Add flex layout support to the block editor

lib/block-supports/layout.php

@@ -25,6 +25,56 @@ function gutenberg_register_layout_support( $block_type ) {
 	}
 }
 
+/**
+ * Generates the CSS corresponding to the provided layout.
+ *
+ * @param string $selector CSS selector.
+ * @param array  $layout   Layout object.
+ *
+ * @return string CSS style.
+ */
+function gutenberg_get_layout_style( $selector, $layout ) {
+	$layout_type = isset( $layout['type'] ) ? $layout['type'] : 'default';
+
+	$style = '';
+	if ( 'default' === $layout_type ) {
+		$content_size = isset( $layout['contentSize'] ) ? $layout['contentSize'] : null;
+		$wide_size    = isset( $layout['wideSize'] ) ? $layout['wideSize'] : null;
+
+		$all_max_width_value  = $content_size ? $content_size : $wide_size;
+		$wide_max_width_value = $wide_size ? $wide_size : $content_size;
+
+		// Make sure there is a single CSS rule, and all tags are stripped for security.
+		// TODO: Use `safecss_filter_attr` instead - once https://core.trac.wordpress.org/ticket/46197 is patched.
+		$all_max_width_value  = wp_strip_all_tags( explode( ';', $all_max_width_value )[0] );
+		$wide_max_width_value = wp_strip_all_tags( explode( ';', $wide_max_width_value )[0] );
+
+		$style = '';
+		if ( $content_size || $wide_size ) {
+			$style  = "$selector > * {";
+			$style .= 'max-width: ' . esc_html( $all_max_width_value ) . ';';
+			$style .= 'margin-left: auto !important;';
+			$style .= 'margin-right: auto !important;';
+			$style .= '}';
+
+			$style .= "$selector > .alignwide { max-width: " . esc_html( $wide_max_width_value ) . ';}';
+
+			$style .= "$selector .alignfull { max-width: none; }";
+		}
+
+		$style .= "$selector .alignleft { float: left; margin-right: 2em; }";
+		$style .= "$selector .alignright { float: right; margin-left: 2em; }";
+	} elseif ( 'flex' === $layout_type ) {
+		$style  = "$selector {";
+		$style .= 'display: flex;';
+		$style .= 'column-gap: 0.5em;';
+		$style .= 'align-items: center;';
+		$style .= '}';
+	}
+
+	return $style;
+}
+
 /**
  * Renders the layout config to the block wrapper.
  *
@@ -49,34 +99,8 @@ function gutenberg_render_layout_support_flag( $block_content, $block ) {
 		$used_layout = $default_layout;
 	}
 
-	$id           = uniqid();
-	$content_size = isset( $used_layout['contentSize'] ) ? $used_layout['contentSize'] : null;
-	$wide_size    = isset( $used_layout['wideSize'] ) ? $used_layout['wideSize'] : null;
-
-	$all_max_width_value  = $content_size ? $content_size : $wide_size;
-	$wide_max_width_value = $wide_size ? $wide_size : $content_size;
-
-	// Make sure there is a single CSS rule, and all tags are stripped for security.
-	// TODO: Use `safecss_filter_attr` instead - once https://core.trac.wordpress.org/ticket/46197 is patched.
-	$all_max_width_value  = wp_strip_all_tags( explode( ';', $all_max_width_value )[0] );
-	$wide_max_width_value = wp_strip_all_tags( explode( ';', $wide_max_width_value )[0] );
-
-	$style = '';
-	if ( $content_size || $wide_size ) {
-		$style  = ".wp-container-$id > * {";
-		$style .= 'max-width: ' . esc_html( $all_max_width_value ) . ';';
-		$style .= 'margin-left: auto !important;';
-		$style .= 'margin-right: auto !important;';
-		$style .= '}';
-
-		$style .= ".wp-container-$id > .alignwide { max-width: " . esc_html( $wide_max_width_value ) . ';}';
-
-		$style .= ".wp-container-$id .alignfull { max-width: none; }";
-	}
-
-	$style .= ".wp-container-$id .alignleft { float: left; margin-right: 2em; }";
-	$style .= ".wp-container-$id .alignright { float: right; margin-left: 2em; }";
-
+	$id    = uniqid();
+	$style = gutenberg_get_layout_style( ".wp-container-$id", $used_layout );
 	// This assumes the hook only applies to blocks with a single wrapper.
 	// I think this is a reasonable limitation for that particular hook.
 	$content = preg_replace(
@@ -99,17 +123,17 @@ function () use ( $style ) {
 	return $content;
 }
 
-// This can be removed when plugin support requires WordPress 5.8.0+.
-if ( ! function_exists( 'wp_render_layout_support_flag' ) ) {
-	// Register the block support.
-	WP_Block_Supports::get_instance()->register(
-		'layout',
-		array(
-			'register_attribute' => 'gutenberg_register_layout_support',
-		)
-	);
-	add_filter( 'render_block', 'gutenberg_render_layout_support_flag', 10, 2 );
+// Register the block support. (overrides core one).
+WP_Block_Supports::get_instance()->register(
+	'layout',
+	array(
+		'register_attribute' => 'gutenberg_register_layout_support',
+	)
+);
+if ( function_exists( 'wp_render_layout_support_flag' ) ) {
+	remove_filter( 'render_block', 'wp_render_layout_support_flag' );
 }
+add_filter( 'render_block', 'gutenberg_render_layout_support_flag', 10, 2 );
 
 /**
  * For themes without theme.json file, make sure

packages/block-editor/src/components/block-alignment-control/use-available-alignments.js

@@ -8,22 +8,35 @@ import { useSelect } from '@wordpress/data';
  */
 import { useLayout } from '../block-list/layout';
 import { store as blockEditorStore } from '../../store';
+import { getLayoutType } from '../../layouts';
 
 const DEFAULT_CONTROLS = [ 'left', 'center', 'right', 'wide', 'full' ];
 const WIDE_CONTROLS = [ 'wide', 'full' ];
 
 export default function useAvailableAlignments( controls = DEFAULT_CONTROLS ) {
-	const { wideControlsEnabled = false } = useSelect( ( select ) => {
-		const { getSettings } = select( blockEditorStore );
-		const settings = getSettings();
-		return {
-			wideControlsEnabled: settings.alignWide,
-		};
-	}, [] );
+	const { wideControlsEnabled = false, themeSupportsLayout } = useSelect(
+		( select ) => {
+			const { getSettings } = select( blockEditorStore );
+			const settings = getSettings();
+			return {
+				wideControlsEnabled: settings.alignWide,
+				themeSupportsLayout: settings.supportsLayout,
+			};
+		},
+		[]
+	);
 	const layout = useLayout();
-	const supportsAlignments = layout.type === 'default';
+	const layoutType = getLayoutType( layout?.type );
+	const layoutAlignments = layoutType.getAlignments( layout );
+
+	if ( themeSupportsLayout ) {
+		return layoutAlignments.filter( ( control ) =>
+			controls.includes( control )
+		);
+	}
 
-	if ( ! supportsAlignments ) {
+	// Starting here, it's the fallback for themes not supporting the layout config.
+	if ( layoutType.name !== 'default' ) {
 		return [];
 	}
 	const { alignments: availableAlignments = DEFAULT_CONTROLS } = layout;

packages/block-editor/src/components/block-list/layout.js

@@ -3,26 +3,15 @@
  */
 import { createContext, useContext } from '@wordpress/element';
 
+/**
+ * Internal dependencies
+ */
+import { getLayoutType } from '../../layouts';
+
 export const defaultLayout = { type: 'default' };
 
 const Layout = createContext( defaultLayout );
 
-function appendSelectors( selectors, append ) {
-	// Ideally we shouldn't need the `.editor-styles-wrapper` increased specificity here
-	// The problem though is that we have a `.editor-styles-wrapper p { margin: reset; }` style
-	// it's used to reset the default margin added by wp-admin to paragraphs
-	// so we need this to be higher speficity otherwise, it won't be applied to paragraphs inside containers
-	// When the post editor is fully iframed, this extra classname could be removed.
-
-	return selectors
-		.split( ',' )
-		.map(
-			( subselector ) =>
-				`.editor-styles-wrapper ${ subselector } ${ append }`
-		)
-		.join( ',' );
-}
-
 /**
  * Allows to define the layout.
  */
@@ -35,39 +24,12 @@ export function useLayout() {
 	return useContext( Layout );
 }
 
-export function LayoutStyle( { selector, layout = {} } ) {
-	const { contentSize, wideSize } = layout;
-
-	let style =
-		!! contentSize || !! wideSize
-			? `
-				${ appendSelectors( selector, '> *' ) } {
-					max-width: ${ contentSize ?? wideSize };
-					margin-left: auto !important;
-					margin-right: auto !important;
-				}
-
-				${ appendSelectors( selector, '> [data-align="wide"]' ) }  {
-					max-width: ${ wideSize ?? contentSize };
-				}
-
-				${ appendSelectors( selector, '> [data-align="full"]' ) } {
-					max-width: none;
-				}
-			`
-			: '';
-
-	style += `
-		${ appendSelectors( selector, '> [data-align="left"]' ) } {
-			float: left;
-			margin-right: 2em;
-		}
+export function LayoutStyle( { layout = {}, ...props } ) {
+	const layoutType = getLayoutType( layout.type );
 
-		${ appendSelectors( selector, '> [data-align="right"]' ) } {
-			float: right;
-			margin-left: 2em;
-		}
-	`;
+	if ( layoutType ) {
+		return <layoutType.save layout={ layout } { ...props } />;
+	}
 
-	return <style>{ style }</style>;
+	return null;
 }

packages/block-editor/src/components/block-list/style.scss

@@ -251,15 +251,6 @@
 	&[data-clear="true"] {
 		float: none;
 	}
-
-	// This essentially duplicates the mobile styles for the appender component.
-	// It would be nice to be able to use element queries in that component instead https://github.com/tomhodgins/element-queries-spec
-	.block-editor-block-list__layout {
-		.block-editor-default-block-appender .block-editor-inserter {
-			left: auto;
-			right: $grid-unit-10;
-		}
-	}
 }
 
 .is-outline-mode .block-editor-block-list__block:not(.remove-outline) {

packages/block-editor/src/components/default-block-appender/index.js

@@ -1,3 +1,8 @@
+/**
+ * External dependencies
+ */
+import classnames from 'classnames';
+
 /**
  * WordPress dependencies
  */
@@ -37,7 +42,9 @@ export function DefaultBlockAppender( {
 	return (
 		<div
 			data-root-client-id={ rootClientId || '' }
-			className="block-editor-default-block-appender"
+			className={ classnames( 'block-editor-default-block-appender', {
+				'has-visible-prompt': showPrompt,
+			} ) }
 		>
 			<p
 				tabIndex="0"

packages/block-editor/src/components/default-block-appender/style.scss

@@ -38,8 +38,6 @@
 // Left side.
 .block-editor-block-list__empty-block-inserter,
 .block-editor-default-block-appender .block-editor-inserter {
-	right: $grid-unit-10; // Show to the right on mobile.
-
 	@include break-small {
 		display: flex;
 		height: 100%;
@@ -49,3 +47,8 @@
 		display: none;
 	}
 }
+
+.block-editor-default-block-appender.has-visible-prompt .block-editor-inserter,
+.block-editor-block-list__empty-block-inserter {
+	right: 0;
+}

packages/block-editor/src/components/default-block-appender/test/__snapshots__/index.js.snap

@@ -2,7 +2,7 @@
 
 exports[`DefaultBlockAppender should append a default block when input focused 1`] = `
 <div
-  className="block-editor-default-block-appender"
+  className="block-editor-default-block-appender has-visible-prompt"
   data-root-client-id=""
 >
   <p
@@ -38,7 +38,7 @@ exports[`DefaultBlockAppender should append a default block when input focused 1
 
 exports[`DefaultBlockAppender should match snapshot 1`] = `
 <div
-  className="block-editor-default-block-appender"
+  className="block-editor-default-block-appender has-visible-prompt"
   data-root-client-id=""
 >
   <p

packages/block-editor/src/components/inner-blocks/index.js

@@ -55,7 +55,8 @@ function UncontrolledInnerBlocks( props ) {
 		allowedBlocks,
 		templateLock,
 		captureToolbars,
-		orientation
+		orientation,
+		__experimentalLayout
 	);
 
 	useInnerBlockTemplateSync(

packages/block-editor/src/components/inner-blocks/use-nested-settings-update.js

@@ -9,6 +9,7 @@ import isShallowEqual from '@wordpress/is-shallow-equal';
  * Internal dependencies
  */
 import { store as blockEditorStore } from '../../store';
+import { getLayoutType } from '../../layouts';
 
 /**
  * This hook is a side effect which updates the block-editor store when changes
@@ -27,13 +28,15 @@ import { store as blockEditorStore } from '../../store';
  *                                   the child block.
  * @param {string}   orientation     The direction in which the block
  *                                   should face.
+ * @param {Object}   layout          The layout object for the block container.
  */
 export default function useNestedSettingsUpdate(
 	clientId,
 	allowedBlocks,
 	templateLock,
 	captureToolbars,
-	orientation
+	orientation,
+	layout
 ) {
 	const { updateBlockListSettings } = useDispatch( blockEditorStore );
 
@@ -71,8 +74,13 @@ export default function useNestedSettingsUpdate(
 			newSettings.__experimentalCaptureToolbars = captureToolbars;
 		}
 
+		// Orientation depends on layout,
+		// ideally the separate orientation prop should be deprecated.
 		if ( orientation !== undefined ) {
 			newSettings.orientation = orientation;
+		} else {
+			const layoutType = getLayoutType( layout?.type );
+			newSettings.orientation = layoutType.getOrientation( layout );
 		}
 
 		if ( ! isShallowEqual( blockListSettings, newSettings ) ) {
@@ -87,5 +95,6 @@ export default function useNestedSettingsUpdate(
 		captureToolbars,
 		orientation,
 		updateBlockListSettings,
+		layout,
 	] );
 }