Plugin Script Enqueue

cu-gallery.php

<?php
/**
 * @package Carleton Gallery
 */
/*
Plugin Name: Carleton Gallery
Plugin URI: http://carleton.ca/webservices
Description: Override Default WP Gallery Shortcode with something better.
Version: 1
Author: Mike Corkum
Author URI: http://carleton.ca/webservices
License: Hi Roy!
Text Domain: cu-gallery
*/

remove_shortcode( 'gallery' );

class Carleton_Gallery_Override {
	static $add_script;

	static function init() {
		add_shortcode('gallery', array(__CLASS__, 'handle_shortcode'));

		add_action('init', array(__CLASS__, 'register_script'));
		add_action('wp_footer', array(__CLASS__, 'print_script'));
	}

	static function handle_shortcode($atts) {
		global $post;
		self::$add_script = true;
		// TODO: Handle Gallery Shortcode here
	}

	static function register_script() {
		wp_register_script('gallery-script', plugins_url('gallery.js', __FILE__), array('jquery'), '1.0', true);
	}

	static function print_script() {
		if ( ! self::$add_script )
			return;
		wp_print_scripts('gallery-script');
	}
}

Carleton_Gallery_Override::init();