/*

* Copyright (c) 2006-2009 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:  Definition of the Context plug-in ECom interface.

*

*/

#ifndef CCONTEXTPLUGIN_H

#define CCONTEXTPLUGIN_H

#include <e32base.h>

#include <implementationinformation.h>

// forward declarations

class CMdEObject;

class CMdESession;

class CHarvesterData;

/** Uid for this interface */

const TUid KCContextPluginInterfaceUid = { 0x200009F7 };

class MContextPluginObserver

	{

public:

    /**

     * A pure virtual method intended to inform about completion of context

     * plug-in initialization. Symbian error codes are used.

     *

     * @param aErrorCode  Error code for error occurred during initialization.

     */

    virtual void PluginInitializationStatus( TInt aErrorCode ) = 0;

    /**

     * A pure virtual method intended to inform about context snapshot taking completion.

     * Symbian error codes are used.

     *

     * @param aErrorCode  Error code for error occurred while taking the snapshot.

     */

    virtual void PluginSnapshotStatus( CHarvesterData* aHD ) = 0;

    };

/**

* This class implements the context plugin interface.

*/

class CContextPlugin : public CBase

    {

public:

    /**

     * Creates an implementation of a desired implementation defined by the parameter.

     *

     * @param aUid 

     * @return A pointer to the created plug-in.

     */

    IMPORT_C static CContextPlugin* NewL( const TUid& aUid );

    /**

     * Destroys the implementation. This is virtual method

     * and this class is not intended for derivation, so not exported.

     */

    IMPORT_C virtual ~CContextPlugin();

    /**

     * Lists all available implementations which implement this interface.

     *

     * @param[out] aImplInfoArray A list of existing implementations of the interface.

     */

    IMPORT_C static void ListImplementationsL( RImplInfoPtrArray& aImplInfoArray );

    /**

     * A pure virtual interface method to initialize the plug-in.

     *

     * @param aObserver An interface class to inform about initialization completion.

     */

    virtual void Init( MContextPluginObserver& aObserver ) = 0;

    /**

     * Set a pointer to MdESession.

     * Session is used to store harvested context data.

     *

     * @param aSession Session pointer to set.

     */

    virtual void SetMdeSession( CMdESession& aSession ) = 0;

    /**

     * This pure virtual method takes the context snapshot for one metadata object

     * and writes the information to the object received as parameter.

     * The observer will be informed about the status of the operation.

     *

     * @param aObserver  An interface class to inform about finishing context snapshot.

     * @param aMetadataObject An object to take the snapshot for.

     */

    virtual void ContextSnapshot( MContextPluginObserver& aObserver, CHarvesterData& aHD ) = 0;

    /**

     * This pure virtual method takes the context snapshot for several

     * metadata object and writes the information to the all the objects received as parameter.

     * The observer will be informed about the status of the operation.

     *

     * @param aObserver  An interface class to inform about finishing context snapshot.

     * @param aMetadataObjectArray Array of objects to take the snapshot for.

     */

    virtual void ContextSnapshot( MContextPluginObserver& aObserver,

                          RPointerArray<CHarvesterData>& aHDArray ) = 0;

private: // data

    /** 

     * Instance identifier key. When instance of an implementation is created

     * by ECOM framework, the framework will assign UID for it.

     * The UID is used in destructor to notify framework that this instance is

     * being destroyed and resources can be released.

     */

    TUid iDtor_ID_Key;

    };

#endif // CCONTEXTPLUGIN_H