Partial support for custom elements

Author: peter-jerry-ye

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

@@ -0,0 +1,9 @@
+package org.scalajs.dom
+
+import scala.scalajs.js
+
+/** A AttachShadowRootOptions object represents additional options associated with Element.attachShadow. */
+trait AttachShadowRootOptions extends js.Object {
+  var mode: js.UndefOr[String] = js.undefined
+  var delegatesFocus: js.UndefOr[Boolean] = js.undefined
+}

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

@@ -0,0 +1,8 @@
+package org.scalajs.dom
+
+import scala.scalajs.js
+
+/** A CustomElementDefineOptions object represents additional options associated with CustomElementRegsitry.define. */
+trait CustomElementDefineOptions extends js.Object {
+  var `extends`: js.UndefOr[Boolean] = js.undefined
+}

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: CustomElementDefineOptions = 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: AttachShadowRootOptions): 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/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/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
 }