<?php
/**
 * CBehavior class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2009 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CBehavior is a convenient base class for behavior classes.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CBehavior.php 564 2009-01-21 22:07:10Z qiang.xue $
 * @package system.base
 * @since 1.0.2
 */
class TBehavior extends TComponent implements IBehavior
{
	private $_enabled;
	private $_owner;

	/**
	 * Declares events and the corresponding event handler methods.
	 * The events are defined by the {@link owner} component, while the handler
	 * methods by the behavior class. The handlers will be attached to the corresponding
	 * events when the behavior is attached to the {@link owner} component; and they
	 * will be detached from the events when the behavior is detached from the component.
	 * @return array events (array keys) and the corresponding event handler methods (array values).
	 */
	public function events()
	{
		return array();
	}

	/**
	 * Attaches the behavior object to the component.
	 * The default implementation will set the {@link owner} property
	 * and attach event handlers as declared in {@link events}.
	 * Make sure you call the parent implementation if you override this method.
	 * @param CComponent the component that this behavior is to be attached to.
	 */
	public function attach($owner)
	{
		$this->_owner=$owner;
		foreach($this->events() as $event=>$handler)
			$owner->attachEventHandler($event,array($this,$handler));
	}

	/**
	 * Detaches the behavior object from the component.
	 * The default implementation will unset the {@link owner} property
	 * and detach event handlers declared in {@link events}.
	 * Make sure you call the parent implementation if you override this method.
	 * @param CComponent the component that this behavior is to be detached from.
	 */
	public function detach($owner)
	{
		foreach($this->events() as $event=>$handler)
			$owner->detachEventHandler($event,array($this,$handler));
		$this->_owner=null;
	}

	/**
	 * @return CComponent the owner component that this behavior is attached to.
	 */
	public function getOwner()
	{
		return $this->_owner;
	}

	/**
	 * @return boolean whether this behavior is enabled
	 */
	public function getEnabled()
	{
		return $this->_enabled;
	}

	/**
	 * @param boolean whether this behavior is enabled
	 */
	public function setEnabled($value)
	{
		$this->_enabled=$value;
	}
}

/**
 * IBehavior interfaces is implemented by all behavior classes.
 *
 * A behavior is a way to enhance a component with additional methods that
 * are defined in the behavior class and not available in the component class.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: interfaces.php 956 2009-04-21 15:16:03Z qiang.xue@gmail.com $
 * @package system.base
 * @since 1.0.2
 */
interface IBehavior
{
	/**
	 * Attaches the behavior object to the component.
	 * @param CComponent the component that this behavior is to be attached to.
	 */
	public function attach($component);
	/**
	 * Detaches the behavior object from the component.
	 * @param CComponent the component that this behavior is to be detached from.
	 */
	public function detach($component);
	/**
	 * @return boolean whether this behavior is enabled
	 */
	public function getEnabled();
	/**
	 * @param boolean whether this behavior is enabled
	 */
	public function setEnabled($value);
}