loongoffice/framework/source/helper/ocomponentenumeration.cxx

/* -*- 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 .
 */

#include <helper/ocomponentenumeration.hxx>

#include <threadhelp/resetableguard.hxx>

#include <vcl/svapp.hxx>

namespace framework{

using namespace ::com::sun::star::container     ;
using namespace ::com::sun::star::lang          ;
using namespace ::com::sun::star::uno           ;
using namespace ::cppu                          ;
using namespace ::osl                           ;
using namespace ::rtl                           ;


//  constructor

OComponentEnumeration::OComponentEnumeration( const Sequence< css::uno::Reference< XComponent > >& seqComponents )
        //  Init baseclasses first
        //  Attention:
        //      Don't change order of initialization!
        //      ThreadHelpBase is a struct with a mutex as member. We can't use a mutex as member, while
        //      we must garant right initialization and a valid value of this! First initialize
        //      baseclasses and then members. And we need the mutex for other baseclasses !!!
        :   ThreadHelpBase  ( &Application::GetSolarMutex() )
        // Init member
        ,   m_nPosition     ( 0                             )   // 0 is the first position for a valid list and the right value for an invalid list to!
        ,   m_seqComponents ( seqComponents                 )
{
    // Safe impossible states
    // "Method" not defined for ALL parameters!
    SAL_WARN_IF( !impldbg_checkParameter_OComponentEnumerationCtor( seqComponents ), "fwk", "OComponentEnumeration::OComponentEnumeration(): Invalid parameter detected!" );
}


//  destructor

OComponentEnumeration::~OComponentEnumeration()
{
    // Reset instance, free memory ....
    impl_resetObject();
}


//  XEventListener
void SAL_CALL OComponentEnumeration::disposing( const EventObject& aEvent ) throw( RuntimeException, std::exception )
{
    // Ready for multithreading
    ResetableGuard aGuard( m_aLock );

    // Safe impossible cases
    // This method is not specified for all incoming parameters.
    (void) aEvent;
    SAL_WARN_IF( !impldbg_checkParameter_disposing( aEvent ), "fwk", "OComponentEnumeration::disposing(): Invalid parameter detected!" );

    // Reset instance to defaults, release references and free memory.
    impl_resetObject();
}


//  XEnumeration
sal_Bool SAL_CALL OComponentEnumeration::hasMoreElements() throw( RuntimeException, std::exception )
{
    // Ready for multithreading
    ResetableGuard aGuard( m_aLock );

    // First position in a valid list is 0.
    // => The last one is getLength() - 1!
    // m_nPosition's current value is the position for the next element, which will be return, if user call "nextElement()"
    // => We have more elements if current position less then the length of the list!
    return ( m_nPosition < (sal_uInt32)(m_seqComponents.getLength()) );
}


//  XEnumeration

Any SAL_CALL OComponentEnumeration::nextElement() throw(    NoSuchElementException  ,
                                                             WrappedTargetException ,
                                                            RuntimeException, std::exception        )
{
    // Ready for multithreading
    ResetableGuard aGuard( m_aLock );

    // If we have no elements or end of enumeration is arrived ...
    if ( hasMoreElements() == sal_False )
    {
        // .. throw an exception!
        throw NoSuchElementException();
    }

    // Else; Get next element from list ...
    Any aComponent;
    aComponent <<= m_seqComponents[m_nPosition];
    // ... and step to next element!
    ++m_nPosition;

    // Return listitem.
    return aComponent;
}


//  proteced method

void OComponentEnumeration::impl_resetObject()
{
    // Attention:
    // Write this for multiple calls - NOT AT THE SAME TIME - but for more then one call again)!
    // It exist two ways to call this method. From destructor and from disposing().
    // I can't say, which one is the first. Normaly the disposing-call - but other way ....

    // Delete list of components.
    m_seqComponents.realloc( 0 );
    // Reset position in list.
    // The list has no elements anymore. m_nPosition is normaly the current position in list for nextElement!
    // But a position of 0 in a list of 0 items is an invalid state. This constellation can't work in future.
    // End of enumeration is arrived!
    // (see hasMoreElements() for more details...)
    m_nPosition = 0 ;
}


//  debug methods


/*-----------------------------------------------------------------------------------------------------------------
    The follow methods checks the parameter for other functions. If a parameter or his value is non valid,
    we return "sal_False". (else sal_True) This mechanism is used to throw an ASSERT!

    ATTENTION

        If you miss a test for one of this parameters, contact the autor or add it himself !(?)
        But ... look for right testing! See using of this methods!
-----------------------------------------------------------------------------------------------------------------*/


// An empty list is allowed ... hasMoreElements() will return false then!
sal_Bool OComponentEnumeration::impldbg_checkParameter_OComponentEnumerationCtor( const Sequence< css::uno::Reference< XComponent > >& seqComponents )
{
    // Set default return value.
    sal_Bool bOK = sal_True;
    // Check parameter.
    if  (
            ( &seqComponents == NULL )
        )
    {
        bOK = sal_False ;
    }
    // Return result of check.
    return bOK ;
}


sal_Bool OComponentEnumeration::impldbg_checkParameter_disposing( const EventObject& aEvent )
{
    return aEvent.Source.is();
}

}       //  namespace framework

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