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 *   Licensed to the Apache Software Foundation (ASF) under one or more
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#ifndef INCLUDED_COMPHELPER_ACCIMPLACCESS_HXX
#define INCLUDED_COMPHELPER_ACCIMPLACCESS_HXX

#include <cppuhelper/implbase1.hxx>
#include <com/sun/star/lang/XUnoTunnel.hpp>
#include <comphelper/comphelperdllapi.h>
#include <memory>

namespace com { namespace sun { namespace star { namespace accessibility {
    class XAccessible;
    class XAccessibleContext;
}}}}

namespace comphelper
{
    //= OAccessibleImplementationAccess

    typedef ::cppu::ImplHelper1 <   css::lang::XUnoTunnel
                                >   OAccImpl_Base;
    struct OAccImpl_Impl;

    /** This is a helper class which allows accessing several aspects of the implementation
        of an AccessibleContext.

        <p>For instance, when you want to implement a context which can be re-parented, you:
            <ul><li>derive your class from OAccessibleImplementationAccess</li>
                <li>use <code>setAccessibleParent( <em>component</em>, <em>new_parent</em> )</code>
            </ul>
        </p>

        <p>Another aspect which can be controlled from the outside are states. If you have a class which
        has only partial control over it's states, you may consider deriving from OAccessibleImplementationAccess.<br/>
        For instance, say you have an implementation (say component A) which is <em>unable</em> to know or to
        determine if the represented object is selected, but another component (say B) which uses A (and integrates
        it into a tree of accessibility components) is.<br/>
        In this case, if A is derived from OAccessibleImplementationAccess, B can manipulate this
        foreign-controlled state flag "SELECTED" by using the static helper methods on this class.</p>

        <p>Please note that the support for foreign controlled states is rather restrictive: You can't have states
        which <em>may be</em> controlled by a foreign instances. This is implied by the fact that a derived
        class can ask for states which are <em>set</em> only, not for the ones which are <em>reset</em> currently.
        </p>
    */
    class COMPHELPER_DLLPUBLIC OAccessibleImplementationAccess : public OAccImpl_Base
    {
    private:
        std::unique_ptr<OAccImpl_Impl>  m_pImpl;

    protected:
        /// retrieves the parent previously set via <method>setAccessibleParent</method>
        const css::uno::Reference< css::accessibility::XAccessible >&
                implGetForeignControlledParent( ) const;

        /** retrieves the set of currently set states which are controlled by a foreign instance
        @return
            a bit mask, where a set bit 2^n means that the AccessibleStateType n has been set
        */
        sal_Int64   implGetForeignControlledStates( ) const;

    protected:
        OAccessibleImplementationAccess( );
        virtual ~OAccessibleImplementationAccess( );

        // XUnoTunnel
        virtual sal_Int64 SAL_CALL getSomething( const css::uno::Sequence< sal_Int8 >& _rIdentifier ) override;

    public:

    private:
        COMPHELPER_DLLPRIVATE static const css::uno::Sequence< sal_Int8 > getUnoTunnelImplementationId();
    };

} // namespace comphelper

#endif // INCLUDED_COMPHELPER_ACCIMPLACCESS_HXX

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