really restored correct sample code

[wxWidgets.git] / samples / dnd / dnd.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        dnd.cpp
// Purpose:     Drag and drop sample
// Author:      Vadim Zeitlin
// Modified by:
// Created:     04/01/98
// RCS-ID:      $Id$
// Copyright:
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif

#include "wx/dnd.h"
#include "wx/dataobj.h"
#include "wx/image.h"
#include "wx/clipbrd.h"
#include "wx/colordlg.h"
#include "wx/metafile.h"

#if defined(__WXGTK__) || defined(__WXX11__) || defined(__WXMOTIF__) || defined(__WXMAC__)
    #include "../sample.xpm"
#if wxUSE_DRAG_AND_DROP
    #include "dnd_copy.xpm"
    #include "dnd_move.xpm"
    #include "dnd_none.xpm"
#endif
#endif

#if wxUSE_DRAG_AND_DROP

// ----------------------------------------------------------------------------
// Derive two simple classes which just put in the listbox the strings (text or
// file names) we drop on them
// ----------------------------------------------------------------------------

class DnDText : public wxTextDropTarget
{
public:
    DnDText(wxListBox *pOwner) { m_pOwner = pOwner; }

    virtual bool OnDropText(wxCoord x, wxCoord y, const wxString& text);

private:
    wxListBox *m_pOwner;
};

class DnDFile : public wxFileDropTarget
{
public:
    DnDFile(wxListBox *pOwner) { m_pOwner = pOwner; }

    virtual bool OnDropFiles(wxCoord x, wxCoord y,
                             const wxArrayString& filenames);

private:
    wxListBox *m_pOwner;
};

// ----------------------------------------------------------------------------
// Define a custom dtop target accepting URLs
// ----------------------------------------------------------------------------

class URLDropTarget : public wxDropTarget
{
public:
    URLDropTarget() { SetDataObject(new wxURLDataObject); }

    void OnDropURL(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y), const wxString& text)
    {
        // of course, a real program would do something more useful here...
        wxMessageBox(text, _T("wxDnD sample: got URL"),
                     wxICON_INFORMATION | wxOK);
    }

    // URLs can't be moved, only copied
    virtual wxDragResult OnDragOver(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y),
                                    wxDragResult WXUNUSED(def))
        {
            return wxDragLink;  // At least IE 5.x needs wxDragLink, the
                                // other browsers on MSW seem okay with it too.
        }

    // translate this to calls to OnDropURL() just for convenience
    virtual wxDragResult OnData(wxCoord x, wxCoord y, wxDragResult def)
    {
        if ( !GetData() )
            return wxDragNone;

        OnDropURL(x, y, ((wxURLDataObject *)m_dataObject)->GetURL());

        return def;
    }
};

#endif // wxUSE_DRAG_AND_DROP

// ----------------------------------------------------------------------------
// Define a new application type
// ----------------------------------------------------------------------------

class DnDApp : public wxApp
{
public:
    virtual bool OnInit();
};

IMPLEMENT_APP(DnDApp)

#if wxUSE_DRAG_AND_DROP || wxUSE_CLIPBOARD

// ----------------------------------------------------------------------------
// Define canvas class to show a bitmap
// ----------------------------------------------------------------------------

class DnDCanvasBitmap : public wxScrolledWindow
{
public:
    DnDCanvasBitmap(wxWindow *parent) : wxScrolledWindow(parent) { }

    void SetBitmap(const wxBitmap& bitmap)
    {
        m_bitmap = bitmap;

        SetScrollbars(10, 10,
                      m_bitmap.GetWidth() / 10, m_bitmap.GetHeight() / 10);

        Refresh();
    }

    void OnPaint(wxPaintEvent& WXUNUSED(event))
    {
        wxPaintDC dc(this);

        if ( m_bitmap.Ok() )
        {
            PrepareDC(dc);

            dc.DrawBitmap(m_bitmap, 0, 0);
        }
    }

private:
    wxBitmap m_bitmap;

    DECLARE_EVENT_TABLE()
};

#if wxUSE_METAFILE

// and the same thing fo metafiles
class DnDCanvasMetafile : public wxScrolledWindow
{
public:
    DnDCanvasMetafile(wxWindow *parent) : wxScrolledWindow(parent) { }

    void SetMetafile(const wxMetafile& metafile)
    {
        m_metafile = metafile;

        SetScrollbars(10, 10,
                      m_metafile.GetWidth() / 10, m_metafile.GetHeight() / 10);

        Refresh();
    }

    void OnPaint(wxPaintEvent&)
    {
        wxPaintDC dc(this);

        if ( m_metafile.Ok() )
        {
            PrepareDC(dc);

            m_metafile.Play(&dc);
        }
    }

private:
    wxMetafile m_metafile;

    DECLARE_EVENT_TABLE()
};

#endif // wxUSE_METAFILE

// ----------------------------------------------------------------------------
// Define a new frame type for the main frame
// ----------------------------------------------------------------------------

class DnDFrame : public wxFrame
{
public:
    DnDFrame(wxFrame *frame, const wxChar *title, int x, int y, int w, int h);
    virtual ~DnDFrame();

    void OnPaint(wxPaintEvent& event);
    void OnSize(wxSizeEvent& event);
    void OnQuit(wxCommandEvent& event);
    void OnAbout(wxCommandEvent& event);
    void OnDrag(wxCommandEvent& event);
    void OnDragMoveByDefault(wxCommandEvent& event);
    void OnDragMoveAllow(wxCommandEvent& event);
    void OnNewFrame(wxCommandEvent& event);
    void OnHelp (wxCommandEvent& event);
#if wxUSE_LOG
    void OnLogClear(wxCommandEvent& event);
#endif // wxUSE_LOG

    void OnCopy(wxCommandEvent& event);
    void OnPaste(wxCommandEvent& event);

    void OnCopyBitmap(wxCommandEvent& event);
    void OnPasteBitmap(wxCommandEvent& event);

#if wxUSE_METAFILE
    void OnPasteMetafile(wxCommandEvent& event);
#endif // wxUSE_METAFILE

    void OnCopyFiles(wxCommandEvent& event);

    void OnLeftDown(wxMouseEvent& event);
    void OnRightDown(wxMouseEvent& event);

    void OnUpdateUIMoveByDefault(wxUpdateUIEvent& event);

    void OnUpdateUIPasteText(wxUpdateUIEvent& event);
    void OnUpdateUIPasteBitmap(wxUpdateUIEvent& event);

    DECLARE_EVENT_TABLE()

private:
    // GUI controls
    wxListBox  *m_ctrlFile,
               *m_ctrlText;

#if wxUSE_LOG
    wxTextCtrl *m_ctrlLog;

    wxLog *m_pLog,
          *m_pLogPrev;
#endif // wxUSE_LOG

    // move the text by default (or copy)?
    bool m_moveByDefault;

    // allow moving the text at all?
    bool m_moveAllow;

    // the text we drag
    wxString  m_strText;
};

// ----------------------------------------------------------------------------
// A shape is an example of application-specific data which may be transported
// via drag-and-drop or clipboard: in our case, we have different geometric
// shapes, each one with its own colour and position
// ----------------------------------------------------------------------------

#if wxUSE_DRAG_AND_DROP

class DnDShape
{
public:
    enum Kind
    {
        None,
        Triangle,
        Rectangle,
        Ellipse
    };

    DnDShape(const wxPoint& pos,
             const wxSize& size,
             const wxColour& col)
        : m_pos(pos), m_size(size), m_col(col)
    {
    }

    // this is for debugging - lets us see when exactly an object is freed
    // (this may be later than you think if it's on the clipboard, for example)
    virtual ~DnDShape() { }

    // the functions used for drag-and-drop: they dump and restore a shape into
    // some bitwise-copiable data (might use streams too...)
    // ------------------------------------------------------------------------

    // restore from buffer
    static DnDShape *New(const void *buf);

    virtual size_t GetDataSize() const
    {
        return sizeof(ShapeDump);
    }

    virtual void GetDataHere(void *buf) const
    {
        ShapeDump& dump = *(ShapeDump *)buf;
        dump.x = m_pos.x;
        dump.y = m_pos.y;
        dump.w = m_size.x;
        dump.h = m_size.y;
        dump.r = m_col.Red();
        dump.g = m_col.Green();
        dump.b = m_col.Blue();
        dump.k = GetKind();
    }

    // accessors
    const wxPoint& GetPosition() const { return m_pos; }
    const wxColour& GetColour() const { return m_col; }
    const wxSize& GetSize() const { return m_size; }

    void Move(const wxPoint& pos) { m_pos = pos; }

    // to implement in derived classes
    virtual Kind GetKind() const = 0;

    virtual void Draw(wxDC& dc)
    {
        dc.SetPen(wxPen(m_col, 1, wxSOLID));
    }

protected:
    //get a point 1 up and 1 left, otherwise the mid-point of a triangle is on the line
    wxPoint GetCentre() const
         { return wxPoint(m_pos.x + m_size.x / 2 - 1, m_pos.y + m_size.y / 2 - 1); }

    struct ShapeDump
    {
        wxCoord x, y,             // position
                w, h;             // size
        int k;                    // kind
        unsigned char r, g, b;    // colour
    };

    wxPoint  m_pos;
    wxSize   m_size;
    wxColour m_col;
};

class DnDTriangularShape : public DnDShape
{
public:
    DnDTriangularShape(const wxPoint& pos,
                       const wxSize& size,
                       const wxColour& col)
        : DnDShape(pos, size, col)
    {
        wxLogMessage(wxT("DnDTriangularShape is being created"));
    }

    virtual ~DnDTriangularShape()
    {
        wxLogMessage(wxT("DnDTriangularShape is being deleted"));
    }

    virtual Kind GetKind() const { return Triangle; }
    virtual void Draw(wxDC& dc)
    {
        DnDShape::Draw(dc);

        // well, it's a bit difficult to describe a triangle by position and
        // size, but we're not doing geometry here, do we? ;-)
        wxPoint p1(m_pos);
        wxPoint p2(m_pos.x + m_size.x, m_pos.y);
        wxPoint p3(m_pos.x, m_pos.y + m_size.y);

        dc.DrawLine(p1, p2);
        dc.DrawLine(p2, p3);
        dc.DrawLine(p3, p1);

        //works in multicolor modes; on GTK (at least) will fail in 16-bit color
        dc.SetBrush(wxBrush(m_col, wxSOLID));
        dc.FloodFill(GetCentre(), m_col, wxFLOOD_BORDER);
    }
};

class DnDRectangularShape : public DnDShape
{
public:
    DnDRectangularShape(const wxPoint& pos,
                        const wxSize& size,
                        const wxColour& col)
        : DnDShape(pos, size, col)
    {
        wxLogMessage(wxT("DnDRectangularShape is being created"));
    }

    virtual ~DnDRectangularShape()
    {
        wxLogMessage(wxT("DnDRectangularShape is being deleted"));
    }

    virtual Kind GetKind() const { return Rectangle; }
    virtual void Draw(wxDC& dc)
    {
        DnDShape::Draw(dc);

        wxPoint p1(m_pos);
        wxPoint p2(p1.x + m_size.x, p1.y);
        wxPoint p3(p2.x, p2.y + m_size.y);
        wxPoint p4(p1.x, p3.y);

        dc.DrawLine(p1, p2);
        dc.DrawLine(p2, p3);
        dc.DrawLine(p3, p4);
        dc.DrawLine(p4, p1);

        dc.SetBrush(wxBrush(m_col, wxSOLID));
        dc.FloodFill(GetCentre(), m_col, wxFLOOD_BORDER);
    }
};

class DnDEllipticShape : public DnDShape
{
public:
    DnDEllipticShape(const wxPoint& pos,
                     const wxSize& size,
                     const wxColour& col)
        : DnDShape(pos, size, col)
    {
        wxLogMessage(wxT("DnDEllipticShape is being created"));
    }

    virtual ~DnDEllipticShape()
    {
        wxLogMessage(wxT("DnDEllipticShape is being deleted"));
    }

    virtual Kind GetKind() const { return Ellipse; }
    virtual void Draw(wxDC& dc)
    {
        DnDShape::Draw(dc);

        dc.DrawEllipse(m_pos, m_size);

        dc.SetBrush(wxBrush(m_col, wxSOLID));
        dc.FloodFill(GetCentre(), m_col, wxFLOOD_BORDER);
    }
};

// ----------------------------------------------------------------------------
// A wxDataObject specialisation for the application-specific data
// ----------------------------------------------------------------------------

static const wxChar *shapeFormatId = wxT("wxShape");

class DnDShapeDataObject : public wxDataObject
{
public:
    // ctor doesn't copy the pointer, so it shouldn't go away while this object
    // is alive
    DnDShapeDataObject(DnDShape *shape = (DnDShape *)NULL)
    {
        if ( shape )
        {
            // we need to copy the shape because the one we're handled may be
            // deleted while it's still on the clipboard (for example) - and we
            // reuse the serialisation methods here to copy it
            void *buf = malloc(shape->DnDShape::GetDataSize());
            shape->GetDataHere(buf);
            m_shape = DnDShape::New(buf);

            free(buf);
        }
        else
        {
            // nothing to copy
            m_shape = NULL;
        }

        // this string should uniquely identify our format, but is otherwise
        // arbitrary
        m_formatShape.SetId(shapeFormatId);

        // we don't draw the shape to a bitmap until it's really needed (i.e.
        // we're asked to do so)
        m_hasBitmap = false;
#if wxUSE_METAFILE
        m_hasMetaFile = false;
#endif // wxUSE_METAFILE
    }

    virtual ~DnDShapeDataObject() { delete m_shape; }

    // after a call to this function, the shape is owned by the caller and it
    // is responsible for deleting it!
    //
    // NB: a better solution would be to make DnDShapes ref counted and this
    //     is what should probably be done in a real life program, otherwise
    //     the ownership problems become too complicated really fast
    DnDShape *GetShape()
    {
        DnDShape *shape = m_shape;

        m_shape = (DnDShape *)NULL;
        m_hasBitmap = false;
#if wxUSE_METAFILE
        m_hasMetaFile = false;
#endif // wxUSE_METAFILE

        return shape;
    }

    // implement base class pure virtuals
    // ----------------------------------

    virtual wxDataFormat GetPreferredFormat(Direction WXUNUSED(dir)) const
    {
        return m_formatShape;
    }

    virtual size_t GetFormatCount(Direction dir) const
    {
        // our custom format is supported by both GetData() and SetData()
        size_t nFormats = 1;
        if ( dir == Get )
        {
            // but the bitmap format(s) are only supported for output
            nFormats += m_dobjBitmap.GetFormatCount(dir);

#if wxUSE_METAFILE
            nFormats += m_dobjMetaFile.GetFormatCount(dir);
#endif // wxUSE_METAFILE
        }

        return nFormats;
    }

    virtual void GetAllFormats(wxDataFormat *formats, Direction dir) const
    {
        formats[0] = m_formatShape;
        if ( dir == Get )
        {
            // in Get direction we additionally support bitmaps and metafiles
            // under Windows
            m_dobjBitmap.GetAllFormats(&formats[1], dir);

#if wxUSE_METAFILE
            // don't assume that m_dobjBitmap has only 1 format
            m_dobjMetaFile.GetAllFormats(&formats[1 +
                    m_dobjBitmap.GetFormatCount(dir)], dir);
#endif // wxUSE_METAFILE
        }
    }

    virtual size_t GetDataSize(const wxDataFormat& format) const
    {
        if ( format == m_formatShape )
        {
            return m_shape->GetDataSize();
        }
#if wxUSE_METAFILE
        else if ( m_dobjMetaFile.IsSupported(format) )
        {
            if ( !m_hasMetaFile )
                CreateMetaFile();

            return m_dobjMetaFile.GetDataSize(format);
        }
#endif // wxUSE_METAFILE
        else
        {
            wxASSERT_MSG( m_dobjBitmap.IsSupported(format),
                          wxT("unexpected format") );

            if ( !m_hasBitmap )
                CreateBitmap();

            return m_dobjBitmap.GetDataSize();
        }
    }

    virtual bool GetDataHere(const wxDataFormat& format, void *pBuf) const
    {
        if ( format == m_formatShape )
        {
            m_shape->GetDataHere(pBuf);

            return true;
        }
#if wxUSE_METAFILE
        else if ( m_dobjMetaFile.IsSupported(format) )
        {
            if ( !m_hasMetaFile )
                CreateMetaFile();

            return m_dobjMetaFile.GetDataHere(format, pBuf);
        }
#endif // wxUSE_METAFILE
        else
        {
            wxASSERT_MSG( m_dobjBitmap.IsSupported(format),
                          wxT("unexpected format") );

            if ( !m_hasBitmap )
                CreateBitmap();

            return m_dobjBitmap.GetDataHere(pBuf);
        }
    }

    virtual bool SetData(const wxDataFormat& format,
                         size_t WXUNUSED(len), const void *buf)
    {
        wxCHECK_MSG( format == m_formatShape, false,
                     wxT( "unsupported format") );

        delete m_shape;
        m_shape = DnDShape::New(buf);

        // the shape has changed
        m_hasBitmap = false;

#if wxUSE_METAFILE
        m_hasMetaFile = false;
#endif // wxUSE_METAFILE

        return true;
    }

private:
    // creates a bitmap and assigns it to m_dobjBitmap (also sets m_hasBitmap)
    void CreateBitmap() const;
#if wxUSE_METAFILE
    void CreateMetaFile() const;
#endif // wxUSE_METAFILE

    wxDataFormat        m_formatShape;  // our custom format

    wxBitmapDataObject  m_dobjBitmap;   // it handles bitmaps
    bool                m_hasBitmap;    // true if m_dobjBitmap has valid bitmap

#if wxUSE_METAFILE
    wxMetaFileDataObject m_dobjMetaFile;// handles metafiles
    bool                 m_hasMetaFile; // true if we have valid metafile
#endif // wxUSE_METAFILE

    DnDShape           *m_shape;        // our data
};

// ----------------------------------------------------------------------------
// A dialog to edit shape properties
// ----------------------------------------------------------------------------

class DnDShapeDialog : public wxDialog
{
public:
    DnDShapeDialog(wxFrame *parent, DnDShape *shape);

    DnDShape *GetShape() const;

    virtual bool TransferDataToWindow();
    virtual bool TransferDataFromWindow();

    void OnColour(wxCommandEvent& event);

private:
    // input
    DnDShape *m_shape;

    // output
    DnDShape::Kind m_shapeKind;
    wxPoint  m_pos;
    wxSize   m_size;
    wxColour m_col;

    // controls
    wxRadioBox *m_radio;
    wxTextCtrl *m_textX,
               *m_textY,
               *m_textW,
               *m_textH;

    DECLARE_EVENT_TABLE()
};

// ----------------------------------------------------------------------------
// A frame for the shapes which can be drag-and-dropped between frames
// ----------------------------------------------------------------------------

class DnDShapeFrame : public wxFrame
{
public:
    DnDShapeFrame(wxFrame *parent);
    ~DnDShapeFrame();

    void SetShape(DnDShape *shape);
    virtual bool SetShape(const wxRegion &region)
    {
        return wxFrame::SetShape( region );
    }

    // callbacks
    void OnNewShape(wxCommandEvent& event);
    void OnEditShape(wxCommandEvent& event);
    void OnClearShape(wxCommandEvent& event);

    void OnCopyShape(wxCommandEvent& event);
    void OnPasteShape(wxCommandEvent& event);

    void OnUpdateUICopy(wxUpdateUIEvent& event);
    void OnUpdateUIPaste(wxUpdateUIEvent& event);

    void OnDrag(wxMouseEvent& event);
    void OnPaint(wxPaintEvent& event);
    void OnDrop(wxCoord x, wxCoord y, DnDShape *shape);

private:
    DnDShape *m_shape;

    static DnDShapeFrame *ms_lastDropTarget;

    DECLARE_EVENT_TABLE()
};

// ----------------------------------------------------------------------------
// wxDropTarget derivation for DnDShapes
// ----------------------------------------------------------------------------

class DnDShapeDropTarget : public wxDropTarget
{
public:
    DnDShapeDropTarget(DnDShapeFrame *frame)
        : wxDropTarget(new DnDShapeDataObject)
    {
        m_frame = frame;
    }

    // override base class (pure) virtuals
    virtual wxDragResult OnEnter(wxCoord x, wxCoord y, wxDragResult def)
    {
#if wxUSE_STATUSBAR
        m_frame->SetStatusText(_T("Mouse entered the frame"));
#endif // wxUSE_STATUSBAR
        return OnDragOver(x, y, def);
    }
    virtual void OnLeave()
    {
#if wxUSE_STATUSBAR
        m_frame->SetStatusText(_T("Mouse left the frame"));
#endif // wxUSE_STATUSBAR
    }
    virtual wxDragResult OnData(wxCoord x, wxCoord y, wxDragResult def)
    {
        if ( !GetData() )
        {
            wxLogError(wxT("Failed to get drag and drop data"));

            return wxDragNone;
        }

        m_frame->OnDrop(x, y,
                        ((DnDShapeDataObject *)GetDataObject())->GetShape());

        return def;
    }

private:
    DnDShapeFrame *m_frame;
};

#endif // wxUSE_DRAG_AND_DROP

// ----------------------------------------------------------------------------
// functions prototypes
// ----------------------------------------------------------------------------

static void ShowBitmap(const wxBitmap& bitmap);

#if wxUSE_METAFILE
static void ShowMetaFile(const wxMetaFile& metafile);
#endif // wxUSE_METAFILE

// ----------------------------------------------------------------------------
// IDs for the menu commands
// ----------------------------------------------------------------------------

enum
{
    Menu_Quit = 1,
    Menu_Drag,
    Menu_DragMoveDef,
    Menu_DragMoveAllow,
    Menu_NewFrame,
    Menu_About = 101,
    Menu_Help,
    Menu_Clear,
    Menu_Copy,
    Menu_Paste,
    Menu_CopyBitmap,
    Menu_PasteBitmap,
    Menu_PasteMFile,
    Menu_CopyFiles,
    Menu_Shape_New = 500,
    Menu_Shape_Edit,
    Menu_Shape_Clear,
    Menu_ShapeClipboard_Copy,
    Menu_ShapeClipboard_Paste,
    Button_Colour = 1001
};

BEGIN_EVENT_TABLE(DnDFrame, wxFrame)
    EVT_MENU(Menu_Quit,       DnDFrame::OnQuit)
    EVT_MENU(Menu_About,      DnDFrame::OnAbout)
    EVT_MENU(Menu_Drag,       DnDFrame::OnDrag)
    EVT_MENU(Menu_DragMoveDef,  DnDFrame::OnDragMoveByDefault)
    EVT_MENU(Menu_DragMoveAllow,DnDFrame::OnDragMoveAllow)
    EVT_MENU(Menu_NewFrame,   DnDFrame::OnNewFrame)
    EVT_MENU(Menu_Help,       DnDFrame::OnHelp)
#if wxUSE_LOG
    EVT_MENU(Menu_Clear,      DnDFrame::OnLogClear)
#endif // wxUSE_LOG
    EVT_MENU(Menu_Copy,       DnDFrame::OnCopy)
    EVT_MENU(Menu_Paste,      DnDFrame::OnPaste)
    EVT_MENU(Menu_CopyBitmap, DnDFrame::OnCopyBitmap)
    EVT_MENU(Menu_PasteBitmap,DnDFrame::OnPasteBitmap)
#if wxUSE_METAFILE
    EVT_MENU(Menu_PasteMFile, DnDFrame::OnPasteMetafile)
#endif // wxUSE_METAFILE
    EVT_MENU(Menu_CopyFiles,  DnDFrame::OnCopyFiles)

    EVT_UPDATE_UI(Menu_DragMoveDef, DnDFrame::OnUpdateUIMoveByDefault)

    EVT_UPDATE_UI(Menu_Paste,       DnDFrame::OnUpdateUIPasteText)
    EVT_UPDATE_UI(Menu_PasteBitmap, DnDFrame::OnUpdateUIPasteBitmap)

    EVT_LEFT_DOWN(            DnDFrame::OnLeftDown)
    EVT_RIGHT_DOWN(           DnDFrame::OnRightDown)
    EVT_PAINT(                DnDFrame::OnPaint)
    EVT_SIZE(                 DnDFrame::OnSize)
END_EVENT_TABLE()

#if wxUSE_DRAG_AND_DROP

BEGIN_EVENT_TABLE(DnDShapeFrame, wxFrame)
    EVT_MENU(Menu_Shape_New,    DnDShapeFrame::OnNewShape)
    EVT_MENU(Menu_Shape_Edit,   DnDShapeFrame::OnEditShape)
    EVT_MENU(Menu_Shape_Clear,  DnDShapeFrame::OnClearShape)

    EVT_MENU(Menu_ShapeClipboard_Copy,  DnDShapeFrame::OnCopyShape)
    EVT_MENU(Menu_ShapeClipboard_Paste, DnDShapeFrame::OnPasteShape)

    EVT_UPDATE_UI(Menu_ShapeClipboard_Copy,  DnDShapeFrame::OnUpdateUICopy)
    EVT_UPDATE_UI(Menu_ShapeClipboard_Paste, DnDShapeFrame::OnUpdateUIPaste)

    EVT_LEFT_DOWN(DnDShapeFrame::OnDrag)

    EVT_PAINT(DnDShapeFrame::OnPaint)
END_EVENT_TABLE()

BEGIN_EVENT_TABLE(DnDShapeDialog, wxDialog)
    EVT_BUTTON(Button_Colour, DnDShapeDialog::OnColour)
END_EVENT_TABLE()

#endif // wxUSE_DRAG_AND_DROP

BEGIN_EVENT_TABLE(DnDCanvasBitmap, wxScrolledWindow)
    EVT_PAINT(DnDCanvasBitmap::OnPaint)
END_EVENT_TABLE()

#if wxUSE_METAFILE
BEGIN_EVENT_TABLE(DnDCanvasMetafile, wxScrolledWindow)
    EVT_PAINT(DnDCanvasMetafile::OnPaint)
END_EVENT_TABLE()
#endif // wxUSE_METAFILE

#endif // wxUSE_DRAG_AND_DROP

// ============================================================================
// implementation
// ============================================================================

// `Main program' equivalent, creating windows and returning main app frame
bool DnDApp::OnInit()
{
#if wxUSE_DRAG_AND_DROP || wxUSE_CLIPBOARD
    // switch on trace messages
#if wxUSE_LOG
#if defined(__WXGTK__)
    wxLog::AddTraceMask(_T("clipboard"));
#elif defined(__WXMSW__)
    wxLog::AddTraceMask(wxTRACE_OleCalls);
#endif
#endif // wxUSE_LOG

#if wxUSE_LIBPNG
    wxImage::AddHandler( new wxPNGHandler );
#endif

    // under X we usually want to use the primary selection by default (which
    // is shared with other apps)
    wxTheClipboard->UsePrimarySelection();

    // create the main frame window
    DnDFrame *frame = new DnDFrame((wxFrame  *) NULL,
                                   _T("Drag-and-Drop/Clipboard wxWidgets Sample"),
                                   10, 100, 650, 340);

    // activate it
    frame->Show(true);

    SetTopWindow(frame);

    return true;
#else
    wxMessageBox( _T("This sample has to be compiled with wxUSE_DRAG_AND_DROP"), _T("Building error"), wxOK);
    return false;
#endif // wxUSE_DRAG_AND_DROP
}

#if wxUSE_DRAG_AND_DROP || wxUSE_CLIPBOARD

DnDFrame::DnDFrame(wxFrame *frame, const wxChar *title, int x, int y, int w, int h)
        : wxFrame(frame, wxID_ANY, title, wxPoint(x, y), wxSize(w, h)),
          m_strText(_T("wxWidgets drag & drop works :-)"))

{
    // frame icon and status bar
    SetIcon(wxICON(sample));

#if wxUSE_STATUSBAR
    CreateStatusBar();
#endif // wxUSE_STATUSBAR

    // construct menu
    wxMenu *file_menu = new wxMenu;
    file_menu->Append(Menu_Drag, _T("&Test drag..."));
    file_menu->AppendCheckItem(Menu_DragMoveDef, _T("&Move by default"));
    file_menu->AppendCheckItem(Menu_DragMoveAllow, _T("&Allow moving"));
    file_menu->AppendSeparator();
    file_menu->Append(Menu_NewFrame, _T("&New frame\tCtrl-N"));
    file_menu->AppendSeparator();
    file_menu->Append(Menu_Quit, _T("E&xit\tCtrl-Q"));

#if wxUSE_LOG
    wxMenu *log_menu = new wxMenu;
    log_menu->Append(Menu_Clear, _T("Clear\tCtrl-L"));
#endif // wxUSE_LOG

    wxMenu *help_menu = new wxMenu;
    help_menu->Append(Menu_Help, _T("&Help..."));
    help_menu->AppendSeparator();
    help_menu->Append(Menu_About, _T("&About"));

    wxMenu *clip_menu = new wxMenu;
    clip_menu->Append(Menu_Copy, _T("&Copy text\tCtrl-C"));
    clip_menu->Append(Menu_Paste, _T("&Paste text\tCtrl-V"));
    clip_menu->AppendSeparator();
    clip_menu->Append(Menu_CopyBitmap, _T("Copy &bitmap\tCtrl-Shift-C"));
    clip_menu->Append(Menu_PasteBitmap, _T("Paste b&itmap\tCtrl-Shift-V"));
#if wxUSE_METAFILE
    clip_menu->AppendSeparator();
    clip_menu->Append(Menu_PasteMFile, _T("Paste &metafile\tCtrl-M"));
#endif // wxUSE_METAFILE
    clip_menu->AppendSeparator();
    clip_menu->Append(Menu_CopyFiles, _T("Copy &files\tCtrl-F"));

    wxMenuBar *menu_bar = new wxMenuBar;
    menu_bar->Append(file_menu, _T("&File"));
#if wxUSE_LOG
    menu_bar->Append(log_menu,  _T("&Log"));
#endif // wxUSE_LOG
    menu_bar->Append(clip_menu, _T("&Clipboard"));
    menu_bar->Append(help_menu, _T("&Help"));

    SetMenuBar(menu_bar);

    // make a panel with 3 subwindows
    wxString strFile(_T("Drop files here!")), strText(_T("Drop text on me"));

    m_ctrlFile  = new wxListBox(this, wxID_ANY, wxDefaultPosition, wxDefaultSize, 1, &strFile,
                                wxLB_HSCROLL | wxLB_ALWAYS_SB );
    m_ctrlText  = new wxListBox(this, wxID_ANY, wxDefaultPosition, wxDefaultSize, 1, &strText,
                                wxLB_HSCROLL | wxLB_ALWAYS_SB );

#if wxUSE_LOG
    m_ctrlLog   = new wxTextCtrl(this, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize,
                                 wxTE_MULTILINE | wxTE_READONLY |
                                 wxSUNKEN_BORDER );

    // redirect log messages to the text window
    m_pLog = new wxLogTextCtrl(m_ctrlLog);
    m_pLogPrev = wxLog::SetActiveTarget(m_pLog);
#endif // wxUSE_LOG

#if wxUSE_DRAG_AND_DROP
    // associate drop targets with the controls
    m_ctrlFile->SetDropTarget(new DnDFile(m_ctrlFile));
    m_ctrlText->SetDropTarget(new DnDText(m_ctrlText));
#if wxUSE_LOG
    m_ctrlLog->SetDropTarget(new URLDropTarget);
#endif // wxUSE_LOG
#endif // wxUSE_DRAG_AND_DROP

    wxBoxSizer *sizer_top = new wxBoxSizer( wxHORIZONTAL );
    sizer_top->Add(m_ctrlFile, 1, wxEXPAND );
    sizer_top->Add(m_ctrlText, 1, wxEXPAND );

    wxBoxSizer *sizer = new wxBoxSizer( wxVERTICAL );
    sizer->Add(sizer_top, 1, wxEXPAND );
#if wxUSE_LOG
    sizer->Add(m_ctrlLog, 2, wxEXPAND);
    sizer->SetItemMinSize(m_ctrlLog, 450, 0);
#endif // wxUSE_LOG
    sizer->AddSpacer(50);

    SetSizer(sizer);
    sizer->SetSizeHints( this );

    // copy data by default but allow moving it as well
    m_moveByDefault = false;
    m_moveAllow = true;
    menu_bar->Check(Menu_DragMoveAllow, true);
}

void DnDFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
{
    Close(true);
}

void DnDFrame::OnSize(wxSizeEvent& event)
{
    Refresh();

    event.Skip();
}

void DnDFrame::OnPaint(wxPaintEvent& WXUNUSED(event))
{
    int w = 0;
    int h = 0;
    GetClientSize( &w, &h );

    wxPaintDC dc(this);
    // dc.Clear(); -- this kills wxGTK
    dc.SetFont( wxFont( 24, wxDECORATIVE, wxNORMAL, wxNORMAL, false, _T("charter") ) );
    dc.DrawText( _T("Drag text from here!"), 100, h-50 );
}

void DnDFrame::OnUpdateUIMoveByDefault(wxUpdateUIEvent& event)
{
    // only can move by default if moving is allowed at all
    event.Enable(m_moveAllow);
}

void DnDFrame::OnUpdateUIPasteText(wxUpdateUIEvent& event)
{
#ifdef __WXDEBUG__
    // too many trace messages if we don't do it - this function is called
    // very often
    wxLogNull nolog;
#endif

    event.Enable( wxTheClipboard->IsSupported(wxDF_TEXT) );
}

void DnDFrame::OnUpdateUIPasteBitmap(wxUpdateUIEvent& event)
{
#ifdef __WXDEBUG__
    // too many trace messages if we don't do it - this function is called
    // very often
    wxLogNull nolog;
#endif

    event.Enable( wxTheClipboard->IsSupported(wxDF_BITMAP) );
}

void DnDFrame::OnNewFrame(wxCommandEvent& WXUNUSED(event))
{
#if wxUSE_DRAG_AND_DROP
    (new DnDShapeFrame(this))->Show(true);

    wxLogStatus(this, wxT("Double click the new frame to select a shape for it"));
#endif // wxUSE_DRAG_AND_DROP
}

void DnDFrame::OnDrag(wxCommandEvent& WXUNUSED(event))
{
#if wxUSE_DRAG_AND_DROP
    wxString strText = wxGetTextFromUser
        (
            _T("After you enter text in this dialog, press any mouse\n")
            _T("button in the bottom (empty) part of the frame and \n")
            _T("drag it anywhere - you will be in fact dragging the\n")
         _T("text object containing this text"),
         _T("Please enter some text"), m_strText, this
        );

    m_strText = strText;
#endif // wxUSE_DRAG_AND_DROP
}

void DnDFrame::OnDragMoveByDefault(wxCommandEvent& event)
{
    m_moveByDefault = event.IsChecked();
}

void DnDFrame::OnDragMoveAllow(wxCommandEvent& event)
{
    m_moveAllow = event.IsChecked();
}

void DnDFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
    wxMessageBox(_T("Drag-&-Drop Demo\n")
                 _T("Please see \"Help|Help...\" for details\n")
                 _T("Copyright (c) 1998 Vadim Zeitlin"),
                 _T("About wxDnD"),
                 wxICON_INFORMATION | wxOK,
                 this);
}

void DnDFrame::OnHelp(wxCommandEvent& /* event */)
{
    wxMessageDialog dialog(this,
                           _T("This small program demonstrates drag & drop support in wxWidgets. The program window\n")
                           _T("consists of 3 parts: the bottom pane is for debug messages, so that you can see what's\n")
                           _T("going on inside. The top part is split into 2 listboxes, the left one accepts files\n")
                           _T("and the right one accepts text.\n")
                           _T("\n")
                           _T("To test wxDropTarget: open wordpad (write.exe), select some text in it and drag it to\n")
                           _T("the right listbox (you'll notice the usual visual feedback, i.e. the cursor will change).\n")
                           _T("Also, try dragging some files (you can select several at once) from Windows Explorer (or \n")
                           _T("File Manager) to the left pane. Hold down Ctrl/Shift keys when you drop text (doesn't \n")
                           _T("work with files) and see what changes.\n")
                           _T("\n")
                           _T("To test wxDropSource: just press any mouse button on the empty zone of the window and drag\n")
                           _T("it to wordpad or any other droptarget accepting text (and of course you can just drag it\n")
                           _T("to the right pane). Due to a lot of trace messages, the cursor might take some time to \n")
                           _T("change, don't release the mouse button until it does. You can change the string being\n")
                           _T("dragged in in \"File|Test drag...\" dialog.\n")
                           _T("\n")
                           _T("\n")
                           _T("Please send all questions/bug reports/suggestions &c to \n")
                           _T("Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>"),
                           _T("wxDnD Help"));

    dialog.ShowModal();
}

#if wxUSE_LOG
void DnDFrame::OnLogClear(wxCommandEvent& /* event */ )
{
    m_ctrlLog->Clear();
    m_ctrlText->Clear();
    m_ctrlFile->Clear();
}
#endif // wxUSE_LOG

void DnDFrame::OnLeftDown(wxMouseEvent &WXUNUSED(event) )
{
#if wxUSE_DRAG_AND_DROP
    if ( !m_strText.empty() )
    {
        // start drag operation
        wxTextDataObject textData(m_strText);
        wxDropSource source(textData, this,
                            wxDROP_ICON(dnd_copy),
                            wxDROP_ICON(dnd_move),
                            wxDROP_ICON(dnd_none));

        int flags = 0;
        if ( m_moveByDefault )
            flags |= wxDrag_DefaultMove;
        else if ( m_moveAllow )
            flags |= wxDrag_AllowMove;

        wxDragResult result = source.DoDragDrop(flags);

#if wxUSE_STATUSBAR
        const wxChar *pc;
        switch ( result )
        {
            case wxDragError:   pc = _T("Error!");    break;
            case wxDragNone:    pc = _T("Nothing");   break;
            case wxDragCopy:    pc = _T("Copied");    break;
            case wxDragMove:    pc = _T("Moved");     break;
            case wxDragCancel:  pc = _T("Cancelled"); break;
            default:            pc = _T("Huh?");      break;
        }

        SetStatusText(wxString(_T("Drag result: ")) + pc);
#else
        wxUnusedVar(result);
#endif // wxUSE_STATUSBAR
    }
#endif // wxUSE_DRAG_AND_DROP
}

void DnDFrame::OnRightDown(wxMouseEvent &event )
{
    wxMenu menu(_T("Dnd sample menu"));

    menu.Append(Menu_Drag, _T("&Test drag..."));
    menu.AppendSeparator();
    menu.Append(Menu_About, _T("&About"));

    PopupMenu( &menu, event.GetX(), event.GetY() );
}

DnDFrame::~DnDFrame()
{
#if wxUSE_LOG
    if ( m_pLog != NULL ) {
        if ( wxLog::SetActiveTarget(m_pLogPrev) == m_pLog )
            delete m_pLog;
    }
#endif // wxUSE_LOG
}

// ---------------------------------------------------------------------------
// bitmap clipboard
// ---------------------------------------------------------------------------

void DnDFrame::OnCopyBitmap(wxCommandEvent& WXUNUSED(event))
{
    // PNG support is not always compiled in under Windows, so use BMP there
#if wxUSE_LIBPNG
    wxFileDialog dialog(this, _T("Open a PNG file"), wxEmptyString, wxEmptyString, _T("PNG files (*.png)|*.png"), 0);
#else
    wxFileDialog dialog(this, _T("Open a BMP file"), wxEmptyString, wxEmptyString, _T("BMP files (*.bmp)|*.bmp"), 0);
#endif

    if (dialog.ShowModal() != wxID_OK)
    {
        wxLogMessage( _T("Aborted file open") );
        return;
    }

    if (dialog.GetPath().empty())
    {
        wxLogMessage( _T("Returned empty string.") );
        return;
    }

    if (!wxFileExists(dialog.GetPath()))
    {
        wxLogMessage( _T("File doesn't exist.") );
        return;
    }

    wxImage image;
    image.LoadFile( dialog.GetPath(),
#if wxUSE_LIBPNG
                    wxBITMAP_TYPE_PNG
#else
                    wxBITMAP_TYPE_BMP
#endif
                  );
    if (!image.Ok())
    {
        wxLogError( _T("Invalid image file...") );
        return;
    }

    wxLogStatus( _T("Decoding image file...") );
    wxYield();

    wxBitmap bitmap( image );

    if ( !wxTheClipboard->Open() )
    {
        wxLogError(_T("Can't open clipboard."));

        return;
    }

    wxLogMessage( _T("Creating wxBitmapDataObject...") );
    wxYield();

    if ( !wxTheClipboard->AddData(new wxBitmapDataObject(bitmap)) )
    {
        wxLogError(_T("Can't copy image to the clipboard."));
    }
    else
    {
        wxLogMessage(_T("Image has been put on the clipboard.") );
        wxLogMessage(_T("You can paste it now and look at it.") );
    }

    wxTheClipboard->Close();
}

void DnDFrame::OnPasteBitmap(wxCommandEvent& WXUNUSED(event))
{
    if ( !wxTheClipboard->Open() )
    {
        wxLogError(_T("Can't open clipboard."));

        return;
    }

    if ( !wxTheClipboard->IsSupported(wxDF_BITMAP) )
    {
        wxLogWarning(_T("No bitmap on clipboard"));

        wxTheClipboard->Close();
        return;
    }

    wxBitmapDataObject data;
    if ( !wxTheClipboard->GetData(data) )
    {
        wxLogError(_T("Can't paste bitmap from the clipboard"));
    }
    else
    {
        const wxBitmap& bmp = data.GetBitmap();

        wxLogMessage(_T("Bitmap %dx%d pasted from the clipboard"),
                     bmp.GetWidth(), bmp.GetHeight());
        ShowBitmap(bmp);
    }

    wxTheClipboard->Close();
}

#if wxUSE_METAFILE

void DnDFrame::OnPasteMetafile(wxCommandEvent& WXUNUSED(event))
{
    if ( !wxTheClipboard->Open() )
    {
        wxLogError(_T("Can't open clipboard."));

        return;
    }

    if ( !wxTheClipboard->IsSupported(wxDF_METAFILE) )
    {
        wxLogWarning(_T("No metafile on clipboard"));
    }
    else
    {
        wxMetaFileDataObject data;
        if ( !wxTheClipboard->GetData(data) )
        {
            wxLogError(_T("Can't paste metafile from the clipboard"));
        }
        else
        {
            const wxMetaFile& mf = data.GetMetafile();

            wxLogMessage(_T("Metafile %dx%d pasted from the clipboard"),
                         mf.GetWidth(), mf.GetHeight());

            ShowMetaFile(mf);
        }
    }

    wxTheClipboard->Close();
}

#endif // wxUSE_METAFILE

// ----------------------------------------------------------------------------
// file clipboard
// ----------------------------------------------------------------------------

void DnDFrame::OnCopyFiles(wxCommandEvent& WXUNUSED(event))
{
#ifdef __WXMSW__
    wxFileDialog dialog(this, _T("Select a file to copy"), wxEmptyString, wxEmptyString,
                         _T("All files (*.*)|*.*"), 0);

    wxArrayString filenames;
    while ( dialog.ShowModal() == wxID_OK )
    {
        filenames.Add(dialog.GetPath());
    }

    if ( !filenames.IsEmpty() )
    {
        wxFileDataObject *dobj = new wxFileDataObject;
        size_t count = filenames.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            dobj->AddFile(filenames[n]);
        }

        wxClipboardLocker locker;
        if ( !locker )
        {
            wxLogError(wxT("Can't open clipboard"));
        }
        else
        {
            if ( !wxTheClipboard->AddData(dobj) )
            {
                wxLogError(wxT("Can't copy file(s) to the clipboard"));
            }
            else
            {
                wxLogStatus(this, wxT("%d file%s copied to the clipboard"),
                            count, count == 1 ? wxEmptyString : wxEmptyString);
            }
        }
    }
    else
    {
        wxLogStatus(this, wxT("Aborted"));
    }
#else // !MSW
    wxLogError(wxT("Sorry, not implemented"));
#endif // MSW/!MSW
}

// ---------------------------------------------------------------------------
// text clipboard
// ---------------------------------------------------------------------------

void DnDFrame::OnCopy(wxCommandEvent& WXUNUSED(event))
{
    if ( !wxTheClipboard->Open() )
    {
        wxLogError(_T("Can't open clipboard."));

        return;
    }

    if ( !wxTheClipboard->AddData(new wxTextDataObject(m_strText)) )
    {
        wxLogError(_T("Can't copy data to the clipboard"));
    }
    else
    {
        wxLogMessage(_T("Text '%s' put on the clipboard"), m_strText.c_str());
    }

    wxTheClipboard->Close();
}

void DnDFrame::OnPaste(wxCommandEvent& WXUNUSED(event))
{
    if ( !wxTheClipboard->Open() )
    {
        wxLogError(_T("Can't open clipboard."));

        return;
    }

    if ( !wxTheClipboard->IsSupported(wxDF_TEXT) )
    {
        wxLogWarning(_T("No text data on clipboard"));

        wxTheClipboard->Close();
        return;
    }

    wxTextDataObject text;
    if ( !wxTheClipboard->GetData(text) )
    {
        wxLogError(_T("Can't paste data from the clipboard"));
    }
    else
    {
        wxLogMessage(_T("Text '%s' pasted from the clipboard"),
                     text.GetText().c_str());
    }

    wxTheClipboard->Close();
}

#if wxUSE_DRAG_AND_DROP

// ----------------------------------------------------------------------------
// Notifications called by the base class
// ----------------------------------------------------------------------------

bool DnDText::OnDropText(wxCoord, wxCoord, const wxString& text)
{
    m_pOwner->Append(text);

    return true;
}

bool DnDFile::OnDropFiles(wxCoord, wxCoord, const wxArrayString& filenames)
{
    size_t nFiles = filenames.GetCount();
    wxString str;
    str.Printf( _T("%d files dropped"), (int)nFiles);
    m_pOwner->Append(str);
    for ( size_t n = 0; n < nFiles; n++ ) {
        m_pOwner->Append(filenames[n]);
    }

    return true;
}

// ----------------------------------------------------------------------------
// DnDShapeDialog
// ----------------------------------------------------------------------------

DnDShapeDialog::DnDShapeDialog(wxFrame *parent, DnDShape *shape)
  :wxDialog( parent, 6001, wxT("Choose Shape"), wxPoint( 10, 10 ),
             wxSize( 40, 40 ),
             wxDEFAULT_DIALOG_STYLE | wxRAISED_BORDER | wxRESIZE_BORDER )
{
    m_shape = shape;
    wxBoxSizer* topSizer = new wxBoxSizer( wxVERTICAL );

    // radio box
    wxBoxSizer* shapesSizer = new wxBoxSizer( wxHORIZONTAL );
    const wxString choices[] = { wxT("None"), wxT("Triangle"),
                                 wxT("Rectangle"), wxT("Ellipse") };

    m_radio = new wxRadioBox( this, wxID_ANY, wxT("&Shape"),
                              wxDefaultPosition, wxDefaultSize, 4, choices, 4,
                              wxRA_SPECIFY_COLS );
    shapesSizer->Add( m_radio, 0, wxGROW|wxALL, 5 );
    topSizer->Add( shapesSizer, 0, wxALL, 2 );

    // attributes
    wxStaticBox* box = new wxStaticBox( this, wxID_ANY, wxT("&Attributes") );
    wxStaticBoxSizer* attrSizer = new wxStaticBoxSizer( box, wxHORIZONTAL );
    wxFlexGridSizer* xywhSizer = new wxFlexGridSizer( 4, 2 );

    wxStaticText* st;

    st = new wxStaticText( this, wxID_ANY, wxT("Position &X:") );
    m_textX = new wxTextCtrl( this, wxID_ANY, wxEmptyString, wxDefaultPosition,
                              wxSize( 30, 20 ) );
    xywhSizer->Add( st, 1, wxGROW|wxALL, 2 );
    xywhSizer->Add( m_textX, 1, wxGROW|wxALL, 2 );

    st = new wxStaticText( this, wxID_ANY, wxT("Size &width:") );
    m_textW = new wxTextCtrl( this, wxID_ANY, wxEmptyString, wxDefaultPosition,
                              wxSize( 30, 20 ) );
    xywhSizer->Add( st, 1, wxGROW|wxALL, 2 );
    xywhSizer->Add( m_textW, 1, wxGROW|wxALL, 2 );

    st = new wxStaticText( this, wxID_ANY, wxT("&Y:") );
    m_textY = new wxTextCtrl( this, wxID_ANY, wxEmptyString, wxDefaultPosition,
                              wxSize( 30, 20 ) );
    xywhSizer->Add( st, 1, wxALL|wxALIGN_RIGHT, 2 );
    xywhSizer->Add( m_textY, 1, wxGROW|wxALL, 2 );

    st = new wxStaticText( this, wxID_ANY, wxT("&height:") );
    m_textH = new wxTextCtrl( this, wxID_ANY, wxEmptyString, wxDefaultPosition,
                              wxSize( 30, 20 ) );
    xywhSizer->Add( st, 1, wxALL|wxALIGN_RIGHT, 2 );
    xywhSizer->Add( m_textH, 1, wxGROW|wxALL, 2 );

    wxButton* col = new wxButton( this, Button_Colour, wxT("&Colour...") );
    attrSizer->Add( xywhSizer, 1, wxGROW );
    attrSizer->Add( col, 0, wxALL|wxALIGN_CENTRE_VERTICAL, 2 );
    topSizer->Add( attrSizer, 0, wxGROW|wxALL, 5 );

    // buttons
    wxBoxSizer* buttonSizer = new wxBoxSizer( wxHORIZONTAL );
    wxButton* bt;
    bt = new wxButton( this, wxID_OK, wxT("Ok") );
    buttonSizer->Add( bt, 0, wxALL, 2 );
    bt = new wxButton( this, wxID_CANCEL, wxT("Cancel") );
    buttonSizer->Add( bt, 0, wxALL, 2 );
    topSizer->Add( buttonSizer, 0, wxALL|wxALIGN_RIGHT, 2 );

    SetSizer( topSizer );
    topSizer->Fit( this );
}

DnDShape *DnDShapeDialog::GetShape() const
{
    switch ( m_shapeKind )
    {
        default:
        case DnDShape::None:      return NULL;
        case DnDShape::Triangle:  return new DnDTriangularShape(m_pos, m_size, m_col);
        case DnDShape::Rectangle: return new DnDRectangularShape(m_pos, m_size, m_col);
        case DnDShape::Ellipse:   return new DnDEllipticShape(m_pos, m_size, m_col);
    }
}

bool DnDShapeDialog::TransferDataToWindow()
{

    if ( m_shape )
    {
        m_radio->SetSelection(m_shape->GetKind());
        m_pos = m_shape->GetPosition();
        m_size = m_shape->GetSize();
        m_col = m_shape->GetColour();
    }
    else
    {
        m_radio->SetSelection(DnDShape::None);
        m_pos = wxPoint(1, 1);
        m_size = wxSize(100, 100);
    }

    m_textX->SetValue(wxString() << m_pos.x);
    m_textY->SetValue(wxString() << m_pos.y);
    m_textW->SetValue(wxString() << m_size.x);
    m_textH->SetValue(wxString() << m_size.y);

    return true;
}

bool DnDShapeDialog::TransferDataFromWindow()
{
    m_shapeKind = (DnDShape::Kind)m_radio->GetSelection();

    m_pos.x = wxAtoi(m_textX->GetValue());
    m_pos.y = wxAtoi(m_textY->GetValue());
    m_size.x = wxAtoi(m_textW->GetValue());
    m_size.y = wxAtoi(m_textH->GetValue());

    if ( !m_pos.x || !m_pos.y || !m_size.x || !m_size.y )
    {
        wxMessageBox(_T("All sizes and positions should be non null!"),
                     _T("Invalid shape"), wxICON_HAND | wxOK, this);

        return false;
    }

    return true;
}

void DnDShapeDialog::OnColour(wxCommandEvent& WXUNUSED(event))
{
    wxColourData data;
    data.SetChooseFull(true);
    for (int i = 0; i < 16; i++)
    {
        wxColour colour((unsigned char)(i*16), (unsigned char)(i*16), (unsigned char)(i*16));
        data.SetCustomColour(i, colour);
    }

    wxColourDialog dialog(this, &data);
    if ( dialog.ShowModal() == wxID_OK )
    {
        m_col = dialog.GetColourData().GetColour();
    }
}

// ----------------------------------------------------------------------------
// DnDShapeFrame
// ----------------------------------------------------------------------------

DnDShapeFrame *DnDShapeFrame::ms_lastDropTarget = NULL;

DnDShapeFrame::DnDShapeFrame(wxFrame *parent)
             : wxFrame(parent, wxID_ANY, _T("Shape Frame"))
{
#if wxUSE_STATUSBAR
    CreateStatusBar();
#endif // wxUSE_STATUSBAR

    wxMenu *menuShape = new wxMenu;
    menuShape->Append(Menu_Shape_New, _T("&New default shape\tCtrl-S"));
    menuShape->Append(Menu_Shape_Edit, _T("&Edit shape\tCtrl-E"));
    menuShape->AppendSeparator();
    menuShape->Append(Menu_Shape_Clear, _T("&Clear shape\tCtrl-L"));

    wxMenu *menuClipboard = new wxMenu;
    menuClipboard->Append(Menu_ShapeClipboard_Copy, _T("&Copy\tCtrl-C"));
    menuClipboard->Append(Menu_ShapeClipboard_Paste, _T("&Paste\tCtrl-V"));

    wxMenuBar *menubar = new wxMenuBar;
    menubar->Append(menuShape, _T("&Shape"));
    menubar->Append(menuClipboard, _T("&Clipboard"));

    SetMenuBar(menubar);

#if wxUSE_STATUSBAR
    SetStatusText(_T("Press Ctrl-S to create a new shape"));
#endif // wxUSE_STATUSBAR

    SetDropTarget(new DnDShapeDropTarget(this));

    m_shape = NULL;

    SetBackgroundColour(*wxWHITE);
}

DnDShapeFrame::~DnDShapeFrame()
{
    if (m_shape)
        delete m_shape;
}

void DnDShapeFrame::SetShape(DnDShape *shape)
{
    if (m_shape)
        delete m_shape;
    m_shape = shape;
    Refresh();
}

// callbacks
void DnDShapeFrame::OnDrag(wxMouseEvent& event)
{
    if ( !m_shape )
    {
        event.Skip();

        return;
    }

    // start drag operation
    DnDShapeDataObject shapeData(m_shape);
    wxDropSource source(shapeData, this);

    const wxChar *pc = NULL;
    switch ( source.DoDragDrop(true) )
    {
        default:
        case wxDragError:
            wxLogError(wxT("An error occurred during drag and drop operation"));
            break;

        case wxDragNone:
#if wxUSE_STATUSBAR
            SetStatusText(_T("Nothing happened"));
#endif // wxUSE_STATUSBAR
            break;

        case wxDragCopy:
            pc = _T("copied");
            break;

        case wxDragMove:
            pc = _T("moved");
            if ( ms_lastDropTarget != this )
            {
                // don't delete the shape if we dropped it on ourselves!
                SetShape(NULL);
            }
            break;

        case wxDragCancel:
#if wxUSE_STATUSBAR
            SetStatusText(_T("Drag and drop operation cancelled"));
#endif // wxUSE_STATUSBAR
            break;
    }

    if ( pc )
    {
#if wxUSE_STATUSBAR
        SetStatusText(wxString(_T("Shape successfully ")) + pc);
#endif // wxUSE_STATUSBAR
    }
    //else: status text already set
}

void DnDShapeFrame::OnDrop(wxCoord x, wxCoord y, DnDShape *shape)
{
    ms_lastDropTarget = this;

    wxPoint pt(x, y);

#if wxUSE_STATUSBAR
    wxString s;
    s.Printf(wxT("Shape dropped at (%d, %d)"), pt.x, pt.y);
    SetStatusText(s);
#endif // wxUSE_STATUSBAR

    shape->Move(pt);
    SetShape(shape);
}

void DnDShapeFrame::OnEditShape(wxCommandEvent& WXUNUSED(event))
{
    DnDShapeDialog dlg(this, m_shape);
    if ( dlg.ShowModal() == wxID_OK )
    {
        SetShape(dlg.GetShape());

#if wxUSE_STATUSBAR
        if ( m_shape )
        {
            SetStatusText(_T("You can now drag the shape to another frame"));
        }
#endif // wxUSE_STATUSBAR
    }
}

void DnDShapeFrame::OnNewShape(wxCommandEvent& WXUNUSED(event))
{
    SetShape(new DnDEllipticShape(wxPoint(10, 10), wxSize(80, 60), *wxRED));

#if wxUSE_STATUSBAR
    SetStatusText(_T("You can now drag the shape to another frame"));
#endif // wxUSE_STATUSBAR
}

void DnDShapeFrame::OnClearShape(wxCommandEvent& WXUNUSED(event))
{
    SetShape(NULL);
}

void DnDShapeFrame::OnCopyShape(wxCommandEvent& WXUNUSED(event))
{
    if ( m_shape )
    {
        wxClipboardLocker clipLocker;
        if ( !clipLocker )
        {
            wxLogError(wxT("Can't open the clipboard"));

            return;
        }

        wxTheClipboard->AddData(new DnDShapeDataObject(m_shape));
    }
}

void DnDShapeFrame::OnPasteShape(wxCommandEvent& WXUNUSED(event))
{
    wxClipboardLocker clipLocker;
    if ( !clipLocker )
    {
        wxLogError(wxT("Can't open the clipboard"));

        return;
    }

    DnDShapeDataObject shapeDataObject(NULL);
    if ( wxTheClipboard->GetData(shapeDataObject) )
    {
        SetShape(shapeDataObject.GetShape());
    }
    else
    {
        wxLogStatus(wxT("No shape on the clipboard"));
    }
}

void DnDShapeFrame::OnUpdateUICopy(wxUpdateUIEvent& event)
{
    event.Enable( m_shape != NULL );
}

void DnDShapeFrame::OnUpdateUIPaste(wxUpdateUIEvent& event)
{
    event.Enable( wxTheClipboard->IsSupported(wxDataFormat(shapeFormatId)) );
}

void DnDShapeFrame::OnPaint(wxPaintEvent& event)
{
    if ( m_shape )
    {
        wxPaintDC dc(this);

        m_shape->Draw(dc);
    }
    else
    {
        event.Skip();
    }
}

// ----------------------------------------------------------------------------
// DnDShape
// ----------------------------------------------------------------------------

DnDShape *DnDShape::New(const void *buf)
{
    const ShapeDump& dump = *(const ShapeDump *)buf;
    switch ( dump.k )
    {
        case Triangle:
            return new DnDTriangularShape(wxPoint(dump.x, dump.y),
                                          wxSize(dump.w, dump.h),
                                          wxColour(dump.r, dump.g, dump.b));

        case Rectangle:
            return new DnDRectangularShape(wxPoint(dump.x, dump.y),
                                           wxSize(dump.w, dump.h),
                                           wxColour(dump.r, dump.g, dump.b));

        case Ellipse:
            return new DnDEllipticShape(wxPoint(dump.x, dump.y),
                                        wxSize(dump.w, dump.h),
                                        wxColour(dump.r, dump.g, dump.b));

        default:
            wxFAIL_MSG(wxT("invalid shape!"));
            return NULL;
    }
}

// ----------------------------------------------------------------------------
// DnDShapeDataObject
// ----------------------------------------------------------------------------

#if wxUSE_METAFILE

void DnDShapeDataObject::CreateMetaFile() const
{
    wxPoint pos = m_shape->GetPosition();
    wxSize size = m_shape->GetSize();

    wxMetaFileDC dcMF(wxEmptyString, pos.x + size.x, pos.y + size.y);

    m_shape->Draw(dcMF);

    wxMetafile *mf = dcMF.Close();

    DnDShapeDataObject *self = (DnDShapeDataObject *)this; // const_cast
    self->m_dobjMetaFile.SetMetafile(*mf);
    self->m_hasMetaFile = true;

    delete mf;
}

#endif // wxUSE_METAFILE

void DnDShapeDataObject::CreateBitmap() const
{
    wxPoint pos = m_shape->GetPosition();
    wxSize size = m_shape->GetSize();
    int x = pos.x + size.x,
        y = pos.y + size.y;
    wxBitmap bitmap(x, y);
    wxMemoryDC dc;
    dc.SelectObject(bitmap);
    dc.SetBrush(wxBrush(wxT("white"), wxSOLID));
    dc.Clear();
    m_shape->Draw(dc);
    dc.SelectObject(wxNullBitmap);

    DnDShapeDataObject *self = (DnDShapeDataObject *)this; // const_cast
    self->m_dobjBitmap.SetBitmap(bitmap);
    self->m_hasBitmap = true;
}

#endif // wxUSE_DRAG_AND_DROP

// ----------------------------------------------------------------------------
// global functions
// ----------------------------------------------------------------------------

static void ShowBitmap(const wxBitmap& bitmap)
{
    wxFrame *frame = new wxFrame(NULL, wxID_ANY, _T("Bitmap view"));
#if wxUSE_STATUSBAR
    frame->CreateStatusBar();
#endif // wxUSE_STATUSBAR
    DnDCanvasBitmap *canvas = new DnDCanvasBitmap(frame);
    canvas->SetBitmap(bitmap);

    int w = bitmap.GetWidth(),
        h = bitmap.GetHeight();
#if wxUSE_STATUSBAR
    frame->SetStatusText(wxString::Format(_T("%dx%d"), w, h));
#endif // wxUSE_STATUSBAR

    frame->SetClientSize(w > 100 ? 100 : w, h > 100 ? 100 : h);
    frame->Show(true);
}

#if wxUSE_METAFILE

static void ShowMetaFile(const wxMetaFile& metafile)
{
    wxFrame *frame = new wxFrame(NULL, wxID_ANY, _T("Metafile view"));
    frame->CreateStatusBar();
    DnDCanvasMetafile *canvas = new DnDCanvasMetafile(frame);
    canvas->SetMetafile(metafile);

    wxSize size = metafile.GetSize();
    frame->SetStatusText(wxString::Format(_T("%dx%d"), size.x, size.y));

    frame->SetClientSize(size.x > 100 ? 100 : size.x,
                         size.y > 100 ? 100 : size.y);
    frame->Show();
}

#endif // wxUSE_METAFILE

#endif // wxUSE_DRAG_AND_DROP || wxUSE_CLIPBOARD