rebase from live enviornment

wp/plugins/divi-builder/includes/builder/scripts/frontend/background-layout.js

@@ -0,0 +1,48 @@
+// External dependencies
+import $ from 'jquery';
+
+/**
+ * Toggle background-layout classname of current module and/or its child modules.
+ *
+ * @since 4.6.0
+ *
+ * @param {object} $module
+ * @param {bool} status
+ */
+export const toggleAllBackgroundLayoutClassnameOnSticky = ($module, status) => {
+  // Toggle background-layout classname if it is on current $module
+  if ($module.is($('[data-background-layout-sticky]'))) {
+    toggleBackgroundLayoutClassnameOnSticky($module, status);
+  }
+
+  // Toggle background-layout classname if it is child module of current module
+  if ($module.find('[data-background-layout-sticky]').length > 0) {
+    $module.find('[data-background-layout-sticky]').each(function() {
+      toggleBackgroundLayoutClassnameOnSticky($(this), status);
+    });
+  }
+};
+
+/**
+ * Toggle background-layout classname of current module.
+ *
+ * @since 4.6.0
+ *
+ * @param {object} $module
+ * @param {bool} status
+ */
+export const toggleBackgroundLayoutClassnameOnSticky = ($module, status) => {
+  const attrPrefix      = status ? '-sticky' : '';
+  const allClassnames   = 'et_pb_bg_layout_dark et_pb_bg_layout_light';
+  const layoutColor     = $module.attr(`data-background-layout${attrPrefix}`);
+  const layoutClassname = `et_pb_bg_layout_${layoutColor}`;
+
+  let $target = $module;
+
+  // Switch the target element for some modules.
+  if ($module.hasClass('et_pb_slide')) {
+    $target = $module.closest('.et_pb_slider');
+  }
+
+  $target.removeClass(allClassnames).addClass(layoutClassname);
+};