include/wx/dnd.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/dnd.h
   3 // Purpose:     Drag and drop classes declarations
   4 // Author:      Vadim Zeitlin, Robert Roebling
   5 // Modified by:
   6 // Created:     26.05.99
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) wxWindows Team
   9 // Licence:     wxWindows license
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_DND_H_BASE_
  13 #define _WX_DND_H_BASE_
  14
  15 #include "wx/defs.h"
  16
  17 #if wxUSE_DRAG_AND_DROP
  18
  19 #include "wx/dataobj.h"
  20
  21 // ----------------------------------------------------------------------------
  22 // constants
  23 // ----------------------------------------------------------------------------
  24
  25 // result of wxDropSource::DoDragDrop() call
  26 enum wxDragResult
  27 {
  28     wxDragError,    // error prevented the d&d operation from completing
  29     wxDragNone,     // drag target didn't accept the data
  30     wxDragCopy,     // the data was successfully copied
  31     wxDragMove,     // the data was successfully moved (MSW only)
  32     wxDragCancel    // the operation was cancelled by user (not an error)
  33 };
  34
  35 // ----------------------------------------------------------------------------
  36 // wxDropSource is the object you need to create (and call DoDragDrop on it)
  37 // to initiate a drag-and-drop operation
  38 // ----------------------------------------------------------------------------
  39
  40 class WXDLLEXPORT wxDropSourceBase
  41 {
  42 public:
  43     wxDropSourceBase() { m_data = (wxDataObject *)NULL; }
  44     virtual ~wxDropSourceBase() { }
  45
  46     // set the data which is transfered by drag and drop
  47     void SetData(wxDataObject& data) { delete m_data; m_data = &data; }
  48
  49     // start drag action, see enum wxDragResult for return value description
  50     //
  51     // if bAllowMove is TRUE, data can be moved, if not - only copied
  52     virtual wxDragResult DoDragDrop( bool bAllowMove = FALSE );
  53
  54     // override to give feedback depending on the current operation result
  55     // "effect"
  56     virtual bool GiveFeedback( wxDragResult WXUNUSED(effect),
  57                                bool WXUNUSED(bScrolling) )
  58     {
  59         return TRUE;
  60     }
  61
  62 protected:
  63     wxDataObject *m_data;
  64 };
  65
  66 // ----------------------------------------------------------------------------
  67 // wxDropTarget should be associated with a window if it wants to be able to
  68 // receive data via drag and drop
  69 // ----------------------------------------------------------------------------
  70
  71 class WXDLLEXPORT wxDropTargetBase
  72 {
  73 public:
  74     // ctor takes a pointer to heap-allocated wxDataObject which will be owned
  75     // by wxDropTarget and deleted by it automatically. If you don't give it
  76     // here, you can use SetDataObject() later.
  77     wxDropTargetBase(wxDataObject *dataObject = NULL)
  78         { m_dataObject = dataObject; }
  79     // dtor deletes our data object
  80     virtual ~wxDropTargetBase()
  81         { delete m_dataObject; }
  82
  83     // get/set the associated wxDataObject
  84     wxDataObject *GetDataObject() const
  85         { return m_dataObject; }
  86     void SetDataObject(wxDataObject *dataObject)
  87         { delete m_dataObject; m_dataObject = dataObject; }
  88
  89     // called when mouse enters/leaves the window: might be used to give
  90     // some visual feedback to the user
  91     virtual void OnEnter() { }
  92     virtual void OnLeave() { }
  93
  94     // this function is called when data is dropped at position (x, y) - if it
  95     // returns TRUE, OnData() will be called immediately afterwards which will
  96     // allow to retrieve the data dropped.
  97     virtual bool OnDrop(wxCoord x, wxCoord y) = 0;
  98
  99     // called after OnDrop() returns TRUE: you will usually just call
 100     // GetData() from here and, probably, also refresh something to update the
 101     // new data
 102     virtual bool OnData() = 0;
 103
 104     // may be called *only* from inside OnData() and will fill m_dataObject
 105     // with the data from the drop source if it returns TRUE
 106     virtual bool GetData() = 0;
 107
 108 protected:
 109     wxDataObject *m_dataObject;
 110 };
 111
 112 // ----------------------------------------------------------------------------
 113 // include platform dependent class declarations
 114 // ----------------------------------------------------------------------------
 115
 116 #if defined(__WXMSW__)
 117     #include "wx/dataobj.h"
 118     #include "wx/msw/ole/dropsrc.h"
 119     #include "wx/msw/ole/droptgt.h"
 120 #elif defined(__WXMOTIF__)
 121     #include "wx/motif/dnd.h"
 122 #elif defined(__WXGTK__)
 123     #include "wx/gtk/dnd.h"
 124 #elif defined(__WXQT__)
 125     #include "wx/qt/dnd.h"
 126 #elif defined(__WXMAC__)
 127     #include "wx/mac/dnd.h"
 128 #elif defined(__WXPM__)
 129     #include "wx/os2/dnd.h"
 130 #elif defined(__WXSTUBS__)
 131     #include "wx/stubs/dnd.h"
 132 #endif
 133
 134 #endif // wxUSE_DRAG_AND_DROP
 135
 136 #endif // _WX_DND_H_BASE_