70 lines
2.5 KiB
PHP
70 lines
2.5 KiB
PHP
<?php
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/*
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* $Id$
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* This software consists of voluntary contributions made by many individuals
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* and is licensed under the LGPL. For more information, see
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* <http://www.doctrine-project.org>.
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*/
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namespace Doctrine\Common;
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/**
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* EventArgs is the base class for classes containing event data.
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*
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* This class contains no event data. It is used by events that do not pass state
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* information to an event handler when an event is raised. The single empty EventArgs
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* instance can be obtained through {@link getEmptyInstance}.
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*
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* @license http://www.opensource.org/licenses/lgpl-license.php LGPL
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* @link www.doctrine-project.org
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* @since 2.0
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* @version $Revision: 3938 $
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* @author Guilherme Blanco <guilhermeblanco@hotmail.com>
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* @author Jonathan Wage <jonwage@gmail.com>
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* @author Roman Borschel <roman@code-factory.org>
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*/
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class EventArgs
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{
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/**
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* @var EventArgs Single instance of EventArgs
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* @static
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*/
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private static $_emptyEventArgsInstance;
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/**
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* Gets the single, empty and immutable EventArgs instance.
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*
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* This instance will be used when events are dispatched without any parameter,
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* like this: EventManager::dispatchEvent('eventname');
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*
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* The benefit from this is that only one empty instance is instantiated and shared
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* (otherwise there would be instances for every dispatched in the abovementioned form)
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*
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* @see EventManager::dispatchEvent
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* @link http://msdn.microsoft.com/en-us/library/system.eventargs.aspx
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* @static
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* @return EventArgs
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*/
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public static function getEmptyInstance()
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{
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if ( ! self::$_emptyEventArgsInstance) {
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self::$_emptyEventArgsInstance = new EventArgs;
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}
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return self::$_emptyEventArgsInstance;
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}
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}
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