[RNMobile] Cover block: Support isDark attribute

packages/block-library/src/cover/edit.js

@@ -2,8 +2,7 @@
  * External dependencies
  */
 import classnames from 'classnames';
-import FastAverageColor from 'fast-average-color';
-import { colord, extend } from 'colord';
+import { extend } from 'colord';
 import namesPlugin from 'colord/plugins/names';
 
 /**
@@ -73,6 +72,7 @@ import {
 	isContentPositionCenter,
 	getPositionClassName,
 } from './shared';
+import useCoverIsDark from './use-cover-is-dark';
 
 extend( [ namesPlugin ] );
 
@@ -89,13 +89,6 @@ function getInnerBlocksTemplate( attributes ) {
 	];
 }
 
-function retrieveFastAverageColor() {
-	if ( ! retrieveFastAverageColor.fastAverageColor ) {
-		retrieveFastAverageColor.fastAverageColor = new FastAverageColor();
-	}
-	return retrieveFastAverageColor.fastAverageColor;
-}
-
 function CoverHeightInput( {
 	onChange,
 	onUnitChange,
@@ -197,55 +190,6 @@ function ResizableCover( {
 	);
 }
 
-/**
- * useCoverIsDark is a hook that returns a boolean variable specifying if the cover
- * background is dark or not.
- *
- * @param {?string} url          Url of the media background.
- * @param {?number} dimRatio     Transparency of the overlay color. If an image and
- *                               color are set, dimRatio is used to decide what is used
- *                               for background darkness checking purposes.
- * @param {?string} overlayColor String containing the overlay color value if one exists.
- * @param {?Object} elementRef   If a media background is set, elementRef should contain a reference to a
- *                               dom element that renders that media.
- *
- * @return {boolean} True if the cover background is considered "dark" and false otherwise.
- */
-function useCoverIsDark( url, dimRatio = 50, overlayColor, elementRef ) {
-	const [ isDark, setIsDark ] = useState( false );
-	useEffect( () => {
-		// If opacity is lower than 50 the dominant color is the image or video color,
-		// so use that color for the dark mode computation.
-		if ( url && dimRatio <= 50 && elementRef.current ) {
-			retrieveFastAverageColor().getColorAsync(
-				elementRef.current,
-				( color ) => {
-					setIsDark( color.isDark );
-				}
-			);
-		}
-	}, [ url, url && dimRatio <= 50 && elementRef.current, setIsDark ] );
-	useEffect( () => {
-		// If opacity is greater than 50 the dominant color is the overlay color,
-		// so use that color for the dark mode computation.
-		if ( dimRatio > 50 || ! url ) {
-			if ( ! overlayColor ) {
-				// If no overlay color exists the overlay color is black (isDark )
-				setIsDark( true );
-				return;
-			}
-			setIsDark( colord( overlayColor ).isDark() );
-		}
-	}, [ overlayColor, dimRatio > 50 || ! url, setIsDark ] );
-	useEffect( () => {
-		if ( ! url && ! overlayColor ) {
-			// Reset isDark.
-			setIsDark( false );
-		}
-	}, [ ! url && ! overlayColor, setIsDark ] );
-	return isDark;
-}
-
 function mediaPosition( { x, y } ) {
 	return `${ Math.round( x * 100 ) }% ${ Math.round( y * 100 ) }%`;
 }

packages/block-library/src/cover/edit.native.js

@@ -9,6 +9,7 @@ import {
 	Platform,
 } from 'react-native';
 import Video from 'react-native-video';
+import classnames from 'classnames/dedupe';
 
 /**
  * WordPress dependencies
@@ -47,7 +48,7 @@ import {
 	store as blockEditorStore,
 } from '@wordpress/block-editor';
 import { compose, withPreferredColorScheme } from '@wordpress/compose';
-import { withSelect, withDispatch } from '@wordpress/data';
+import { useDispatch, withSelect, withDispatch } from '@wordpress/data';
 import {
 	useEffect,
 	useState,
@@ -71,6 +72,7 @@ import {
 	COVER_DEFAULT_HEIGHT,
 } from './shared';
 import Controls from './controls';
+import useCoverIsDark from './use-cover-is-dark';
 
 /**
  * Constants
@@ -113,6 +115,7 @@ const Cover = ( {
 		customGradient,
 		gradient,
 		overlayColor,
+		isDark,
 	} = attributes;
 	const [ isScreenReaderEnabled, setIsScreenReaderEnabled ] = useState(
 		false
@@ -180,18 +183,6 @@ const Cover = ( {
 
 	const openMediaOptionsRef = useRef();
 
-	// Used to set a default color for its InnerBlocks
-	// since there's no system to inherit styles yet
-	// the RichText component will check if there are
-	// parent styles for the current block. If there are,
-	// it will use that color instead.
-	useEffect( () => {
-		// While we don't support theme colors.
-		if ( ! attributes.overlayColor || ( ! attributes.overlay && url ) ) {
-			setAttributes( { childrenStyles: styles.defaultColor } );
-		}
-	}, [ setAttributes ] );
-
 	// Initialize uploading flag to false, awaiting sync.
 	const [ isUploadInProgress, setIsUploadInProgress ] = useState( false );
 
@@ -257,6 +248,42 @@ const Cover = ( {
 		openGeneralSidebar();
 	}
 
+	const { __unstableMarkNextChangeAsNotPersistent } = useDispatch(
+		blockEditorStore
+	);
+	const isCoverDark = useCoverIsDark(
+		isDark,
+		url,
+		dimRatio,
+		overlayColorValue?.color
+	);
+
+	useEffect( () => {
+		// This side-effect should not create an undo level.
+		__unstableMarkNextChangeAsNotPersistent();
+		// Used to set a default color for its InnerBlocks
+		// since there's no system to inherit styles yet
+		// the RichText component will check if there are
+		// parent styles for the current block. If there are,
+		// it will use that color instead.
+		setAttributes( {
+			isDark: isCoverDark,
+			childrenStyles: isCoverDark
+				? styles.defaultColor
+				: styles.defaultColorLightMode,
+		} );
+
+		// Ensure that "is-light" is removed from "className" attribute if cover background is dark.
+		if ( isCoverDark && attributes.className?.includes( 'is-light' ) ) {
+			const className = classnames( attributes.className, {
+				'is-light': false,
+			} );
+			setAttributes( {
+				className: className !== '' ? className : undefined,
+			} );
+		}
+	}, [ isCoverDark ] );
+
 	const backgroundColor = getStylesFromColorScheme(
 		styles.backgroundSolid,
 		styles.backgroundSolidDark

packages/block-library/src/cover/style.native.scss

@@ -49,6 +49,10 @@
 	color: $white;
 }
 
+.defaultColorLightMode {
+	color: $black;
+}
+
 .background {
 	width: 100%;
 	height: 100%;

packages/block-library/src/cover/test/__snapshots__/edit.native.js.snap

@@ -1,8 +1,8 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`color settings clears the selected overlay color and mantains the inner blocks 1`] = `
-"<!-- wp:cover -->
-<div class=\\"wp-block-cover\\"><span aria-hidden=\\"true\\" class=\\"wp-block-cover__background has-background-dim-100 has-background-dim\\"></span><div class=\\"wp-block-cover__inner-container\\"><!-- wp:paragraph {\\"align\\":\\"center\\",\\"placeholder\\":\\"Write title…\\"} -->
+"<!-- wp:cover {\\"isDark\\":false} -->
+<div class=\\"wp-block-cover is-light\\"><span aria-hidden=\\"true\\" class=\\"wp-block-cover__background has-background-dim-100 has-background-dim\\"></span><div class=\\"wp-block-cover__inner-container\\"><!-- wp:paragraph {\\"align\\":\\"center\\",\\"placeholder\\":\\"Write title…\\"} -->
 <p class=\\"has-text-align-center\\"></p>
 <!-- /wp:paragraph --></div></div>
 <!-- /wp:cover -->"
@@ -17,16 +17,16 @@ exports[`color settings sets a color for the overlay background when the placeho
 `;
 
 exports[`color settings sets a gradient overlay background when a solid background was already selected 1`] = `
-"<!-- wp:cover {\\"gradient\\":\\"light-green-cyan-to-vivid-green-cyan\\"} -->
-<div class=\\"wp-block-cover\\"><span aria-hidden=\\"true\\" class=\\"wp-block-cover__background has-background-dim-100 has-background-dim has-background-gradient has-light-green-cyan-to-vivid-green-cyan-gradient-background\\"></span><div class=\\"wp-block-cover__inner-container\\"><!-- wp:paragraph {\\"align\\":\\"center\\",\\"placeholder\\":\\"Write title…\\"} -->
+"<!-- wp:cover {\\"gradient\\":\\"light-green-cyan-to-vivid-green-cyan\\",\\"isDark\\":false} -->
+<div class=\\"wp-block-cover is-light\\"><span aria-hidden=\\"true\\" class=\\"wp-block-cover__background has-background-dim-100 has-background-dim has-background-gradient has-light-green-cyan-to-vivid-green-cyan-gradient-background\\"></span><div class=\\"wp-block-cover__inner-container\\"><!-- wp:paragraph {\\"align\\":\\"center\\",\\"placeholder\\":\\"Write title…\\"} -->
 <p class=\\"has-text-align-center\\"></p>
 <!-- /wp:paragraph --></div></div>
 <!-- /wp:cover -->"
 `;
 
 exports[`color settings toggles between solid colors and gradients 1`] = `
-"<!-- wp:cover {\\"gradient\\":\\"light-green-cyan-to-vivid-green-cyan\\"} -->
-<div class=\\"wp-block-cover\\"><span aria-hidden=\\"true\\" class=\\"wp-block-cover__background has-background-dim-100 has-background-dim has-background-gradient has-light-green-cyan-to-vivid-green-cyan-gradient-background\\"></span><div class=\\"wp-block-cover__inner-container\\"><!-- wp:paragraph {\\"align\\":\\"center\\",\\"placeholder\\":\\"Write title…\\"} -->
+"<!-- wp:cover {\\"gradient\\":\\"light-green-cyan-to-vivid-green-cyan\\",\\"isDark\\":false} -->
+<div class=\\"wp-block-cover is-light\\"><span aria-hidden=\\"true\\" class=\\"wp-block-cover__background has-background-dim-100 has-background-dim has-background-gradient has-light-green-cyan-to-vivid-green-cyan-gradient-background\\"></span><div class=\\"wp-block-cover__inner-container\\"><!-- wp:paragraph {\\"align\\":\\"center\\",\\"placeholder\\":\\"Write title…\\"} -->
 <p class=\\"has-text-align-center\\"></p>
 <!-- /wp:paragraph --></div></div>
 <!-- /wp:cover -->"

packages/block-library/src/cover/use-cover-is-dark.js

@@ -0,0 +1,71 @@
+/**
+ * External dependencies
+ */
+import FastAverageColor from 'fast-average-color';
+import { colord } from 'colord';
+
+/**
+ * WordPress dependencies
+ */
+import { useEffect, useState } from '@wordpress/element';
+
+function retrieveFastAverageColor() {
+	if ( ! retrieveFastAverageColor.fastAverageColor ) {
+		retrieveFastAverageColor.fastAverageColor = new FastAverageColor();
+	}
+	return retrieveFastAverageColor.fastAverageColor;
+}
+
+/**
+ * useCoverIsDark is a hook that returns a boolean variable specifying if the cover
+ * background is dark or not.
+ *
+ * @param {?string} url          Url of the media background.
+ * @param {?number} dimRatio     Transparency of the overlay color. If an image and
+ *                               color are set, dimRatio is used to decide what is used
+ *                               for background darkness checking purposes.
+ * @param {?string} overlayColor String containing the overlay color value if one exists.
+ * @param {?Object} elementRef   If a media background is set, elementRef should contain a reference to a
+ *                               dom element that renders that media.
+ *
+ * @return {boolean} True if the cover background is considered "dark" and false otherwise.
+ */
+export default function useCoverIsDark(
+	url,
+	dimRatio = 50,
+	overlayColor,
+	elementRef
+) {
+	const [ isDark, setIsDark ] = useState( false );
+	useEffect( () => {
+		// If opacity is lower than 50 the dominant color is the image or video color,
+		// so use that color for the dark mode computation.
+		if ( url && dimRatio <= 50 && elementRef.current ) {
+			retrieveFastAverageColor().getColorAsync(
+				elementRef.current,
+				( color ) => {
+					setIsDark( color.isDark );
+				}
+			);
+		}
+	}, [ url, url && dimRatio <= 50 && elementRef.current, setIsDark ] );
+	useEffect( () => {
+		// If opacity is greater than 50 the dominant color is the overlay color,
+		// so use that color for the dark mode computation.
+		if ( dimRatio > 50 || ! url ) {
+			if ( ! overlayColor ) {
+				// If no overlay color exists the overlay color is black (isDark )
+				setIsDark( true );
+				return;
+			}
+			setIsDark( colord( overlayColor ).isDark() );
+		}
+	}, [ overlayColor, dimRatio > 50 || ! url, setIsDark ] );
+	useEffect( () => {
+		if ( ! url && ! overlayColor ) {
+			// Reset isDark.
+			setIsDark( false );
+		}
+	}, [ ! url && ! overlayColor, setIsDark ] );
+	return isDark;
+}

packages/block-library/src/cover/use-cover-is-dark.native.js

@@ -0,0 +1,51 @@
+/**
+ * External dependencies
+ */
+
+import { colord } from 'colord';
+
+/**
+ * WordPress dependencies
+ */
+import { useEffect, useState } from '@wordpress/element';
+
+/**
+ * useCoverIsDark is a hook that returns a boolean variable specifying if the cover
+ * background is dark or not.
+ *
+ * @param {?boolean} initialValue Initial value.
+ * @param {?string}  url          Url of the media background.
+ * @param {?number}  dimRatio     Transparency of the overlay color. If an image and
+ *                                color are set, dimRatio is used to decide what is used
+ *                                for background darkness checking purposes.
+ * @param {?string}  overlayColor String containing the overlay color value if one exists.
+ *
+ * @return {boolean} True if the cover background is considered "dark" and false otherwise.
+ */
+export default function useCoverIsDark(
+	initialValue = false,
+	url,
+	dimRatio = 50,
+	overlayColor
+) {
+	const [ isDark, setIsDark ] = useState( initialValue );
+	useEffect( () => {
+		// If opacity is greater than 50 the dominant color is the overlay color,
+		// so use that color for the dark mode computation.
+		if ( dimRatio > 50 || ! url ) {
+			if ( ! overlayColor ) {
+				// If no overlay color exists the overlay color is black (isDark )
+				setIsDark( true );
+				return;
+			}
+			setIsDark( colord( overlayColor ).isDark() );
+		}
+	}, [ overlayColor, dimRatio > 50 || ! url, setIsDark ] );
+	useEffect( () => {
+		if ( ! url && ! overlayColor ) {
+			// Reset isDark.
+			setIsDark( false );
+		}
+	}, [ ! url && ! overlayColor, setIsDark ] );
+	return isDark;
+}

packages/react-native-editor/CHANGELOG.md

@@ -11,6 +11,8 @@ For each user feature we should also add a importance categorization label  to i
 
 ## Unreleased
 
+-   [**] [Cover block] Improve color contrast between background and text [#40691]
+
 ## 1.75.0
 
 -   [*] [Latest Posts block] Add featured image settings [#39257]