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_DRAG_AND_DROP
  37
  38 #include "wx/log.h"
  39 #include "wx/dataobj.h"
  40 #include "wx/msw/ole/dropsrc.h"
  41
  42 #include <windows.h>
  43 #ifdef 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
  76 // ============================================================================
  77 // Implementation
  78 // ============================================================================
  79
  80 // ----------------------------------------------------------------------------
  81 // wxIDropSource implementation
  82 // ----------------------------------------------------------------------------
  83 BEGIN_IID_TABLE(wxIDropSource)
  84   ADD_IID(Unknown)
  85   ADD_IID(DropSource)
  86 END_IID_TABLE;
  87
  88 IMPLEMENT_IUNKNOWN_METHODS(wxIDropSource)
  89
  90 wxIDropSource::wxIDropSource(wxDropSource *pDropSource)
  91 {
  92   wxASSERT( pDropSource != NULL );
  93
  94   m_pDropSource = pDropSource;
  95   m_grfInitKeyState = 0;
  96   m_cRef = 0;
  97 }
  98
  99 // Name    : wxIDropSource::QueryContinueDrag
 100 // Purpose : decide if drag operation must be continued or not
 101 // Returns : HRESULT: S_OK              if we should continue
 102 //                    DRAGDROP_S_DROP   to drop right now
 103 //                    DRAGDROP_S_CANCEL to cancel everything
 104 // Params  : [in] BOOL  fEscapePressed  <Esc> pressed since last call?
 105 //           [in] DWORD grfKeyState     mask containing state of kbd keys
 106 // Notes   : as there is no reasonably simple portable way to implement this
 107 //           function, we currently don't give the possibility to override the
 108 //           default behaviour implemented here
 109 STDMETHODIMP wxIDropSource::QueryContinueDrag(BOOL fEscapePressed,
 110                                               DWORD grfKeyState)
 111 {
 112   if ( fEscapePressed )
 113     return DRAGDROP_S_CANCEL;
 114
 115   // initialize ourself with the drag begin button
 116   if ( m_grfInitKeyState == 0 ) {
 117     m_grfInitKeyState = grfKeyState & (MK_LBUTTON | MK_RBUTTON | MK_MBUTTON);
 118   }
 119
 120   if ( !(grfKeyState & m_grfInitKeyState) ) {
 121     // button which started d&d released, go!
 122     return DRAGDROP_S_DROP;
 123   }
 124
 125   return S_OK;
 126 }
 127
 128 // Name    : wxIDropSource::GiveFeedback
 129 // Purpose : give UI feedback according to current state of operation
 130 // Returns : STDMETHODIMP
 131 // Params  : [in] DWORD dwEffect - what would happen if we dropped now
 132 // Notes   : default implementation is ok in more than 99% of cases
 133 STDMETHODIMP wxIDropSource::GiveFeedback(DWORD dwEffect)
 134 {
 135   wxDragResult effect;
 136   if ( dwEffect & DROPEFFECT_COPY )
 137     effect = wxDragCopy;
 138   else if ( dwEffect & DROPEFFECT_MOVE )
 139     effect = wxDragMove;
 140   else
 141     effect = wxDragNone;
 142
 143   if ( m_pDropSource->GiveFeedback(effect,
 144                                    (dwEffect & DROPEFFECT_SCROLL) != 0 ) )
 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 {
 165   Init();
 166   m_pData = NULL;
 167 }
 168
 169 wxDropSource::wxDropSource(wxDataObject& data, wxWindow* WXUNUSED(win))
 170 {
 171   Init();
 172   SetData(data);
 173 }
 174
 175 void wxDropSource::SetData(wxDataObject& data)
 176 {
 177   m_pData = &data;
 178 }
 179
 180 wxDropSource::~wxDropSource()
 181 {
 182   m_pIDropSource->Release();
 183 }
 184
 185 // Name    : DoDragDrop
 186 // Purpose : start drag and drop operation
 187 // Returns : wxDragResult - the code of performed operation
 188 // Params  : [in] bool bAllowMove: if false, only copy is allowed
 189 // Notes   : you must call SetData() before if you had used def ctor
 190 wxDragResult wxDropSource::DoDragDrop(bool bAllowMove)
 191 {
 192   wxCHECK_MSG( m_pData != NULL, wxDragNone, T("No data in wxDropSource!") );
 193
 194   DWORD dwEffect;
 195   HRESULT hr = ::DoDragDrop(m_pData->GetInterface(),
 196                             m_pIDropSource,
 197                             bAllowMove ? 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 !bAllowMove, but in practice it does happen quite often
 211       if ( bAllowMove )
 212         return wxDragMove;
 213       else
 214         return wxDragCopy;
 215     }
 216     else {
 217       // not copy or move
 218       return wxDragNone;
 219     }
 220   }
 221   else {
 222     if ( FAILED(hr) ) {
 223       wxLogApiError("DoDragDrop", hr);
 224       wxLogError(T("Drag & drop operation failed."));
 225     }
 226     else {
 227       wxLogDebug(T("Unexpected success return code %08lx from DoDragDrop."), hr);
 228     }
 229
 230     return wxDragError;
 231   }
 232 }
 233
 234 // Name    : wxDropSource::GiveFeedback
 235 // Purpose : visually inform the user about d&d operation state
 236 // Returns : bool: true if we do all ourselves or false for default feedback
 237 // Params  : [in] DragResult effect - what would happen if we dropped now
 238 //           [in] bool bScrolling   - true if target is scrolling
 239 // Notes   : here we just leave this stuff for default implementation
 240 bool wxDropSource::GiveFeedback(wxDragResult effect, bool bScrolling)
 241 {
 242   return FALSE;
 243 }
 244
 245 #endif  //USE_DRAG_AND_DROP