dnd.cpp

很牛的GUI源码wxWidgets-2.8.0.zip 可在多种平台下运行.

///////////////////////////////////////////////////////////////////////////////
// Name:        src/mac/classic/dnd.cpp
// Purpose:     wxDropTarget, wxDropSource, wxDataObject implementation
// Author:      Stefan Csomor
// Modified by:
// Created:     1998-01-01
// RCS-ID:      $Id: dnd.cpp,v 1.10 2006/06/19 20:18:32 ABX Exp $
// Copyright:   (c) 1998 Stefan Csomor
// Licence:     wxWindows licence
///////////////////////////////////////////////////////////////////////////////

#include "wx/wxprec.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#if wxUSE_DRAG_AND_DROP

#include "wx/dnd.h"

#ifndef WX_PRECOMP
    #include "wx/app.h"
    #include "wx/window.h"
    #include "wx/toplevel.h"
    #include "wx/gdicmn.h"
#endif // WX_PRECOMP

#include "wx/mac/private.h"

// ----------------------------------------------------------------------------
// global
// ----------------------------------------------------------------------------

void wxMacEnsureTrackingHandlersInstalled() ;

typedef struct
{
    wxWindow* m_currentTargetWindow ;
    wxDropTarget* m_currentTarget ;
    wxDropSource* m_currentSource ;
} MacTrackingGlobals ;

MacTrackingGlobals gTrackingGlobals ;

//----------------------------------------------------------------------------
// wxDropTarget
//----------------------------------------------------------------------------

wxDropTarget::wxDropTarget( wxDataObject *data )
            : wxDropTargetBase( data )
{
    wxMacEnsureTrackingHandlersInstalled() ;
}

wxDragResult wxDropTarget::OnDragOver( wxCoord WXUNUSED(x),
                                       wxCoord WXUNUSED(y),
                                       wxDragResult def )
{

    return CurrentDragHasSupportedFormat() ? def : wxDragNone;
}

bool wxDropTarget::OnDrop( wxCoord WXUNUSED(x), wxCoord WXUNUSED(y) )
{
    if (!m_dataObject)
        return false;

    return CurrentDragHasSupportedFormat() ;
}

wxDragResult wxDropTarget::OnData( wxCoord WXUNUSED(x), wxCoord WXUNUSED(y),
                                   wxDragResult def )
{
    if (!m_dataObject)
        return wxDragNone;

    if (!CurrentDragHasSupportedFormat())
        return wxDragNone;

    return GetData() ? def : wxDragNone;
}

bool wxDropTarget::CurrentDragHasSupportedFormat()
{
    bool supported = false ;
    if ( gTrackingGlobals.m_currentSource != NULL )
    {
        wxDataObject* data = gTrackingGlobals.m_currentSource->GetDataObject() ;

        if ( data )
        {
            size_t formatcount = data->GetFormatCount() ;
            wxDataFormat *array = new wxDataFormat[ formatcount  ];
            data->GetAllFormats( array );
            for (size_t i = 0; !supported && i < formatcount ; i++)
            {
                wxDataFormat format = array[i] ;
                if ( m_dataObject->IsSupported( format ) )
                {
                    supported = true ;
                    break ;
                }
            }
            delete[] array ;
        }
    }
    if ( !supported )
    {
        UInt16 items ;
        OSErr result;
        CountDragItems((DragReference)m_currentDrag, &items);
        for (UInt16 index = 1; index <= items && supported == false ; ++index)
        {
            ItemReference theItem;
            FlavorType theType ;
            UInt16 flavors = 0 ;
            GetDragItemReferenceNumber((DragReference)m_currentDrag, index, &theItem);
            CountDragItemFlavors( (DragReference)m_currentDrag, theItem , &flavors ) ;
            for ( UInt16 flavor = 1 ; flavor <= flavors ; ++flavor )
            {
                result = GetFlavorType((DragReference)m_currentDrag, theItem, flavor , &theType);
                if ( m_dataObject->IsSupportedFormat( wxDataFormat( theType ) ) )
                {
                    supported = true ;
                    break ;
                }
            }
        }
    }
    return supported ;
}

bool wxDropTarget::GetData()
{
    if (!m_dataObject)
        return false;

    if ( !CurrentDragHasSupportedFormat() )
        return false ;

    bool transferred = false ;
    if ( gTrackingGlobals.m_currentSource != NULL )
    {
        wxDataObject* data = gTrackingGlobals.m_currentSource->GetDataObject() ;

        if ( data )
        {
            size_t formatcount = data->GetFormatCount() ;
            wxDataFormat *array = new wxDataFormat[ formatcount  ];
            data->GetAllFormats( array );
            for (size_t i = 0; !transferred && i < formatcount ; i++)
            {
                wxDataFormat format = array[i] ;
                if ( m_dataObject->IsSupported( format ) )
                {
                    int size = data->GetDataSize( format );
                    transferred = true ;

                    if (size == 0)
                    {
                        m_dataObject->SetData(format , 0 , 0 ) ;
                    }
                    else
                    {
                        char *d = new char[size];
                        data->GetDataHere( format , (void*) d );
                        m_dataObject->SetData( format , size , d ) ;
                        delete[] d ;
                    }
                }
            }
            delete[] array ;
        }
    }
    if ( !transferred )
    {
        UInt16 items ;
        OSErr result;
        bool firstFileAdded = false ;
        CountDragItems((DragReference)m_currentDrag, &items);
        for (UInt16 index = 1; index <= items; ++index)
        {
            ItemReference theItem;
            FlavorType theType ;
            UInt16 flavors = 0 ;
            GetDragItemReferenceNumber((DragReference)m_currentDrag, index, &theItem);
            CountDragItemFlavors( (DragReference)m_currentDrag, theItem , &flavors ) ;
            for ( UInt16 flavor = 1 ; flavor <= flavors ; ++flavor )
            {
                result = GetFlavorType((DragReference)m_currentDrag, theItem, flavor , &theType);
                wxDataFormat format(theType) ;
                if ( m_dataObject->IsSupportedFormat( format ) )
                {
                    FlavorFlags theFlags;
                    result = GetFlavorFlags((DragReference)m_currentDrag, theItem, theType, &theFlags);
                    if (result == noErr)
                    {
                        Size dataSize ;
                        Ptr theData ;
                        GetFlavorDataSize((DragReference)m_currentDrag, theItem, theType, &dataSize);
                        if ( theType == 'TEXT' )
                        {
                            // this increment is only valid for allocating, on the next GetFlavorData
                            // call it is reset again to the original value
                            dataSize++ ;
                        }
                        theData = new char[dataSize];
                        GetFlavorData((DragReference)m_currentDrag, theItem, theType, (void*) theData, &dataSize, 0L);
                        if( theType == 'TEXT' )
                        {
                            theData[dataSize]=0 ;
                            wxString convert( theData , wxConvLocal ) ;
                            m_dataObject->SetData( format, convert.length() * sizeof(wxChar), (const wxChar*) convert );
                        }
                        else if ( theType == kDragFlavorTypeHFS )
                        {
                            HFSFlavor* theFile = (HFSFlavor*) theData ;
                            wxString name = wxMacFSSpec2MacFilename( &theFile->fileSpec ) ;
                            if (  firstFileAdded )
                                ((wxFileDataObject*)m_dataObject)->AddFile( name ) ;
                            else
                            {
                                ((wxFileDataObject*)m_dataObject)->SetData( 0 , name.c_str() ) ;
                                firstFileAdded = true ;
                            }
                        }
                        else
                        {
                            m_dataObject->SetData( format, dataSize, theData );
                        }
                        delete[] theData;
                    }
                    break ;
                }
            }
        }
    }
    return true ;
}

//-------------------------------------------------------------------------
// wxDropSource
//-------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// drag request

wxDropSource::wxDropSource(wxWindow *win,
                           const wxCursor &cursorCopy,
                           const wxCursor &cursorMove,
                           const wxCursor &cursorStop)
            : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
{
    wxMacEnsureTrackingHandlersInstalled() ;
    m_window = win;
}

wxDropSource::wxDropSource(wxDataObject& data,
                           wxWindow *win,
                           const wxCursor &cursorCopy,
                           const wxCursor &cursorMove,
                           const wxCursor &cursorStop)
            : wxDropSourceBase(cursorCopy, cursorMove, cursorStop)
{
    wxMacEnsureTrackingHandlersInstalled() ;
    SetData( data );
    m_window = win;
}

wxDropSource::~wxDropSource()
{
}


wxDragResult wxDropSource::DoDragDrop(int WXUNUSED(flags))
{
    wxASSERT_MSG( m_data, wxT("Drop source: no data") );

    if (!m_data)
        return (wxDragResult) wxDragNone;

    if (m_data->GetFormatCount() == 0)
        return (wxDragResult) wxDragNone;

    OSErr result;
    DragReference theDrag;
    RgnHandle dragRegion;
    if ((result = NewDrag(&theDrag)))
    {
        return wxDragNone ;
    }
    // add data to drag
    size_t formatCount = m_data->GetFormatCount() ;
    wxDataFormat *formats = new wxDataFormat[formatCount] ;
    m_data->GetAllFormats( formats ) ;
    ItemReference theItem = 1 ;
    for ( size_t i = 0 ; i < formatCount ; ++i )
    {
        size_t dataSize = m_data->GetDataSize( formats[i] ) ;
        Ptr dataPtr = new char[dataSize] ;
        m_data->GetDataHere( formats[i] , dataPtr ) ;
        OSType type = formats[i].GetFormatId() ;
        if ( type == 'TEXT' )
        {
            dataSize-- ;