Image: Improve focus management in lightbox (#55428)

* Improve focus management

This commit removes the logic to set focus differently
based on event.pointerType and instead sets focus on the
dialog itself when the lightbox opens, and on the lightbox
trigger when the lightbox closes.

* Add delay before focusing when closing lightbox

* Put focus back on close button when opening lightbox

It turns out that placing focus on the modal was causing
inconsistent behavior in Safari, so I've put the focus back
on the close button when the lightbox opens, which
performs predictably.

I've also added a tabindex to the image, which prevents
the focus ring from erroneously showing when opening the lightbox
with a mouse in Chrome and Firefox.

* Move focus to the dialog when opening the lightbox.

* Fix SVG markup.

* Consistent indentation with spaces.

* Remove unnecessary tabindex

---------

Co-authored-by: Andrea Fercia <a.fercia@gmail.com>

packages/block-library/src/image/index.php

@@ -235,6 +235,7 @@ function block_core_image_render_lightbox( $block_content, $block ) {
 	$button =
 		$img[0]
 		. '<button
+			class="lightbox-trigger"
 			type="button"
 			aria-haspopup="dialog"
 			aria-label="' . esc_attr( $aria_label ) . '"
@@ -243,7 +244,7 @@ function block_core_image_render_lightbox( $block_content, $block ) {
 			data-wp-style--top="context.core.image.imageButtonTop"
 			style="background: #000"
 		>
-			<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="#FFFFFF">
+			<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" aria-hidden="true" focusable="false">
 				<Path stroke="#FFFFFF" d="M6 4a2 2 0 0 0-2 2v3h1.5V6a.5.5 0 0 1 .5-.5h3V4H6Zm3 14.5H6a.5.5 0 0 1-.5-.5v-3H4v3a2 2 0 0 0 2 2h3v-1.5Zm6 1.5v-1.5h3a.5.5 0 0 0 .5-.5v-3H20v3a2 2 0 0 1-2 2h-3Zm3-16a2 2 0 0 1 2 2v3h-1.5V6a.5.5 0 0 0-.5-.5h-3V4h3Z" />
 			</svg>
 		</button>';
@@ -319,12 +320,13 @@ function block_core_image_render_lightbox( $block_content, $block ) {
             data-wp-on--touchmove="actions.core.image.handleTouchMove"
             data-wp-on--touchend="actions.core.image.handleTouchEnd"
             data-wp-on--click="actions.core.image.hideLightbox"
+            tabindex="-1"
             >
                 <button type="button" aria-label="$close_button_label" style="fill: $close_button_color" class="close-button" data-wp-on--click="actions.core.image.hideLightbox">
                     $close_button_icon
                 </button>
                 <div class="lightbox-image-container">$initial_image_content</div>
-				<div class="lightbox-image-container">$enlarged_image_content</div>
+                <div class="lightbox-image-container">$enlarged_image_content</div>
                 <div class="scrim" style="background-color: $background_color" aria-hidden="true"></div>
         </div>
 HTML;

packages/block-library/src/image/view.js

@@ -135,7 +135,7 @@ store(
 							false
 						);
 					},
-					hideLightbox: async ( { context, event } ) => {
+					hideLightbox: async ( { context } ) => {
 						context.core.image.hideAnimationEnabled = true;
 						if ( context.core.image.lightboxEnabled ) {
 							// We want to wait until the close animation is completed
@@ -149,19 +149,15 @@ store(
 									'scroll',
 									scrollCallback
 								);
+								// If we don't delay before changing the focus,
+								// the focus ring will appear on Firefox before
+								// the image has finished animating, which looks broken.
+								context.core.image.lightboxTriggerRef.focus( {
+									preventScroll: true,
+								} );
 							}, 450 );
 
 							context.core.image.lightboxEnabled = false;
-
-							// We want to avoid drawing attention to the button
-							// after the lightbox closes for mouse and touch users.
-							// Note that the `event.pointerType` property returns
-							// as an empty string if a keyboard fired the event.
-							if ( event.pointerType === '' ) {
-								context.core.image.lastFocusedElement.focus( {
-									preventScroll: true,
-								} );
-							}
 						}
 					},
 					handleKeydown: ( { context, actions, event } ) => {
@@ -266,6 +262,10 @@ store(
 				image: {
 					initOriginImage: ( { context, ref } ) => {
 						context.core.image.imageRef = ref;
+						context.core.image.lightboxTriggerRef =
+							ref.parentElement.querySelector(
+								'.lightbox-trigger'
+							);
 						if ( ref.complete ) {
 							context.core.image.imageLoaded = true;
 							context.core.image.imageCurrentSrc = ref.currentSrc;
@@ -282,14 +282,8 @@ store(
 									focusableElements.length - 1
 								];
 
-							// We want to avoid drawing unnecessary attention to the close
-							// button for mouse and touch users. Note that even if opening
-							// the lightbox via keyboard, the event fired is of type
-							// `pointerEvent`, so we need to rely on the `event.pointerType`
-							// property, which returns an empty string for keyboard events.
-							if ( context.core.image.pointerType === '' ) {
-								ref.querySelector( '.close-button' ).focus();
-							}
+							// Move focus to the dialog when opening it.
+							ref.focus();
 						}
 					},
 					setButtonStyles: ( { context, ref } ) => {