/*

* Copyright (c) 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: This file implements utilities like CPluginData.

*

*/

#ifndef EMAILAPIUTILS_H

#define EMAILAPIUTILS_H

#include <e32base.h>

#include "cfsmailcommon.h"

#include <emailapidefs.h>

//using namespace EmailInterface;

class CFSMailPlugin;

enum TDataOwner

    {

    EClientOwns,

    EAPIOwns

    };

/**

* Helper container class for storing plugin pointer and implementation UID

* @since S60 v5.2

*/

NONSHARABLE_CLASS( TPluginData )

    {

    public:

        inline TPluginData( TUid aUid ) : iPlugin( NULL ), iUid( TUid::Uid( aUid.iUid ) ) {}

        CFSMailPlugin* iPlugin;

        const TUid     iUid;

    };

/**

* Plugin data is a utility for protocol plugin creation and book 

* keeping. Objects using the plugin should access it via this

* class for optimised reference counting.

*/

NONSHARABLE_CLASS( CPluginData ) : public CBase

{

public:    

    /**

    * returns plugin instance or null if failed to instantiate.

    * LoadResult() will return error code in instantiation

    */

    CFSMailPlugin* ClaimInstance();

    /**

    * returns plugin instance or leaves if failed to instantiate.

    */

    CFSMailPlugin* ClaimInstanceL();

    /**

    *  Decreases access count of the plugin and deletes if reaches zero.

    * Note! this should be called only aftre succesful ClaimInstance or 

    * ClaimInstanceL.

    */

    void ReleaseInstance();

    /**

    * Adds cleanup operation calling ReleaseInstance to cleanup stack

    */                                                 

    void ReleasePushL();

    /**

    * Cleanup operation for CleanupReleasePluginPushL

    */

    static void CleanupOperation( TAny* aAny );

    TUid Uid() const;

    TInt LoadResult() const;

private: 

    /* only CEmailClientApi owns instances of this, it should make sure that

     * no duplicates exist, otherwise reference counting of plugins fail

     * (this is not singleton class)

     */

    friend class CEmailClientApi;

    friend class CEmailMailboxCache;

    CPluginData( TUid aUid );

    ~CPluginData();

private:    

    // plugin pointer and uid

    TPluginData iData;

    TInt iPluginLoadError;

    // >0 when iPlugin is instantiated

    TUint          iRefCount;

    // EFalse if shared from Email Framework (CFSMailClient). If true,

    // ReleaseInstance() doesn't delete plugin

    TBool          iOwned;

};

/**

* Constructs internal message id type from plugin data and mailbox/folder/message id 

*/

TFSMailMsgId FsMsgId( const CPluginData& aPluginData, const EmailInterface::TBaseId& aId );

/**

* Cleanup support for pointer arrays

*/

template<class T>

class CleanupResetAndDestroy

{

public:

    inline static void PushL( T& aItem );

private:

    inline static void ResetAndDestroy( TAny *aPtr );

} ;

template <class T>

inline void CleanupResetAndDestroyPushL( T& aRef )

    {

    CleanupResetAndDestroy<T>::PushL( aRef );

    }

/**

* Cleanup support for email interface objects.

*/

class CleanupReleasePush

{

public:

    static void PushL( EmailInterface::MEmailInterface& aItem );

private:

    static void Release( TAny *aPtr );

} ;

#include "emailapiutils.inl"

#endif // EMAILAPIUTILS_H

// End of file