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