Image size class for WordPress

class.image-size.php

<?php
/**
 * ImageSizes
 * Define and create image sizes
 * 
 * @todo Add setter method for adding image sizes
 * 
 * @package ImageSizes
 * @author Jess Green <jgreen@psy-dreamer.com>
 * @version $Id$
 */
namespace JesGs;
/**
 * Class for image sizes
 * 
 * @package ImageSizes
 * @author Jess Green <jgreen@psy-dreamer.com>
 */
class ImageSizes
{
    const MEDSQUARE = 'thumbnail-medium-square';   // square 300x300
    const LONG      = 'thumbnail-long'; // long 16:9 640x360
    
    /**
     * Array of image sizes, defined above
     * 
     * @var array
     */
    protected $_sizes = array(
        self::MEDSQUARE => array(
            'height' => 300,
            'width'  => 300,
            'crop'   => false,
        ),
        
        self::LONG => array(
            'height' => 640,
            'width'  => 360,
            'crop'   => false,
        ),
    );

    /**
     * Instance of class
     * 
     * @var \JesGs\ImageSizes 
     */
    protected static $_instance;
    
    /**
     * PHP5 Constructor function
     * 
     * @return \JesGs\ImageSizes
     */
    protected function __construct()
    {
        return $this;
    }
    
    /**
     * Get instance of class
     * 
     * @return \JesGs\ImageSizes
     */
    public static function get_instance()
    {
        if (self::$_instance === null) {
            self::$_instance = new self();
        }
        
        return self::$_instance;
    }

    /**
     * Get sizes
     * 
     * @return array
     */
    public function get_sizes()
    {
        return $this->_sizes;
    }
    
    /**
     * Get an image size
     * 
     * @return array
     */
    public function get_size($size)
    {
        if (!isset($this->_sizes[$size])) {
            return false;
        }
        
        return $this->_sizes[$size];
    }
    
    /**
     * Create image sizes
     * 
     * @return void
     */
    public function create_image_sizes()
    {
        foreach ($this->_sizes as $size_name => $size_data) {
            add_image_size(
                $size_name,
                $size_data['width'],
                $size_data['height'],
                $size_data['crop']
            );        
        }
    }
    
}