wp_default_styles

wp_default_styles是一个WordPress函数，负责注册加载在WordPress站点每个页面上的默认样式。这些样式提供了核心功能，是WordPress正常运行所必需的。

为$styles对象分配默认样式。

没有任何东西被返回，因为$styles参数是通过引用传递的。意味着无论传递什么对象都会被更新，而不必将传递的变量重新分配到相同的值。这就节省了内存。

添加默认样式并不是唯一的任务，它还分配了base_url 属性、默认版本，以及对象的文本方向。

function wp_default_styles( $styles ) {
	global $editor_styles;

	// Include an unmodified $wp_version.
	require ABSPATH . WPINC . '/version.php';

	if ( ! defined( 'SCRIPT_DEBUG' ) ) {
		define( 'SCRIPT_DEBUG', false !== strpos( $wp_version, '-src' ) );
	}

	$guessurl = site_url();

	if ( ! $guessurl ) {
		$guessurl = wp_guess_url();
	}

	$styles->base_url        = $guessurl;
	$styles->content_url     = defined( 'WP_CONTENT_URL' ) ? WP_CONTENT_URL : '';
	$styles->default_version = get_bloginfo( 'version' );
	$styles->text_direction  = function_exists( 'is_rtl' ) && is_rtl() ? 'rtl' : 'ltr';
	$styles->default_dirs    = array( '/wp-admin/', '/wp-includes/css/' );

	// Open Sans is no longer used by core, but may be relied upon by themes and plugins.
	$open_sans_font_url = '';

	/*
	 * translators: If there are characters in your language that are not supported
	 * by Open Sans, translate this to 'off'. Do not translate into your own language.
	 */
	if ( 'off' !== _x( 'on', 'Open Sans font: on or off' ) ) {
		$subsets = 'latin,latin-ext';

		/*
		 * translators: To add an additional Open Sans character subset specific to your language,
		 * translate this to 'greek', 'cyrillic' or 'vietnamese'. Do not translate into your own language.
		 */
		$subset = _x( 'no-subset', 'Open Sans font: add new subset (greek, cyrillic, vietnamese)' );

		if ( 'cyrillic' === $subset ) {
			$subsets .= ',cyrillic,cyrillic-ext';
		} elseif ( 'greek' === $subset ) {
			$subsets .= ',greek,greek-ext';
		} elseif ( 'vietnamese' === $subset ) {
			$subsets .= ',vietnamese';
		}

		// Hotlink Open Sans, for now.
		$open_sans_font_url = "https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,300,400,600&subset=$subsets&display=fallback";
	}

	// Register a stylesheet for the selected admin color scheme.
	$styles->add( 'colors', true, array( 'wp-admin', 'buttons' ) );

	$suffix = SCRIPT_DEBUG ? '' : '.min';

	// Admin CSS.
	$styles->add( 'common', "/wp-admin/css/common$suffix.css" );
	$styles->add( 'forms', "/wp-admin/css/forms$suffix.css" );
	$styles->add( 'admin-menu', "/wp-admin/css/admin-menu$suffix.css" );
	$styles->add( 'dashboard', "/wp-admin/css/dashboard$suffix.css" );
	$styles->add( 'list-tables', "/wp-admin/css/list-tables$suffix.css" );
	$styles->add( 'edit', "/wp-admin/css/edit$suffix.css" );
	$styles->add( 'revisions', "/wp-admin/css/revisions$suffix.css" );
	$styles->add( 'media', "/wp-admin/css/media$suffix.css" );
	$styles->add( 'themes', "/wp-admin/css/themes$suffix.css" );
	$styles->add( 'about', "/wp-admin/css/about$suffix.css" );
	$styles->add( 'nav-menus', "/wp-admin/css/nav-menus$suffix.css" );
	$styles->add( 'widgets', "/wp-admin/css/widgets$suffix.css", array( 'wp-pointer' ) );
	$styles->add( 'site-icon', "/wp-admin/css/site-icon$suffix.css" );
	$styles->add( 'l10n', "/wp-admin/css/l10n$suffix.css" );
	$styles->add( 'code-editor', "/wp-admin/css/code-editor$suffix.css", array( 'wp-codemirror' ) );
	$styles->add( 'site-health', "/wp-admin/css/site-health$suffix.css" );

	$styles->add( 'wp-admin', false, array( 'dashicons', 'common', 'forms', 'admin-menu', 'dashboard', 'list-tables', 'edit', 'revisions', 'media', 'themes', 'about', 'nav-menus', 'widgets', 'site-icon', 'l10n' ) );

	$styles->add( 'login', "/wp-admin/css/login$suffix.css", array( 'dashicons', 'buttons', 'forms', 'l10n' ) );
	$styles->add( 'install', "/wp-admin/css/install$suffix.css", array( 'dashicons', 'buttons', 'forms', 'l10n' ) );
	$styles->add( 'wp-color-picker', "/wp-admin/css/color-picker$suffix.css" );
	$styles->add( 'customize-controls', "/wp-admin/css/customize-controls$suffix.css", array( 'wp-admin', 'colors', 'imgareaselect' ) );
	$styles->add( 'customize-widgets', "/wp-admin/css/customize-widgets$suffix.css", array( 'wp-admin', 'colors' ) );
	$styles->add( 'customize-nav-menus', "/wp-admin/css/customize-nav-menus$suffix.css", array( 'wp-admin', 'colors' ) );

	// Common dependencies.
	$styles->add( 'buttons', "/wp-includes/css/buttons$suffix.css" );
	$styles->add( 'dashicons', "/wp-includes/css/dashicons$suffix.css" );

	// Includes CSS.
	$styles->add( 'admin-bar', "/wp-includes/css/admin-bar$suffix.css", array( 'dashicons' ) );
	$styles->add( 'wp-auth-check', "/wp-includes/css/wp-auth-check$suffix.css", array( 'dashicons' ) );
	$styles->add( 'editor-buttons', "/wp-includes/css/editor$suffix.css", array( 'dashicons' ) );
	$styles->add( 'media-views', "/wp-includes/css/media-views$suffix.css", array( 'buttons', 'dashicons', 'wp-mediaelement' ) );
	$styles->add( 'wp-pointer', "/wp-includes/css/wp-pointer$suffix.css", array( 'dashicons' ) );
	$styles->add( 'customize-preview', "/wp-includes/css/customize-preview$suffix.css", array( 'dashicons' ) );
	$styles->add( 'wp-embed-template-ie', "/wp-includes/css/wp-embed-template-ie$suffix.css" );
	$styles->add_data( 'wp-embed-template-ie', 'conditional', 'lte IE 8' );

	// External libraries and friends.
	$styles->add( 'imgareaselect', '/wp-includes/js/imgareaselect/imgareaselect.css', array(), '0.9.8' );
	$styles->add( 'wp-jquery-ui-dialog', "/wp-includes/css/jquery-ui-dialog$suffix.css", array( 'dashicons' ) );
	$styles->add( 'mediaelement', '/wp-includes/js/mediaelement/mediaelementplayer-legacy.min.css', array(), '4.2.17' );
	$styles->add( 'wp-mediaelement', "/wp-includes/js/mediaelement/wp-mediaelement$suffix.css", array( 'mediaelement' ) );
	$styles->add( 'thickbox', '/wp-includes/js/thickbox/thickbox.css', array( 'dashicons' ) );
	$styles->add( 'wp-codemirror', '/wp-includes/js/codemirror/codemirror.min.css', array(), '5.29.1-alpha-ee20357' );

	// Deprecated CSS.
	$styles->add( 'deprecated-media', "/wp-admin/css/deprecated-media$suffix.css" );
	$styles->add( 'farbtastic', "/wp-admin/css/farbtastic$suffix.css", array(), '1.3u1' );
	$styles->add( 'jcrop', '/wp-includes/js/jcrop/jquery.Jcrop.min.css', array(), '0.9.15' );
	$styles->add( 'colors-fresh', false, array( 'wp-admin', 'buttons' ) ); // Old handle.
	$styles->add( 'open-sans', $open_sans_font_url ); // No longer used in core as of 4.6.

	// Noto Serif is no longer used by core, but may be relied upon by themes and plugins.
	$fonts_url = '';

	/*
	 * translators: Use this to specify the proper Google Font name and variants
	 * to load that is supported by your language. Do not translate.
	 * Set to 'off' to disable loading.
	 */
	$font_family = _x( 'Noto Serif:400,400i,700,700i', 'Google Font Name and Variants' );
	if ( 'off' !== $font_family ) {
		$fonts_url = 'https://fonts.googleapis.com/css?family=' . urlencode( $font_family );
	}
	$styles->add( 'wp-editor-font', $fonts_url ); // No longer used in core as of 5.7.
	$block_library_theme_path = WPINC . "/css/dist/block-library/theme$suffix.css";
	$styles->add( 'wp-block-library-theme', "/$block_library_theme_path" );
	$styles->add_data( 'wp-block-library-theme', 'path', ABSPATH . $block_library_theme_path );

	$styles->add(
		'wp-reset-editor-styles',
		"/wp-includes/css/dist/block-library/reset$suffix.css",
		array( 'common', 'forms' ) // Make sure the reset is loaded after the default WP Admin styles.
	);

	$styles->add(
		'wp-editor-classic-layout-styles',
		"/wp-includes/css/dist/edit-post/classic$suffix.css",
		array()
	);

	$wp_edit_blocks_dependencies = array(
		'wp-components',
		'wp-editor',
		// This need to be added before the block library styles,
		// The block library styles override the "reset" styles.
		'wp-reset-editor-styles',
		'wp-block-library',
		'wp-reusable-blocks',
	);

	// Only load the default layout and margin styles for themes without theme.json file.
	if ( ! WP_Theme_JSON_Resolver::theme_has_support() ) {
		$wp_edit_blocks_dependencies[] = 'wp-editor-classic-layout-styles';
	}

	if ( ! is_array( $editor_styles ) || count( $editor_styles ) === 0 ) {
		// Include opinionated block styles if no $editor_styles are declared, so the editor never appears broken.
		$wp_edit_blocks_dependencies[] = 'wp-block-library-theme';
	}

	$styles->add(
		'wp-edit-blocks',
		"/wp-includes/css/dist/block-library/editor$suffix.css",
		$wp_edit_blocks_dependencies
	);

	$package_styles = array(
		'block-editor'         => array( 'wp-components' ),
		'block-library'        => array(),
		'block-directory'      => array(),
		'components'           => array(),
		'edit-post'            => array(
			'wp-components',
			'wp-block-editor',
			'wp-editor',
			'wp-edit-blocks',
			'wp-block-library',
			'wp-nux',
		),
		'editor'               => array(
			'wp-components',
			'wp-block-editor',
			'wp-nux',
			'wp-reusable-blocks',
		),
		'format-library'       => array(),
		'list-reusable-blocks' => array( 'wp-components' ),
		'reusable-blocks'      => array( 'wp-components' ),
		'nux'                  => array( 'wp-components' ),
		'widgets'              => array(
			'wp-components',
		),
		'edit-widgets'         => array(
			'wp-widgets',
			'wp-block-editor',
			'wp-edit-blocks',
			'wp-block-library',
			'wp-reusable-blocks',
		),
		'customize-widgets'    => array(
			'wp-widgets',
			'wp-block-editor',
			'wp-edit-blocks',
			'wp-block-library',
			'wp-reusable-blocks',
		),
		'edit-site'            => array(
			'wp-components',
			'wp-block-editor',
			'wp-edit-blocks',
		),
	);

	foreach ( $package_styles as $package => $dependencies ) {
		$handle = 'wp-' . $package;
		$path   = "/wp-includes/css/dist/$package/style$suffix.css";

		if ( 'block-library' === $package && wp_should_load_separate_core_block_assets() ) {
			$path = "/wp-includes/css/dist/$package/common$suffix.css";
		}
		$styles->add( $handle, $path, $dependencies );
		$styles->add_data( $handle, 'path', ABSPATH . $path );
	}

	// RTL CSS.
	$rtl_styles = array(
		// Admin CSS.
		'common',
		'forms',
		'admin-menu',
		'dashboard',
		'list-tables',
		'edit',
		'revisions',
		'media',
		'themes',
		'about',
		'nav-menus',
		'widgets',
		'site-icon',
		'l10n',
		'install',
		'wp-color-picker',
		'customize-controls',
		'customize-widgets',
		'customize-nav-menus',
		'customize-preview',
		'login',
		'site-health',
		// Includes CSS.
		'buttons',
		'admin-bar',
		'wp-auth-check',
		'editor-buttons',
		'media-views',
		'wp-pointer',
		'wp-jquery-ui-dialog',
		// Package styles.
		'wp-reset-editor-styles',
		'wp-editor-classic-layout-styles',
		'wp-block-library-theme',
		'wp-edit-blocks',
		'wp-block-editor',
		'wp-block-library',
		'wp-block-directory',
		'wp-components',
		'wp-customize-widgets',
		'wp-edit-post',
		'wp-edit-site',
		'wp-edit-widgets',
		'wp-editor',
		'wp-format-library',
		'wp-list-reusable-blocks',
		'wp-reusable-blocks',
		'wp-nux',
		'wp-widgets',
		// Deprecated CSS.
		'deprecated-media',
		'farbtastic',
	);

	foreach ( $rtl_styles as $rtl_style ) {
		$styles->add_data( $rtl_style, 'rtl', 'replace' );
		if ( $suffix ) {
			$styles->add_data( $rtl_style, 'suffix', $suffix );
		}
	}
}