Partial façade for custom element support

dom/src/main/scala-2/org/scalajs/dom/ShadowRootMode.scala

@@ -0,0 +1,11 @@
+package org.scalajs.dom
+
+import scala.scalajs.js
+
+@js.native
+sealed trait ShadowRootMode extends js.Any
+
+object ShadowRootMode {
+  val open: ShadowRootMode = "open".asInstanceOf[ShadowRootMode]
+  val closed: ShadowRootMode = "closed".asInstanceOf[ShadowRootMode]
+}

dom/src/main/scala-3/org/scalajs/dom/ShadowRootMode.scala

@@ -0,0 +1,8 @@
+package org.scalajs.dom
+
+opaque type ShadowRootMode <: String = String
+
+object ShadowRootMode {
+  val open: ShadowRootMode = "open"
+  val closed: ShadowRootMode = "closed"
+}

dom/src/main/scala/org/scalajs/dom/CustomElementRegistry.scala

@@ -0,0 +1,21 @@
+/** All documentation for facades is thanks to Mozilla Contributors at https://developer.mozilla.org/en-US/docs/Web/API
+  * and available under the Creative Commons Attribution-ShareAlike v2.5 or later.
+  * http://creativecommons.org/licenses/by-sa/2.5/
+  *
+  * Everything else is under the MIT License http://opensource.org/licenses/MIT
+  */
+package org.scalajs.dom
+
+import scala.scalajs.js
+import scala.scalajs.js.annotation._
+
+/** The CustomElementRegistry interface provides methods for registering custom elements and querying registered
+  * elements. To get an instance of it, use the window.customElements property.
+  */
+@js.native
+@JSGlobal
+abstract class CustomElementRegistry extends js.Object {
+
+  /** Defines a new custom element. */
+  def define(name: String, constructor: js.Dynamic, options: ElementDefinitionOptions = js.native): Unit
+}

dom/src/main/scala/org/scalajs/dom/Element.scala

@@ -259,4 +259,10 @@ abstract class Element extends Node with NodeSelector with ParentNode with NonDo
     * pointerlockerror events at the Document level.
     */
   def requestPointerLock(): Unit = js.native
+
+  /** Attaches a shadow DOM tree to the specified element and returns a reference to its ShadowRoot. */
+  def attachShadow(init: ShadowRootInit): ShadowRoot = js.native
+
+  /** Returns the open shadow root that is hosted by the element, or null if no open shadow root is present. */
+  def shadowRoot: ShadowRoot = js.native
 }

dom/src/main/scala/org/scalajs/dom/ElementDefinitionOptions.scala

@@ -0,0 +1,10 @@
+package org.scalajs.dom
+
+import scala.scalajs.js
+
+/** An ElementDefinitionOptions object represents additional options associated with CustomElementRegsitry.define. */
+trait ElementDefinitionOptions extends js.Object {
+
+  /** String specifying the name of a built-in element to extend. Used to create a customized built-in element. */
+  var `extends`: js.UndefOr[String] = js.undefined
+}

dom/src/main/scala/org/scalajs/dom/HTMLTemplateElement.scala

@@ -0,0 +1,21 @@
+/** All documentation for facades is thanks to Mozilla Contributors at https://developer.mozilla.org/en-US/docs/Web/API
+  * and available under the Creative Commons Attribution-ShareAlike v2.5 or later.
+  * http://creativecommons.org/licenses/by-sa/2.5/
+  *
+  * Everything else is under the MIT License http://opensource.org/licenses/MIT
+  */
+package org.scalajs.dom
+
+import scala.scalajs.js
+import scala.scalajs.js.annotation._
+
+/** The HTMLTemplateElement interface enables access to the contents of an HTML <template> element. */
+@js.native
+@JSGlobal
+abstract class HTMLTemplateElement extends HTMLElement {
+
+  /** A read-only DocumentFragment which contains the DOM subtree representing the <template> element's template
+    * contents.
+    */
+  def content: DocumentFragment = js.native
+}

dom/src/main/scala/org/scalajs/dom/ShadowRoot.scala

@@ -0,0 +1,24 @@
+/** All documentation for facades is thanks to Mozilla Contributors at https://developer.mozilla.org/en-US/docs/Web/API
+  * and available under the Creative Commons Attribution-ShareAlike v2.5 or later.
+  * http://creativecommons.org/licenses/by-sa/2.5/
+  *
+  * Everything else is under the MIT License http://opensource.org/licenses/MIT
+  */
+package org.scalajs.dom
+
+import scala.scalajs.js
+import scala.scalajs.js.annotation._
+
+/** The ShadowRoot interface of the Shadow DOM API is the root node of a DOM subtree that is rendered separately from a
+  * document's main DOM tree.
+  *
+  * You can retrieve a reference to an element's shadow root using its Element.shadowRoot property, provided it was
+  * created using Element.attachShadow() with the mode option set to open.
+  */
+@js.native
+@JSGlobal
+abstract class ShadowRoot extends DocumentFragment {
+
+  /** Returns the Element within the shadow tree that has focus. */
+  def activeElement: Element = js.native
+}

dom/src/main/scala/org/scalajs/dom/ShadowRootInit.scala

@@ -0,0 +1,23 @@
+package org.scalajs.dom
+
+import scala.scalajs.js
+
+/** A ShadowRootInit object represents additional options associated with Element.attachShadow. */
+trait ShadowRootInit extends js.Object {
+
+  /** A string specifying the encapsulation mode for the shadow DOM tree. This can be one of:
+    *
+    * open: Elements of the shadow root are accessible from JavaScript outside the root, for example using
+    * Element.shadowRoot: element.shadowRoot; // Returns a ShadowRoot obj
+    *
+    * closed: Denies access to the node(s) of a closed shadow root from JavaScript outside it: element.shadowRoot; //
+    * Returns null
+    */
+  var mode: ShadowRootMode
+
+  /** A boolean that, when set to true, specifies behavior that mitigates custom element issues around focusability.
+    * When a non-focusable part of the shadow DOM is clicked, the first focusable part is given focus, and the shadow
+    * host is given any available :focus styling.
+    */
+  var delegatesFocus: js.UndefOr[Boolean] = js.undefined
+}

dom/src/main/scala/org/scalajs/dom/Window.scala

@@ -445,4 +445,9 @@ class Window
     * number. You can get the number of pixels the document is scrolled horizontally from the scrollX property.
     */
   def scrollY: Double = js.native
+
+  /** Returns a reference to the CustomElementRegistry object, which can be used to register new custom elements and get
+    * information about previously registered custom elements.
+    */
+  def customElements: CustomElementRegistry = js.native
 }