dom/base/ShadowRoot.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_shadowroot_h__
   8 #define mozilla_dom_shadowroot_h__
   9
  10 #include "mozilla/DOMEventTargetHelper.h"
  11 #include "mozilla/dom/DocumentBinding.h"
  12 #include "mozilla/dom/DocumentFragment.h"
  13 #include "mozilla/dom/DocumentOrShadowRoot.h"
  14 #include "mozilla/dom/NameSpaceConstants.h"
  15 #include "mozilla/dom/ShadowRootBinding.h"
  16 #include "mozilla/ServoBindings.h"
  17 #include "nsCOMPtr.h"
  18 #include "nsCycleCollectionParticipant.h"
  19 #include "nsStubMutationObserver.h"
  20 #include "nsTHashtable.h"
  21
  22 class nsAtom;
  23 class nsIContent;
  24
  25 namespace mozilla {
  26
  27 class EventChainPreVisitor;
  28 class ServoStyleRuleMap;
  29
  30 enum class StyleRuleChangeKind : uint32_t;
  31
  32 namespace css {
  33 class Rule;
  34 }
  35
  36 namespace dom {
  37
  38 class CSSImportRule;
  39 class Element;
  40 class HTMLInputElement;
  41
  42 class ShadowRoot final : public DocumentFragment, public DocumentOrShadowRoot {
  43   friend class DocumentOrShadowRoot;
  44
  45   using Declarative = Element::ShadowRootDeclarative;
  46   using IsClonable = Element::ShadowRootClonable;
  47   using IsSerializable = Element::ShadowRootSerializable;
  48
  49  public:
  50   NS_IMPL_FROMNODE_HELPER(ShadowRoot, IsShadowRoot());
  51
  52   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ShadowRoot, DocumentFragment)
  53   NS_DECL_ISUPPORTS_INHERITED
  54
  55   ShadowRoot(Element* aElement, ShadowRootMode aMode,
  56              Element::DelegatesFocus aDelegatesFocus,
  57              SlotAssignmentMode aSlotAssignment, IsClonable aClonable,
  58              IsSerializable aIsSerializable, Declarative aDeclarative,
  59              already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
  60
  61   void AddSizeOfExcludingThis(nsWindowSizes&, size_t* aNodeSize) const final;
  62
  63   // Try to reassign an element or text to a slot.
  64   void MaybeReassignContent(nsIContent& aElementOrText);
  65   // Called when an element is inserted as a direct child of our host. Tries to
  66   // slot the child in one of our slots.
  67   void MaybeSlotHostChild(nsIContent&);
  68   // Called when a direct child of our host is removed. Tries to un-slot the
  69   // child from the currently-assigned slot, if any.
  70   void MaybeUnslotHostChild(nsIContent&);
  71
  72   // Shadow DOM v1
  73   Element* Host() const {
  74     MOZ_ASSERT(GetHost(),
  75                "ShadowRoot always has a host, how did we create "
  76                "this ShadowRoot?");
  77     return GetHost();
  78   }
  79
  80   ShadowRootMode Mode() const { return mMode; }
  81   bool DelegatesFocus() const {
  82     return mDelegatesFocus == Element::DelegatesFocus::Yes;
  83   }
  84   SlotAssignmentMode SlotAssignment() const { return mSlotAssignment; }
  85   bool Clonable() const { return mIsClonable == IsClonable::Yes; }
  86   bool IsClosed() const { return mMode == ShadowRootMode::Closed; }
  87   bool Serializable() const { return mIsSerializable == IsSerializable::Yes; }
  88
  89   void RemoveSheetFromStyles(StyleSheet&);
  90   void RuleAdded(StyleSheet&, css::Rule&);
  91   void RuleRemoved(StyleSheet&, css::Rule&);
  92   void RuleChanged(StyleSheet&, css::Rule*, StyleRuleChangeKind);
  93   void ImportRuleLoaded(CSSImportRule&, StyleSheet&);
  94   void SheetCloned(StyleSheet&);
  95   void StyleSheetApplicableStateChanged(StyleSheet&);
  96
  97   /**
  98    * Clones internal state, for example stylesheets, of aOther to 'this'.
  99    */
 100   void CloneInternalDataFrom(ShadowRoot* aOther);
 101   void InsertSheetAt(size_t aIndex, StyleSheet&);
 102
 103   // Calls UnbindFromTree for each of our kids, and also flags us as no longer
 104   // being connected.
 105   void Unbind();
 106
 107   // Only intended for UA widgets / special shadow roots, or for handling
 108   // failure cases when adopting (see BlastSubtreeToPieces).
 109   //
 110   // Forgets our shadow host and unbinds all our kids.
 111   void Unattach();
 112
 113   // Calls BindToTree on each of our kids, and also maybe flags us as being
 114   // connected.
 115   nsresult Bind();
 116
 117   /**
 118    * Explicitly invalidates the style and layout of the flattened-tree subtree
 119    * rooted at the element.
 120    *
 121    * You need to use this whenever the flat tree is going to be shuffled in a
 122    * way that layout doesn't understand via the usual ContentInserted /
 123    * ContentAppended / ContentRemoved notifications. For example, if removing an
 124    * element will cause a change in the flat tree such that other element will
 125    * start showing up (like fallback content), this method needs to be called on
 126    * an ancestor of that element.
 127    *
 128    * It is important that this runs _before_ actually shuffling the flat tree
 129    * around, so that layout knows the actual tree that it needs to invalidate.
 130    */
 131   void InvalidateStyleAndLayoutOnSubtree(Element*);
 132
 133  private:
 134   void InsertSheetIntoAuthorData(size_t aIndex, StyleSheet&,
 135                                  const nsTArray<RefPtr<StyleSheet>>&);
 136
 137   void AppendStyleSheet(StyleSheet& aSheet) {
 138     InsertSheetAt(SheetCount(), aSheet);
 139   }
 140
 141   /**
 142    * Represents the insertion point in a slot for a given node.
 143    */
 144   struct SlotInsertionPoint {
 145     HTMLSlotElement* mSlot = nullptr;
 146     Maybe<uint32_t> mIndex;
 147
 148     SlotInsertionPoint() = default;
 149     SlotInsertionPoint(HTMLSlotElement* aSlot, const Maybe<uint32_t>& aIndex)
 150         : mSlot(aSlot), mIndex(aIndex) {}
 151   };
 152
 153   /**
 154    * Return the assignment corresponding to the content node at this particular
 155    * point in time.
 156    *
 157    * It's the caller's responsibility to actually call InsertAssignedNode /
 158    * AppendAssignedNode in the slot as needed.
 159    */
 160   SlotInsertionPoint SlotInsertionPointFor(nsIContent&);
 161
 162   /**
 163    * Returns the effective slot name for a given slottable. In most cases, this
 164    * is just the value of the slot attribute, if any, or the empty string, but
 165    * this also deals with the <details> shadow tree specially.
 166    */
 167   void GetSlotNameFor(const nsIContent&, nsAString&) const;
 168
 169   /**
 170    * Re-assign the current main summary if it has changed.
 171    *
 172    * Must be called only if mIsDetailsShadowTree is true.
 173    */
 174   enum class SummaryChangeReason { Deletion, Insertion };
 175   void MaybeReassignMainSummary(SummaryChangeReason);
 176
 177  public:
 178   void AddSlot(HTMLSlotElement* aSlot);
 179   void RemoveSlot(HTMLSlotElement* aSlot);
 180   bool HasSlots() const { return !mSlotMap.IsEmpty(); };
 181   HTMLSlotElement* GetDefaultSlot() const {
 182     SlotArray* list = mSlotMap.Get(u""_ns);
 183     return list ? (*list)->ElementAt(0) : nullptr;
 184   }
 185
 186   void PartAdded(const Element&);
 187   void PartRemoved(const Element&);
 188
 189   IMPL_EVENT_HANDLER(slotchange);
 190
 191   const nsTArray<const Element*>& Parts() const { return mParts; }
 192
 193   const StyleAuthorStyles* GetServoStyles() const { return mServoStyles.get(); }
 194
 195   StyleAuthorStyles* GetServoStyles() { return mServoStyles.get(); }
 196
 197   mozilla::ServoStyleRuleMap& ServoStyleRuleMap();
 198
 199   JSObject* WrapNode(JSContext*, JS::Handle<JSObject*> aGivenProto) final;
 200
 201   void NodeInfoChanged(Document* aOldDoc) override;
 202
 203   void AddToIdTable(Element* aElement, nsAtom* aId);
 204   void RemoveFromIdTable(Element* aElement, nsAtom* aId);
 205
 206   // WebIDL methods.
 207   using mozilla::dom::DocumentOrShadowRoot::GetElementById;
 208
 209   Element* GetActiveElement();
 210
 211   /**
 212    * These methods allow UA Widget to insert DOM elements into the Shadow ROM
 213    * without putting their DOM reflectors to content scope first.
 214    * The inserted DOM will have their reflectors in the UA Widget scope.
 215    */
 216   nsINode* ImportNodeAndAppendChildAt(nsINode& aParentNode, nsINode& aNode,
 217                                       bool aDeep, mozilla::ErrorResult& rv);
 218
 219   nsINode* CreateElementAndAppendChildAt(nsINode& aParentNode,
 220                                          const nsAString& aTagName,
 221                                          mozilla::ErrorResult& rv);
 222
 223   bool IsUAWidget() const { return HasBeenInUAWidget(); }
 224
 225   void SetIsUAWidget() {
 226     MOZ_ASSERT(!HasChildren());
 227     SetIsNativeAnonymousRoot();
 228     SetFlags(NODE_HAS_BEEN_IN_UA_WIDGET);
 229   }
 230
 231   bool IsAvailableToElementInternals() const {
 232     return mIsAvailableToElementInternals;
 233   }
 234
 235   void SetAvailableToElementInternals() {
 236     mIsAvailableToElementInternals = true;
 237   }
 238
 239   void GetEventTargetParent(EventChainPreVisitor& aVisitor) override;
 240
 241   bool IsDeclarative() const { return mIsDeclarative == Declarative::Yes; }
 242   void SetIsDeclarative(Declarative aIsDeclarative) {
 243     mIsDeclarative = aIsDeclarative;
 244   }
 245   void SetIsDeclarative(bool aIsDeclarative) {
 246     mIsDeclarative = aIsDeclarative ? Declarative::Yes : Declarative::No;
 247   }
 248
 249   MOZ_CAN_RUN_SCRIPT
 250   void SetHTMLUnsafe(const nsAString& aHTML);
 251
 252   void GetHTML(const GetHTMLOptions& aOptions, nsAString& aResult);
 253
 254  protected:
 255   // FIXME(emilio): This will need to become more fine-grained.
 256   void ApplicableRulesChanged();
 257
 258   virtual ~ShadowRoot();
 259
 260   // Make sure that the first field is pointer-aligned so it doesn't get packed
 261   // in the base class' padding, since otherwise rust-bindgen can't generate
 262   // correct bindings for it, see
 263   // https://github.com/rust-lang/rust-bindgen/issues/380
 264
 265   // The computed data from the style sheets.
 266   UniquePtr<StyleAuthorStyles> mServoStyles;
 267   UniquePtr<mozilla::ServoStyleRuleMap> mStyleRuleMap;
 268
 269   using SlotArray = TreeOrderedArray<HTMLSlotElement*>;
 270   // Map from name of slot to an array of all slots in the shadow DOM with with
 271   // the given name. The slots are stored as a weak pointer because the elements
 272   // are in the shadow tree and should be kept alive by its parent.
 273   nsClassHashtable<nsStringHashKey, SlotArray> mSlotMap;
 274
 275   // Unordered array of all elements that have a part attribute in this shadow
 276   // tree.
 277   nsTArray<const Element*> mParts;
 278
 279   const ShadowRootMode mMode;
 280
 281   Element::DelegatesFocus mDelegatesFocus;
 282
 283   const SlotAssignmentMode mSlotAssignment;
 284
 285   // Whether this is the <details> internal shadow tree.
 286   bool mIsDetailsShadowTree : 1;
 287
 288   // https://dom.spec.whatwg.org/#shadowroot-available-to-element-internals
 289   bool mIsAvailableToElementInternals : 1;
 290
 291   // https://dom.spec.whatwg.org/#shadowroot-declarative
 292   Declarative mIsDeclarative;
 293
 294   // https://dom.spec.whatwg.org/#shadowroot-clonable
 295   const IsClonable mIsClonable;
 296
 297   // https://dom.spec.whatwg.org/#shadowroot-serializable
 298   const IsSerializable mIsSerializable;
 299
 300   nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;
 301 };
 302
 303 }  // namespace dom
 304 }  // namespace mozilla
 305
 306 #endif  // mozilla_dom_shadowroot_h__