wpseek.com
A WordPress-centric search engine for devs and theme authors

function block_core_gallery_get_responsive_aspect_ratio_style_rules( $selector, $viewport_style, $media_query ) {
	if ( ! is_array( $viewport_style ) || ! is_string( $media_query ) ) {
		return array();
	}

	$aspect_ratio = $viewport_style['aspectRatio'] ?? null;
	if ( ! block_core_gallery_is_valid_aspect_ratio( $aspect_ratio ) ) {
		return array();
	}

	$aspect_ratio = trim( $aspect_ratio );

	/*
	 * The base aspect ratio is an inline style on each image, so these
	 * declarations have to be important to win for the viewport.
	 *
	 * Original cancels the base ratio, which means rolling the declaration out
	 * of the cascade rather than giving it a value. `auto` - and `initial`,
	 * `unset` and `revert`, which all compute to it - would override the
	 * `width`/`height` presentational hint that gives a lazy-loaded image its
	 * placeholder ratio, collapsing the image to zero height until it loads:
	 * the Featured Image bug fixed in #80386. `revert-layer` drops the
	 * declaration instead, so the image falls back to that hint while loading,
	 * to its natural ratio once loaded, and to any ratio a theme set in a lower
	 * cascade layer. `object-fit` is left as the base set it, so a cropped
	 * Gallery still crops.
	 */
	$declarations = 'auto' === $aspect_ratio
		? array( 'aspect-ratio' => 'revert-layer !important' )
		: array(
			'aspect-ratio' => "{$aspect_ratio} !important",
			'object-fit'   => 'cover !important',
		);

	return array(
		array(
			'selector'     => "{$selector}.wp-block-gallery.has-nested-images figure.wp-block-image:not(#individual-image) img",
			'declarations' => $declarations,
			'rules_group'  => $media_query,
		),
	);
}