/*

* Copyright (c) 2007,2009 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:  Calculates playback time for rendering state machine

*

*/

#ifndef UPNPRENDERINGPLAYTIMECALCULATOR_H

#define UPNPRENDERINGPLAYTIMECALCULATOR_H

//  INCLUDES

#include <e32base.h>

// FORWARD DECLARATIONS

// CLASS DECLARATION

/**

* A class that keeps track of playback time by setting a timestamp at given

* play, pause, resume and stop events and maybe also comparing that to given

* fixed progress positions along the way. By doing that we will be able to

* tell how long the track has been playing when a stop signal arrives. This

* is important so that we can tell if it is a natural "track complete" stop

* or an "user interrupt" type of stop.

*/

NONSHARABLE_CLASS( CUpnpRenderingPlaytimeCalculator )

    {

public: // the interface

    /**

     * Default constructor

     */

    CUpnpRenderingPlaytimeCalculator();

    /**

     * Marks START timestamp.

     * Calling Start() will reset the calculator.

     */

    void Start();

    /**

     * Marks PAUSE timestamp.

     * Can be called multiple times, ceach Pause will replace previous mark.

     */

    void Pause();

    /**

     * Marks RESUME timestamp.

     * Can NOT be called multiple times.

     */

    void Resume();

    /**

     * Marks STOP timestamp.

     * Can be called multiple times.

     */

    void Stop();

    /**

     * Sets the track duration as it is represented in the media server.

     * This method should be used to set the initial duration so that

     * the calculator works even if renderer NEVER sends position info.

     * @param aDuration track duration in milliseconds

     */

    void SetDuration( TInt aDuration );

    /**

     * Returns the track duration if it is known, otherwise KErrNotFound.

     */

    TInt Duration() const;

    /**

     * Acknowledges track duration and position info that was received from

     * the renderer. Following things are done here:

     * 1. The renderer's understanding of duration might be different from

     * media server's understanding. If it is, we MAY modify it.

     * 2. The position is compared to the calculated position and if it is

     * different, an offset is calculated and used in future Position calls.

     */

    void AcknowledgePositionInfo( TInt aDuration, TInt aPosition );

    /**

     * Estimates position now, or returns total playtime of previous track.

     */

    TInt Position() const;

    /**

     * returns true if last track track playtime would indicate that it was

     * played back entirely.

     */

    TBool IsTrackComplete() const;

    /**

     * Returns true if calculator is in playing state.

     */

    TBool IsPlaying() const;

    /**

     * Adjust the start mark according to the new postion; use case is seek

     */

   void RestartAt( TInt aNewPosition );

private:

    /**

     * calculates playtime estimate starting from PLAY mark until given time,

     * tacking in account all time spent in PAUSE and also cinsidering offset.

     */

    TInt PositionAt( TTime& aTime ) const;

    /**

     * calculates time spent in pause

     */

    TInt PausetimeAt( TTime& aTime ) const;

    /**

     * calculates the offset from current time and the position

     */

    TInt OffsetFromNow( TInt aPosition ) const;

private:

    // duration of the track

    TInt iDuration;

    // the start timestamp

    TTime iStartMark;

    // the stop timestamp

    TTime iStopMark;

    // the pause mark

    TTime iPauseMark;

    // total time spent in pause

    TInt iPauseTime;

    // the offset to real position

    TInt iOffset;

    // is a track playing

    TBool iPlaying;

    // is track paused

    TBool iPaused;

    };

#endif  // UPNPRENDERINGPLAYTIMECALCULATOR_H

// End of File