/*************************************************************************
 *
 *  $RCSfile: accessibleeventnotifier.cxx,v $
 *
 *  $Revision: 1.6 $
 *
 *  last change: $Author: vg $ $Date: 2003-05-19 12:57:08 $
 *
 *  The Contents of this file are made available subject to the terms of
 *  either of the following licenses
 *
 *         - GNU Lesser General Public License Version 2.1
 *         - Sun Industry Standards Source License Version 1.1
 *
 *  Sun Microsystems Inc., October, 2000
 *
 *  GNU Lesser General Public License Version 2.1
 *  =============================================
 *  Copyright 2000 by Sun Microsystems, Inc.
 *  901 San Antonio Road, Palo Alto, CA 94303, USA
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License version 2.1, as published by the Free Software Foundation.
 *
 *  This library 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 for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA  02111-1307  USA
 *
 *
 *  Sun Industry Standards Source License Version 1.1
 *  =================================================
 *  The contents of this file are subject to the Sun Industry Standards
 *  Source License Version 1.1 (the "License"); You may not use this file
 *  except in compliance with the License. You may obtain a copy of the
 *  License at http://www.openoffice.org/license.html.
 *
 *  Software provided under this License is provided on an "AS IS" basis,
 *  WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
 *  WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
 *  MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
 *  See the License for the specific provisions governing your rights and
 *  obligations concerning the Software.
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 *  The Initial Developer of the Original Code is: Sun Microsystems, Inc.
 *
 *  Copyright: 2000 by Sun Microsystems, Inc.
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 *  All Rights Reserved.
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 *  Contributor(s): _______________________________________
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 *
 ************************************************************************/

#ifndef COMPHELPER_ACCESSIBLE_EVENT_NOTIFIER
#include <comphelper/accessibleeventnotifier.hxx>
#endif

#ifndef _OSL_DIAGNOSE_H_
#include <osl/diagnose.h>
#endif

#ifndef _COMPHELPER_GUARDING_HXX_
#include <comphelper/guarding.hxx>
#endif

//.........................................................................
namespace comphelper
{
//.........................................................................

    using namespace ::com::sun::star::uno;
    using namespace ::com::sun::star::lang;
    using namespace ::com::sun::star::accessibility;
    using namespace ::comphelper;

    //=====================================================================
    //= AccessibleEventNotifier
    //=====================================================================
    //---------------------------------------------------------------------
    ::osl::Mutex                        AccessibleEventNotifier::s_aMutex;
    AccessibleEventNotifier::ClientMap  AccessibleEventNotifier::s_aClients;

    //---------------------------------------------------------------------
    AccessibleEventNotifier::TClientId AccessibleEventNotifier::generateId()
    {
        TClientId nBiggestUsedId = 0;
        TClientId nFreeId = 0;

        // look through all registered clients until we find a "gap" in the ids

        // Note that the following relies on the fact the elements in the map are traveled with
        // ascending keys (aka client ids)

        for (   ClientMap::const_iterator aLookup = s_aClients.begin();
                aLookup != s_aClients.end();
                ++aLookup
            )
        {
            TClientId nCurrent = aLookup->first;
            OSL_ENSURE( nCurrent > nBiggestUsedId, "AccessibleEventNotifier::generateId: map is expected to be sorted ascending!" );

            if ( nCurrent - nBiggestUsedId > 1 )
            {   // found a "gap"
                nFreeId = nBiggestUsedId + 1;
                break;
            }

            nBiggestUsedId = nCurrent;
        }

        if ( !nFreeId )
            nFreeId = nBiggestUsedId + 1;

        OSL_ENSURE( s_aClients.end() == s_aClients.find( nFreeId ),
            "AccessibleEventNotifier::generateId: algorithm broken!" );

        return nFreeId;
    }

    //---------------------------------------------------------------------
    AccessibleEventNotifier::TClientId AccessibleEventNotifier::registerClient( )
    {
        ::osl::MutexGuard aGuard( s_aMutex );

        // generate a new client id
        TClientId nNewClientId = generateId( );

        // the event listeners for the new client
        EventListeners* pNewListeners = new EventListeners( s_aMutex );
            // note that we're using our own mutex here, so the listener containers for all
            // our clients share this same mutex.
            // this is a reminiscense to the days where the notifier was asynchronous. Today this is
            // completely nonsense, and potentially slowing down the Office me thinks ...

        // add the client
        s_aClients.insert( ClientMap::value_type( nNewClientId, pNewListeners ) );

        // outta here
        return nNewClientId;
    }

    //---------------------------------------------------------------------
    sal_Bool AccessibleEventNotifier::implLookupClient( const TClientId _nClient, ClientMap::iterator& _rPos )
    {
        // look up this client
        _rPos = s_aClients.find( _nClient );
        OSL_ENSURE( s_aClients.end() != _rPos, "AccessibleEventNotifier::implLookupClient: invalid client id (did you register your client?)!" );

        return ( s_aClients.end() != _rPos );
    }

    //---------------------------------------------------------------------
    void AccessibleEventNotifier::revokeClient( const TClientId _nClient )
    {
        ::osl::MutexGuard aGuard( s_aMutex );

        ClientMap::iterator aClientPos;
        if ( !implLookupClient( _nClient, aClientPos ) )
            // already asserted in implLookupClient
            return;

        // remove it from the clients map
        delete aClientPos->second;
        s_aClients.erase( aClientPos );
    }

    //---------------------------------------------------------------------
    void AccessibleEventNotifier::revokeClientNotifyDisposing( const TClientId _nClient,
            const Reference< XInterface >& _rxEventSource ) SAL_THROW( ( ) )
    {
        ::osl::MutexGuard aGuard( s_aMutex );

        ClientMap::iterator aClientPos;
        if ( !implLookupClient( _nClient, aClientPos ) )
            // already asserted in implLookupClient
            return;

        // notify the "disposing" event for this client
        EventObject aDisposalEvent;
        aDisposalEvent.Source = _rxEventSource;

        // notify the listeners
        EventListeners* pListeners = aClientPos->second;

        // we do not need the entry in the clients map anymore
        // (do this before actually notifying, because some client implementations have re-entrance
        // problems and call into revokeClient while we are notifying from hereing)
        s_aClients.erase( aClientPos );

        // now really do the notification
        pListeners->disposeAndClear( aDisposalEvent );
        delete pListeners;

    }

    //---------------------------------------------------------------------
    sal_Int32 AccessibleEventNotifier::addEventListener(
        const TClientId _nClient, const Reference< XAccessibleEventListener >& _rxListener ) SAL_THROW( ( ) )
    {
        ::osl::MutexGuard aGuard( s_aMutex );

        ClientMap::iterator aClientPos;
        if ( !implLookupClient( _nClient, aClientPos ) )
            // already asserted in implLookupClient
            return 0;

        if ( _rxListener.is() )
            aClientPos->second->addInterface( _rxListener );

        return aClientPos->second->getLength();
    }

    //---------------------------------------------------------------------
    sal_Int32 AccessibleEventNotifier::removeEventListener(
        const TClientId _nClient, const Reference< XAccessibleEventListener >& _rxListener ) SAL_THROW( ( ) )
    {
        ::osl::MutexGuard aGuard( s_aMutex );

        ClientMap::iterator aClientPos;
        if ( !implLookupClient( _nClient, aClientPos ) )
            // already asserted in implLookupClient
            return 0;

        if ( _rxListener.is() )
            aClientPos->second->removeInterface( _rxListener );

        return aClientPos->second->getLength();
    }

    //---------------------------------------------------------------------
    Sequence< Reference< XInterface > > AccessibleEventNotifier::getEventListeners( const TClientId _nClient ) SAL_THROW( ( ) )
    {
        Sequence< Reference< XInterface > > aListeners;

        ::osl::MutexGuard aGuard( s_aMutex );

        ClientMap::iterator aClientPos;
        if ( implLookupClient( _nClient, aClientPos ) )
            aListeners = aClientPos->second->getElements();

        return aListeners;
    }

    //---------------------------------------------------------------------
    void AccessibleEventNotifier::addEvent( const TClientId _nClient, const AccessibleEventObject& _rEvent ) SAL_THROW( ( ) )
    {
        Sequence< Reference< XInterface > > aListeners;

        // --- <mutex lock> -------------------------------
        {
            ::osl::MutexGuard aGuard( s_aMutex );

            ClientMap::iterator aClientPos;
            if ( !implLookupClient( _nClient, aClientPos ) )
                // already asserted in implLookupClient
                return;

            // since we're synchronous, again, we want to notify immediately
            aListeners = aClientPos->second->getElements();
        }
        // --- </mutex lock> ------------------------------

            // default handling: loop through all listeners, and notify them
        const Reference< XInterface >* pListeners = aListeners.getConstArray();
        const Reference< XInterface >* pListenersEnd = pListeners + aListeners.getLength();
        while ( pListeners != pListenersEnd )
        {
            try
            {
                static_cast< XAccessibleEventListener* >( pListeners->get() )->notifyEvent( _rEvent );
            }
            catch( const Exception& e )
            {
                e;
                // silent this
                // no assertion, because a broken access remote bridge or something like this
                // can cause this exception
            }
            ++pListeners;
        }
    }

//.........................................................................
}   // namespace comphelper
//.........................................................................