Editor: Introduce sticky position block support.

In the Gutenberg plugin, a position block support feature was introduced last year, that allows a Group block to be set to a "sticky" position, meaning that when the page scrolls, the block will stick to the top of the window.

This change merges the "sticky" position feature for blocks introduced in Gutenberg 15.0.

Props andrewserong, flixos90, mukesh27.
Fixes #57618.
Built from https://develop.svn.wordpress.org/trunk@55285


git-svn-id: http://core.svn.wordpress.org/trunk@54818 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-theme-json.php

@@ -304,7 +304,8 @@ class WP_Theme_JSON {
 	 *              and `typography`, and renamed others according to the new schema.
 	 * @since 6.0.0 Added `color.defaultDuotone`.
 	 * @since 6.1.0 Added `layout.definitions` and `useRootPaddingAwareAlignments`.
-	 * @since 6.2.0 Added `dimensions.minHeight`, 'shadow.presets', and 'shadow.defaultPresets'.
+	 * @since 6.2.0 Added `dimensions.minHeight`, 'shadow.presets', 'shadow.defaultPresets',
+	 *              `position.fixed` and `position.sticky`.
 	 * @var array
 	 */
 	const VALID_SETTINGS = array(
@@ -339,6 +340,10 @@ class WP_Theme_JSON {
 			'definitions' => null,
 			'wideSize'    => null,
 		),
+		'position'                      => array(
+			'fixed'  => null,
+			'sticky' => null,
+		),
 		'spacing'                       => array(
 			'customSpacingSize' => null,
 			'spacingSizes'      => null,
@@ -513,7 +518,7 @@ public static function get_element_class_name( $element ) {
 	 * Options that settings.appearanceTools enables.
 	 *
 	 * @since 6.0.0
-	 * @since 6.2.0 Added `dimensions.minHeight`.
+	 * @since 6.2.0 Added `dimensions.minHeight` and `position.sticky`.
 	 * @var array
 	 */
 	const APPEARANCE_TOOLS_OPT_INS = array(
@@ -523,6 +528,7 @@ public static function get_element_class_name( $element ) {
 		array( 'border', 'width' ),
 		array( 'color', 'link' ),
 		array( 'dimensions', 'minHeight' ),
+		array( 'position', 'sticky' ),
 		array( 'spacing', 'blockGap' ),
 		array( 'spacing', 'margin' ),
 		array( 'spacing', 'padding' ),

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.2-alpha-55284';
+$wp_version = '6.2-alpha-55285';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.

wp-settings.php

@@ -336,6 +336,7 @@
 require ABSPATH . WPINC . '/block-supports/elements.php';
 require ABSPATH . WPINC . '/block-supports/generated-classname.php';
 require ABSPATH . WPINC . '/block-supports/layout.php';
+require ABSPATH . WPINC . '/block-supports/position.php';
 require ABSPATH . WPINC . '/block-supports/spacing.php';
 require ABSPATH . WPINC . '/block-supports/typography.php';
 require ABSPATH . WPINC . '/block-supports/settings.php';