wxWidgets/include/wx/dnd.h

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///////////////////////////////////////////////////////////////////////////////
// Name: wx/dnd.h
// Purpose: Drag and drop classes declarations
// Author: Vadim Zeitlin, Robert Roebling
// Modified by:
// Created: 26.05.99
// RCS-ID: $Id$
// Copyright: (c) wxWindows Team
// Licence: wxWindows license
///////////////////////////////////////////////////////////////////////////////
#ifndef _WX_DND_H_BASE_
#define _WX_DND_H_BASE_
#ifdef __GNUG__
#pragma interface "dndbase.h"
#endif
#include "wx/defs.h"
#if wxUSE_DRAG_AND_DROP
#include "wx/dataobj.h"
#include "wx/cursor.h"
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
// flags for wxDropSource::DoDragDrop()
//
// NB: wxDrag_CopyOnly must be 0 (== FALSE) and wxDrag_AllowMove must be 1
// (== TRUE) for compatibility with the old DoDragDrop(bool) method!
enum
{
wxDrag_CopyOnly = 0, // allow only copying
wxDrag_AllowMove = 1, // allow moving (copying is always allowed)
wxDrag_DefaultMove = 3 // the default operation is move, not copy
};
// result of wxDropSource::DoDragDrop() call
enum wxDragResult
{
wxDragError, // error prevented the d&d operation from completing
wxDragNone, // drag target didn't accept the data
wxDragCopy, // the data was successfully copied
wxDragMove, // the data was successfully moved (MSW only)
wxDragLink, // operation is a drag-link
wxDragCancel // the operation was cancelled by user (not an error)
};
inline WXDLLEXPORT bool wxIsDragResultOk(wxDragResult res)
{
return res == wxDragCopy || res == wxDragMove || res == wxDragLink;
}
// ----------------------------------------------------------------------------
// wxDropSource is the object you need to create (and call DoDragDrop on it)
// to initiate a drag-and-drop operation
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxDropSourceBase
{
public:
wxDropSourceBase(const wxCursor &cursorCopy = wxNullCursor,
const wxCursor &cursorMove = wxNullCursor,
const wxCursor &cursorStop = wxNullCursor)
: m_cursorCopy(cursorCopy),
m_cursorMove(cursorMove),
m_cursorStop(cursorStop)
{ m_data = (wxDataObject *)NULL; }
virtual ~wxDropSourceBase() { }
// set the data which is transfered by drag and drop
void SetData(wxDataObject& data)
{ m_data = &data; }
wxDataObject *GetDataObject()
{ return m_data; }
// set the icon corresponding to given drag result
void SetCursor(wxDragResult res, const wxCursor& cursor)
{
if ( res == wxDragCopy )
m_cursorCopy = cursor;
else if ( res == wxDragMove )
m_cursorMove = cursor;
else
m_cursorStop = cursor;
}
// start drag action, see enum wxDragResult for return value description
//
// if flags contains wxDrag_AllowMove, moving (and only copying) data is
// allowed, if it contains wxDrag_DefaultMove (which includes the previous
// flag), it is even the default operation
virtual wxDragResult DoDragDrop(int flags = wxDrag_CopyOnly) = 0;
// override to give feedback depending on the current operation result
// "effect" and return TRUE if you did something, FALSE to let the library
// give the default feedback
virtual bool GiveFeedback(wxDragResult WXUNUSED(effect)) { return FALSE; }
protected:
const wxCursor& GetCursor(wxDragResult res) const
{
if ( res == wxDragCopy )
return m_cursorCopy;
else if ( res == wxDragMove )
return m_cursorMove;
else
return m_cursorStop;
}
// the data we're dragging
wxDataObject *m_data;
// the cursors to use for feedback
wxCursor m_cursorCopy,
m_cursorMove,
m_cursorStop;
};
// ----------------------------------------------------------------------------
// wxDropTarget should be associated with a window if it wants to be able to
// receive data via drag and drop.
//
// To use this class, you should derive from wxDropTarget and implement
// OnData() pure virtual method. You may also wish to override OnDrop() if you
// want to accept the data only inside some region of the window (this may
// avoid having to copy the data to this application which happens only when
// OnData() is called)
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxDropTargetBase
{
public:
// ctor takes a pointer to heap-allocated wxDataObject which will be owned
// by wxDropTarget and deleted by it automatically. If you don't give it
// here, you can use SetDataObject() later.
wxDropTargetBase(wxDataObject *dataObject = (wxDataObject*)NULL)
{ m_dataObject = dataObject; }
// dtor deletes our data object
virtual ~wxDropTargetBase()
{ delete m_dataObject; }
// get/set the associated wxDataObject
wxDataObject *GetDataObject() const
{ return m_dataObject; }
void SetDataObject(wxDataObject *dataObject)
{ if (m_dataObject) delete m_dataObject;
m_dataObject = dataObject; }
// these functions are called when data is moved over position (x, y) and
// may return either wxDragCopy, wxDragMove or wxDragNone depending on
// what would happen if the data were dropped here.
//
// the last parameter is what would happen by default and is determined by
// the platform-specific logic (for example, under Windows it's wxDragCopy
// if Ctrl key is pressed and wxDragMove otherwise) except that it will
// always be wxDragNone if the carried data is in an unsupported format.
// called when the mouse enters the window (only once until OnLeave())
virtual wxDragResult OnEnter(wxCoord x, wxCoord y, wxDragResult def)
{ return OnDragOver(x, y, def); }
// called when the mouse moves in the window - shouldn't take long to
// execute or otherwise mouse movement would be too slow
virtual wxDragResult OnDragOver(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y),
wxDragResult def)
{ return def; }
// called when mouse leaves the window: might be used to remove the
// feedback which was given in OnEnter()
virtual void OnLeave() { }
// this function is called when data is dropped at position (x, y) - if it
// returns TRUE, OnData() will be called immediately afterwards which will
// allow to retrieve the data dropped.
virtual bool OnDrop(wxCoord x, wxCoord y) = 0;
// called after OnDrop() returns TRUE: you will usually just call
// GetData() from here and, probably, also refresh something to update the
// new data and, finally, return the code indicating how did the operation
// complete (returning default value in case of success and wxDragError on
// failure is usually ok)
virtual wxDragResult OnData(wxCoord x, wxCoord y, wxDragResult def) = 0;
// may be called *only* from inside OnData() and will fill m_dataObject
// with the data from the drop source if it returns TRUE
virtual bool GetData() = 0;
protected:
wxDataObject *m_dataObject;
};
// ----------------------------------------------------------------------------
// include platform dependent class declarations
// ----------------------------------------------------------------------------
#if defined(__WXMSW__)
#include "wx/msw/ole/dropsrc.h"
#include "wx/msw/ole/droptgt.h"
#elif defined(__WXMOTIF__)
#include "wx/motif/dnd.h"
#elif defined(__WXX11__)
#include "wx/x11/dnd.h"
#elif defined(__WXGTK__)
#include "wx/gtk/dnd.h"
#elif defined(__WXMAC__)
#include "wx/mac/dnd.h"
#elif defined(__WXPM__)
#include "wx/os2/dnd.h"
#elif defined(__WXSTUBS__)
#include "wx/stubs/dnd.h"
#endif
// ----------------------------------------------------------------------------
// standard wxDropTarget implementations (implemented in common/dobjcmn.cpp)
// ----------------------------------------------------------------------------
// A simple wxDropTarget derived class for text data: you only need to
// override OnDropText() to get something working
class WXDLLEXPORT wxTextDropTarget : public wxDropTarget
{
public:
wxTextDropTarget();
virtual bool OnDropText(wxCoord x, wxCoord y, const wxString& text) = 0;
virtual wxDragResult OnData(wxCoord x, wxCoord y, wxDragResult def);
};
// A drop target which accepts files (dragged from File Manager or Explorer)
class WXDLLEXPORT wxFileDropTarget : public wxDropTarget
{
public:
wxFileDropTarget();
// parameters are the number of files and the array of file names
virtual bool OnDropFiles(wxCoord x, wxCoord y,
const wxArrayString& filenames) = 0;
virtual wxDragResult OnData(wxCoord x, wxCoord y, wxDragResult def);
};
#endif // wxUSE_DRAG_AND_DROP
#endif // _WX_DND_H_BASE_