include/wx/msw/ole/droptgt.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        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 license
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // prolog
  14 // ============================================================================
  15 #ifndef   _OLEDROPTGT_H
  16 #define   _OLEDROPTGT_H
  17
  18 #ifdef __GNUG__
  19 #pragma interface "droptgt.h"
  20 #endif
  21
  22 #if !USE_DRAG_AND_DROP
  23   #error  "You should #define USE_DRAG_AND_DROP to 1 to compile this file!"
  24 #endif  //WX_DRAG_DROP
  25
  26 // ----------------------------------------------------------------------------
  27 // forward declarations
  28 // ----------------------------------------------------------------------------
  29 class  wxIDropTarget;
  30 struct IDataObject;
  31
  32 // ----------------------------------------------------------------------------
  33 // An instance of the class wxDropTarget may be associated with any wxWindow
  34 // derived object via SetDropTarget() function. If this is done, the virtual
  35 // methods of wxDropTarget are called when something is dropped on the window.
  36 //
  37 // Note that wxDropTarget is an abstract base class (ABC) and you should derive
  38 // your own class from it implementing pure virtual function in order to use it
  39 // (all of them, including protected ones which are called by the class itself)
  40 // ----------------------------------------------------------------------------
  41 class WXDLLEXPORT wxDropTarget
  42 {
  43 public:
  44   // ctor & dtor
  45   wxDropTarget();
  46   virtual ~wxDropTarget();
  47
  48   // normally called by wxWindow on window creation/destruction, but might be
  49   // called `manually' as well. Register() returns true on success.
  50   bool Register(WXHWND hwnd);
  51   void Revoke(WXHWND hwnd);
  52
  53   // do we accept this kind of data?
  54   virtual bool IsAcceptedData(IDataObject *pIDataSource) const;
  55
  56   // called when mouse enters/leaves the window: might be used to give
  57   // some visual feedback to the user
  58   virtual void OnEnter() { }
  59   virtual void OnLeave() { }
  60
  61   // this function is called when data is dropped.
  62   // (x, y) are the coordinates of the drop
  63   virtual bool OnDrop(long x, long y, const void *pData) = 0;
  64
  65 protected:
  66   // Override these to indicate what kind of data you support: the first
  67   // format to which data can be converted is used. The classes below show
  68   // how it can be done in the simplest cases.
  69     // how many different (clipboard) formats do you support?
  70   virtual size_t GetFormatCount() const = 0;
  71     // return the n-th supported format
  72   virtual wxDataFormat GetFormat(size_t n) const = 0;
  73
  74 private:
  75   wxIDropTarget    *m_pIDropTarget; // the pointer to COM interface
  76 };
  77
  78 // ----------------------------------------------------------------------------
  79 // A simple wxDropTarget derived class for text data: you only need to
  80 // override OnDropText() to get something working
  81 // ----------------------------------------------------------------------------
  82 class WXDLLEXPORT wxTextDropTarget : public wxDropTarget
  83 {
  84 public:
  85   virtual bool OnDrop(long x, long y, const void *pData);
  86   virtual bool OnDropText(long x, long y, const char *psz) = 0;
  87
  88 protected:
  89   virtual size_t GetFormatCount() const;
  90   virtual wxDataFormat GetFormat(size_t n) const;
  91 };
  92
  93 // ----------------------------------------------------------------------------
  94 // A drop target which accepts files (dragged from File Manager or Explorer)
  95 // ----------------------------------------------------------------------------
  96 class WXDLLEXPORT wxFileDropTarget : public wxDropTarget
  97 {
  98 public:
  99   virtual bool OnDrop(long x, long y, const void *pData);
 100
 101   // params: the number of files and the array of file names
 102   virtual bool OnDropFiles(long x, long y,
 103                            size_t nFiles, const char * const aszFiles[]) = 0;
 104
 105 protected:
 106   virtual size_t GetFormatCount() const;
 107   virtual wxDataFormat GetFormat(size_t n) const;
 108 };
 109
 110 // ============================================================================
 111 #endif  //_OLEDROPTGT_H