libreoffice/cppu/inc/com/sun/star/uno/Reference.h

/*************************************************************************
 *
 *  $RCSfile: Reference.h,v $
 *
 *  $Revision: 1.2 $
 *
 *  last change: $Author: dbo $ $Date: 2000-12-21 14:35:22 $
 *
 *  The Contents of this file are made available subject to the terms of
 *  either of the following licenses
 *
 *         - GNU Lesser General Public License Version 2.1
 *         - Sun Industry Standards Source License Version 1.1
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 *  Sun Microsystems Inc., October, 2000
 *
 *  GNU Lesser General Public License Version 2.1
 *  =============================================
 *  Copyright 2000 by Sun Microsystems, Inc.
 *  901 San Antonio Road, Palo Alto, CA 94303, USA
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 *  Lesser General Public License for more details.
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 *
 *
 *  Sun Industry Standards Source License Version 1.1
 *  =================================================
 *  The contents of this file are subject to the Sun Industry Standards
 *  Source License Version 1.1 (the "License"); You may not use this file
 *  except in compliance with the License. You may obtain a copy of the
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 ************************************************************************/
#ifndef _COM_SUN_STAR_UNO_REFERENCE_H_
#define _COM_SUN_STAR_UNO_REFERENCE_H_

#ifndef _RTL_ALLOC_H_
#include <rtl/alloc.h>
#endif


/** */ //for docpp
namespace com
{
/** */ //for docpp
namespace sun
{
/** */ //for docpp
namespace star
{
/** */ //for docpp
namespace uno
{

class XInterface;

/** Enum defining UNO_REF_NO_ACQUIRE for setting reference without acquiring a given interface.
    <br>
*/
enum __UnoReference_NoAcquire
{
    /** This enum value can be used for creating a reference granting a given
        interface, i.e. transferring ownership to it.
        <br>
    */
    UNO_REF_NO_ACQUIRE = 0xbebeef
};

/** Base reference class holding/ acquiring an interface.<br>
    Constructors acquire an interface while the destructor releases it.
    This class serves as a base class for all template reference classes and
    has been introduced due to compiler problems with templated operators ==, =!.
    <br>
*/
class BaseReference
{
    /** the interface pointer<br>
    */
    XInterface * _pInterface;

protected:
    /** Default Constructor:
        Sets null reference.
        <br>
    */
    inline BaseReference() throw ();
    /** Constructor:
        Sets given interface pointer.
        <br>
        @param pInterface an interface pointer
    */
    inline BaseReference( XInterface * pInterface ) throw ();
    /** Constructor:
        Sets reference to given interface pointer without acquiring it.
        <br>
        @param pInterface interface pointer
        @param dummy UNO_REF_NO_ACQUIRE to force obvious distinction to other constructors
    */
    inline BaseReference( XInterface * pInterface, __UnoReference_NoAcquire ) throw ();
    /** Copy constructor:
        Copies interface reference.
        <br>
        @param rRef another reference
    */
    inline BaseReference( const BaseReference & rRef ) throw ();
    /** Destructor:
        Releases interface reference.
        <br>
    */
    inline ~BaseReference() throw ();

public:
    // these are here to force memory de/allocation to sal lib.
    inline static void * SAL_CALL operator new( size_t nSize ) throw ()
        { return ::rtl_allocateMemory( nSize ); }
    inline static void SAL_CALL operator delete( void * pMem ) throw ()
        { ::rtl_freeMemory( pMem ); }
    inline static void * SAL_CALL operator new( size_t, void * pMem ) throw ()
        { return pMem; }
    inline static void SAL_CALL operator delete( void *, void * ) throw ()
        {}

    /** Sets interface pointer. An interface already set will be released.
        <br>
        @param pInterface an interface pointer
    */
    inline void SAL_CALL set( XInterface * pInterface ) throw ();
    /** Clears reference, i.e. releases interface.
        Reference is null after clear() call.
        <br>
    */
    inline void SAL_CALL clear() throw ();
    /** Gets interface pointer.
        This call does <b>not</b> acquire the interface.
        <br>
        @return <b>un</b>acquired interface pointer
    */
    inline XInterface * SAL_CALL get() const throw ()
        { return _pInterface; }
    /** Checks if reference is null.
        <br>
        @return true if reference acquires an interface, i.e. is not null
    */
    inline sal_Bool SAL_CALL is() const throw ()
        { return (_pInterface != 0); }
    /** Equality operator: compares two interfaces<br>
        Checks if both references are null or refer to the same object.
        <br>
        @param rRef another reference
        @return true if both references are null or refer to the same object, false otherwise
    */
    inline sal_Bool SAL_CALL operator == ( const BaseReference & rRef ) const throw ();
    /** Unequality operator: compares two interfaces<br>
        Checks if both references are null or refer to the same object.
        <br>
        @param rRef another reference
        @return false if both references are null or refer to the same object, true otherwise
    */
    inline sal_Bool SAL_CALL operator != ( const BaseReference & rRef ) const throw ()
        { return (! operator == ( rRef )); }

    // needed for stl container operations, though this makes no sense on pointers
    inline sal_Bool SAL_CALL operator < ( const BaseReference& rRef ) const throw ()
        { return (_pInterface < rRef._pInterface); }
};

/** Enum defining UNO_QUERY and UNO_REF_NO_ACQUIRE for query interface constructor
    of reference template.
    <br>
*/
enum __UnoReference_Query
{
    /** This enum value can be used for querying interface constructor of reference template.
        <br>
    */
    UNO_REF_QUERY = 0xdb0e121e,
    UNO_QUERY = 0xdb0
};

/** Template reference class for interface type derived from BaseReference.
    A special constructor given the UNO_QUERY or UNO_REF_QUERY identifier queries interfaces
    for reference type.
    <br>
*/
template< class interface_type >
class Reference : public BaseReference
{
public:
    // these are here to force memory de/allocation to sal lib.
    static void * SAL_CALL operator new( size_t nSize ) throw ()
        { return ::rtl_allocateMemory( nSize ); }
    static void SAL_CALL operator delete( void * pMem ) throw ()
        { ::rtl_freeMemory( pMem ); }
    static void * SAL_CALL operator new( size_t, void * pMem ) throw ()
        { return pMem; }
    static void SAL_CALL operator delete( void *, void * ) throw ()
        {}

    /** Default Constructor:
        Sets null reference.
        <br>
    */
    inline Reference() throw ()
        : BaseReference()
        {}
    /** Copy constructor:
        Copies interface reference.
        <br>
        @param rRef another reference
    */
    inline Reference( const Reference< interface_type > & rRef ) throw ()
        : BaseReference( rRef )
        {}
    /** Constructor:
        Sets given interface pointer.
        <br>
        @param pInterface an interface pointer
    */
    inline Reference( interface_type * pInterface ) throw ()
        : BaseReference( pInterface )
        {}

    /** Constructor:
        Sets given interface pointer without acquiring it.
        <br>
        @param pInterface another reference
        @param dummy UNO_REF_NO_ACQUIRE to force obvious distinction to other constructors
    */
    inline Reference( XInterface * pInterface, __UnoReference_NoAcquire ) throw ()
        : BaseReference( pInterface, UNO_REF_NO_ACQUIRE )
        {}

    /** Constructor:
        Queries given interface for reference interface type (<b>interface_type</b>).
        <br>
        @param rRef another reference
        @param dummy UNO_QUERY or UNO_REF_QUERY to force obvious distinction to other constructors
    */
    inline Reference( const BaseReference & rRef, __UnoReference_Query ) throw ()
        : BaseReference( query( rRef ) )
        {}
    /** Constructor:
        Queries given interface for reference interface type (<b>interface_type</b>).
        <br>
        @param pInterface an interface pointer
        @param dummy UNO_QUERY to force obvious distinction to other constructors
    */
    inline Reference( XInterface * pInterface, __UnoReference_Query ) throw ()
        : BaseReference( query( pInterface ) )
        {}

    /** Assignment operator:
        Acquires given interface pointer and sets reference.
        An interface already set will be released.
        <br>
        @param pInterface an interface pointer
        @return this reference
    */
    inline Reference< interface_type > & SAL_CALL operator = ( interface_type * pInterface ) throw ();
    /** Assignment operator:
        Acquires given interface reference and sets reference.
        An interface already set will be released.
        <br>
        @param rRef an interface reference
        @return this reference
    */
    inline Reference< interface_type > & SAL_CALL operator = ( const Reference< interface_type > & rRef ) throw ()
        { return operator = ( rRef.get() ); }

    /** Queries given interface for type <b>interface_type</b>.
        <br>
        @param pInterface interface pointer
        @return interface reference of demanded type (may be null)
    */
    inline static Reference< interface_type > SAL_CALL query( XInterface * pInterface ) throw ();
    /** Queries given interface reference for type <b>interface_type</b>.
        <br>
        @param rRef interface reference
        @return interface reference of demanded type (may be null)
    */
    inline static Reference< interface_type > SAL_CALL query( const BaseReference & rRef ) throw ()
        { return query( rRef.get() ); }

    /** Cast operatory to Reference< XInterface >:
        Reference objects are binary compatible and any interface must be derived
        from com.sun.star.uno.XInterface.
        This a useful direct cast possibility.
        <br>
    */
    inline SAL_CALL operator const Reference< XInterface > & () const throw ()
        { return * reinterpret_cast< const Reference< XInterface > * >( this ); }

    /** Dereference operator:
        Used to call interface methods.
        <br>
        @return <b>un</b>acquired interface pointer
    */
    interface_type * SAL_CALL operator -> () const throw ()
        { return static_cast< interface_type * >( BaseReference::get() ); }

    /** Gets interface pointer.
        This call does <b>not</b> acquire the interface.
        <br>
        @return <b>un</b>acquired interface pointer
    */
    interface_type * SAL_CALL get() const throw ()
        { return static_cast< interface_type * >( BaseReference::get() ); }
};

}
}
}
}

#endif