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