Initial import.

vendor/doctrine/common/lib/Doctrine/Common/EventArgs.php

@@ -0,0 +1,67 @@
+<?php
+/*
+ *  $Id$
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\Common;
+
+/**
+ * EventArgs is the base class for classes containing event data.
+ *
+ * This class contains no event data. It is used by events that do not pass state
+ * information to an event handler when an event is raised. The single empty EventArgs
+ * instance can be obtained through {@link getEmptyInstance}.
+ *
+ * @license http://www.opensource.org/licenses/lgpl-license.php LGPL
+ * @link    www.doctrine-project.org
+ * @since   2.0
+ * @version $Revision: 3938 $
+ * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
+ * @author  Jonathan Wage <jonwage@gmail.com>
+ * @author  Roman Borschel <roman@code-factory.org>
+ */
+class EventArgs
+{
+    /**
+     * @var EventArgs Single instance of EventArgs
+     */
+    private static $_emptyEventArgsInstance;
+
+    /**
+     * Gets the single, empty and immutable EventArgs instance.
+     *
+     * This instance will be used when events are dispatched without any parameter,
+     * like this: EventManager::dispatchEvent('eventname');
+     *
+     * The benefit from this is that only one empty instance is instantiated and shared
+     * (otherwise there would be instances for every dispatched in the abovementioned form)
+     *
+     * @see EventManager::dispatchEvent
+     * @link http://msdn.microsoft.com/en-us/library/system.eventargs.aspx
+     * @return EventArgs
+     */
+    public static function getEmptyInstance()
+    {
+        if ( ! self::$_emptyEventArgsInstance) {
+            self::$_emptyEventArgsInstance = new EventArgs;
+        }
+
+        return self::$_emptyEventArgsInstance;
+    }
+}