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 license
  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 #if wxUSE_NORLANDER_HEADERS
  44     #include <ole2.h>
  45 #endif
  46
  47 #ifndef __WIN32__
  48     #include <ole2.h>
  49     #include <olestd.h>
  50 #endif
  51
  52 #include <oleauto.h>
  53
  54 #include "wx/msw/ole/oleutils.h"
  55
  56 // ----------------------------------------------------------------------------
  57 // wxIDropSource implementation of IDropSource interface
  58 // ----------------------------------------------------------------------------
  59
  60 class wxIDropSource : public IDropSource
  61 {
  62 public:
  63   wxIDropSource(wxDropSource *pDropSource);
  64
  65   DECLARE_IUNKNOWN_METHODS;
  66
  67   // IDropSource
  68   STDMETHODIMP QueryContinueDrag(BOOL fEscapePressed, DWORD grfKeyState);
  69   STDMETHODIMP GiveFeedback(DWORD dwEffect);
  70
  71 private:
  72   DWORD         m_grfInitKeyState;  // button which started the d&d operation
  73   wxDropSource *m_pDropSource;      // pointer to C++ class we belong to
  74
  75     DECLARE_NO_COPY_CLASS(wxIDropSource)
  76 };
  77
  78 // ============================================================================
  79 // Implementation
  80 // ============================================================================
  81
  82 // ----------------------------------------------------------------------------
  83 // wxIDropSource implementation
  84 // ----------------------------------------------------------------------------
  85 BEGIN_IID_TABLE(wxIDropSource)
  86   ADD_IID(Unknown)
  87   ADD_IID(DropSource)
  88 END_IID_TABLE;
  89
  90 IMPLEMENT_IUNKNOWN_METHODS(wxIDropSource)
  91
  92 wxIDropSource::wxIDropSource(wxDropSource *pDropSource)
  93 {
  94   wxASSERT( pDropSource != NULL );
  95
  96   m_pDropSource = pDropSource;
  97   m_grfInitKeyState = 0;
  98 }
  99
 100 // Name    : wxIDropSource::QueryContinueDrag
 101 // Purpose : decide if drag operation must be continued or not
 102 // Returns : HRESULT: S_OK              if we should continue
 103 //                    DRAGDROP_S_DROP   to drop right now
 104 //                    DRAGDROP_S_CANCEL to cancel everything
 105 // Params  : [in] BOOL  fEscapePressed  <Esc> pressed since last call?
 106 //           [in] DWORD grfKeyState     mask containing state of kbd keys
 107 // Notes   : as there is no reasonably simple portable way to implement this
 108 //           function, we currently don't give the possibility to override the
 109 //           default behaviour implemented here
 110 STDMETHODIMP wxIDropSource::QueryContinueDrag(BOOL fEscapePressed,
 111                                               DWORD grfKeyState)
 112 {
 113   if ( fEscapePressed )
 114     return DRAGDROP_S_CANCEL;
 115
 116   // initialize ourself with the drag begin button
 117   if ( m_grfInitKeyState == 0 ) {
 118     m_grfInitKeyState = grfKeyState & (MK_LBUTTON | MK_RBUTTON | MK_MBUTTON);
 119   }
 120
 121   if ( !(grfKeyState & m_grfInitKeyState) ) {
 122     // button which started d&d released, go!
 123     return DRAGDROP_S_DROP;
 124   }
 125
 126   return S_OK;
 127 }
 128
 129 // Name    : wxIDropSource::GiveFeedback
 130 // Purpose : give UI feedback according to current state of operation
 131 // Returns : STDMETHODIMP
 132 // Params  : [in] DWORD dwEffect - what would happen if we dropped now
 133 // Notes   : default implementation is ok in more than 99% of cases
 134 STDMETHODIMP wxIDropSource::GiveFeedback(DWORD dwEffect)
 135 {
 136   wxDragResult effect;
 137   if ( dwEffect & DROPEFFECT_COPY )
 138     effect = wxDragCopy;
 139   else if ( dwEffect & DROPEFFECT_MOVE )
 140     effect = wxDragMove;
 141   else
 142     effect = wxDragNone;
 143
 144   if ( m_pDropSource->GiveFeedback(effect) )
 145     return S_OK;
 146
 147   return DRAGDROP_S_USEDEFAULTCURSORS;
 148 }
 149
 150 // ----------------------------------------------------------------------------
 151 // wxDropSource implementation
 152 // ----------------------------------------------------------------------------
 153
 154 // ctors
 155
 156 // common part of all ctors
 157 void wxDropSource::Init()
 158 {
 159     m_pIDropSource = new wxIDropSource(this);
 160     m_pIDropSource->AddRef();
 161 }
 162
 163 wxDropSource::wxDropSource(wxWindow* WXUNUSED(win),
 164                            const wxCursor &cursorCopy,
 165                            const wxCursor &cursorMove,
 166                            const wxCursor &cursorStop)
 167             : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
 168 {
 169     Init();
 170 }
 171
 172 wxDropSource::wxDropSource(wxDataObject& data,
 173                            wxWindow* WXUNUSED(win),
 174                            const wxCursor &cursorCopy,
 175                            const wxCursor &cursorMove,
 176                            const wxCursor &cursorStop)
 177             : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
 178 {
 179     Init();
 180     SetData(data);
 181 }
 182
 183 wxDropSource::~wxDropSource()
 184 {
 185     m_pIDropSource->Release();
 186 }
 187
 188 // Name    : DoDragDrop
 189 // Purpose : start drag and drop operation
 190 // Returns : wxDragResult - the code of performed operation
 191 // Params  : [in] int flags: specifies if moving is allowe (or only copying)
 192 // Notes   : you must call SetData() before if you had used def ctor
 193 wxDragResult wxDropSource::DoDragDrop(int flags)
 194 {
 195   wxCHECK_MSG( m_data != NULL, wxDragNone, wxT("No data in wxDropSource!") );
 196
 197   DWORD dwEffect;
 198   HRESULT hr = ::DoDragDrop(m_data->GetInterface(),
 199                             m_pIDropSource,
 200                             (flags & wxDrag_AllowMove)
 201                                 ? DROPEFFECT_COPY | DROPEFFECT_MOVE
 202                                 : DROPEFFECT_COPY,
 203                             &dwEffect);
 204
 205   if ( hr == DRAGDROP_S_CANCEL ) {
 206     return wxDragCancel;
 207   }
 208   else if ( hr == DRAGDROP_S_DROP ) {
 209     if ( dwEffect & DROPEFFECT_COPY ) {
 210       return wxDragCopy;
 211     }
 212     else if ( dwEffect & DROPEFFECT_MOVE ) {
 213       // consistency check: normally, we shouldn't get "move" at all
 214       // here if we don't allow it, but in practice it does happen quite often
 215       return (flags & wxDrag_AllowMove) ? wxDragMove : wxDragCopy;
 216     }
 217     else {
 218       // not copy or move
 219       return wxDragNone;
 220     }
 221   }
 222   else {
 223     if ( FAILED(hr) ) {
 224       wxLogApiError(wxT("DoDragDrop"), hr);
 225       wxLogError(wxT("Drag & drop operation failed."));
 226     }
 227     else {
 228       wxLogDebug(wxT("Unexpected success return code %08lx from DoDragDrop."),
 229                  hr);
 230     }
 231
 232     return wxDragError;
 233   }
 234 }
 235
 236 // Name    : wxDropSource::GiveFeedback
 237 // Purpose : visually inform the user about d&d operation state
 238 // Returns : bool: true if we do all ourselves or false for default feedback
 239 // Params  : [in] DragResult effect - what would happen if we dropped now
 240 // Notes   : here we just leave this stuff for default implementation
 241 bool wxDropSource::GiveFeedback(wxDragResult effect)
 242 {
 243     const wxCursor& cursor = GetCursor(effect);
 244     if ( cursor.Ok() )
 245     {
 246         ::SetCursor((HCURSOR)cursor.GetHCURSOR());
 247
 248         return TRUE;
 249     }
 250     else
 251     {
 252         return FALSE;
 253     }
 254 }
 255
 256 #endif  //USE_DRAG_AND_DROP