functions.php

<?php
/**
 * @package WordPress
 * @subpackage Coraline
 */

/**
 * Set the content width based on the theme's design and stylesheet.
 */
if ( ! isset( $content_width ) )
    $content_width = 500;

/** Tell WordPress to run coraline_setup() when the 'after_setup_theme' hook is run. */
add_action( 'after_setup_theme', 'coraline_setup' );

if ( ! function_exists( 'coraline_setup' ) ):
/**
 * Sets up theme defaults and registers support for various WordPress features.
 *
 * To override coraline_setup() in a child theme, add your own coraline_setup to your child theme's
 * functions.php file.
 *
 * @uses add_theme_support() To add support for post thumbnails and automatic feed links.
 * @uses register_nav_menus() To add support for navigation menus.
 * @uses add_custom_background() To add support for a custom background.
 * @uses add_editor_style() To style the visual editor.
 * @uses load_theme_textdomain() For translation/localization support.
 * @uses add_custom_image_header() To add support for a custom header.
 * @uses register_default_headers() To register the default custom header images provided with the theme.
 * @uses set_post_thumbnail_size() To set a custom post thumbnail size.
 *
 * @since Coraline 1.0
 */
function coraline_setup() {

    // This theme has some pretty cool theme options
    require_once ( get_template_directory() . '/inc/theme-options.php' );

    // This theme styles the visual editor with editor-style.css to match the theme style.
    add_editor_style();

    // Post Format support. Legacy category chooser will display in Theme Options for sites that set a category before post formats were added.
    add_theme_support( 'post-formats', array( 'aside', 'gallery' ) );

    // This theme uses post thumbnails
    add_theme_support( 'post-thumbnails' );

    // Add default posts and comments RSS feed links to head
    add_theme_support( 'automatic-feed-links' );

    // Make theme available for translation
    // Translations can be filed in the /languages/ directory
    load_theme_textdomain( 'coraline', get_template_directory() . '/languages' );

    $locale = get_locale();
    $locale_file = get_template_directory() . "/languages/$locale.php";
    if ( is_readable( $locale_file ) )
        require_once( $locale_file );

    // This theme uses wp_nav_menu() in one location.
    register_nav_menus( array(
        'primary' => __( 'Primary Navigation', 'coraline' ),
    ) );

    // This theme allows users to set a custom background
    add_custom_background();

    // Your changeable header business starts here
    define( 'HEADER_TEXTCOLOR', '000' );
    // No CSS, just an IMG call. The %s is a placeholder for the theme template directory URI.
    define( 'HEADER_IMAGE', '%s/images/headers/water-drops.jpg' );

    // The height and width of your custom header. You can hook into the theme's own filters to change these values.
    // Add a filter to coraline_header_image_width and coraline_header_image_height to change these values.
    define( 'HEADER_IMAGE_WIDTH', apply_filters( 'coraline_header_image_width', 990 ) );
    define( 'HEADER_IMAGE_HEIGHT', apply_filters( 'coraline_header_image_height', 180 ) );

    // We'll be using post thumbnails for custom header images on posts and pages.
    // We want them to be 940 pixels wide by 198 pixels tall.
    // Larger images will be auto-cropped to fit, smaller ones will be ignored. See header.php.
    set_post_thumbnail_size( HEADER_IMAGE_WIDTH, HEADER_IMAGE_HEIGHT, true );

    // Add a way for the custom header to be styled in the admin panel that controls
    // custom headers. See coraline_admin_header_style(), below.
    add_custom_image_header( 'coraline_header_style', 'coraline_admin_header_style', 'coraline_admin_header_image' );

    // ... and thus ends the changeable header business.

    // Default custom headers packaged with the theme. %s is a placeholder for the theme template directory URI.
    register_default_headers( array(
        'water-drops' => array(
            'url' => '%s/images/headers/water-drops.jpg',
            'thumbnail_url' => '%s/images/headers/water-drops-thumbnail.jpg',
            /* translators: header image description */
            'description' => __( 'Water drops', 'coraline' )
        ),
        'limestone-cave' => array(
            'url' => '%s/images/headers/limestone-cave.jpg',
            'thumbnail_url' => '%s/images/headers/limestone-cave-thumbnail.jpg',
            /* translators: header image description */
            'description' => __( 'Limestone cave', 'coraline' )
        ),
        'Cactii' => array(
            'url' => '%s/images/headers/cactii.jpg',
            'thumbnail_url' => '%s/images/headers/cactii-thumbnail.jpg',
            /* translators: header image description */
            'description' => __( 'Cactii', 'coraline' )
        )
    ) );
}
endif;
?>