/*******************************************************************************

 * Copyright (c) 2005, 2010 Nokia Corporation and/or its subsidiary(-ies).

 * All rights reserved. This program and the accompanying materials

 * are made available under the terms of the Eclipse Public License v1.0

 * which accompanies this distribution, and is available at

 * http://www.eclipse.org/legal/epl-v10.html

 *

 * Contributors:

 *     Nokia Corporation - S60 implementation

 *******************************************************************************/

#ifndef JAVALOCALREF_H

#define JAVALOCALREF_H

#include <e32base.h>

#include <jni.h>

/**

 * Helper class for dealing with Java local references

 *

 * The local reference held by the object will be deleted when the object is

 * itself destroyed or when its Close method is called.

 *

 * The purpose of this object is easing deletion of local references when the

 * code path is not straightforward (the function may exit from several places

 * or leaves may occur). In order to protect against leaves, PushToCleanupStackL()

 * ought ot be called.

 */

template<class T>

class RJavaLocalRef

{

public:

    inline RJavaLocalRef(JNIEnv* aJniEnv, T aLocalRef);

    inline bool operator!() const;

    inline operator T();

    inline void Close();

    inline void Release();

private:

    JNIEnv& iJniEnv;

    T       iLocalRef;

};

/**

 * Constructs an object holding a Java local reference.

 */

template<class T>

inline RJavaLocalRef<T>::RJavaLocalRef(JNIEnv* aJniEnv, T aLocalRef)

        : iJniEnv(*aJniEnv)

        , iLocalRef(aLocalRef)

{

    ASSERT(aJniEnv!=NULL);

}

template<class T>

inline bool RJavaLocalRef<T>::operator!() const

{

    return (iLocalRef==NULL);

}

/**

 * Returns the held local reference

 */

template<class T>

inline RJavaLocalRef<T>::operator T()

{

    return iLocalRef;

}

/**

 * Deletes and releases the held local reference.

 */

template<class T>

inline void RJavaLocalRef<T>::Close()

{

    iJniEnv.DeleteLocalRef(iLocalRef);

    iLocalRef = NULL;

}

/**

 * Releases the held local reference without deleting it.

 *

 * Subsequent calls to Close() will have no effect.

 */

template<class T>

inline void RJavaLocalRef<T>::Release()

{

    iLocalRef = NULL;

}

#endif // JAVALOCALREF_H