1 files changed, 299 insertions, 0 deletions
diff --git a/dom/base/ShadowRoot.h b/dom/base/ShadowRoot.h
new file mode 100644
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--- /dev/null
+++ b/dom/base/ShadowRoot.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_shadowroot_h__
+#define mozilla_dom_shadowroot_h__
+
+#include "mozilla/DOMEventTargetHelper.h"
+#include "mozilla/dom/DocumentBinding.h"
+#include "mozilla/dom/DocumentFragment.h"
+#include "mozilla/dom/DocumentOrShadowRoot.h"
+#include "mozilla/dom/NameSpaceConstants.h"
+#include "mozilla/dom/ShadowRootBinding.h"
+#include "mozilla/ServoBindings.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsStubMutationObserver.h"
+#include "nsTHashtable.h"
+
+class nsAtom;
+class nsIContent;
+
+namespace mozilla {
+
+class EventChainPreVisitor;
+class ServoStyleRuleMap;
+
+enum class StyleRuleChangeKind : uint32_t;
+
+namespace css {
+class Rule;
+}
+
+namespace dom {
+
+class CSSImportRule;
+class Element;
+class HTMLInputElement;
+
+class ShadowRoot final : public DocumentFragment, public DocumentOrShadowRoot {
+  friend class DocumentOrShadowRoot;
+
+  using Declarative = Element::ShadowRootDeclarative;
+  using IsClonable = Element::ShadowRootClonable;
+
+ public:
+  NS_IMPL_FROMNODE_HELPER(ShadowRoot, IsShadowRoot());
+
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ShadowRoot, DocumentFragment)
+  NS_DECL_ISUPPORTS_INHERITED
+
+  ShadowRoot(Element* aElement, ShadowRootMode aMode,
+             Element::DelegatesFocus aDelegatesFocus,
+             SlotAssignmentMode aSlotAssignment, IsClonable aClonable,
+             Declarative aDeclarative,
+             already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
+
+  void AddSizeOfExcludingThis(nsWindowSizes&, size_t* aNodeSize) const final;
+
+  // Try to reassign an element or text to a slot.
+  void MaybeReassignContent(nsIContent& aElementOrText);
+  // Called when an element is inserted as a direct child of our host. Tries to
+  // slot the child in one of our slots.
+  void MaybeSlotHostChild(nsIContent&);
+  // Called when a direct child of our host is removed. Tries to un-slot the
+  // child from the currently-assigned slot, if any.
+  void MaybeUnslotHostChild(nsIContent&);
+
+  // Shadow DOM v1
+  Element* Host() const {
+    MOZ_ASSERT(GetHost(),
+               "ShadowRoot always has a host, how did we create "
+               "this ShadowRoot?");
+    return GetHost();
+  }
+
+  ShadowRootMode Mode() const { return mMode; }
+  bool DelegatesFocus() const {
+    return mDelegatesFocus == Element::DelegatesFocus::Yes;
+  }
+  SlotAssignmentMode SlotAssignment() const { return mSlotAssignment; }
+  bool Clonable() const { return mIsClonable == IsClonable::Yes; }
+  bool IsClosed() const { return mMode == ShadowRootMode::Closed; }
+
+  void RemoveSheetFromStyles(StyleSheet&);
+  void RuleAdded(StyleSheet&, css::Rule&);
+  void RuleRemoved(StyleSheet&, css::Rule&);
+  void RuleChanged(StyleSheet&, css::Rule*, StyleRuleChangeKind);
+  void ImportRuleLoaded(CSSImportRule&, StyleSheet&);
+  void SheetCloned(StyleSheet&);
+  void StyleSheetApplicableStateChanged(StyleSheet&);
+
+  /**
+   * Clones internal state, for example stylesheets, of aOther to 'this'.
+   */
+  void CloneInternalDataFrom(ShadowRoot* aOther);
+  void InsertSheetAt(size_t aIndex, StyleSheet&);
+
+  // Calls UnbindFromTree for each of our kids, and also flags us as no longer
+  // being connected.
+  void Unbind();
+
+  // Only intended for UA widgets / special shadow roots, or for handling
+  // failure cases when adopting (see BlastSubtreeToPieces).
+  //
+  // Forgets our shadow host and unbinds all our kids.
+  void Unattach();
+
+  // Calls BindToTree on each of our kids, and also maybe flags us as being
+  // connected.
+  nsresult Bind();
+
+  /**
+   * Explicitly invalidates the style and layout of the flattened-tree subtree
+   * rooted at the element.
+   *
+   * You need to use this whenever the flat tree is going to be shuffled in a
+   * way that layout doesn't understand via the usual ContentInserted /
+   * ContentAppended / ContentRemoved notifications. For example, if removing an
+   * element will cause a change in the flat tree such that other element will
+   * start showing up (like fallback content), this method needs to be called on
+   * an ancestor of that element.
+   *
+   * It is important that this runs _before_ actually shuffling the flat tree
+   * around, so that layout knows the actual tree that it needs to invalidate.
+   */
+  void InvalidateStyleAndLayoutOnSubtree(Element*);
+
+ private:
+  void InsertSheetIntoAuthorData(size_t aIndex, StyleSheet&,
+                                 const nsTArray<RefPtr<StyleSheet>>&);
+
+  void AppendStyleSheet(StyleSheet& aSheet) {
+    InsertSheetAt(SheetCount(), aSheet);
+  }
+
+  /**
+   * Represents the insertion point in a slot for a given node.
+   */
+  struct SlotInsertionPoint {
+    HTMLSlotElement* mSlot = nullptr;
+    Maybe<uint32_t> mIndex;
+
+    SlotInsertionPoint() = default;
+    SlotInsertionPoint(HTMLSlotElement* aSlot, const Maybe<uint32_t>& aIndex)
+        : mSlot(aSlot), mIndex(aIndex) {}
+  };
+
+  /**
+   * Return the assignment corresponding to the content node at this particular
+   * point in time.
+   *
+   * It's the caller's responsibility to actually call InsertAssignedNode /
+   * AppendAssignedNode in the slot as needed.
+   */
+  SlotInsertionPoint SlotInsertionPointFor(nsIContent&);
+
+  /**
+   * Returns the effective slot name for a given slottable. In most cases, this
+   * is just the value of the slot attribute, if any, or the empty string, but
+   * this also deals with the <details> shadow tree specially.
+   */
+  void GetSlotNameFor(const nsIContent&, nsAString&) const;
+
+  /**
+   * Re-assign the current main summary if it has changed.
+   *
+   * Must be called only if mIsDetailsShadowTree is true.
+   */
+  enum class SummaryChangeReason { Deletion, Insertion };
+  void MaybeReassignMainSummary(SummaryChangeReason);
+
+ public:
+  void AddSlot(HTMLSlotElement* aSlot);
+  void RemoveSlot(HTMLSlotElement* aSlot);
+  bool HasSlots() const { return !mSlotMap.IsEmpty(); };
+  HTMLSlotElement* GetDefaultSlot() const {
+    SlotArray* list = mSlotMap.Get(u""_ns);
+    return list ? (*list)->ElementAt(0) : nullptr;
+  }
+
+  void PartAdded(const Element&);
+  void PartRemoved(const Element&);
+
+  IMPL_EVENT_HANDLER(slotchange);
+
+  const nsTArray<const Element*>& Parts() const { return mParts; }
+
+  const StyleAuthorStyles* GetServoStyles() const { return mServoStyles.get(); }
+
+  StyleAuthorStyles* GetServoStyles() { return mServoStyles.get(); }
+
+  mozilla::ServoStyleRuleMap& ServoStyleRuleMap();
+
+  JSObject* WrapNode(JSContext*, JS::Handle<JSObject*> aGivenProto) final;
+
+  void NodeInfoChanged(Document* aOldDoc) override;
+
+  void AddToIdTable(Element* aElement, nsAtom* aId);
+  void RemoveFromIdTable(Element* aElement, nsAtom* aId);
+
+  // WebIDL methods.
+  using mozilla::dom::DocumentOrShadowRoot::GetElementById;
+
+  Element* GetActiveElement();
+
+  /**
+   * These methods allow UA Widget to insert DOM elements into the Shadow ROM
+   * without putting their DOM reflectors to content scope first.
+   * The inserted DOM will have their reflectors in the UA Widget scope.
+   */
+  nsINode* ImportNodeAndAppendChildAt(nsINode& aParentNode, nsINode& aNode,
+                                      bool aDeep, mozilla::ErrorResult& rv);
+
+  nsINode* CreateElementAndAppendChildAt(nsINode& aParentNode,
+                                         const nsAString& aTagName,
+                                         mozilla::ErrorResult& rv);
+
+  bool IsUAWidget() const { return HasBeenInUAWidget(); }
+
+  void SetIsUAWidget() {
+    MOZ_ASSERT(!HasChildren());
+    SetIsNativeAnonymousRoot();
+    SetFlags(NODE_HAS_BEEN_IN_UA_WIDGET);
+  }
+
+  bool IsAvailableToElementInternals() const {
+    return mIsAvailableToElementInternals;
+  }
+
+  void SetAvailableToElementInternals() {
+    mIsAvailableToElementInternals = true;
+  }
+
+  void GetEventTargetParent(EventChainPreVisitor& aVisitor) override;
+
+  bool IsDeclarative() const { return mIsDeclarative == Declarative::Yes; }
+  void SetIsDeclarative(Declarative aIsDeclarative) {
+    mIsDeclarative = aIsDeclarative;
+  }
+  void SetIsDeclarative(bool aIsDeclarative) {
+    mIsDeclarative = aIsDeclarative ? Declarative::Yes : Declarative::No;
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void SetHTMLUnsafe(const nsAString& aHTML);
+
+ protected:
+  // FIXME(emilio): This will need to become more fine-grained.
+  void ApplicableRulesChanged();
+
+  virtual ~ShadowRoot();
+
+  // Make sure that the first field is pointer-aligned so it doesn't get packed
+  // in the base class' padding, since otherwise rust-bindgen can't generate
+  // correct bindings for it, see
+  // https://github.com/rust-lang/rust-bindgen/issues/380
+
+  // The computed data from the style sheets.
+  UniquePtr<StyleAuthorStyles> mServoStyles;
+  UniquePtr<mozilla::ServoStyleRuleMap> mStyleRuleMap;
+
+  using SlotArray = TreeOrderedArray<HTMLSlotElement*>;
+  // Map from name of slot to an array of all slots in the shadow DOM with with
+  // the given name. The slots are stored as a weak pointer because the elements
+  // are in the shadow tree and should be kept alive by its parent.
+  nsClassHashtable<nsStringHashKey, SlotArray> mSlotMap;
+
+  // Unordered array of all elements that have a part attribute in this shadow
+  // tree.
+  nsTArray<const Element*> mParts;
+
+  const ShadowRootMode mMode;
+
+  Element::DelegatesFocus mDelegatesFocus;
+
+  const SlotAssignmentMode mSlotAssignment;
+
+  // Whether this is the <details> internal shadow tree.
+  bool mIsDetailsShadowTree : 1;
+
+  // https://dom.spec.whatwg.org/#shadowroot-available-to-element-internals
+  bool mIsAvailableToElementInternals : 1;
+
+  // https://dom.spec.whatwg.org/#shadowroot-declarative
+  Declarative mIsDeclarative;
+
+  // https://dom.spec.whatwg.org/#shadowroot-clonable
+  const IsClonable mIsClonable;
+
+  nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_shadowroot_h__