| @@ -44,9 +44,9 @@ | ||
| 44 | 44 | 'font_display_swap' => array( |
| 45 | 45 | 'type' => 'bool', |
| 46 | 46 | 'default' => true, |
| 47 | 47 | 'label' => __( 'Show text while fonts load', 'xspeed' ), |
| 48 | - 'description' => __( 'Google Fonts text shows at once in a standard font, then switches when the web font arrives.', 'xspeed' ), | |
| 48 | + 'description' => __( 'Text in Google Fonts, and in fonts added to WordPress itself, shows at once in a standard font, then switches when the web font arrives.', 'xspeed' ), | |
| 49 | 49 | ), |
| 50 | 50 | 'preload_fonts' => array( |
| 51 | 51 | 'type' => 'list', |
| 52 | 52 | 'default' => array(), |
| @@ -94,8 +94,27 @@ | ||
| 94 | 94 | $opts = $this->get_settings(); |
| 95 | 95 | |
| 96 | 96 | if ( ! empty( $opts['font_display_swap'] ) ) { |
| 97 | 97 | add_filter( 'style_loader_tag', array( __CLASS__, 'inject_display_swap' ), 10, 2 ); |
| 98 | + | |
| 99 | + // Fonts added through the Font Library or theme.json are printed | |
| 100 | + // by core with font-display: fallback, and core offers no filter | |
| 101 | + // for it. Fallback hides the text for up to 100ms while the font | |
| 102 | + // loads; when that text is the LCP, the hero paints after the | |
| 103 | + // font instead of at first paint. Measured on a live text hero: | |
| 104 | + // LCP landed ~85ms after FCP with fallback and on FCP with swap, | |
| 105 | + // CLS unchanged, and PageSpeed mobile moved between 81 and 90 | |
| 106 | + // depending on which side of that window the font fell. So core's | |
| 107 | + // own printer runs with swap as the default. Only an exact | |
| 108 | + // priority-50 hook is replaced: anything that already moved or | |
| 109 | + // removed it is left alone. | |
| 110 | + if ( function_exists( 'wp_print_font_faces' ) | |
| 111 | + && class_exists( '\WP_Font_Face_Resolver' ) | |
| 112 | + && 50 === has_action( 'wp_head', 'wp_print_font_faces' ) | |
| 113 | + ) { | |
| 114 | + remove_action( 'wp_head', 'wp_print_font_faces', 50 ); | |
| 115 | + add_action( 'wp_head', array( __CLASS__, 'print_font_faces_swap' ), 50 ); | |
| 116 | + } | |
| 98 | 117 | } |
| 99 | 118 | |
| 100 | 119 | if ( ! empty( $opts['preload_fonts'] ) ) { |
| 101 | 120 | add_action( |
| @@ -160,8 +179,46 @@ | ||
| 160 | 179 | $separator = ( false === strpos( $href_decoded, '?' ) ) ? '?' : '&'; |
| 161 | 180 | $new_href = $href . $separator . 'display=swap'; |
| 162 | 181 | |
| 163 | 182 | return str_replace( $href, $new_href, $tag ); |
| 183 | + } | |
| 184 | + | |
| 185 | + /** | |
| 186 | + * Print core's font faces as wp_print_font_faces() does, with swap as | |
| 187 | + * the font-display default. | |
| 188 | + */ | |
| 189 | + public static function print_font_faces_swap(): void { | |
| 190 | + $fonts = \WP_Font_Face_Resolver::get_fonts_from_theme_json(); | |
| 191 | + if ( empty( $fonts ) ) { | |
| 192 | + return; | |
| 193 | + } | |
| 194 | + // WordPress 6.4+. Only hooked when the function exists (see | |
| 195 | + // boot_on_init()), called by name so a 6.0 floor stays compatible. | |
| 196 | + call_user_func( 'wp_print_font_faces', self::default_display_swap( $fonts ) ); | |
| 197 | + } | |
| 198 | + | |
| 199 | + /** | |
| 200 | + * Give every font face without its own font-display a swap one. | |
| 201 | + * | |
| 202 | + * The resolver only sets font-display when a theme.json fontFace | |
| 203 | + * declares fontDisplay, so a face that has one was chosen on purpose | |
| 204 | + * and keeps it. Public + static so the test suite can drive it. | |
| 205 | + * | |
| 206 | + * @param array<int|string,mixed> $fonts Font families, each a list of faces. | |
| 207 | + * @return array<int|string,mixed> | |
| 208 | + */ | |
| 209 | + public static function default_display_swap( array $fonts ): array { | |
| 210 | + foreach ( $fonts as $family => $faces ) { | |
| 211 | + if ( ! is_array( $faces ) ) { | |
| 212 | + continue; | |
| 213 | + } | |
| 214 | + foreach ( $faces as $i => $face ) { | |
| 215 | + if ( is_array( $face ) && ! isset( $face['font-display'] ) ) { | |
| 216 | + $fonts[ $family ][ $i ]['font-display'] = 'swap'; | |
| 217 | + } | |
| 218 | + } | |
| 219 | + } | |
| 220 | + return $fonts; | |
| 164 | 221 | } |
| 165 | 222 | |
| 166 | 223 | /** |
| 167 | 224 | * Render the preload <link> markup for a list of font URLs. |
