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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=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 */
#ifndef mozilla_a11y_RemoteAccessibleBase_h
#define mozilla_a11y_RemoteAccessibleBase_h
#include "mozilla/a11y/Accessible.h"
#include "mozilla/a11y/CacheConstants.h"
#include "mozilla/a11y/HyperTextAccessibleBase.h"
#include "mozilla/a11y/Role.h"
#include "AccAttributes.h"
#include "nsIAccessibleText.h"
#include "nsIAccessibleTypes.h"
#include "nsTArray.h"
#include "nsRect.h"
#include "LocalAccessible.h"
namespace mozilla {
namespace a11y {
class Attribute;
class DocAccessibleParent;
class RemoteAccessible;
enum class RelationType;
template <class Derived>
class RemoteAccessibleBase : public Accessible, public HyperTextAccessibleBase {
virtual ~RemoteAccessibleBase() { MOZ_ASSERT(!mWrapper); }
virtual bool IsRemote() const override { return true; }
void AddChildAt(uint32_t aIdx, Derived* aChild) {
mChildren.InsertElementAt(aIdx, aChild);
if (IsHyperText()) {
virtual uint32_t ChildCount() const override { return mChildren.Length(); }
Derived* RemoteChildAt(uint32_t aIdx) const {
return mChildren.SafeElementAt(aIdx);
Derived* RemoteFirstChild() const {
return mChildren.Length() ? mChildren[0] : nullptr;
Derived* RemoteLastChild() const {
return mChildren.Length() ? mChildren[mChildren.Length() - 1] : nullptr;
Derived* RemotePrevSibling() const {
if (IsDoc()) {
// The normal code path doesn't work for documents because the parent
// might be a local OuterDoc, but IndexInParent() will return 1.
// A document is always a single child of an OuterDoc anyway.
return nullptr;
int32_t idx = IndexInParent();
if (idx == -1) {
return nullptr; // No parent.
return idx > 0 ? RemoteParent()->mChildren[idx - 1] : nullptr;
Derived* RemoteNextSibling() const {
if (IsDoc()) {
// The normal code path doesn't work for documents because the parent
// might be a local OuterDoc, but IndexInParent() will return 1.
// A document is always a single child of an OuterDoc anyway.
return nullptr;
int32_t idx = IndexInParent();
if (idx == -1) {
return nullptr; // No parent.
MOZ_ASSERT(idx >= 0);
size_t newIdx = idx + 1;
return newIdx < RemoteParent()->mChildren.Length()
? RemoteParent()->mChildren[newIdx]
: nullptr;
// Accessible hierarchy method overrides
virtual Accessible* Parent() const override { return RemoteParent(); }
virtual Accessible* ChildAt(uint32_t aIndex) const override {
return RemoteChildAt(aIndex);
virtual Accessible* NextSibling() const override {
return RemoteNextSibling();
virtual Accessible* PrevSibling() const override {
return RemotePrevSibling();
// XXX evaluate if this is fast enough.
virtual int32_t IndexInParent() const override {
Derived* parent = RemoteParent();
if (!parent) {
return -1;
return parent->mChildren.IndexOf(static_cast<const Derived*>(this));
virtual uint32_t EmbeddedChildCount() override;
virtual int32_t IndexOfEmbeddedChild(Accessible* aChild) override;
virtual Accessible* EmbeddedChildAt(uint32_t aChildIdx) override;
void Shutdown();
void SetChildDoc(DocAccessibleParent* aChildDoc);
void ClearChildDoc(DocAccessibleParent* aChildDoc);
* Remove The given child.
void RemoveChild(Derived* aChild) {
if (IsHyperText()) {
* Return the proxy for the parent of the wrapped accessible.
Derived* RemoteParent() const;
LocalAccessible* OuterDocOfRemoteBrowser() const;
* Get the role of the accessible we're proxying.
virtual role Role() const override { return mRole; }
* Return true if this is an embedded object.
bool IsEmbeddedObject() const { return !IsText(); }
virtual bool IsLink() const override {
if (IsHTMLLink()) {
// XXX: HTML links always return true for IsLink.
return true;
if (IsText()) {
return false;
if (Accessible* parent = Parent()) {
return parent->IsHyperText();
return false;
virtual bool HasNumericValue() const override {
// XXX: We combine the aria and native "has numeric value" field
// when we serialize the local accessible into eNumericValue.
return HasGenericType(eNumericValue);
// Methods that potentially access a cache.
virtual ENameValueFlag Name(nsString& aName) const override;
virtual void Description(nsString& aDescription) const override;
virtual void Value(nsString& aValue) const override;
virtual double CurValue() const override;
virtual double MinValue() const override;
virtual double MaxValue() const override;
virtual double Step() const override;
virtual Accessible* ChildAtPoint(
int32_t aX, int32_t aY,
LocalAccessible::EWhichChildAtPoint aWhichChild) override;
virtual LayoutDeviceIntRect Bounds() const override;
virtual nsRect BoundsInAppUnits() const override;
virtual Relation RelationByType(RelationType aType) const override;
virtual uint64_t State() override;
virtual already_AddRefed<AccAttributes> Attributes() override;
virtual nsAtom* TagName() const override;
virtual already_AddRefed<nsAtom> DisplayStyle() const override;
virtual Maybe<float> Opacity() const override;
virtual void LiveRegionAttributes(nsAString* aLive, nsAString* aRelevant,
Maybe<bool>* aAtomic,
nsAString* aBusy) const override;
virtual uint8_t ActionCount() const override;
virtual void ActionNameAt(uint8_t aIndex, nsAString& aName) override;
virtual bool DoAction(uint8_t aIndex) const override;
virtual KeyBinding AccessKey() const override;
virtual void SelectionRanges(nsTArray<TextRange>* aRanges) const override;
virtual Maybe<int32_t> GetIntARIAAttr(nsAtom* aAttrName) const override;
// SelectAccessible
virtual void SelectedItems(nsTArray<Accessible*>* aItems) override;
virtual uint32_t SelectedItemCount() override;
virtual Accessible* GetSelectedItem(uint32_t aIndex) override;
virtual bool IsItemSelected(uint32_t aIndex) override;
virtual bool AddItemToSelection(uint32_t aIndex) override;
virtual bool RemoveItemFromSelection(uint32_t aIndex) override;
virtual bool SelectAll() override;
virtual bool UnselectAll() override;
virtual void TakeSelection() override;
virtual void SetSelected(bool aSelect) override;
// Methods that interact with content.
virtual void TakeFocus() const override;
virtual void ScrollTo(uint32_t aHow) const override;
virtual void SetCaretOffset(int32_t aOffset) override;
* Allow the platform to store a pointers worth of data on us.
uintptr_t GetWrapper() const { return mWrapper; }
void SetWrapper(uintptr_t aWrapper) { mWrapper = aWrapper; }
virtual uint64_t ID() const override { return mID; }
* Return the document containing this proxy, or the proxy itself if it is a
* document.
DocAccessibleParent* Document() const { return mDoc; }
DocAccessibleParent* AsDoc() const { return IsDoc() ? mDoc : nullptr; }
void ApplyCache(CacheUpdateType aUpdateType, AccAttributes* aFields) {
const nsTArray<bool> relUpdatesNeeded = PreProcessRelations(aFields);
if (aUpdateType == CacheUpdateType::Initial) {
mCachedFields = aFields;
} else {
if (!mCachedFields) {
// The fields cache can be uninitialized if there were no cache-worthy
// fields in the initial cache push.
// We don't do a simple assign because we don't want to store the
// DeleteEntry entries.
mCachedFields = new AccAttributes();
if (IsTextLeaf()) {
Derived* parent = RemoteParent();
if (parent && parent->IsHyperText()) {
void UpdateStateCache(uint64_t aState, bool aEnabled) {
if (aState & kRemoteCalculatedStates) {
uint64_t state = 0;
if (mCachedFields) {
if (auto oldState =
mCachedFields->GetAttribute<uint64_t>(nsGkAtoms::state)) {
state = *oldState;
} else {
mCachedFields = new AccAttributes();
if (aEnabled) {
state |= aState;
} else {
state &= ~aState;
mCachedFields->SetAttribute(nsGkAtoms::state, state);
void InvalidateGroupInfo();
virtual void AppendTextTo(nsAString& aText, uint32_t aStartOffset = 0,
uint32_t aLength = UINT32_MAX) override;
virtual bool TableIsProbablyForLayout();
* Iterates through each atom in kRelationTypeAtoms, checking to see
* if it is present in aFields. If it is present (or if aFields contains
* a DeleteEntry() for this atom) and mCachedFields is initialized,
* fetches the old rel targets and removes their existing reverse relations
* stored in mReverseRelations.
* Returns an array of bools where the ith array entry corresponds
* to whether or not the rel at the ith entry of kRelationTypeAtoms
* requires a post-processing update.
nsTArray<bool> PreProcessRelations(AccAttributes* aFields);
* Takes in the array returned from PreProcessRelations.
* For each entry requiring an update, fetches the new relation
* targets stored in mCachedFields and appropriately
* updates their reverse relations in mReverseRelations.
void PostProcessRelations(const nsTArray<bool>& aToUpdate);
uint32_t GetCachedTextLength();
Maybe<const nsTArray<int32_t>&> GetCachedTextLines();
Maybe<nsTArray<nsRect>> GetCachedCharData();
RefPtr<const AccAttributes> GetCachedTextAttributes();
RefPtr<const AccAttributes> GetCachedARIAAttributes() const;
virtual HyperTextAccessibleBase* AsHyperTextBase() override {
return IsHyperText() ? static_cast<HyperTextAccessibleBase*>(this)
: nullptr;
virtual TableAccessibleBase* AsTableBase() override;
virtual TableCellAccessibleBase* AsTableCellBase() override;
virtual void DOMNodeID(nsString& aID) const override;
// HyperTextAccessibleBase
virtual already_AddRefed<AccAttributes> DefaultTextAttributes() override;
virtual void InvalidateCachedHyperTextOffsets() override {
if (mCachedFields) {
RemoteAccessibleBase(uint64_t aID, Derived* aParent,
DocAccessibleParent* aDoc, role aRole, AccType aType,
AccGenericType aGenericTypes, uint8_t aRoleMapEntryIndex)
: Accessible(aType, aGenericTypes, aRoleMapEntryIndex),
mRole(aRole) {}
explicit RemoteAccessibleBase(DocAccessibleParent* aThisAsDoc)
: Accessible(),
mRole(roles::DOCUMENT) {
mGenericTypes = eDocument | eHyperText;
void SetParent(Derived* aParent);
Maybe<nsRect> RetrieveCachedBounds() const;
bool ApplyTransform(nsRect& aBounds) const;
void ApplyScrollOffset(nsRect& aBounds) const;
void ApplyCrossProcOffset(nsRect& aBounds) const;
LayoutDeviceIntRect BoundsWithOffset(Maybe<nsRect> aOffset) const;
virtual void ARIAGroupPosition(int32_t* aLevel, int32_t* aSetSize,
int32_t* aPosInSet) const override;
virtual AccGroupInfo* GetGroupInfo() const override;
virtual AccGroupInfo* GetOrCreateGroupInfo() override;
virtual bool HasPrimaryAction() const override;
nsAtom* GetPrimaryAction() const;
virtual const nsTArray<int32_t>& GetCachedHyperTextOffsets() const override;
uintptr_t mParent;
static const uintptr_t kNoParent = UINTPTR_MAX;
friend Derived;
friend DocAccessibleParent;
friend TextLeafPoint;
friend HyperTextAccessibleBase;
friend class xpcAccessible;
friend class CachedTableCellAccessible;
nsTArray<Derived*> mChildren;
DocAccessibleParent* mDoc;
uintptr_t mWrapper;
uint64_t mID;
virtual const Accessible* Acc() const override { return this; }
RefPtr<AccAttributes> mCachedFields;
// XXX DocAccessibleParent gets to change this to change the role of
// documents.
role mRole : 27;
extern template class RemoteAccessibleBase<RemoteAccessible>;
} // namespace a11y
} // namespace mozilla