/*

* Copyright (c) 2005 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: class to handle event notification to subscribers.

*

*

*/

#ifndef CPOSLMEVENTHANDLER_H

#define CPOSLMEVENTHANDLER_H

// INCLUDES

#include <e32base.h>

#include <EPos_Landmarks.h>

// CLASS DECLARATION

/**

* This class handles event notification to subscribers.

*/

class CPosLmEventHandler : public CBase

    {

    /**

    * Specifies which events that should be removed from the event queue in

    * @p RemoveEvents.

    */

    enum TRemoveEventType

        {

        ESpecificLandmarks = 0,

        ESpecificCategories,

        ENewDefaultDbs

        };

    public:  // Constructor & Destructor

        /**

        * Two-phased constructor.

        */

        static CPosLmEventHandler* NewL();

        /**

        * Destructor.

        */

        ~CPosLmEventHandler();

    public:     // New functions

        /**

        * If there is at least one event waiting in the event queue, this

        * message will be completed directly. Otherwise the message will be

        * put on hold until an event arrives.

        *

        * @param aMessagePtr A message.

        */

        void HandleRequestForEventL(

        /* IN */        const RMessagePtr2& aMessage

        );

        /**

        * Called when a landmark operation has generated an event.

        * If there is a message waiting for an event it will be completed

        * directly. Otherwise this event will be put in the event queue.

        *

        * @param aEvent An event.

        */

        void HandleIncomingEventL(

        /* IN */        TPosLmEvent aEvent

        );

        /**

        * Completes an outstanding event if it exists.

        *

        * @param aError The error code to complete with.

        */

        void CompleteAnyOutStandingRequest(

        /* IN */        TInt aError

        );

    private:

        /**

        * C++ default constructor.

        */

        CPosLmEventHandler();

        void WriteEventAndComplete(

        /* IN */        const RMessagePtr2& aMessage,

        /* IN */        TPosLmEvent aEvent

        );

        void AddToEventQueueL(

        /* IN */        TPosLmEvent aEvent

        );

        TBool MergeEventsIfPossibleL(

        /* IN */        TPosLmEvent aEvent

        );

        void HandleUnknownEvent(

        /* IN */        TPosLmEventType aEventInQueue,

        /* IN */        TBool aExpression,

        /* IN/OUT */    TBool& aAddEvent,

        /* IN/OUT */    TInt& aIndex

        );

        void HandleSpecificEvent(

        /* IN */        TPosLmEventType aEventInQueue,

        /* IN */        TPosLmEventType aCompareEventType,

        /* IN/OUT */    TBool& aAddEvent,

        /* IN/OUT */    TInt& aNoOfSpecificCats,

        /* IN/OUT */    TInt& aNoOfSpecificLms

        );

        TBool IsSpecificLandmark(

        /* IN */        TPosLmEventType aEventType

        );

        TBool IsSpecificCategory(

        /* IN */        TPosLmEventType aEventType

        );

        /**

        * Removes events of a specified type from the queue.

        *

        * @param aRemoveType A type of events to remove from the queue.

        * @param aQueuePosition Holds the queue position where the first

        *   occurrence of the event type was found. Set to KErrNotFound if

        *   no events was found. Note: the event at that position was removed,

        *   but another event may have been moved to that position.

        */

        void RemoveEvents(

        /* IN */        TRemoveEventType aRemoveType,

        /* OUT */       TInt& aQueuePosition

        );

        // By default, prohibit copy constructor

        CPosLmEventHandler( const CPosLmEventHandler& );

        // Prohibit assigment operator

        CPosLmEventHandler& operator= ( const CPosLmEventHandler& );

    private:    // Data

        RArray<TPosLmEvent> iEventQueue;

        RMessagePtr2 iHoldingMessage;

    };

#endif  // CPOSLMEVENTHANDLER_H

// End of File