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 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #if defined(__BORLANDC__)
  24   #pragma hdrstop
  25 #endif
  26 #ifndef WX_PRECOMP
  27 #include "wx/window.h"
  28 #endif
  29
  30 #include "wx/setup.h"
  31
  32 #if wxUSE_OLE && wxUSE_DRAG_AND_DROP
  33
  34 #include "wx/log.h"
  35 #include "wx/dnd.h"
  36
  37 #include "wx/msw/private.h"
  38
  39 // for some compilers, the entire ole2.h must be included, not only oleauto.h
  40 #if wxUSE_NORLANDER_HEADERS || defined(__WATCOMC__) || defined(__WXWINCE__)
  41     #include <ole2.h>
  42 #endif
  43
  44 #include <oleauto.h>
  45
  46 #include "wx/msw/ole/oleutils.h"
  47
  48 // ----------------------------------------------------------------------------
  49 // wxIDropSource implementation of IDropSource interface
  50 // ----------------------------------------------------------------------------
  51
  52 class wxIDropSource : public IDropSource
  53 {
  54 public:
  55   wxIDropSource(wxDropSource *pDropSource);
  56   virtual ~wxIDropSource() { }
  57
  58   DECLARE_IUNKNOWN_METHODS;
  59
  60   // IDropSource
  61   STDMETHODIMP QueryContinueDrag(BOOL fEscapePressed, DWORD grfKeyState);
  62   STDMETHODIMP GiveFeedback(DWORD dwEffect);
  63
  64 private:
  65   DWORD         m_grfInitKeyState;  // button which started the d&d operation
  66   wxDropSource *m_pDropSource;      // pointer to C++ class we belong to
  67
  68   DECLARE_NO_COPY_CLASS(wxIDropSource)
  69 };
  70
  71 // ============================================================================
  72 // Implementation
  73 // ============================================================================
  74
  75 // ----------------------------------------------------------------------------
  76 // wxIDropSource implementation
  77 // ----------------------------------------------------------------------------
  78 BEGIN_IID_TABLE(wxIDropSource)
  79   ADD_IID(Unknown)
  80   ADD_IID(DropSource)
  81 END_IID_TABLE;
  82
  83 IMPLEMENT_IUNKNOWN_METHODS(wxIDropSource)
  84
  85 wxIDropSource::wxIDropSource(wxDropSource *pDropSource)
  86 {
  87   wxASSERT( pDropSource != NULL );
  88
  89   m_pDropSource = pDropSource;
  90   m_grfInitKeyState = 0;
  91 }
  92
  93 // Name    : wxIDropSource::QueryContinueDrag
  94 // Purpose : decide if drag operation must be continued or not
  95 // Returns : HRESULT: S_OK              if we should continue
  96 //                    DRAGDROP_S_DROP   to drop right now
  97 //                    DRAGDROP_S_CANCEL to cancel everything
  98 // Params  : [in] BOOL  fEscapePressed  <Esc> pressed since last call?
  99 //           [in] DWORD grfKeyState     mask containing state of kbd keys
 100 // Notes   : as there is no reasonably simple portable way to implement this
 101 //           function, we currently don't give the possibility to override the
 102 //           default behaviour implemented here
 103 STDMETHODIMP wxIDropSource::QueryContinueDrag(BOOL fEscapePressed,
 104                                               DWORD grfKeyState)
 105 {
 106   if ( fEscapePressed )
 107     return DRAGDROP_S_CANCEL;
 108
 109   // initialize ourself with the drag begin button
 110   if ( m_grfInitKeyState == 0 ) {
 111     m_grfInitKeyState = grfKeyState & (MK_LBUTTON | MK_RBUTTON | MK_MBUTTON);
 112   }
 113
 114   if ( !(grfKeyState & m_grfInitKeyState) ) {
 115     // button which started d&d released, go!
 116     return DRAGDROP_S_DROP;
 117   }
 118
 119   return S_OK;
 120 }
 121
 122 // Name    : wxIDropSource::GiveFeedback
 123 // Purpose : give UI feedback according to current state of operation
 124 // Returns : STDMETHODIMP
 125 // Params  : [in] DWORD dwEffect - what would happen if we dropped now
 126 // Notes   : default implementation is ok in more than 99% of cases
 127 STDMETHODIMP wxIDropSource::GiveFeedback(DWORD dwEffect)
 128 {
 129   wxDragResult effect;
 130   if ( dwEffect & DROPEFFECT_COPY )
 131     effect = wxDragCopy;
 132   else if ( dwEffect & DROPEFFECT_MOVE )
 133     effect = wxDragMove;
 134   else
 135     effect = wxDragNone;
 136
 137   if ( m_pDropSource->GiveFeedback(effect) )
 138     return S_OK;
 139
 140   return DRAGDROP_S_USEDEFAULTCURSORS;
 141 }
 142
 143 // ----------------------------------------------------------------------------
 144 // wxDropSource implementation
 145 // ----------------------------------------------------------------------------
 146
 147 // ctors
 148
 149 // common part of all ctors
 150 void wxDropSource::Init()
 151 {
 152     m_pIDropSource = new wxIDropSource(this);
 153     m_pIDropSource->AddRef();
 154 }
 155
 156 wxDropSource::wxDropSource(wxWindow* WXUNUSED(win),
 157                            const wxCursor &cursorCopy,
 158                            const wxCursor &cursorMove,
 159                            const wxCursor &cursorStop)
 160             : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
 161 {
 162     Init();
 163 }
 164
 165 wxDropSource::wxDropSource(wxDataObject& data,
 166                            wxWindow* WXUNUSED(win),
 167                            const wxCursor &cursorCopy,
 168                            const wxCursor &cursorMove,
 169                            const wxCursor &cursorStop)
 170             : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
 171 {
 172     Init();
 173     SetData(data);
 174 }
 175
 176 wxDropSource::~wxDropSource()
 177 {
 178     m_pIDropSource->Release();
 179 }
 180
 181 // Name    : DoDragDrop
 182 // Purpose : start drag and drop operation
 183 // Returns : wxDragResult - the code of performed operation
 184 // Params  : [in] int flags: specifies if moving is allowe (or only copying)
 185 // Notes   : you must call SetData() before if you had used def ctor
 186 wxDragResult wxDropSource::DoDragDrop(int flags)
 187 {
 188   wxCHECK_MSG( m_data != NULL, wxDragNone, wxT("No data in wxDropSource!") );
 189
 190   DWORD dwEffect;
 191   HRESULT hr = ::DoDragDrop(m_data->GetInterface(),
 192                             m_pIDropSource,
 193                             (flags & wxDrag_AllowMove)
 194                                 ? DROPEFFECT_COPY | DROPEFFECT_MOVE
 195                                 : DROPEFFECT_COPY,
 196                             &dwEffect);
 197
 198   if ( hr == DRAGDROP_S_CANCEL ) {
 199     return wxDragCancel;
 200   }
 201   else if ( hr == DRAGDROP_S_DROP ) {
 202     if ( dwEffect & DROPEFFECT_COPY ) {
 203       return wxDragCopy;
 204     }
 205     else if ( dwEffect & DROPEFFECT_MOVE ) {
 206       // consistency check: normally, we shouldn't get "move" at all
 207       // here if we don't allow it, but in practice it does happen quite often
 208       return (flags & wxDrag_AllowMove) ? wxDragMove : wxDragCopy;
 209     }
 210     else {
 211       // not copy or move
 212       return wxDragNone;
 213     }
 214   }
 215   else {
 216     if ( FAILED(hr) ) {
 217       wxLogApiError(wxT("DoDragDrop"), hr);
 218       wxLogError(wxT("Drag & drop operation failed."));
 219     }
 220     else {
 221       wxLogDebug(wxT("Unexpected success return code %08lx from DoDragDrop."),
 222                  hr);
 223     }
 224
 225     return wxDragError;
 226   }
 227 }
 228
 229 // Name    : wxDropSource::GiveFeedback
 230 // Purpose : visually inform the user about d&d operation state
 231 // Returns : bool: true if we do all ourselves or false for default feedback
 232 // Params  : [in] DragResult effect - what would happen if we dropped now
 233 // Notes   : here we just leave this stuff for default implementation
 234 bool wxDropSource::GiveFeedback(wxDragResult effect)
 235 {
 236     const wxCursor& cursor = GetCursor(effect);
 237     if ( cursor.Ok() )
 238     {
 239         ::SetCursor((HCURSOR)cursor.GetHCURSOR());
 240
 241         return true;
 242     }
 243     else
 244     {
 245         return false;
 246     }
 247 }
 248
 249 #endif  //USE_DRAG_AND_DROP