Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 729 insertions, 0 deletions

diff --git a/accessible/generic/DocAccessible.h b/accessible/generic/DocAccessible.h
new file mode 100644
index 0000000000..dc1cca0d15
--- /dev/null
+++ b/accessible/generic/DocAccessible.h
@@ -0,0 +1,729 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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_a11y_DocAccessible_h__
+#define mozilla_a11y_DocAccessible_h__
+
+#include "nsIAccessiblePivot.h"
+
+#include "HyperTextAccessibleWrap.h"
+#include "AccEvent.h"
+
+#include "nsClassHashtable.h"
+#include "nsDataHashtable.h"
+#include "mozilla/UniquePtr.h"
+#include "nsIDocumentObserver.h"
+#include "nsIObserver.h"
+#include "nsITimer.h"
+#include "nsWeakReference.h"
+
+class nsAccessiblePivot;
+
+const uint32_t kDefaultCacheLength = 128;
+
+namespace mozilla {
+
+class PresShell;
+class TextEditor;
+
+namespace dom {
+class Document;
+}
+
+namespace a11y {
+
+class DocManager;
+class NotificationController;
+class DocAccessibleChild;
+class RelatedAccIterator;
+template <class Class, class... Args>
+class TNotification;
+
+class DocAccessible : public HyperTextAccessibleWrap,
+                      public nsIDocumentObserver,
+                      public nsIObserver,
+                      public nsSupportsWeakReference,
+                      public nsIAccessiblePivotObserver {
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DocAccessible, Accessible)
+
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSIACCESSIBLEPIVOTOBSERVER
+
+ protected:
+  typedef mozilla::dom::Document Document;
+
+ public:
+  DocAccessible(Document* aDocument, PresShell* aPresShell);
+
+  // nsIDocumentObserver
+  NS_DECL_NSIDOCUMENTOBSERVER
+
+  // Accessible
+  virtual void Init();
+  virtual void Shutdown() override;
+  virtual nsIFrame* GetFrame() const override;
+  virtual nsINode* GetNode() const override;
+  Document* DocumentNode() const { return mDocumentNode; }
+
+  virtual mozilla::a11y::ENameValueFlag Name(nsString& aName) const override;
+  virtual void Description(nsString& aDescription) override;
+  virtual Accessible* FocusedChild() override;
+  virtual mozilla::a11y::role NativeRole() const override;
+  virtual uint64_t NativeState() const override;
+  virtual uint64_t NativeInteractiveState() const override;
+  virtual bool NativelyUnavailable() const override;
+  virtual void ApplyARIAState(uint64_t* aState) const override;
+  virtual already_AddRefed<nsIPersistentProperties> Attributes() override;
+
+  virtual void TakeFocus() const override;
+
+#ifdef A11Y_LOG
+  virtual nsresult HandleAccEvent(AccEvent* aEvent) override;
+#endif
+
+  virtual nsRect RelativeBounds(nsIFrame** aRelativeFrame) const override;
+
+  // HyperTextAccessible
+  virtual already_AddRefed<TextEditor> GetEditor() const override;
+
+  // DocAccessible
+
+  /**
+   * Return document URL.
+   */
+  void URL(nsAString& aURL) const;
+
+  /**
+   * Return DOM document title.
+   */
+  void Title(nsString& aTitle) const;
+
+  /**
+   * Return DOM document mime type.
+   */
+  void MimeType(nsAString& aType) const;
+  /**
+   * Return DOM document type.
+   */
+  void DocType(nsAString& aType) const;
+
+  /**
+   * Return virtual cursor associated with the document.
+   */
+  nsIAccessiblePivot* VirtualCursor();
+
+  /**
+   * Returns true if the instance has shutdown.
+   */
+  bool HasShutdown() const { return !mPresShell; }
+
+  /**
+   * Return presentation shell for this document accessible.
+   */
+  PresShell* PresShellPtr() const {
+    MOZ_DIAGNOSTIC_ASSERT(!HasShutdown());
+    return mPresShell;
+  }
+
+  /**
+   * Return the presentation shell's context.
+   */
+  nsPresContext* PresContext() const;
+
+  /**
+   * Return true if associated DOM document was loaded and isn't unloading.
+   */
+  bool IsContentLoaded() const;
+
+  bool IsHidden() const;
+
+  /**
+   * Document load states.
+   */
+  enum LoadState {
+    // initial tree construction is pending
+    eTreeConstructionPending = 0,
+    // initial tree construction done
+    eTreeConstructed = 1,
+    // DOM document is loaded.
+    eDOMLoaded = 1 << 1,
+    // document is ready
+    eReady = eTreeConstructed | eDOMLoaded,
+    // document and all its subdocuments are ready
+    eCompletelyLoaded = eReady | 1 << 2
+  };
+
+  /**
+   * Return true if the document has given document state.
+   */
+  bool HasLoadState(LoadState aState) const {
+    return (mLoadState & static_cast<uint32_t>(aState)) ==
+           static_cast<uint32_t>(aState);
+  }
+
+  /**
+   * Return a native window handler or pointer depending on platform.
+   */
+  virtual void* GetNativeWindow() const;
+
+  /**
+   * Return the parent document.
+   */
+  DocAccessible* ParentDocument() const {
+    return mParent ? mParent->Document() : nullptr;
+  }
+
+  /**
+   * Return the child document count.
+   */
+  uint32_t ChildDocumentCount() const { return mChildDocuments.Length(); }
+
+  /**
+   * Return the child document at the given index.
+   */
+  DocAccessible* GetChildDocumentAt(uint32_t aIndex) const {
+    return mChildDocuments.SafeElementAt(aIndex, nullptr);
+  }
+
+  /**
+   * Fire accessible event asynchronously.
+   */
+  void FireDelayedEvent(AccEvent* aEvent);
+  void FireDelayedEvent(uint32_t aEventType, Accessible* aTarget);
+  void FireEventsOnInsertion(Accessible* aContainer);
+
+  /**
+   * Fire value change event on the given accessible if applicable.
+   */
+  void MaybeNotifyOfValueChange(Accessible* aAccessible);
+
+  /**
+   * Get/set the anchor jump.
+   */
+  Accessible* AnchorJump() { return GetAccessibleOrContainer(mAnchorJumpElm); }
+
+  void SetAnchorJump(nsIContent* aTargetNode) { mAnchorJumpElm = aTargetNode; }
+
+  /**
+   * Bind the child document to the tree.
+   */
+  void BindChildDocument(DocAccessible* aDocument);
+
+  /**
+   * Process the generic notification.
+   *
+   * @note  The caller must guarantee that the given instance still exists when
+   *          notification is processed.
+   * @see   NotificationController::HandleNotification
+   */
+  template <class Class, class... Args>
+  void HandleNotification(
+      Class* aInstance,
+      typename TNotification<Class, Args...>::Callback aMethod, Args*... aArgs);
+
+  /**
+   * Return the cached accessible by the given DOM node if it's in subtree of
+   * this document accessible or the document accessible itself, otherwise null.
+   *
+   * @return the accessible object
+   */
+  Accessible* GetAccessible(nsINode* aNode) const;
+
+  /**
+   * Return an accessible for the given node even if the node is not in
+   * document's node map cache (like HTML area element).
+   *
+   * XXX: it should be really merged with GetAccessible().
+   */
+  Accessible* GetAccessibleEvenIfNotInMap(nsINode* aNode) const;
+  Accessible* GetAccessibleEvenIfNotInMapOrContainer(nsINode* aNode) const;
+
+  /**
+   * Return whether the given DOM node has an accessible or not.
+   */
+  bool HasAccessible(nsINode* aNode) const { return GetAccessible(aNode); }
+
+  /**
+   * Return the cached accessible by the given unique ID within this document.
+   *
+   * @note   the unique ID matches with the uniqueID() of Accessible
+   *
+   * @param  aUniqueID  [in] the unique ID used to cache the node.
+   */
+  Accessible* GetAccessibleByUniqueID(void* aUniqueID) {
+    return UniqueID() == aUniqueID ? this : mAccessibleCache.GetWeak(aUniqueID);
+  }
+
+  /**
+   * Return the cached accessible by the given unique ID looking through
+   * this and nested documents.
+   */
+  Accessible* GetAccessibleByUniqueIDInSubtree(void* aUniqueID);
+
+  /**
+   * Return an accessible for the given DOM node or container accessible if
+   * the node is not accessible. If aNoContainerIfPruned is true it will return
+   * null if the node is in a pruned subtree (eg. aria-hidden or unselected deck
+   * panel)
+   */
+  Accessible* GetAccessibleOrContainer(nsINode* aNode,
+                                       bool aNoContainerIfPruned = false) const;
+
+  /**
+   * Return a container accessible for the given DOM node.
+   */
+  Accessible* GetContainerAccessible(nsINode* aNode) const {
+    return aNode ? GetAccessibleOrContainer(aNode->GetParentNode()) : nullptr;
+  }
+
+  /**
+   * Return an accessible for the given node if any, or an immediate accessible
+   * container for it.
+   */
+  Accessible* AccessibleOrTrueContainer(
+      nsINode* aNode, bool aNoContainerIfPruned = false) const;
+
+  /**
+   * Return an accessible for the given node or its first accessible descendant.
+   */
+  Accessible* GetAccessibleOrDescendant(nsINode* aNode) const;
+
+  /**
+   * Returns aria-owns seized child at the given index.
+   */
+  Accessible* ARIAOwnedAt(Accessible* aParent, uint32_t aIndex) const {
+    nsTArray<RefPtr<Accessible>>* children = mARIAOwnsHash.Get(aParent);
+    if (children) {
+      return children->SafeElementAt(aIndex);
+    }
+    return nullptr;
+  }
+  uint32_t ARIAOwnedCount(Accessible* aParent) const {
+    nsTArray<RefPtr<Accessible>>* children = mARIAOwnsHash.Get(aParent);
+    return children ? children->Length() : 0;
+  }
+
+  /**
+   * Return true if the given ID is referred by relation attribute.
+   */
+  bool IsDependentID(dom::Element* aElement, const nsAString& aID) const {
+    return GetRelProviders(aElement, aID);
+  }
+
+  /**
+   * Initialize the newly created accessible and put it into document caches.
+   *
+   * @param  aAccessible    [in] created accessible
+   * @param  aRoleMapEntry  [in] the role map entry role the ARIA role or
+   * nullptr if none
+   */
+  void BindToDocument(Accessible* aAccessible,
+                      const nsRoleMapEntry* aRoleMapEntry);
+
+  /**
+   * Remove from document and shutdown the given accessible.
+   */
+  void UnbindFromDocument(Accessible* aAccessible);
+
+  /**
+   * Notify the document accessible that content was inserted.
+   */
+  void ContentInserted(nsIContent* aStartChildNode, nsIContent* aEndChildNode);
+
+  /**
+   * Update the tree on content removal.
+   */
+  void ContentRemoved(Accessible* aAccessible);
+  void ContentRemoved(nsIContent* aContentNode);
+
+  /**
+   * Updates accessible tree when rendered text is changed.
+   */
+  void UpdateText(nsIContent* aTextNode);
+
+  /**
+   * Recreate an accessible, results in hide/show events pair.
+   */
+  void RecreateAccessible(nsIContent* aContent);
+
+  /**
+   * Schedule ARIA owned element relocation if needed. Return true if relocation
+   * was scheduled.
+   */
+  bool RelocateARIAOwnedIfNeeded(nsIContent* aEl);
+
+  /**
+   * Return a notification controller associated with the document.
+   */
+  NotificationController* Controller() const { return mNotificationController; }
+
+  /**
+   * If this document is in a content process return the object responsible for
+   * communicating with the main process for it.
+   */
+  DocAccessibleChild* IPCDoc() const { return mIPCDoc; }
+
+  /**
+   * Notify the document that a DOM node has been scrolled. document will
+   * dispatch throttled accessibility events for scrolling, and a scroll-end
+   * event.
+   */
+  void HandleScroll(nsINode* aTarget);
+
+ protected:
+  virtual ~DocAccessible();
+
+  void LastRelease();
+
+  // DocAccessible
+  virtual nsresult AddEventListeners();
+  virtual nsresult RemoveEventListeners();
+
+  /**
+   * Marks this document as loaded or loading.
+   */
+  void NotifyOfLoad(uint32_t aLoadEventType);
+  void NotifyOfLoading(bool aIsReloading);
+
+  friend class DocManager;
+
+  /**
+   * Perform initial update (create accessible tree).
+   * Can be overridden by wrappers to prepare initialization work.
+   */
+  virtual void DoInitialUpdate();
+
+  /**
+   * Updates root element and picks up ARIA role on it if any.
+   */
+  void UpdateRootElIfNeeded();
+
+  /**
+   * Process document load notification, fire document load and state busy
+   * events if applicable.
+   */
+  void ProcessLoad();
+
+  /**
+   * Append the given document accessible to this document's child document
+   * accessibles.
+   */
+  bool AppendChildDocument(DocAccessible* aChildDocument) {
+    // XXX(Bug 1631371) Check if this should use a fallible operation as it
+    // pretended earlier, or change the return type to void.
+    mChildDocuments.AppendElement(aChildDocument);
+    return true;
+  }
+
+  /**
+   * Remove the given document accessible from this document's child document
+   * accessibles.
+   */
+  void RemoveChildDocument(DocAccessible* aChildDocument) {
+    mChildDocuments.RemoveElement(aChildDocument);
+  }
+
+  /**
+   * Add dependent IDs pointed by accessible element by relation attribute to
+   * cache. If the relation attribute is missed then all relation attributes
+   * are checked.
+   *
+   * @param aRelProvider [in] accessible that element has relation attribute
+   * @param aRelAttr     [in, optional] relation attribute
+   */
+  void AddDependentIDsFor(Accessible* aRelProvider, nsAtom* aRelAttr = nullptr);
+
+  /**
+   * Remove dependent IDs pointed by accessible element by relation attribute
+   * from cache. If the relation attribute is absent then all relation
+   * attributes are checked.
+   *
+   * @param aRelProvider [in] accessible that element has relation attribute
+   * @param aRelAttr     [in, optional] relation attribute
+   */
+  void RemoveDependentIDsFor(Accessible* aRelProvider,
+                             nsAtom* aRelAttr = nullptr);
+
+  /**
+   * Update or recreate an accessible depending on a changed attribute.
+   *
+   * @param aElement   [in] the element the attribute was changed on
+   * @param aAttribute [in] the changed attribute
+   * @return            true if an action was taken on the attribute change
+   */
+  bool UpdateAccessibleOnAttrChange(mozilla::dom::Element* aElement,
+                                    nsAtom* aAttribute);
+
+  /**
+   * Fire accessible events when attribute is changed.
+   *
+   * @param aAccessible   [in] accessible the DOM attribute is changed for
+   * @param aNameSpaceID  [in] namespace of changed attribute
+   * @param aAttribute    [in] changed attribute
+   * @param aModType      [in] modification type (changed/added/removed)
+   */
+  void AttributeChangedImpl(Accessible* aAccessible, int32_t aNameSpaceID,
+                            nsAtom* aAttribute, int32_t aModType);
+
+  /**
+   * Fire accessible events when ARIA attribute is changed.
+   *
+   * @param aAccessible  [in] accesislbe the DOM attribute is changed for
+   * @param aAttribute   [in] changed attribute
+   */
+  void ARIAAttributeChanged(Accessible* aAccessible, nsAtom* aAttribute);
+
+  /**
+   * Process ARIA active-descendant attribute change.
+   */
+  void ARIAActiveDescendantChanged(Accessible* aAccessible);
+
+  /**
+   * Update the accessible tree for inserted content.
+   */
+  void ProcessContentInserted(
+      Accessible* aContainer,
+      const nsTArray<nsCOMPtr<nsIContent>>* aInsertedContent);
+  void ProcessContentInserted(Accessible* aContainer,
+                              nsIContent* aInsertedContent);
+
+  /**
+   * Used to notify the document to make it process the invalidation list.
+   *
+   * While children are cached we may encounter the case there's no accessible
+   * for referred content by related accessible. Store these related nodes to
+   * invalidate their containers later.
+   */
+  void ProcessInvalidationList();
+
+  /**
+   * Steals or puts back accessible subtrees.
+   */
+  void DoARIAOwnsRelocation(Accessible* aOwner);
+
+  /**
+   * Moves children back under their original parents.
+   */
+  void PutChildrenBack(nsTArray<RefPtr<Accessible>>* aChildren,
+                       uint32_t aStartIdx);
+
+  bool MoveChild(Accessible* aChild, Accessible* aNewParent,
+                 int32_t aIdxInParent);
+
+  /**
+   * Create accessible tree.
+   *
+   * @param aRoot       [in] a root of subtree to create
+   * @param aFocusedAcc [in, optional] a focused accessible under created
+   *                      subtree if any
+   */
+  void CacheChildrenInSubtree(Accessible* aRoot,
+                              Accessible** aFocusedAcc = nullptr);
+  void CreateSubtree(Accessible* aRoot);
+
+  /**
+   * Remove accessibles in subtree from node to accessible map.
+   */
+  void UncacheChildrenInSubtree(Accessible* aRoot);
+
+  /**
+   * Shutdown any cached accessible in the subtree.
+   *
+   * @param aAccessible  [in] the root of the subrtee to invalidate accessible
+   *                      child/parent refs in
+   */
+  void ShutdownChildrenInSubtree(Accessible* aAccessible);
+
+  /**
+   * Return true if the document is a target of document loading events
+   * (for example, state busy change or document reload events).
+   *
+   * Rules: The root chrome document accessible is never an event target
+   * (for example, Firefox UI window). If the sub document is loaded within its
+   * parent document then the parent document is a target only (aka events
+   * coalescence).
+   */
+  bool IsLoadEventTarget() const;
+
+  /*
+   * Set the object responsible for communicating with the main process on
+   * behalf of this document.
+   */
+  void SetIPCDoc(DocAccessibleChild* aIPCDoc);
+
+  friend class DocAccessibleChildBase;
+
+  /**
+   * Used to fire scrolling end event after page scroll.
+   *
+   * @param aTimer    [in] the timer object
+   * @param aClosure  [in] the document accessible where scrolling happens
+   */
+  static void ScrollTimerCallback(nsITimer* aTimer, void* aClosure);
+
+  void DispatchScrollingEvent(nsINode* aTarget, uint32_t aEventType);
+
+  /**
+   * Check if an id attribute change affects aria-activedescendant and handle
+   * the aria-activedescendant change if appropriate.
+   * If the currently focused element has aria-activedescendant and an
+   * element's id changes to match this, the id was probably moved from the
+   * previous active descendant, thus making this element the new active
+   * descendant. In that case, accessible focus must be changed accordingly.
+   */
+  void ARIAActiveDescendantIDMaybeMoved(dom::Element* aElm);
+
+  /**
+   * Traverse content subtree and for each node do one of 3 things:
+   * 1. Check if content node has an accessible that should be removed and
+   *    remove it.
+   * 2. Check if content node has an accessible that needs to be recreated.
+   *    Remove it and schedule it for reinsertion.
+   * 3. Check if content node has no accessible but needs one. Schedule one for
+   *    insertion.
+   *
+   * Returns true if the root node should be reinserted.
+   */
+  bool PruneOrInsertSubtree(nsIContent* aRoot);
+
+ protected:
+  /**
+   * State and property flags, kept by mDocFlags.
+   */
+  enum {
+    // Whether the document is a top level content document in this process.
+    eTopLevelContentDocInProcess = 1 << 0
+  };
+
+  /**
+   * Cache of accessibles within this document accessible.
+   */
+  AccessibleHashtable mAccessibleCache;
+  nsDataHashtable<nsPtrHashKey<const nsINode>, Accessible*>
+      mNodeToAccessibleMap;
+
+  Document* mDocumentNode;
+  nsCOMPtr<nsITimer> mScrollWatchTimer;
+  nsDataHashtable<nsPtrHashKey<nsINode>, TimeStamp> mLastScrollingDispatch;
+
+  /**
+   * Bit mask of document load states (@see LoadState).
+   */
+  uint32_t mLoadState : 3;
+
+  /**
+   * Bit mask of other states and props.
+   */
+  uint32_t mDocFlags : 28;
+
+  /**
+   * Type of document load event fired after the document is loaded completely.
+   */
+  uint32_t mLoadEventType;
+
+  /**
+   * Reference to anchor jump element.
+   */
+  nsCOMPtr<nsIContent> mAnchorJumpElm;
+
+  /**
+   * A generic state (see items below) before the attribute value was changed.
+   * @see AttributeWillChange and AttributeChanged notifications.
+   */
+  union {
+    // ARIA attribute value
+    const nsAtom* mARIAAttrOldValue;
+
+    // Previous state bits before attribute change
+    uint64_t mPrevStateBits;
+  };
+
+  nsTArray<RefPtr<DocAccessible>> mChildDocuments;
+
+  /**
+   * The virtual cursor of the document.
+   */
+  RefPtr<nsAccessiblePivot> mVirtualCursor;
+
+  /**
+   * A storage class for pairing content with one of its relation attributes.
+   */
+  class AttrRelProvider {
+   public:
+    AttrRelProvider(nsAtom* aRelAttr, nsIContent* aContent)
+        : mRelAttr(aRelAttr), mContent(aContent) {}
+
+    nsAtom* mRelAttr;
+    nsCOMPtr<nsIContent> mContent;
+
+   private:
+    AttrRelProvider();
+    AttrRelProvider(const AttrRelProvider&);
+    AttrRelProvider& operator=(const AttrRelProvider&);
+  };
+
+  typedef nsTArray<mozilla::UniquePtr<AttrRelProvider>> AttrRelProviders;
+  typedef nsClassHashtable<nsStringHashKey, AttrRelProviders>
+      DependentIDsHashtable;
+
+  /**
+   * Returns/creates/removes attribute relation providers associated with
+   * a DOM document if the element is in uncomposed document or associated
+   * with shadow DOM the element is in.
+   */
+  AttrRelProviders* GetRelProviders(dom::Element* aElement,
+                                    const nsAString& aID) const;
+  AttrRelProviders* GetOrCreateRelProviders(dom::Element* aElement,
+                                            const nsAString& aID);
+  void RemoveRelProvidersIfEmpty(dom::Element* aElement, const nsAString& aID);
+
+  /**
+   * The cache of IDs pointed by relation attributes.
+   */
+  nsClassHashtable<nsPtrHashKey<dom::DocumentOrShadowRoot>,
+                   DependentIDsHashtable>
+      mDependentIDsHashes;
+
+  friend class RelatedAccIterator;
+
+  /**
+   * Used for our caching algorithm. We store the list of nodes that should be
+   * invalidated.
+   *
+   * @see ProcessInvalidationList
+   */
+  nsTArray<RefPtr<nsIContent>> mInvalidationList;
+
+  /**
+   * Holds a list of aria-owns relocations.
+   */
+  nsClassHashtable<nsPtrHashKey<Accessible>, nsTArray<RefPtr<Accessible>>>
+      mARIAOwnsHash;
+
+  /**
+   * Used to process notification from core and accessible events.
+   */
+  RefPtr<NotificationController> mNotificationController;
+  friend class EventTree;
+  friend class NotificationController;
+
+ private:
+  void SetRoleMapEntryForDoc(dom::Element* aElement);
+
+  PresShell* mPresShell;
+
+  // Exclusively owned by IPDL so don't manually delete it!
+  DocAccessibleChild* mIPCDoc;
+};
+
+inline DocAccessible* Accessible::AsDoc() {
+  return IsDoc() ? static_cast<DocAccessible*>(this) : nullptr;
+}
+
+}  // namespace a11y
+}  // namespace mozilla
+
+#endif