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/carbon/dnd.cpp
// Purpose:     wxDropTarget, wxDropSource implementations
// Author:      Stefan Csomor
// Modified by:
// Created:     1998-01-01
// RCS-ID:      $Id: dnd.cpp,v 1.56 2006/10/14 16:01:54 SC Exp $
// Copyright:   (c) 1998 Stefan Csomor
// Licence:     wxWindows licence
///////////////////////////////////////////////////////////////////////////////

#include "wx/wxprec.h"

#if wxUSE_DRAG_AND_DROP

#include "wx/dnd.h"

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

#include "wx/mac/private.h"

#ifndef __DARWIN__
    #include <Scrap.h>
#endif


// ----------------------------------------------------------------------------
// globals
// ----------------------------------------------------------------------------

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

MacTrackingGlobals gTrackingGlobals;

void wxMacEnsureTrackingHandlersInstalled();

//----------------------------------------------------------------------------
// 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 == NULL)
        return false;

    return CurrentDragHasSupportedFormat();
}

wxDragResult wxDropTarget::OnData(
    wxCoord WXUNUSED(x), wxCoord WXUNUSED(y),
    wxDragResult def )
{
    if (m_dataObject == NULL)
        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;
        ItemReference theItem;
        FlavorType theType;
        UInt16 flavors = 0;

        CountDragItems( (DragReference)m_currentDrag, &items );
        for (UInt16 index = 1; index <= items && !supported; ++index)
        {
            flavors = 0;
            GetDragItemReferenceNumber( (DragReference)m_currentDrag, index, &theItem );
            CountDragItemFlavors( (DragReference)m_currentDrag, theItem, &flavors );

            for ( UInt16 flavor = 1; flavor <= flavors; ++flavor )
            {
                GetFlavorType( (DragReference)m_currentDrag, theItem, flavor, &theType );
                if ( m_dataObject->IsSupportedFormat( wxDataFormat( theType ) ) )
                {
                    supported = true;
                    break;
                }
            }
        }
    }

    return supported;
}

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

    if ( !CurrentDragHasSupportedFormat() )
        return false;

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

        if (data != NULL)
        {
            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;
        ItemReference theItem;
        FlavorType theType;
        FlavorFlags theFlags;
        UInt16 flavors;
        wxString filenamesPassed;

        CountDragItems( (DragReference)m_currentDrag, &items );
        for (UInt16 index = 1; index <= items; ++index)
        {
            flavors = 0;
            GetDragItemReferenceNumber( (DragReference)m_currentDrag, index, &theItem );
            CountDragItemFlavors( (DragReference)m_currentDrag, theItem, &flavors );
            wxDataFormat preferredFormat = m_dataObject->GetPreferredFormat( wxDataObject::Set );
            bool hasPreferredFormat = false;

            for (UInt16 flavor = 1; flavor <= flavors; ++flavor)
            {
                result = GetFlavorType( (DragReference)m_currentDrag, theItem, flavor, &theType );
                wxDataFormat format( theType );
                if (preferredFormat == format)
                {
                    hasPreferredFormat = true;
                    break;
                }
            }

            for (UInt16 flavor = 1; flavor <= flavors; ++flavor)
            {
                result = GetFlavorType( (DragReference)m_currentDrag, theItem, flavor, &theType );
                wxDataFormat format( theType );
                if ((hasPreferredFormat && format == preferredFormat)
                    || (!hasPreferredFormat && m_dataObject->IsSupportedFormat( format )))
                {
                    result = GetFlavorFlags( (DragReference)m_currentDrag, theItem, theType, &theFlags );
                    if (result == noErr)
                    {
                        Size dataSize;
                        Ptr theData;

                        GetFlavorDataSize( (DragReference)m_currentDrag, theItem, theType, &dataSize );
                        if (theType == kScrapFlavorTypeText)
                        {
                            // this increment is only valid for allocating:
                            // on the next GetFlavorData call it is reset again to the original value
                            dataSize++;
                        }
                        else if (theType == kScrapFlavorTypeUnicode)
                        {
                            // this increment is only valid for allocating:
                            // on the next GetFlavorData call it is reset again to the original value
                            dataSize++;
                            dataSize++;
                        }

                        if (dataSize > 0)
                            theData = new char[dataSize];
                        else
                            theData = NULL;

                        GetFlavorData( (DragReference)m_currentDrag, theItem, theType, (void*)theData, &dataSize, 0L );
                        switch (theType)
                        {
                        case kScrapFlavorTypeText:
                            theData[dataSize] = 0;
                            m_dataObject->SetData( wxDataFormat(wxDF_TEXT), dataSize, theData );
                            break;

#if wxUSE_UNICODE
                        case kScrapFlavorTypeUnicode:
                            theData[dataSize + 0] =
                            theData[dataSize + 1] = 0;
                            m_dataObject->SetData( wxDataFormat(wxDF_UNICODETEXT), dataSize, theData );
                            break;
#endif

                        case kDragFlavorTypeHFS:
                            if (theData != NULL)
                            {
                                HFSFlavor* theFile = (HFSFlavor*)theData;
#ifndef __LP64__
                                wxString name = wxMacFSSpec2MacFilename( &theFile->fileSpec );

                                if (!name.empty())
                                    filenamesPassed += name + wxT("\n");
#endif
                            }
                            break;

                        default:
                            m_dataObject->SetData( format, dataSize, theData );
                            break;
                        }

                        delete [] theData;
                    }
                    break;
                }
            }
        }

        if (filenamesPassed.length() > 0)
        {
            wxCharBuffer buf = filenamesPassed.fn_str();
            m_dataObject->SetData( wxDataFormat(wxDF_FILENAME), strlen( buf ), (const char*)buf );
        }
    }

    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 flags)
{
    wxASSERT_MSG( m_data, wxT("Drop source: no data") );

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

    DragReference theDrag;
    RgnHandle dragRegion;

    if (NewDrag( &theDrag ) != noErr)
        return wxDragNone;

    // add data to drag
    size_t formatCount = m_data->GetFormatCount();
    wxDataFormat *formats = new wxDataFormat[formatCount];
    m_data->GetAllFormats( formats );
    ItemReference theItem = (ItemReference) 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' || type == 'utxt' )
        {