<?php

/**
 * Creation:     17.02.2007  fabian
 * Last Update:  $Id$
 *
 * Copyright (c) 2007 Fabian Wolter <fabian@eisfair.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

abstract class Composite implements Component {
    protected $children = array();
    protected $parent;

    /**
     *
     * @param Component $ comp
     */
    public function add(Component $comp) {
        $comp->setParent($this);
        $this->children[] = $comp;
        return $comp;
    }

    /**
     *
     * @param Component $ comp
     */
    public function remove(Component $comp) {
        $index = array_search($comp, $this->children, true);
        if ($index === false) {
            return false;
        }
        array_splice($this->children, $index, 1);
        return true;
    }

    /**
     *
     * @param Component $ comp
     */
    public function setParent(Component $parent) {
        $this->parent = $parent;
    }

    /**
     *
     * @return Component Parent Component
     */
    public function getParent() {
        if (isset ($this->parent)) {
            return $this->parent;
        } else
            throw new Exception("This child has no parents.");
    }

    /**
     * Returns true if this is the root node
     *
     * @return Bool
     */
    public function isRoot() {
        return !isset($this->parent->parent);
    }

    /**
     * Returns true if this Component has no children
     *
     * @return Bool
     */
    public function isLeaf() {
        return empty ($this->children);
    }

    /**
     * Returns the root node.
     *
     * @return Component Root node
     */
    public function getRoot() {
        if ($this->isParent()) {
            $this->getRootNode();
        } else {
            return $this;
        }
    }

    public function numberOfChildren() {
        return count($this->children);
    }

    public function allChildrenOfType($type) {
        foreach($this->children as $child) {
            if(!($child instanceof $type))
                return false;
        }
        return true;
    }

    public function __clone() {
        $kids = array ();
        foreach ($this->children as $child) {
            $kids[] = clone ($child);
        }
        $this->children = $kids;
    }

    /**
     *
     * @return int Number of children
     */
    public function number() {
        $total = 1;
        foreach ($this->children as $child) {
            $total += $child->number();
        }
        return $total;
    }
}

?>