visually inform the user about d&d operation state
 234 // Returns : bool: true if we do all ourselves or false for default feedback
 235 // Params  : [in] DragResult effect - what would happen if we dropped now
 236 // Notes   : here we just leave this stuff for default implementation
 237 bool wxDropSource::GiveFeedback(wxDragResult effect)
 238 {
 239     const wxCursor& cursor = GetCursor(effect);
 240     if ( cursor.Ok() )
 241     {
 242         ::SetCursor((HCURSOR)cursor.GetHCURSOR());
 243
 244         return TRUE;
 245     }
 246     else
 247     {
 248         return FALSE;
 249     }
 250 }
 251
 252 #endif  //USE_DRAG_AND_DROP