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 * 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
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 */

#ifndef INCLUDED_COMPHELPER_PROPARRHLP_HXX
#define INCLUDED_COMPHELPER_PROPARRHLP_HXX

#include <comphelper/propagg.hxx>
#include <cppuhelper/propshlp.hxx>
#include <mutex>
#include <osl/diagnose.h>

namespace comphelper
{

template <class TYPE>
class OPropertyArrayUsageHelper
{
protected:
    static sal_Int32                        s_nRefCount;
    static ::cppu::IPropertyArrayHelper*    s_pProps;
    static std::mutex& theMutex()
    {
        static std::mutex SINGLETON;
        return SINGLETON;
    }
public:
    OPropertyArrayUsageHelper();
    virtual ~OPropertyArrayUsageHelper();

    /** call this in the getInfoHelper method of your derived class. The method returns the array helper of the
        class, which is created if necessary.
    */
    ::cppu::IPropertyArrayHelper*   getArrayHelper();

protected:
    /** used to implement the creation of the array helper which is shared amongst all instances of the class.
        This method needs to be implemented in derived classes.
        <BR>
        The method gets called with Mutex acquired.
        @return                         a pointer to the newly created array helper. Must not be NULL.
    */
    virtual ::cppu::IPropertyArrayHelper* createArrayHelper( ) const = 0;
};

/** an OPropertyArrayUsageHelper which will create an OPropertyArrayAggregationHelper
*/
template <class TYPE>
class OAggregationArrayUsageHelper: public OPropertyArrayUsageHelper<TYPE>
{
protected:
    /** overwrite this in your derived class. initialize the two sequences with your and your aggregate's
        properties.
        <BR>
        The method gets called with Mutex acquired.
        @param      _rProps             out parameter to be filled with the property descriptions of your own class
        @param      _rAggregateProps    out parameter to be filled with the properties of your aggregate.
    */
    virtual void fillProperties(
        css::uno::Sequence< css::beans::Property >& /* [out] */ _rProps,
        css::uno::Sequence< css::beans::Property >& /* [out] */ _rAggregateProps
        ) const = 0;

    /** creates an OPropertyArrayAggregationHelper filled with properties for which's initialization
        fillProperties is called. getInfoService and getFirstAggregateId may be overwritten to determine
        the additional parameters of the OPropertyArrayAggregationHelper.
    */
    virtual ::cppu::IPropertyArrayHelper* createArrayHelper( ) const final;
};

template<class TYPE>
sal_Int32                       OPropertyArrayUsageHelper< TYPE >::s_nRefCount  = 0;

template<class TYPE>
::cppu::IPropertyArrayHelper*   OPropertyArrayUsageHelper< TYPE >::s_pProps = nullptr;

template <class TYPE>
OPropertyArrayUsageHelper<TYPE>::OPropertyArrayUsageHelper()
{
    std::unique_lock aGuard(theMutex());
    ++s_nRefCount;
}

template <class TYPE>
OPropertyArrayUsageHelper<TYPE>::~OPropertyArrayUsageHelper()
{
    std::unique_lock aGuard(theMutex());
    OSL_ENSURE(s_nRefCount > 0, "OPropertyArrayUsageHelper::~OPropertyArrayUsageHelper : suspicious call : have a refcount of 0 !");
    if (!--s_nRefCount)
    {
        delete s_pProps;
        s_pProps = nullptr;
    }
}

template <class TYPE>
::cppu::IPropertyArrayHelper* OPropertyArrayUsageHelper<TYPE>::getArrayHelper()
{
    OSL_ENSURE(s_nRefCount, "OPropertyArrayUsageHelper::getArrayHelper : suspicious call : have a refcount of 0 !");
    if (!s_pProps)
    {
        std::unique_lock aGuard(theMutex());
        if (!s_pProps)
        {
            s_pProps = createArrayHelper();
            OSL_ENSURE(s_pProps, "OPropertyArrayUsageHelper::getArrayHelper : createArrayHelper returned nonsense !");
        }
    }
    return s_pProps;
}

template <class TYPE> inline
::cppu::IPropertyArrayHelper* OAggregationArrayUsageHelper<TYPE>::createArrayHelper() const
{
    css::uno::Sequence< css::beans::Property > aProps;
    css::uno::Sequence< css::beans::Property > aAggregateProps;
    fillProperties(aProps, aAggregateProps);
    OSL_ENSURE(aProps.hasElements(), "OAggregationArrayUsageHelper::createArrayHelper : fillProperties returned nonsense !");
    return new OPropertyArrayAggregationHelper(aProps, aAggregateProps, nullptr, DEFAULT_AGGREGATE_PROPERTY_ID);
}

}

#endif // INCLUDED_COMPHELPER_PROPARRHLP_HXX

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