Add defaultFontSizes option to theme.json (#56661)

* Add defaultFontSizes option for theme.json

* Fix defaultFontSizes causing errors when missing

* Simplify useMergedSettings

* Simplify more

* Remove the memo because it's probably fine

* Try ignoring how overrides are handled in the dropdown

* Minor performance improvement using reverse instead of toReversed

* Link to a new issue with a more complete description

* Refactor hack into its own funtion

docs/reference-guides/theme-json-reference/theme-json-living.md

@@ -177,6 +177,7 @@ Settings related to typography.
 
 | Property  | Type   | Default | Props  |
 | ---       | ---    | ---    |---   |
+| defaultFontSizes | boolean | true |  |
 | customFontSize | boolean | true |  |
 | fontStyle | boolean | true |  |
 | fontWeight | boolean | true |  |

lib/class-wp-theme-json-gutenberg.php

@@ -151,7 +151,7 @@ class WP_Theme_JSON_Gutenberg {
 		),
 		array(
 			'path'              => array( 'typography', 'fontSizes' ),
-			'prevent_override'  => false,
+			'prevent_override'  => array( 'typography', 'defaultFontSizes' ),
 			'use_default_names' => true,
 			'value_func'        => 'gutenberg_get_typography_font_size_value',
 			'css_vars'          => '--wp--preset--font-size--$slug',
@@ -409,19 +409,20 @@ class WP_Theme_JSON_Gutenberg {
 			'defaultPresets' => null,
 		),
 		'typography'                    => array(
-			'fluid'          => null,
-			'customFontSize' => null,
-			'dropCap'        => null,
-			'fontFamilies'   => null,
-			'fontSizes'      => null,
-			'fontStyle'      => null,
-			'fontWeight'     => null,
-			'letterSpacing'  => null,
-			'lineHeight'     => null,
-			'textColumns'    => null,
-			'textDecoration' => null,
-			'textTransform'  => null,
-			'writingMode'    => null,
+			'fluid'            => null,
+			'customFontSize'   => null,
+			'defaultFontSizes' => null,
+			'dropCap'          => null,
+			'fontFamilies'     => null,
+			'fontSizes'        => null,
+			'fontStyle'        => null,
+			'fontWeight'       => null,
+			'letterSpacing'    => null,
+			'lineHeight'       => null,
+			'textColumns'      => null,
+			'textDecoration'   => null,
+			'textTransform'    => null,
+			'writingMode'      => null,
 		),
 	);
 

lib/theme.json

@@ -236,6 +236,7 @@
 		},
 		"typography": {
 			"customFontSize": true,
+			"defaultFontSizes": true,
 			"dropCap": true,
 			"fontSizes": [
 				{

packages/block-editor/src/components/global-styles/hooks.js

@@ -67,6 +67,7 @@ const VALID_SETTINGS = [
 	'spacing.units',
 	'typography.fluid',
 	'typography.customFontSize',
+	'typography.defaultFontSizes',
 	'typography.dropCap',
 	'typography.fontFamilies',
 	'typography.fontSizes',
@@ -239,6 +240,7 @@ export function useSettingsForBlockElement(
 				...updatedSettings.typography,
 				fontSizes: {},
 				customFontSize: false,
+				defaultFontSizes: false,
 			};
 		}
 

packages/block-editor/src/components/global-styles/typography-panel.js

@@ -22,7 +22,7 @@ import TextTransformControl from '../text-transform-control';
 import TextDecorationControl from '../text-decoration-control';
 import WritingModeControl from '../writing-mode-control';
 import { getValueFromVariable, TOOLSPANEL_DROPDOWNMENU_PROPS } from './utils';
-import { setImmutably } from '../../utils/object';
+import { setImmutably, uniqByProperty } from '../../utils/object';
 
 const MIN_TEXT_COLUMNS = 1;
 const MAX_TEXT_COLUMNS = 6;
@@ -53,7 +53,10 @@ export function useHasTypographyPanel( settings ) {
 
 function useHasFontSizeControl( settings ) {
 	return (
-		hasMergedOrigins( settings?.typography?.fontSizes ) ||
+		( settings?.typography?.defaultFontSizes !== false &&
+			settings?.typography?.fontSizes?.default?.length ) ||
+		settings?.typography?.fontSizes?.theme?.length ||
+		settings?.typography?.fontSizes?.custom?.length ||
 		settings?.typography?.customFontSize
 	);
 }
@@ -100,16 +103,45 @@ function useHasTextColumnsControl( settings ) {
 	return settings?.typography?.textColumns;
 }
 
-function getUniqueFontSizesBySlug( settings ) {
-	const fontSizes = settings?.typography?.fontSizes;
-	const mergedFontSizes = fontSizes ? mergeOrigins( fontSizes ) : [];
-	const uniqueSizes = [];
-	for ( const currentSize of mergedFontSizes ) {
-		if ( ! uniqueSizes.some( ( { slug } ) => slug === currentSize.slug ) ) {
-			uniqueSizes.push( currentSize );
-		}
-	}
-	return uniqueSizes;
+/**
+ * TODO: The reversing and filtering of default font sizes is a hack so the
+ * dropdown UI matches what is generated in the global styles CSS stylesheet.
+ *
+ * This is a temporary solution until #57733 is resolved. At which point,
+ * the mergedFontSizes would just need to be the concatenated array of all
+ * presets or a custom dropdown with sections for each.
+ *
+ * @see {@link https://github.com/WordPress/gutenberg/issues/57733}
+ *
+ * @param {Object} settings The global styles settings.
+ *
+ * @return {Array} The merged font sizes.
+ */
+function getMergedFontSizes( settings ) {
+	// The font size presets are merged in reverse order so that the duplicates
+	// that may defined later in the array have higher priority to match the CSS.
+	const mergedFontSizesAll = uniqByProperty(
+		[
+			settings?.typography?.fontSizes?.custom,
+			settings?.typography?.fontSizes?.theme,
+			settings?.typography?.fontSizes?.default,
+		].flatMap( ( presets ) => presets?.toReversed() ?? [] ),
+		'slug'
+	).reverse();
+
+	// Default presets exist in the global styles CSS no matter the setting, so
+	// filtering them out in the UI has to be done after merging.
+	const mergedFontSizes =
+		settings?.typography?.defaultFontSizes === false
+			? mergedFontSizesAll.filter(
+					( { slug } ) =>
+						! [ 'small', 'medium', 'large', 'x-large' ].includes(
+							slug
+						)
+			  )
+			: mergedFontSizesAll;
+
+	return mergedFontSizes;
 }
 
 function TypographyToolsPanel( {
@@ -185,7 +217,7 @@ export default function TypographyPanel( {
 	// Font Size
 	const hasFontSizeEnabled = useHasFontSizeControl( settings );
 	const disableCustomFontSizes = ! settings?.typography?.customFontSize;
-	const mergedFontSizes = getUniqueFontSizesBySlug( settings );
+	const mergedFontSizes = getMergedFontSizes( settings );
 
 	const fontSize = decodeValue( inheritedValue?.typography?.fontSize );
 	const setFontSize = ( newValue, metadata ) => {

packages/block-editor/src/hooks/utils.js

@@ -177,7 +177,10 @@ export function useBlockSettings( name, parentLayout ) {
 		backgroundImage,
 		backgroundSize,
 		fontFamilies,
-		fontSizes,
+		userFontSizes,
+		themeFontSizes,
+		defaultFontSizes,
+		defaultFontSizesEnabled,
 		customFontSize,
 		fontStyle,
 		fontWeight,
@@ -224,7 +227,10 @@ export function useBlockSettings( name, parentLayout ) {
 		'background.backgroundImage',
 		'background.backgroundSize',
 		'typography.fontFamilies',
-		'typography.fontSizes',
+		'typography.fontSizes.custom',
+		'typography.fontSizes.theme',
+		'typography.fontSizes.default',
+		'typography.defaultFontSizes',
 		'typography.customFontSize',
 		'typography.fontStyle',
 		'typography.fontWeight',
@@ -308,9 +314,12 @@ export function useBlockSettings( name, parentLayout ) {
 					custom: fontFamilies,
 				},
 				fontSizes: {
-					custom: fontSizes,
+					custom: userFontSizes,
+					theme: themeFontSizes,
+					default: defaultFontSizes,
 				},
 				customFontSize,
+				defaultFontSizes: defaultFontSizesEnabled,
 				fontStyle,
 				fontWeight,
 				lineHeight,
@@ -347,7 +356,10 @@ export function useBlockSettings( name, parentLayout ) {
 		backgroundImage,
 		backgroundSize,
 		fontFamilies,
-		fontSizes,
+		userFontSizes,
+		themeFontSizes,
+		defaultFontSizes,
+		defaultFontSizesEnabled,
 		customFontSize,
 		fontStyle,
 		fontWeight,

packages/block-editor/src/utils/object.js

@@ -49,3 +49,19 @@ export const getValueFromObjectPath = ( object, path, defaultValue ) => {
 	} );
 	return value ?? defaultValue;
 };
+
+/**
+ * Helper util to filter out objects with duplicate values for a given property.
+ *
+ * @param {Object[]} array    Array of objects to filter.
+ * @param {string}   property Property to filter unique values by.
+ *
+ * @return {Object[]} Array of objects with unique values for the specified property.
+ */
+export function uniqByProperty( array, property ) {
+	const seen = new Set();
+	return array.filter( ( item ) => {
+		const value = item[ property ];
+		return seen.has( value ) ? false : seen.add( value );
+	} );
+}

schemas/json/theme.json

@@ -489,6 +489,11 @@
 					"description": "Settings related to typography.",
 					"type": "object",
 					"properties": {
+						"defaultFontSizes": {
+							"description": "Allow users to choose font sizes from the default font size presets.",
+							"type": "boolean",
+							"default": true
+						},
 						"customFontSize": {
 							"description": "Allow users to set custom font sizes.",
 							"type": "boolean",