class CSts::CPlayerNode

    {

public:

    CPlayerNode(CStsPlayer* aPlayer);

    CPlayerNode(CStsPlayer* aPlayer, MStsPlayAlarmObserver& aObserver);

    ~CPlayerNode();

    bool HasObserver();

    CStsPlayer* Player();

    MStsPlayAlarmObserver& Observer();

private:

    CStsPlayer* iPlayer;

    MStsPlayAlarmObserver* iObserver;

    };

CSts::CPlayerNode::CPlayerNode(CStsPlayer* aPlayer) :

    iPlayer(aPlayer), iObserver(0)

    {

    }

CSts::CPlayerNode::CPlayerNode(CStsPlayer* aPlayer,

        MStsPlayAlarmObserver& aObserver) :

    iPlayer(aPlayer), iObserver(&aObserver)

    {

    }

CSts::CPlayerNode::~CPlayerNode()

    {

    delete iPlayer;

    }

bool CSts::CPlayerNode::HasObserver()

    {

    return iObserver != 0;

    }

CStsPlayer* CSts::CPlayerNode::Player()

    {

    return iPlayer;

    }

MStsPlayAlarmObserver& CSts::CPlayerNode::Observer()

    {

    return *iObserver;

    }

void CSts::PlayTone(CSystemToneService::TToneType aTone)

    CStsPlayer* player = CStsPlayer::CreateTonePlayer(*this, aTone,

            iNextContext);

        iPlayerMap[iNextContext] = new CPlayerNode(player);

        if (iNextContext == 0)

            iNextContext++;

        //TODO: Add trace here

void CSts::PlayAlarm(CSystemToneService::TAlarmType aAlarm,

        unsigned int& aAlarmContext, MStsPlayAlarmObserver& aObserver)

    CStsPlayer* player = CStsPlayer::CreateAlarmPlayer(*this, aAlarm,

            iNextContext);

    if (player != 0)

        {

        iPlayerMap[iNextContext] = new CPlayerNode(player, aObserver);

        aAlarmContext = iNextContext;

        iNextContext++;

        if (iNextContext == 0)

            iNextContext++;

        player->Play();

        }

    else

        //TODO: Add trace here

        aAlarmContext = 0;

        }

    }

void CSts::StopAlarm(unsigned int aAlarmContext)

    {

    CPlayerNode* node = iPlayerMap[aAlarmContext];

    iPlayerMap.erase(aAlarmContext);

    if (node)

        {

        node->Player()->Stop();

        delete node;

        }

    else

        {

        //TODO: Add trace here

        while (!iPlayerMap.empty())

            {

            //TODO: Add trace here

            StopAlarm(iPlayerMap.begin()->first);

            }

void CSts::PlayComplete(unsigned int aContext)

    CPlayerNode* node = iPlayerMap[aContext];

    iPlayerMap.erase(aContext);

    if (node)

        CStsPlayer* player = node->Player();

        if (node->HasObserver())

            {

            node->Observer().PlayAlarmComplete(aContext);

            }

        delete node;

        }

    else

        {

        // TODO: log unexpected error