/*

* Copyright (c) 2002 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:    LandmarksUi Content File -

*

*/

// INCLUDE FILES

#include "CLmkDbEventListener.h"

#include "MLmkDbObserver.h"

#include <EPos_CPosLandmarkDatabase.h>

#include <lmkerrors.h>

// CONSTANTS

/// Unnamed namespace for local definitions

namespace {

const TInt KLmkEventObserversGranularity( 5 );

#if defined(_DEBUG)

_LIT( KPanicMsg, "CLmkDbEventListener" );

void Panic( TPanicCode aReason )

    {

    User::Panic( KPanicMsg, aReason );

    }

#endif

}  // namespace

// ============================ MEMBER FUNCTIONS ===============================

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

// CLmkDbEventListener::CLmkDbEventListener

// C++ constructor can NOT contain any code, that

// might leave.

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

//

CLmkDbEventListener::CLmkDbEventListener()

    : CActive( EPriorityStandard ),

      iObservers( KLmkEventObserversGranularity )

    {

    }

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

// CLmkDbEventListener::ConstructL

// Symbian 2nd phase constructor can leave.

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

//

void CLmkDbEventListener::ConstructL()

    {

    CActiveScheduler::Add( this );

    }

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

// CLmkDbEventListener::NewL

// Two-phased constructor.

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

//

CLmkDbEventListener* CLmkDbEventListener::NewL()

    {

    CLmkDbEventListener* self =

        new ( ELeave ) CLmkDbEventListener();

    CleanupStack::PushL( self );

    self->ConstructL();

    CleanupStack::Pop();

    return self;

    }

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

// CLmkDbEventListener::~CLmkDbEventListener

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

//

CLmkDbEventListener::~CLmkDbEventListener()

    {

    Cancel();

    iObservers.Close();

    delete iDbURI;

    }

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

// CLmkDbEventListener::AddObserverL

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

//

void CLmkDbEventListener::AddObserverL(

    MLmkDbObserver& aObserver,

    CPosLandmarkDatabase& aDb )

    {

    HBufC* paramURI = aDb.DatabaseUriLC();

    if ( iDb )

        { // Only one database currently supported

        if ( iDbURI->Compare( *paramURI ) != 0 )

            {

            User::Leave( KErrNotSupported );

            }

        }

    TInt index = iObservers.Find( &aObserver );

    if ( index >= 0 )

        {

        User::Leave( KErrAlreadyExists );

        }

    User::LeaveIfError( iObservers.Append( &aObserver ) );

    if ( iObservers.Count() == 1 )

        {

        iDb = &aDb;

        StartListening();

        }

    // For simplicity we always assign new value to iDbURI although often

    // the content remains the same as it was.

    delete iDbURI;

    iDbURI = paramURI;

    CleanupStack::Pop(); // paramURI, ownership was transferred

    }

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

// CLmkDbEventListener::RemoveObserver

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

//

void CLmkDbEventListener::RemoveObserver( MLmkDbObserver& aObserver )

    {

    TInt index = iObservers.Find( &aObserver );

    if ( index >= 0 )

        {

        iObservers.Remove( index );

        }

    if ( iObservers.Count() == 0 )

        {

        Cancel();

        }

    }

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

// CLmkDbEventListener::StartListening

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

//

void CLmkDbEventListener::StartListening()

    {

    iEvent.iEventType = EPosLmEventUnknownChanges;

    iEvent.iLandmarkItemId = KPosLmNullItemId;

    __ASSERT_DEBUG( !IsActive(), Panic( KLmkPanicAlreadyActive ) );

    __ASSERT_DEBUG( iDb, Panic( KLmkPanicNullMember ) );

    iDb->NotifyDatabaseEvent( iEvent, iStatus );

    SetActive();

    }

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

// CLmkDbEventListener::RunL

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

//

void CLmkDbEventListener::RunL()

    {

    // No need for implementing RunError() as long as RunL() is non-leaving.

    for ( TInt i( 0 ); i < iObservers.Count(); ++i )

        {

        iObservers[i]->HandleDatabaseEvent( iEvent );

        }

    StartListening();

    }

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

// CLmkDbEventListener::DoCancel

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

//

void CLmkDbEventListener::DoCancel()

    {

    if ( iDb )

        {

        iDb->CancelNotifyDatabaseEvent();

        // The policy is that when database observation is stopped we

        // release the database association. It may become invalid after that.

        iDb = NULL;

        delete iDbURI;

        iDbURI = NULL;

        }

    }

//  End of File