Improve cover z-index solution

packages/base-styles/_z-index.scss

@@ -31,12 +31,14 @@ $z-layers: (
 	".interface-interface-skeleton__header": 30,
 	".interface-interface-skeleton__content": 20,
 	".edit-widgets-header": 30,
-	".wp-block-cover__inner-container": 1, // InnerBlocks area inside cover image block.
+
 	".wp-block-cover.is-placeholder .components-placeholder.is-large": 1, // Cover block resizer component inside a large placeholder.
+	// These z-index are now used only for a deprecated version of the cover block.
+	".wp-block-cover__inner-container": 1, // InnerBlocks area inside cover image block.
 	".wp-block-cover.has-background-dim::before": 1, // Overlay area inside block cover need to be higher than the video background.
-	".block-library-cover__padding-visualizer": 2, // BoxControl visualizer needs to be +1 higher than .wp-block-cover.has-background-dim::before
 	".wp-block-cover__image-background": 0, // Image background inside cover block.
 	".wp-block-cover__video-background": 0, // Video background inside cover block.
+
 	".wp-block-template-part__placeholder-preview-filter-input": 1,
 
 	// Fixed position appender:

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

@@ -164,7 +164,7 @@ const v8ToV11BlockAttributes = {
 	},
 };
 
-const v12BlockAttributes = {
+const v12toV13BlockAttributes = {
 	...v8ToV11BlockAttributes,
 	useFeaturedImage: {
 		type: 'boolean',
@@ -176,6 +176,20 @@ const v12BlockAttributes = {
 	},
 };
 
+const v14BlockAttributes = {
+	...v12toV13BlockAttributes,
+	isUserOverlayColor: {
+		type: 'boolean',
+	},
+	sizeSlug: {
+		type: 'string',
+	},
+	alt: {
+		type: 'string',
+		default: '',
+	},
+};
+
 const v7toV11BlockSupports = {
 	anchor: true,
 	align: true,
@@ -244,9 +258,173 @@ const v12BlockSupports = {
 	},
 };
 
+const v14BlockSupports = {
+	...v12BlockSupports,
+	shadow: true,
+	dimensions: {
+		aspectRatio: true,
+	},
+	interactivity: {
+		clientNavigation: true,
+	},
+};
+
+// Deprecation for blocks that have z-index.
+const v14 = {
+	attributes: v14BlockAttributes,
+	supports: v14BlockSupports,
+	save( { attributes } ) {
+		const {
+			backgroundType,
+			gradient,
+			contentPosition,
+			customGradient,
+			customOverlayColor,
+			dimRatio,
+			focalPoint,
+			useFeaturedImage,
+			hasParallax,
+			isDark,
+			isRepeated,
+			overlayColor,
+			url,
+			alt,
+			id,
+			minHeight: minHeightProp,
+			minHeightUnit,
+			tagName: Tag,
+			sizeSlug,
+		} = attributes;
+		const overlayColorClass = getColorClassName(
+			'background-color',
+			overlayColor
+		);
+		const gradientClass = __experimentalGetGradientClass( gradient );
+		const minHeight =
+			minHeightProp && minHeightUnit
+				? `${ minHeightProp }${ minHeightUnit }`
+				: minHeightProp;
+
+		const isImageBackground = IMAGE_BACKGROUND_TYPE === backgroundType;
+		const isVideoBackground = VIDEO_BACKGROUND_TYPE === backgroundType;
+
+		const isImgElement = ! ( hasParallax || isRepeated );
+
+		const style = {
+			minHeight: minHeight || undefined,
+		};
+
+		const bgStyle = {
+			backgroundColor: ! overlayColorClass
+				? customOverlayColor
+				: undefined,
+			background: customGradient ? customGradient : undefined,
+		};
+
+		const objectPosition =
+			// prettier-ignore
+			focalPoint && isImgElement
+				  ? mediaPosition(focalPoint)
+				  : undefined;
+
+		const backgroundImage = url ? `url(${ url })` : undefined;
+
+		const backgroundPosition = mediaPosition( focalPoint );
+
+		const classes = clsx(
+			{
+				'is-light': ! isDark,
+				'has-parallax': hasParallax,
+				'is-repeated': isRepeated,
+				'has-custom-content-position':
+					! isContentPositionCenter( contentPosition ),
+			},
+			getPositionClassName( contentPosition )
+		);
+
+		const imgClasses = clsx(
+			'wp-block-cover__image-background',
+			id ? `wp-image-${ id }` : null,
+			{
+				[ `size-${ sizeSlug }` ]: sizeSlug,
+				'has-parallax': hasParallax,
+				'is-repeated': isRepeated,
+			}
+		);
+
+		const gradientValue = gradient || customGradient;
+
+		return (
+			<Tag { ...useBlockProps.save( { className: classes, style } ) }>
+				<span
+					aria-hidden="true"
+					className={ clsx(
+						'wp-block-cover__background',
+						overlayColorClass,
+						dimRatioToClass( dimRatio ),
+						{
+							'has-background-dim': dimRatio !== undefined,
+							// For backwards compatibility. Former versions of the Cover Block applied
+							// `.wp-block-cover__gradient-background` in the presence of
+							// media, a gradient and a dim.
+							'wp-block-cover__gradient-background':
+								url && gradientValue && dimRatio !== 0,
+							'has-background-gradient': gradientValue,
+							[ gradientClass ]: gradientClass,
+						}
+					) }
+					style={ bgStyle }
+				/>
+
+				{ ! useFeaturedImage &&
+					isImageBackground &&
+					url &&
+					( isImgElement ? (
+						<img
+							className={ imgClasses }
+							alt={ alt }
+							src={ url }
+							style={ { objectPosition } }
+							data-object-fit="cover"
+							data-object-position={ objectPosition }
+						/>
+					) : (
+						<div
+							role={ alt ? 'img' : undefined }
+							aria-label={ alt ? alt : undefined }
+							className={ imgClasses }
+							style={ { backgroundPosition, backgroundImage } }
+						/>
+					) ) }
+				{ isVideoBackground && url && (
+					<video
+						className={ clsx(
+							'wp-block-cover__video-background',
+							'intrinsic-ignore'
+						) }
+						autoPlay
+						muted
+						loop
+						playsInline
+						src={ url }
+						style={ { objectPosition } }
+						data-object-fit="cover"
+						data-object-position={ objectPosition }
+					/>
+				) }
+				<div
+					{ ...useInnerBlocksProps.save( {
+						className: 'wp-block-cover__inner-container',
+					} ) }
+				/>
+			</Tag>
+		);
+	},
+};
+
 // Deprecation for blocks that does not have the aria-label when the image background is fixed or repeated.
 const v13 = {
-	attributes: v12BlockAttributes,
+	attributes: v12toV13BlockAttributes,
 	supports: v12BlockSupports,
 	save( { attributes } ) {
 		const {
@@ -396,7 +574,7 @@ const v13 = {
 
 // Deprecation for blocks to prevent auto overlay color from overriding previously set values.
 const v12 = {
-	attributes: v12BlockAttributes,
+	attributes: v12toV13BlockAttributes,
 	supports: v12BlockSupports,
 	isEligible( attributes ) {
 		return (
@@ -1824,4 +2002,4 @@ const v1 = {
 	},
 };
 
-export default [ v13, v12, v11, v10, v9, v8, v7, v6, v5, v4, v3, v2, v1 ];
+export default [ v14, v13, v12, v11, v10, v9, v8, v7, v6, v5, v4, v3, v2, v1 ];

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

@@ -528,27 +528,6 @@ function CoverEdit( {
 				data-url={ url }
 			>
 				{ resizeListener }
-				{ showOverlay && (
-					<span
-						aria-hidden="true"
-						className={ clsx(
-							'wp-block-cover__background',
-							dimRatioToClass( dimRatio ),
-							{
-								[ overlayColor.class ]: overlayColor.class,
-								'has-background-dim': dimRatio !== undefined,
-								// For backwards compatibility. Former versions of the Cover Block applied
-								// `.wp-block-cover__gradient-background` in the presence of
-								// media, a gradient and a dim.
-								'wp-block-cover__gradient-background':
-									url && gradientValue && dimRatio !== 0,
-								'has-background-gradient': gradientValue,
-								[ gradientClass ]: gradientClass,
-							}
-						) }
-						style={ { backgroundImage: gradientValue, ...bgStyle } }
-					/>
-				) }
 
 				{ ! url && useFeaturedImage && (
 					<Placeholder
@@ -590,7 +569,31 @@ function CoverEdit( {
 						style={ mediaStyle }
 					/>
 				) }
+
+				{ showOverlay && (
+					<span
+						aria-hidden="true"
+						className={ clsx(
+							'wp-block-cover__background',
+							dimRatioToClass( dimRatio ),
+							{
+								[ overlayColor.class ]: overlayColor.class,
+								'has-background-dim': dimRatio !== undefined,
+								// For backwards compatibility. Former versions of the Cover Block applied
+								// `.wp-block-cover__gradient-background` in the presence of
+								// media, a gradient and a dim.
+								'wp-block-cover__gradient-background':
+									url && gradientValue && dimRatio !== 0,
+								'has-background-gradient': gradientValue,
+								[ gradientClass ]: gradientClass,
+							}
+						) }
+						style={ { backgroundImage: gradientValue, ...bgStyle } }
+					/>
+				) }
+
 				{ isUploadingMedia && <Spinner /> }
+
 				<CoverPlaceholder
 					disableMediaButtons
 					onSelectMedia={ onSelectMedia }

packages/block-library/src/cover/editor.scss

@@ -37,12 +37,15 @@
 			width: 100%;
 			z-index: 1;
 		}
+
+		.wp-block-cover__inner-container {
+			z-index: 2;
+		}
 	}
 
 	// Shown while media is being uploaded
 	.components-spinner {
 		position: absolute;
-		z-index: z-index(".wp-block-cover__inner-container");
 		top: 50%;
 		left: 50%;
 		transform: translate(-50%, -50%); // Account for spinner dimensions

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

@@ -106,26 +106,6 @@ export default function save( { attributes } ) {
 
 	return (
 		<Tag { ...useBlockProps.save( { className: classes, style } ) }>
-			<span
-				aria-hidden="true"
-				className={ clsx(
-					'wp-block-cover__background',
-					overlayColorClass,
-					dimRatioToClass( dimRatio ),
-					{
-						'has-background-dim': dimRatio !== undefined,
-						// For backwards compatibility. Former versions of the Cover Block applied
-						// `.wp-block-cover__gradient-background` in the presence of
-						// media, a gradient and a dim.
-						'wp-block-cover__gradient-background':
-							url && gradientValue && dimRatio !== 0,
-						'has-background-gradient': gradientValue,
-						[ gradientClass ]: gradientClass,
-					}
-				) }
-				style={ bgStyle }
-			/>
-
 			{ ! useFeaturedImage &&
 				isImageBackground &&
 				url &&
@@ -162,6 +142,33 @@ export default function save( { attributes } ) {
 					data-object-position={ objectPosition }
 				/>
 			) }
+
+			{ /* The `wp-block-cover__background` needs to be immediately before
+			the `wp-block-cover__inner-container`, so the exclusion CSS selector
+			`.wp-block-cover__background + .wp-block-cover__inner-container`
+			works properly. If it needs to be changed in the future, the
+			selector for the backward compatibility for v14 deprecation also
+			needs change. */ }
+			<span
+				aria-hidden="true"
+				className={ clsx(
+					'wp-block-cover__background',
+					overlayColorClass,
+					dimRatioToClass( dimRatio ),
+					{
+						'has-background-dim': dimRatio !== undefined,
+						// For backwards compatibility. Former versions of the Cover Block applied
+						// `.wp-block-cover__gradient-background` in the presence of
+						// media, a gradient and a dim.
+						'wp-block-cover__gradient-background':
+							url && gradientValue && dimRatio !== 0,
+						'has-background-gradient': gradientValue,
+						[ gradientClass ]: gradientClass,
+					}
+				) }
+				style={ bgStyle }
+			/>
+
 			<div
 				{ ...useInnerBlocksProps.save( {
 					className: 'wp-block-cover__inner-container',