/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

/*
 * This file is part of LibreOffice published API.
 */
#ifndef INCLUDED_CPPUHELPER_WEAKAGG_HXX
#define INCLUDED_CPPUHELPER_WEAKAGG_HXX

#include "cppuhelper/weak.hxx"
#include "cppuhelper/weakref.hxx"
#include "com/sun/star/uno/XAggregation.hpp"
#include "cppuhelper/cppuhelperdllapi.h"


namespace cppu
{

/** Base class to implement a UNO object supporting weak references, i.e. the object can be held
    weakly (by a css::uno::WeakReference) and aggregation, i.e. the object can be
    aggregated by another (delegator).
    This implementation copes with reference counting.  Upon last release(), the virtual dtor
    is called.

    @derive
    Inherit from this class and delegate acquire()/ release() calls.  Re-implement
    XAggregation::queryInterface().
*/
class CPPUHELPER_DLLPUBLIC OWeakAggObject
    : public ::cppu::OWeakObject
    , public css::uno::XAggregation
{
public:
    /** Constructor.  No delegator set.
    */
    OWeakAggObject()
        {}

    /** If a delegator is set, then the delegators gets acquired.  Otherwise call is delegated to
        base class ::cppu::OWeakObject.
    */
    virtual void SAL_CALL acquire() SAL_NOEXCEPT SAL_OVERRIDE;
    /** If a delegator is set, then the delegators gets released.  Otherwise call is delegated to
        base class ::cppu::OWeakObject.
    */
    virtual void SAL_CALL release() SAL_NOEXCEPT SAL_OVERRIDE;
    /** If a delegator is set, then the delegator is queried for the demanded interface.  If the
        delegator cannot provide the demanded interface, it calls queryAggregation() on its
        aggregated objects.

        @param rType demanded interface type
        @return demanded type or empty any
        @see queryAggregation.
    */
    virtual css::uno::Any SAL_CALL queryInterface( const css::uno::Type & rType ) SAL_OVERRIDE;

    /** Set the delegator.  The delegator member reference is a weak reference.

        @param Delegator the object that delegate its queryInterface to this aggregate.
    */
    virtual void SAL_CALL setDelegator( const css::uno::Reference< css::uno::XInterface > & Delegator ) SAL_OVERRIDE;
    /** Called by the delegator or queryInterface. Re-implement this method instead of
        queryInterface.

        @see queryInterface
    */
    virtual css::uno::Any SAL_CALL queryAggregation( const css::uno::Type & rType ) SAL_OVERRIDE;

protected:
    /** Virtual dtor. Called when reference count is 0.

        @attention
        Despite the fact that a RuntimeException is allowed to be thrown, you must not throw any
        exception upon destruction!
    */
    virtual ~OWeakAggObject() SAL_OVERRIDE;

    /** weak reference to delegator.
    */
    css::uno::WeakReferenceHelper xDelegator;
private:
    OWeakAggObject( const OWeakAggObject & rObj ) SAL_DELETED_FUNCTION;
    OWeakAggObject & operator = ( const OWeakAggObject & rObj )
        SAL_DELETED_FUNCTION;
};

}

#endif

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