/*

* Copyright (c) 2008 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:  Context publishing helper dll

 *

*/

#ifndef HGCONTEXTUTILITYBASE_H

#define HGCONTEXTUTILITYBASE_H

#include <e32base.h>

#include <bamdesca.h>

class CHgContextUtilityImpl;

/**

 *  Utility base class to publish and access context through the Context Framework.

 *  @lib hgcontextutility.lib

 */

class CHgContextUtilityBase : public CBase

    {

public:    

    /**

     * Publishes context.

     * Also defines the context if it has not been defined.

     * Publishing empty value is not allowed, however such errors are ignored

     * here so the function will not leave when CFW responds with KErrArgument.

     * The security policy for the context will be set to require

     * LocalServices capability.

     * @param   aContextType    context type, source is always KHgCFSource

     * @param   aContextData    value for the context

     */

    IMPORT_C void PublishContextL( const TDesC& aContextType,

        const TDesC& aContextData );

    /**

     * Publishes context, the value will contain all the strings

     * from the given array, typically by using some separator character.

     * @see PublishContextL

     * @param   aContextType    context type, source is always KHgCFSource

     * @param   aContextData    value for the context will be a combined

     * version of all the strings from this array

     */

    IMPORT_C void PublishContextL( const TDesC& aContextType,

        const MDesCArray& aContextData );

    /**

     * Publishes context but only after a short interval, using a timer.

     * If it is called again before the timer expires then the timer

     * is restarted (and so the previous pending value is never published).

     * @param   aContextType    context type, source is always KHgCFSource

     * @param   aContextData    value for the context

     * @param   aDelay          delay for the timer, in microseconds

     */

    IMPORT_C void PublishContextDelayedL( const TDesC& aContextType,

        const TDesC& aContextData, const TTimeIntervalMicroSeconds32& aDelay );

    /**

     * Overload for delayed publishing of a value combined from multiple strings.

     * @param   aContextType    context type

     * @param   aContextData    string array

     * @param   aDelay          delay for the timer, in microseconds

     */

    IMPORT_C void PublishContextDelayedL( const TDesC& aContextType,

        const MDesCArray& aContextData, const TTimeIntervalMicroSeconds32& aDelay );

    /**

     * Requests the given context and returns the value for the

     * first result. Returns NULL if not found.

     * @param   aContextType    context type, the source is always KHgCFSource

     */        

    IMPORT_C HBufC* GetContextL( const TDesC& aContextType );

    /**

     * Requests the given context and returns the value for the

     * first result. Returns NULL if not found.

     * @param   aContextSource  context source

     * @param   aContextType    context type

     */

    IMPORT_C HBufC* GetContextL( const TDesC& aContextSource,

        const TDesC& aContextType );

protected:

    CHgContextUtilityBase();

    ~CHgContextUtilityBase();

    void BaseConstructL();

    CHgContextUtilityImpl* iImpl;

    };

#endif /* HGCONTEXTUTILITYBASE_H */