Bug 1404842 - Implement Element.attachShadow and Element.slot

Tag #1375

dom/base/Element.cpp

@@ -1092,9 +1092,78 @@ Element::RemoveFromIdTable()
   }
 }
 
+void
+Element::SetSlot(const nsAString& aName, ErrorResult& aError)
+{
+  aError = SetAttr(kNameSpaceID_None, nsGkAtoms::slot, aName, true);
+}
+
+void
+Element::GetSlot(nsAString& aName)
+{
+  GetAttr(kNameSpaceID_None, nsGkAtoms::slot, aName);
+}
+
+// https://dom.spec.whatwg.org/#dom-element-attachshadow
+already_AddRefed<ShadowRoot>
+Element::AttachShadow(const ShadowRootInit& aInit, ErrorResult& aError)
+{
+  /**
+   * 1. If context object’s namespace is not the HTML namespace,
+   *    then throw a "NotSupportedError" DOMException.
+   */
+  if (!IsHTMLElement()) {
+    aError.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
+    return nullptr;
+  }
+
+  /**
+   * 2. If context object’s local name is not
+   *      a valid custom element name, "article", "aside", "blockquote",
+   *      "body", "div", "footer", "h1", "h2", "h3", "h4", "h5", "h6",
+   *      "header", "main" "nav", "p", "section", or "span",
+   *    then throw a "NotSupportedError" DOMException.
+   */
+  nsIAtom* nameAtom = NodeInfo()->NameAtom();
+  if (!(nsContentUtils::IsCustomElementName(nameAtom) ||
+        nameAtom == nsGkAtoms::article ||
+        nameAtom == nsGkAtoms::aside ||
+        nameAtom == nsGkAtoms::blockquote ||
+        nameAtom == nsGkAtoms::body ||
+        nameAtom == nsGkAtoms::div ||
+        nameAtom == nsGkAtoms::footer ||
+        nameAtom == nsGkAtoms::h1 ||
+        nameAtom == nsGkAtoms::h2 ||
+        nameAtom == nsGkAtoms::h3 ||
+        nameAtom == nsGkAtoms::h4 ||
+        nameAtom == nsGkAtoms::h5 ||
+        nameAtom == nsGkAtoms::h6 ||
+        nameAtom == nsGkAtoms::header ||
+        nameAtom == nsGkAtoms::main ||
+        nameAtom == nsGkAtoms::nav ||
+        nameAtom == nsGkAtoms::p ||
+        nameAtom == nsGkAtoms::section ||
+        nameAtom == nsGkAtoms::span)) {
+    aError.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
+    return nullptr;
+  }
+
+  return AttachShadowInternal(aInit.mMode == ShadowRootMode::Closed, aError);
+}
+
 already_AddRefed<ShadowRoot>
 Element::CreateShadowRoot(ErrorResult& aError)
 {
+  return AttachShadowInternal(false, aError);
+}
+
+already_AddRefed<ShadowRoot>
+Element::AttachShadowInternal(bool aClosed, ErrorResult& aError)
+{
+  /**
+   * 3. If context object is a shadow host, then throw
+   *    an "InvalidStateError" DOMException.
+   */
   if (GetShadowRoot()) {
     aError.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
     return nullptr;
@@ -1131,11 +1200,19 @@ Element::CreateShadowRoot(ErrorResult& aError)
   // Calling SetPrototypeBinding takes ownership of protoBinding.
   docInfo->SetPrototypeBinding(NS_LITERAL_CSTRING("shadowroot"), protoBinding);
 
-  RefPtr<ShadowRoot> shadowRoot = new ShadowRoot(this, nodeInfo.forget(),
-                                                   protoBinding);
+  /**
+   * 4. Let shadow be a new shadow root whose node document is
+   *    context object’s node document, host is context object,
+   *    and mode is init’s mode.
+   */
+  RefPtr<ShadowRoot> shadowRoot =
+    new ShadowRoot(this, aClosed, nodeInfo.forget(), protoBinding);
 
   shadowRoot->SetIsComposedDocParticipant(IsInComposedDoc());
 
+  /**
+   * 5. Set context object’s shadow root to shadow.
+   */
   SetShadowRoot(shadowRoot);
 
   // xblBinding takes ownership of docInfo.
@@ -1145,6 +1222,9 @@ Element::CreateShadowRoot(ErrorResult& aError)
 
   SetXBLBinding(xblBinding);
 
+  /**
+   * 6. Return shadow.
+   */
   return shadowRoot.forget();
 }
 

dom/base/Element.h

@@ -471,6 +471,9 @@ protected:
     mState &= ~aStates;
   }
 
+  already_AddRefed<ShadowRoot> AttachShadowInternal(bool aClosed,
+                                                    ErrorResult& aError);
+
 private:
   // Need to allow the ESM, nsGlobalWindow, and the focus manager to
   // set our state
@@ -921,6 +924,13 @@ public:
   already_AddRefed<DOMRectList> GetClientRects();
   already_AddRefed<DOMRect> GetBoundingClientRect();
 
+  // Shadow DOM v1
+  already_AddRefed<ShadowRoot> AttachShadow(const ShadowRootInit& aInit,
+                                            ErrorResult& aError);
+  void SetSlot(const nsAString& aName, ErrorResult& aError);
+  void GetSlot(nsAString& aName);
+
+  // [deprecated] Shadow DOM v0
   already_AddRefed<ShadowRoot> CreateShadowRoot(ErrorResult& aError);
   already_AddRefed<DestinationInsertionPointList> GetDestinationInsertionPoints();
 

dom/base/ShadowRoot.cpp

@@ -51,7 +51,7 @@ NS_INTERFACE_MAP_END_INHERITING(DocumentFragment)
 NS_IMPL_ADDREF_INHERITED(ShadowRoot, DocumentFragment)
 NS_IMPL_RELEASE_INHERITED(ShadowRoot, DocumentFragment)
 
-ShadowRoot::ShadowRoot(Element* aElement,
+ShadowRoot::ShadowRoot(Element* aElement, bool aClosed,
                        already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
                        nsXBLPrototypeBinding* aProtoBinding)
   : DocumentFragment(aNodeInfo)
@@ -60,6 +60,7 @@ ShadowRoot::ShadowRoot(Element* aElement,
   , mIsComposedDocParticipant(false)
 {
   SetHost(aElement);
+  mMode = aClosed ? ShadowRootMode::Closed : ShadowRootMode::Open;
 
   // Nodes in a shadow tree should never store a value
   // in the subtree root pointer, nodes in the shadow tree

dom/base/ShadowRoot.h

@@ -41,10 +41,18 @@ public:
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
 
-  ShadowRoot(Element* aElement,
+  ShadowRoot(Element* aElement, bool aClosed,
              already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
              nsXBLPrototypeBinding* aProtoBinding);
 
+  // Shadow DOM v1
+  Element* Host();
+  ShadowRootMode Mode()
+  {
+    return mMode;
+  }
+
+  // [deprecated] Shadow DOM v0
   void AddToIdTable(Element* aElement, nsIAtom* aId);
   void RemoveFromIdTable(Element* aElement, nsIAtom* aId);
   void InsertSheet(StyleSheet* aSheet, nsIContent* aLinkingContent);
@@ -121,7 +129,6 @@ public:
     GetElementsByClassName(const nsAString& aClasses);
   void GetInnerHTML(nsAString& aInnerHTML);
   void SetInnerHTML(const nsAString& aInnerHTML, ErrorResult& aError);
-  Element* Host();
   void StyleSheetChanged();
 
   bool IsComposedDocParticipant() { return mIsComposedDocParticipant; }
@@ -133,6 +140,8 @@ public:
 protected:
   virtual ~ShadowRoot();
 
+  ShadowRootMode mMode;
+
   // An array of content insertion points that are a descendant of the ShadowRoot
   // sorted in tree order. Insertion points are responsible for notifying
   // the ShadowRoot when they are removed or added as a descendant. The insertion