include/wx/msw/ole/droptgt.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/msw/ole/droptgt.h
   3 // Purpose:     declaration of the wxDropTarget class
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     06.03.98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef   _WX_OLEDROPTGT_H
  13 #define   _WX_OLEDROPTGT_H
  14
  15 #if wxUSE_DRAG_AND_DROP
  16
  17 // ----------------------------------------------------------------------------
  18 // forward declarations
  19 // ----------------------------------------------------------------------------
  20
  21 class  wxIDropTarget;
  22 struct wxIDropTargetHelper;
  23 struct IDataObject;
  24
  25 // ----------------------------------------------------------------------------
  26 // An instance of the class wxDropTarget may be associated with any wxWindow
  27 // derived object via SetDropTarget() function. If this is done, the virtual
  28 // methods of wxDropTarget are called when something is dropped on the window.
  29 //
  30 // Note that wxDropTarget is an abstract base class (ABC) and you should derive
  31 // your own class from it implementing pure virtual function in order to use it
  32 // (all of them, including protected ones which are called by the class itself)
  33 // ----------------------------------------------------------------------------
  34
  35 class WXDLLIMPEXP_CORE wxDropTarget : public wxDropTargetBase
  36 {
  37 public:
  38     // ctor & dtor
  39     wxDropTarget(wxDataObject *dataObject = NULL);
  40     virtual ~wxDropTarget();
  41
  42     // normally called by wxWindow on window creation/destruction, but might be
  43     // called `manually' as well. Register() returns true on success.
  44     bool Register(WXHWND hwnd);
  45     void Revoke(WXHWND hwnd);
  46
  47     // provide default implementation for base class pure virtuals
  48     virtual bool OnDrop(wxCoord x, wxCoord y);
  49     virtual bool GetData();
  50
  51     // Can only be called during OnXXX methods.
  52     wxDataFormat GetMatchingPair();
  53
  54     // implementation only from now on
  55     // -------------------------------
  56
  57     // do we accept this kind of data?
  58     bool MSWIsAcceptedData(IDataObject *pIDataSource) const;
  59
  60     // give us the data source from IDropTarget::Drop() - this is later used by
  61     // GetData() when it's called from inside OnData()
  62     void MSWSetDataSource(IDataObject *pIDataSource);
  63
  64     // These functions take care of all things necessary to support native drag
  65     // images.
  66     //
  67     // {Init,End}DragImageSupport() are called during Register/Revoke,
  68     // UpdateDragImageOnXXX() functions are called on the corresponding drop
  69     // target events.
  70     void MSWInitDragImageSupport();
  71     void MSWEndDragImageSupport();
  72     void MSWUpdateDragImageOnData(wxCoord x, wxCoord y, wxDragResult res);
  73     void MSWUpdateDragImageOnDragOver(wxCoord x, wxCoord y, wxDragResult res);
  74     void MSWUpdateDragImageOnEnter(wxCoord x, wxCoord y, wxDragResult res);
  75     void MSWUpdateDragImageOnLeave();
  76
  77 private:
  78     // helper used by IsAcceptedData() and GetData()
  79     wxDataFormat MSWGetSupportedFormat(IDataObject *pIDataSource) const;
  80
  81     wxIDropTarget     *m_pIDropTarget; // the pointer to our COM interface
  82     IDataObject       *m_pIDataSource; // the pointer to the source data object
  83     wxIDropTargetHelper *m_dropTargetHelper; // the drop target helper
  84
  85     wxDECLARE_NO_COPY_CLASS(wxDropTarget);
  86 };
  87
  88 #endif  //wxUSE_DRAG_AND_DROP
  89
  90 #endif  //_WX_OLEDROPTGT_H