/*************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * Copyright 2000, 2010 Oracle and/or its affiliates.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
 * This file is part of OpenOffice.org.
 *
 * OpenOffice.org is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenOffice.org is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenOffice.org.  If not, see
 * <http://www.openoffice.org/license.html>
 * for a copy of the LGPLv3 License.
 *
 ************************************************************************/

// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_extensions.hxx"
#include <com/sun/star/uno/Any.hxx>
#include <com/sun/star/uno/Reference.hxx>
#include <com/sun/star/util/XCloseable.hpp>
#include <com/sun/star/util/XCloseBroadcaster.hpp>
#include <com/sun/star/util/XCloseListener.hpp>
#include <com/sun/star/frame/XFrame.hpp>
#include <com/sun/star/frame/XDesktop.hpp>
#include <com/sun/star/beans/XPropertySet.hpp>
#include <cppuhelper/implbase1.hxx>
#include <comphelper/processfactory.hxx>

#include <math.h>
#include <tools/svwin.h>
#include <tools/stream.hxx>
#include <vos/mutex.hxx>
#include <vos/module.hxx>
#include <vcl/svapp.hxx>
#include <vcl/wrkwin.hxx>
#include <vcl/sysdata.hxx>
#include <vcl/salbtype.hxx>
#include "scanner.hxx"

#pragma warning (push,1)
#pragma warning (disable:4668)
#include "twain/twain.h"
#pragma warning (pop)

using namespace ::com::sun::star;

// -----------
// - Defines -
// -----------

#define TWAIN_SELECT            0x00000001UL
#define TWAIN_ACQUIRE           0x00000002UL
#define TWAIN_TERMINATE         0xFFFFFFFFUL

#define TWAIN_EVENT_NONE        0x00000000UL
#define TWAIN_EVENT_QUIT        0x00000001UL
#define TWAIN_EVENT_SCANNING    0x00000002UL
#define TWAIN_EVENT_XFER        0x00000004UL

#define PFUNC                   (*pDSM)
#define PTWAINMSG               MSG*
#define FIXTODOUBLE( nFix )     ((double)nFix.Whole+(double)nFix.Frac/65536.)
#define FIXTOLONG( nFix )       ((long)floor(FIXTODOUBLE(nFix)+0.5))

#if defined WIN
#define TWAIN_LIBNAME           "TWAIN.DLL"
#define TWAIN_FUNCNAME          "DSM_Entry"
#elif defined WNT
#define TWAIN_LIBNAME           "TWAIN_32.DLL"
#define TWAIN_FUNCNAME          "DSM_Entry"
#endif

// --------------
// - TwainState -
// --------------

enum TwainState
{
    TWAIN_STATE_NONE = 0,
    TWAIN_STATE_SCANNING = 1,
    TWAIN_STATE_DONE = 2,
    TWAIN_STATE_CANCELED = 3
};

// ------------
// - ImpTwain -
// ------------

class ImpTwain : public ::cppu::WeakImplHelper1< util::XCloseListener >
{
    friend LRESULT CALLBACK TwainMsgProc( int nCode, WPARAM wParam, LPARAM lParam );

    uno::Reference< uno::XInterface >           mxSelfRef;
    uno::Reference< scanner::XScannerManager >  mxMgr;
    ScannerManager&                             mrMgr;
    TW_IDENTITY                                 aAppIdent;
    TW_IDENTITY                                 aSrcIdent;
    Link                                        aNotifyLink;
    DSMENTRYPROC                                pDSM;
    NAMESPACE_VOS( OModule )*                   pMod;
    ULONG                                       nCurState;
    HWND                                        hTwainWnd;
    HHOOK                                       hTwainHook;
    bool                                        mbCloseFrameOnExit;

    bool                                        ImplHandleMsg( void* pMsg );
    void                                        ImplCreate();
    void                                        ImplOpenSourceManager();
    void                                        ImplOpenSource();
    bool                                        ImplEnableSource();
    void                                        ImplXfer();
    void                                        ImplFallback( ULONG nEvent );
    void                                        ImplSendCloseEvent();
    void                                        ImplDeregisterCloseListener();
    void                                        ImplRegisterCloseListener();
    uno::Reference< frame::XFrame >             ImplGetActiveFrame();
    uno::Reference< util::XCloseBroadcaster >   ImplGetActiveFrameCloseBroadcaster();

                                                DECL_LINK( ImplFallbackHdl, void* );
                                                DECL_LINK( ImplDestroyHdl, void* );

    // from util::XCloseListener
    virtual void SAL_CALL queryClosing( const lang::EventObject& Source, sal_Bool GetsOwnership ) throw (util::CloseVetoException, uno::RuntimeException);
    virtual void SAL_CALL notifyClosing( const lang::EventObject& Source ) throw (uno::RuntimeException);

    // from lang::XEventListener
    virtual void SAL_CALL disposing( const lang::EventObject& Source ) throw (uno::RuntimeException);

public:

                                                ImpTwain( ScannerManager& rMgr, const Link& rNotifyLink );
                                                ~ImpTwain();

    void                                        Destroy();

    bool                                        SelectSource();
    bool                                        InitXfer();
};

// ---------
// - Procs -
// ---------

static ImpTwain* pImpTwainInstance = NULL;

// -------------------------------------------------------------------------

LRESULT CALLBACK TwainWndProc( HWND hWnd,UINT nMsg, WPARAM nPar1, LPARAM nPar2 )
{
    return DefWindowProc( hWnd, nMsg, nPar1, nPar2 );
}

// -------------------------------------------------------------------------

LRESULT CALLBACK TwainMsgProc( int nCode, WPARAM wParam, LPARAM lParam )
{
    MSG* pMsg = (MSG*) lParam;

    if( ( nCode < 0 ) || ( pImpTwainInstance->hTwainWnd != pMsg->hwnd ) || !pImpTwainInstance->ImplHandleMsg( (void*) lParam ) )
    {
        return CallNextHookEx( pImpTwainInstance->hTwainHook, nCode, wParam, lParam );
    }
    else
    {
        pMsg->message = WM_USER;
        pMsg->lParam = 0;

        return 0;
    }
}

// -----------------------------------------------------------------------------

// #107835# hold reference to ScannerManager, to prevent premature death
ImpTwain::ImpTwain( ScannerManager& rMgr, const Link& rNotifyLink ) :
            mrMgr( rMgr ),
            mxMgr( uno::Reference< scanner::XScannerManager >( static_cast< OWeakObject* >( &rMgr ), uno::UNO_QUERY) ),
            aNotifyLink( rNotifyLink ),
            pDSM( NULL ),
            pMod( NULL ),
            hTwainWnd( 0 ),
            hTwainHook( 0 ),
            nCurState( 1 ),
            mbCloseFrameOnExit( false )
{
    // setup TWAIN window
    pImpTwainInstance = this;

    aAppIdent.Id = 0;
    aAppIdent.Version.MajorNum = 1;
    aAppIdent.Version.MinorNum = 0;
    aAppIdent.Version.Language = TWLG_USA;
    aAppIdent.Version.Country = TWCY_USA;
    aAppIdent.ProtocolMajor = TWON_PROTOCOLMAJOR;
    aAppIdent.ProtocolMinor = TWON_PROTOCOLMINOR;
    aAppIdent.SupportedGroups = DG_IMAGE | DG_CONTROL;
    strncpy( aAppIdent.Version.Info, "8.0", 32 );
    aAppIdent.Version.Info[32] = aAppIdent.Version.Info[33] = 0;
    strncpy( aAppIdent.Manufacturer, "Sun Microsystems", 32 );
    aAppIdent.Manufacturer[32] = aAppIdent.Manufacturer[33] = 0;
    strncpy( aAppIdent.ProductFamily,"Office", 32 );
    aAppIdent.ProductFamily[32] = aAppIdent.ProductFamily[33] = 0;
    strncpy( aAppIdent.ProductName, "Office", 32 );
    aAppIdent.ProductName[32] = aAppIdent.ProductName[33] = 0;

    WNDCLASS aWc = { 0, &TwainWndProc, 0, sizeof( WNDCLASS ), GetModuleHandle( NULL ), NULL, NULL, NULL, NULL, "TwainClass" };
    RegisterClass( &aWc );

    hTwainWnd = CreateWindowEx( WS_EX_TOPMOST, aWc.lpszClassName, "TWAIN", 0, 0, 0, 0, 0, HWND_DESKTOP, NULL, aWc.hInstance, 0 );
    hTwainHook = SetWindowsHookEx( WH_GETMESSAGE, &TwainMsgProc, NULL, GetCurrentThreadId() );

    // #107835# block destruction until ImplDestroyHdl is called
    mxSelfRef = static_cast< ::cppu::OWeakObject* >( this );
}

// -----------------------------------------------------------------------------

ImpTwain::~ImpTwain()
{
    // are we responsible for application shutdown?
    if( mbCloseFrameOnExit )
        ImplSendCloseEvent();
}

// -----------------------------------------------------------------------------

void ImpTwain::Destroy()
{
    ImplFallback( TWAIN_EVENT_NONE );
    Application::PostUserEvent( LINK( this, ImpTwain, ImplDestroyHdl ), NULL );
}

// -----------------------------------------------------------------------------

bool ImpTwain::SelectSource()
{
    TW_UINT16 nRet = TWRC_FAILURE;

    ImplOpenSourceManager();

    if( 3 == nCurState )
    {
        TW_IDENTITY aIdent;

        aIdent.Id = 0, aIdent.ProductName[ 0 ] = '\0';
        aNotifyLink.Call( (void*) TWAIN_EVENT_SCANNING );
        nRet = PFUNC( &aAppIdent, NULL, DG_CONTROL, DAT_IDENTITY, MSG_USERSELECT, &aIdent );
    }

    ImplFallback( TWAIN_EVENT_QUIT );

    return( TWRC_SUCCESS == nRet );
}

// -----------------------------------------------------------------------------

bool ImpTwain::InitXfer()
{
    bool bRet = false;

    ImplOpenSourceManager();

    if( 3 == nCurState )
    {
        ImplOpenSource();

        if( 4 == nCurState )
            bRet = ImplEnableSource();
    }

    if( !bRet )
        ImplFallback( TWAIN_EVENT_QUIT );

    return bRet;
}

// -----------------------------------------------------------------------------

void ImpTwain::ImplOpenSourceManager()
{
    if( 1 == nCurState )
    {
        pMod = new ::vos::OModule( ::rtl::OUString() );

        if( pMod->load( ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( TWAIN_LIBNAME ) ) ) )
        {
            nCurState = 2;

            if( ( ( pDSM = (DSMENTRYPROC) pMod->getSymbol( String( RTL_CONSTASCII_USTRINGPARAM( TWAIN_FUNCNAME ) ) ) ) != NULL ) &&
                ( PFUNC( &aAppIdent, NULL, DG_CONTROL, DAT_PARENT, MSG_OPENDSM, &hTwainWnd ) == TWRC_SUCCESS ) )
            {
                nCurState = 3;
            }
        }
        else
        {
            delete pMod;
            pMod = NULL;
        }
    }
}

// -----------------------------------------------------------------------------

void ImpTwain::ImplOpenSource()
{
    if( 3 == nCurState )
    {
        if( ( PFUNC( &aAppIdent, NULL, DG_CONTROL, DAT_IDENTITY, MSG_GETDEFAULT, &aSrcIdent ) == TWRC_SUCCESS ) &&
            ( PFUNC( &aAppIdent, NULL, DG_CONTROL, DAT_IDENTITY, MSG_OPENDS, &aSrcIdent ) == TWRC_SUCCESS ) )
        {
            TW_CAPABILITY   aCap = { CAP_XFERCOUNT, TWON_ONEVALUE, GlobalAlloc( GHND, sizeof( TW_ONEVALUE ) ) };
            TW_ONEVALUE*    pVal = (TW_ONEVALUE*) GlobalLock( aCap.hContainer );

            pVal->ItemType = TWTY_INT16, pVal->Item = 1;
            GlobalUnlock( aCap.hContainer );
            PFUNC( &aAppIdent, &aSrcIdent, DG_CONTROL, DAT_CAPABILITY, MSG_SET, &aCap );
            GlobalFree( aCap.hContainer );
            nCurState = 4;
        }
    }
}

// -----------------------------------------------------------------------------

bool ImpTwain::ImplEnableSource()
{
    bool bRet = false;

    if( 4 == nCurState )
    {
        TW_USERINTERFACE aUI = { true, true, hTwainWnd };

        aNotifyLink.Call( (void*) TWAIN_EVENT_SCANNING );
        nCurState = 5;

        // #107835# register as vetoable close listener, to prevent application to die under us
        ImplRegisterCloseListener();

        if( PFUNC( &aAppIdent, &aSrcIdent, DG_CONTROL, DAT_USERINTERFACE, MSG_ENABLEDS, &aUI ) == TWRC_SUCCESS )
        {
            bRet = true;
        }
        else
        {
            nCurState = 4;

            // #107835# deregister as vetoable close listener, dialog failed
            ImplDeregisterCloseListener();
        }
    }

    return bRet;
}

// -----------------------------------------------------------------------------

bool ImpTwain::ImplHandleMsg( void* pMsg )
{
    TW_UINT16   nRet;
    PTWAINMSG   pMess = (PTWAINMSG) pMsg;
    TW_EVENT    aEvt = { pMess, MSG_NULL };

    nRet = PFUNC( &aAppIdent, &aSrcIdent, DG_CONTROL, DAT_EVENT, MSG_PROCESSEVENT, &aEvt );

    if( aEvt.TWMessage != MSG_NULL )
    {
        switch( aEvt.TWMessage )
        {
            case MSG_XFERREADY:
            {
                ULONG nEvent = TWAIN_EVENT_QUIT;

                if( 5 == nCurState )
                {
                    nCurState = 6;
                    ImplXfer();

                    if( mrMgr.GetData() )
                        nEvent = TWAIN_EVENT_XFER;
                }

                ImplFallback( nEvent );
            }
            break;

            case MSG_CLOSEDSREQ:
                ImplFallback( TWAIN_EVENT_QUIT );
            break;

            default:
            break;
        }
    }
    else
        nRet = TWRC_NOTDSEVENT;

    return( TWRC_DSEVENT == nRet );
}

// -----------------------------------------------------------------------------

void ImpTwain::ImplXfer()
{
    if( nCurState == 6 )
    {
        TW_IMAGEINFO    aInfo;
        TW_UINT32       hDIB = 0;
        long            nWidth, nHeight, nXRes, nYRes;

        if( PFUNC( &aAppIdent, &aSrcIdent, DG_IMAGE, DAT_IMAGEINFO, MSG_GET, &aInfo ) == TWRC_SUCCESS )
        {
            nWidth = aInfo.ImageWidth;
            nHeight = aInfo.ImageLength;
            nXRes = FIXTOLONG( aInfo.XResolution );
            nYRes = FIXTOLONG( aInfo.YResolution );
        }
        else
            nWidth = nHeight = nXRes = nYRes = -1L;

        switch( PFUNC( &aAppIdent, &aSrcIdent, DG_IMAGE, DAT_IMAGENATIVEXFER, MSG_GET, &hDIB ) )
        {
            case( TWRC_CANCEL ):
                nCurState = 7;
            break;

            case( TWRC_XFERDONE ):
            {
                if( hDIB )
                {
                    if( ( nXRes != -1 ) && ( nYRes != - 1 ) && ( nWidth != - 1 ) && ( nHeight != - 1 ) )
                    {
                        // set resolution of bitmap
                        BITMAPINFOHEADER*   pBIH = (BITMAPINFOHEADER*) GlobalLock( (HGLOBAL) hDIB );
                        static const double fFactor = 100.0 / 2.54;

                        pBIH->biXPelsPerMeter = FRound( fFactor * nXRes );
                        pBIH->biYPelsPerMeter = FRound( fFactor * nYRes );

                        GlobalUnlock( (HGLOBAL) hDIB );
                    }

                    mrMgr.SetData( (void*)(long) hDIB );
                }
                else
                    GlobalFree( (HGLOBAL) hDIB );

                nCurState = 7;
            }
            break;

            default:
            break;
        }
    }
}

// -----------------------------------------------------------------------------

void ImpTwain::ImplFallback( ULONG nEvent )
{
    Application::PostUserEvent( LINK( this, ImpTwain, ImplFallbackHdl ), (void*) nEvent );
}

// -----------------------------------------------------------------------------

IMPL_LINK( ImpTwain, ImplFallbackHdl, void*, pData )
{
    const ULONG nEvent = (ULONG) pData;
    bool        bFallback = true;

    switch( nCurState )
    {
        case( 7 ):
        case( 6 ):
        {
            TW_PENDINGXFERS aXfers;

            if( PFUNC( &aAppIdent, &aSrcIdent, DG_CONTROL, DAT_PENDINGXFERS, MSG_ENDXFER, &aXfers ) == TWRC_SUCCESS )
            {
                if( aXfers.Count != 0 )
                    PFUNC( &aAppIdent, &aSrcIdent, DG_CONTROL, DAT_PENDINGXFERS, MSG_RESET, &aXfers );
            }

            nCurState = 5;
        }
        break;

        case( 5 ):
        {
            TW_USERINTERFACE aUI = { true, true, hTwainWnd };

            PFUNC( &aAppIdent, &aSrcIdent, DG_CONTROL, DAT_USERINTERFACE, MSG_DISABLEDS, &aUI );
            nCurState = 4;

            // #107835# deregister as vetoable close listener
            ImplDeregisterCloseListener();
        }
        break;

        case( 4 ):
        {
            PFUNC( &aAppIdent, NULL, DG_CONTROL, DAT_IDENTITY, MSG_CLOSEDS, &aSrcIdent );
            nCurState = 3;
        }
        break;

        case( 3 ):
        {
            PFUNC( &aAppIdent, NULL, DG_CONTROL, DAT_PARENT, MSG_CLOSEDSM, &hTwainWnd );
            nCurState = 2;
        }
        break;

        case( 2 ):
        {
            delete pMod;
            pMod = NULL;
            nCurState = 1;
        }
        break;

        default:
        {
            if( nEvent != TWAIN_EVENT_NONE )
                aNotifyLink.Call( (void*) nEvent );

            bFallback = false;
        }
        break;
    }

    if( bFallback )
        ImplFallback( nEvent );

    return 0L;
}

// -----------------------------------------------------------------------------

IMPL_LINK( ImpTwain, ImplDestroyHdl, void*, /*p*/ )
{
    if( hTwainWnd )
        DestroyWindow( hTwainWnd );

    if( hTwainHook )
        UnhookWindowsHookEx( hTwainHook );

    // #107835# permit destruction of ourselves (normally, refcount
    // should drop to zero exactly here)
    mxSelfRef = NULL;
    pImpTwainInstance = NULL;

    return 0L;
}

// -----------------------------------------------------------------------------

uno::Reference< frame::XFrame > ImpTwain::ImplGetActiveFrame()
{
    try
    {
        uno::Reference< lang::XMultiServiceFactory >  xMgr( ::comphelper::getProcessServiceFactory() );

        if( xMgr.is() )
        {
            // query desktop instance
            uno::Reference< frame::XDesktop > xDesktop( xMgr->createInstance(
                                                            OUString::createFromAscii( "com.sun.star.frame.Desktop" ) ), uno::UNO_QUERY );

            if( xDesktop.is() )
            {
                // query property set from desktop, which contains the currently active frame
                uno::Reference< beans::XPropertySet > xDesktopProps( xDesktop, uno::UNO_QUERY );

                if( xDesktopProps.is() )
                {
                    uno::Any aActiveFrame;

                    try
                    {
                        aActiveFrame = xDesktopProps->getPropertyValue(
                            OUString::createFromAscii( "ActiveFrame" ) );
                    }
                    catch( const beans::UnknownPropertyException& )
                    {
                        // property unknown.
                        DBG_ERROR("ImpTwain::ImplGetActiveFrame: ActiveFrame property unknown, cannot determine active frame!");
                        return uno::Reference< frame::XFrame >();
                    }

                    uno::Reference< frame::XFrame > xActiveFrame;

                    if( (aActiveFrame >>= xActiveFrame) &&
                        xActiveFrame.is() )
                    {
                        return xActiveFrame;
                    }
                }
            }
        }
    }
    catch( const uno::Exception& )
    {
    }

    DBG_ERROR("ImpTwain::ImplGetActiveFrame: Could not determine active frame!");
    return uno::Reference< frame::XFrame >();
}

// -----------------------------------------------------------------------------

uno::Reference< util::XCloseBroadcaster > ImpTwain::ImplGetActiveFrameCloseBroadcaster()
{
    try
    {
        return uno::Reference< util::XCloseBroadcaster >( ImplGetActiveFrame(), uno::UNO_QUERY );
    }
    catch( const uno::Exception& )
    {
    }

    DBG_ERROR("ImpTwain::ImplGetActiveFrameCloseBroadcaster: Could determine close broadcaster on active frame!");
    return uno::Reference< util::XCloseBroadcaster >();
}

// -----------------------------------------------------------------------------

void ImpTwain::ImplRegisterCloseListener()
{
    try
    {
        uno::Reference< util::XCloseBroadcaster > xCloseBroadcaster( ImplGetActiveFrameCloseBroadcaster() );

        if( xCloseBroadcaster.is() )
        {
            xCloseBroadcaster->addCloseListener(this);
            return; // successfully registered as a close listener
        }
        else
        {
            // interface unknown. don't register, then
            DBG_ERROR("ImpTwain::ImplRegisterCloseListener: XFrame has no XCloseBroadcaster!");
            return;
        }
    }
    catch( const uno::Exception& )
    {
    }

    DBG_ERROR("ImpTwain::ImplRegisterCloseListener: Could not register as close listener!");
}

// -----------------------------------------------------------------------------

void ImpTwain::ImplDeregisterCloseListener()
{
    try
    {
        uno::Reference< util::XCloseBroadcaster > xCloseBroadcaster(
            ImplGetActiveFrameCloseBroadcaster() );

        if( xCloseBroadcaster.is() )
        {
            xCloseBroadcaster->removeCloseListener(this);
            return; // successfully deregistered as a close listener
        }
        else
        {
            // interface unknown. don't deregister, then
            DBG_ERROR("ImpTwain::ImplDeregisterCloseListener: XFrame has no XCloseBroadcaster!");
            return;
        }
    }
    catch( const uno::Exception& )
    {
    }

    DBG_ERROR("ImpTwain::ImplDeregisterCloseListener: Could not deregister as close listener!");
}

// -----------------------------------------------------------------------------

void SAL_CALL ImpTwain::queryClosing( const lang::EventObject& /*Source*/, sal_Bool GetsOwnership ) throw (util::CloseVetoException, uno::RuntimeException)
{
    // shall we re-send the close query later on?
    mbCloseFrameOnExit = GetsOwnership;

    // the sole purpose of this listener is to forbid closing of the listened-at frame
    throw util::CloseVetoException();
}

// -----------------------------------------------------------------------------

void SAL_CALL ImpTwain::notifyClosing( const lang::EventObject& /*Source*/ ) throw (uno::RuntimeException)
{
    // should not happen
    DBG_ERROR("ImpTwain::notifyClosing called, but we vetoed the closing before!");
}

// -----------------------------------------------------------------------------

void SAL_CALL ImpTwain::disposing( const lang::EventObject& /*Source*/ ) throw (uno::RuntimeException)
{
    // we're not holding any references to the frame, thus noop
}

// -----------------------------------------------------------------------------

void ImpTwain::ImplSendCloseEvent()
{
    try
    {
        uno::Reference< util::XCloseable > xCloseable( ImplGetActiveFrame(), uno::UNO_QUERY );

        if( xCloseable.is() )
            xCloseable->close( true );
    }
    catch( const uno::Exception& )
    {
    }

    DBG_ERROR("ImpTwain::ImplSendCloseEvent: Could not send required close broadcast!");
}


// ---------
// - Twain -
// ---------

class Twain
{
    uno::Reference< lang::XEventListener >      mxListener;
    uno::Reference< scanner::XScannerManager >  mxMgr;
    const ScannerManager*                       mpCurMgr;
    ImpTwain*                                   mpImpTwain;
    TwainState                                  meState;

                                                DECL_LINK( ImpNotifyHdl, ImpTwain* );

public:

                                    Twain();
                                    ~Twain();

    bool                            SelectSource( ScannerManager& rMgr );
    bool                            PerformTransfer( ScannerManager& rMgr, const uno::Reference< lang::XEventListener >& rxListener );

    TwainState                      GetState() const { return meState; }
};

// ------------------------------------------------------------------------

Twain::Twain() :
        mpCurMgr( NULL ),
        mpImpTwain( NULL ),
        meState( TWAIN_STATE_NONE )
{
}

// ------------------------------------------------------------------------

Twain::~Twain()
{
    if( mpImpTwain )
        mpImpTwain->Destroy();
}

// ------------------------------------------------------------------------

bool Twain::SelectSource( ScannerManager& rMgr )
{
    bool bRet;

    if( !mpImpTwain )
    {
        // #107835# hold reference to ScannerManager, to prevent premature death
        mxMgr = uno::Reference< scanner::XScannerManager >( static_cast< OWeakObject* >( const_cast< ScannerManager* >( mpCurMgr = &rMgr ) ),
                                                            uno::UNO_QUERY ),

        meState = TWAIN_STATE_NONE;
        mpImpTwain = new ImpTwain( rMgr, LINK( this, Twain, ImpNotifyHdl ) );
        bRet = mpImpTwain->SelectSource();
    }
    else
        bRet = false;

    return bRet;
}

// ------------------------------------------------------------------------

bool Twain::PerformTransfer( ScannerManager& rMgr, const uno::Reference< lang::XEventListener >& rxListener )
{
    bool bRet;

    if( !mpImpTwain )
    {
        // #107835# hold reference to ScannerManager, to prevent premature death
        mxMgr = uno::Reference< scanner::XScannerManager >( static_cast< OWeakObject* >( const_cast< ScannerManager* >( mpCurMgr = &rMgr ) ),
                                                            uno::UNO_QUERY ),

        mxListener = rxListener;
        meState = TWAIN_STATE_NONE;
        mpImpTwain = new ImpTwain( rMgr, LINK( this, Twain, ImpNotifyHdl ) );
        bRet = mpImpTwain->InitXfer();
    }
    else
        bRet = false;

    return bRet;
}

// ------------------------------------------------------------------------

IMPL_LINK( Twain, ImpNotifyHdl, ImpTwain*, nEvent )
{
    switch( (ULONG)(void*) nEvent )
    {
        case( TWAIN_EVENT_SCANNING ):
            meState = TWAIN_STATE_SCANNING;
        break;

        case( TWAIN_EVENT_QUIT ):
        {
            if( meState != TWAIN_STATE_DONE )
                meState = TWAIN_STATE_CANCELED;

            if( mpImpTwain )
            {
                mpImpTwain->Destroy();
                mpImpTwain = NULL;
                mpCurMgr = NULL;
            }

            if( mxListener.is() )
                mxListener->disposing( lang::EventObject( mxMgr ) );

            mxListener = NULL;
        }
        break;

        case( TWAIN_EVENT_XFER ):
        {
            if( mpImpTwain )
            {
                meState = ( mpCurMgr->GetData() ? TWAIN_STATE_DONE : TWAIN_STATE_CANCELED );

                mpImpTwain->Destroy();
                mpImpTwain = NULL;
                mpCurMgr = NULL;

                if( mxListener.is() )
                    mxListener->disposing( lang::EventObject( mxMgr ) );
            }

            mxListener = NULL;
        }
        break;

        default:
        break;
    }

    return 0L;
}

// -----------
// - statics -
// -----------

static Twain aTwain;

// ------------------
// - ScannerManager -
// ------------------

void ScannerManager::DestroyData()
{
    if( mpData )
    {
        GlobalFree( (HGLOBAL)(long) mpData );
        mpData = NULL;
    }
}

// -----------------------------------------------------------------------------

AWT::Size ScannerManager::getSize() throw()
{
    AWT::Size   aRet;
    HGLOBAL     hDIB = (HGLOBAL)(long) mpData;

    if( hDIB )
    {
        BITMAPINFOHEADER* pBIH = (BITMAPINFOHEADER*) GlobalLock( hDIB );

        if( pBIH )
        {
            aRet.Width = pBIH->biWidth;
            aRet.Height = pBIH->biHeight;
        }
        else
            aRet.Width = aRet.Height = 0;

        GlobalUnlock( hDIB );
    }
    else
        aRet.Width = aRet.Height = 0;

    return aRet;
}

// -----------------------------------------------------------------------------

SEQ( sal_Int8 ) ScannerManager::getDIB() throw()
{
    SEQ( sal_Int8 ) aRet;

    if( mpData )
    {
        HGLOBAL             hDIB = (HGLOBAL)(long) mpData;
        const sal_uInt32    nDIBSize = GlobalSize( hDIB );
        BITMAPINFOHEADER*   pBIH = (BITMAPINFOHEADER*) GlobalLock( hDIB );

        if( pBIH )
        {
            sal_uInt32  nColEntries;

            switch( pBIH->biBitCount )
            {
                case( 1 ):
                case( 4 ):
                case( 8 ):
                    nColEntries = pBIH->biClrUsed ? pBIH->biClrUsed : ( 1 << pBIH->biBitCount );
                break;

                case( 24 ):
                    nColEntries = pBIH->biClrUsed ? pBIH->biClrUsed : 0;
                break;

                case( 16 ):
                case( 32 ):
                {
                    nColEntries = pBIH->biClrUsed;

                    if( pBIH->biCompression == BI_BITFIELDS )
                        nColEntries += 3;
                }
                break;

                default:
                    nColEntries = 0;
                break;
            }

            aRet = SEQ( sal_Int8 )( sizeof( BITMAPFILEHEADER ) + nDIBSize );

            sal_Int8*       pBuf = aRet.getArray();
            SvMemoryStream* pMemStm = new SvMemoryStream( (char*) pBuf, sizeof( BITMAPFILEHEADER ), STREAM_WRITE );

            *pMemStm << 'B' << 'M' << (sal_uInt32) 0 << (sal_uInt32) 0;
            *pMemStm << (sal_uInt32) ( sizeof( BITMAPFILEHEADER ) + pBIH->biSize + ( nColEntries * sizeof( RGBQUAD ) ) );

            delete pMemStm;
            memcpy( pBuf + sizeof( BITMAPFILEHEADER ), pBIH, nDIBSize );
        }

        GlobalUnlock( hDIB );
        DestroyData();
    }

    return aRet;
}

// -----------------------------------------------------------------------------

SEQ( ScannerContext ) SAL_CALL ScannerManager::getAvailableScanners() throw()
{
    vos::OGuard             aGuard( maProtector );
    SEQ( ScannerContext )   aRet( 1 );

    aRet.getArray()[0].ScannerName = ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "TWAIN" ) );
    aRet.getArray()[0].InternalData = 0;

    return aRet;
}

// -----------------------------------------------------------------------------

BOOL SAL_CALL ScannerManager::configureScanner( ScannerContext& rContext )
    throw( ScannerException )
{
    vos::OGuard                         aGuard( maProtector );
    uno::Reference< XScannerManager >   xThis( this );

    if( rContext.InternalData != 0 || rContext.ScannerName != ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "TWAIN" ) ) )
        throw ScannerException( ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "Scanner does not exist" ) ), xThis, ScanError_InvalidContext );

    DestroyData();

    return aTwain.SelectSource( *this );
}

// -----------------------------------------------------------------------------

void SAL_CALL ScannerManager::startScan( const ScannerContext& rContext, const uno::Reference< lang::XEventListener >& rxListener )
    throw( ScannerException )
{
    vos::OGuard                         aGuard( maProtector );
    uno::Reference< XScannerManager >   xThis( this );

    if( rContext.InternalData != 0 || rContext.ScannerName != ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "TWAIN" ) ) )
        throw ScannerException( ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "Scanner does not exist" ) ), xThis, ScanError_InvalidContext );

    DestroyData();
    aTwain.PerformTransfer( *this, rxListener );
}

// -----------------------------------------------------------------------------

ScanError SAL_CALL ScannerManager::getError( const ScannerContext& rContext )
    throw( ScannerException )
{
    vos::OGuard                         aGuard( maProtector );
    uno::Reference< XScannerManager >   xThis( this );

    if( rContext.InternalData != 0 || rContext.ScannerName != ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "TWAIN" ) ) )
        throw ScannerException( ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "Scanner does not exist" ) ), xThis, ScanError_InvalidContext );

    return( ( aTwain.GetState() == TWAIN_STATE_CANCELED ) ? ScanError_ScanCanceled : ScanError_ScanErrorNone );
}

// -----------------------------------------------------------------------------

uno::Reference< awt::XBitmap > SAL_CALL ScannerManager::getBitmap( const ScannerContext& /*rContext*/ )
    throw( ScannerException )
{
    vos::OGuard aGuard( maProtector );
    return uno::Reference< awt::XBitmap >( this );
}
