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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_DocAccessibleParent_h
#define mozilla_a11y_DocAccessibleParent_h
#include "nsAccessibilityService.h"
#include "mozilla/a11y/PDocAccessibleParent.h"
#include "mozilla/a11y/RemoteAccessible.h"
#include "mozilla/dom/BrowserBridgeParent.h"
#include "nsClassHashtable.h"
#include "nsHashKeys.h"
#include "nsISupportsImpl.h"
namespace mozilla {
namespace dom {
class CanonicalBrowsingContext;
namespace a11y {
class TextRange;
class xpcAccessibleGeneric;
#if !defined(XP_WIN)
class DocAccessiblePlatformExtParent;
* These objects live in the main process and comunicate with and represent
* an accessible document in a content process.
class DocAccessibleParent : public RemoteAccessible,
public PDocAccessibleParent {
* Set this as a top level document; i.e. it is not embedded by another remote
* document. This also means it is a top level document in its content
* process.
* Tab documents are top level documents.
void SetTopLevel() {
mTopLevel = true;
mTopLevelInContentProcess = true;
bool IsTopLevel() const { return mTopLevel; }
* Set this as a top level document in its content process.
* Note that this could be an out-of-process iframe embedded by a remote
* embedder document. In that case, IsToplevel() will return false, but
* IsTopLevelInContentProcess() will return true.
void SetTopLevelInContentProcess() { mTopLevelInContentProcess = true; }
bool IsTopLevelInContentProcess() const { return mTopLevelInContentProcess; }
bool IsShutdown() const { return mShutdown; }
* Mark this actor as shutdown without doing any cleanup. This should only
* be called on actors that have just been initialized, so probably only from
* RecvPDocAccessibleConstructor.
void MarkAsShutdown() {
MOZ_ASSERT(mAccessibles.Count() == 0);
mShutdown = true;
void SetBrowsingContext(dom::CanonicalBrowsingContext* aBrowsingContext);
dom::CanonicalBrowsingContext* GetBrowsingContext() const {
return mBrowsingContext;
* Called when a message from a document in a child process notifies the main
* process it is firing an event.
virtual mozilla::ipc::IPCResult RecvEvent(const uint64_t& aID,
const uint32_t& aType) override;
virtual mozilla::ipc::IPCResult RecvShowEvent(const ShowEventData& aData,
const bool& aFromUser) override;
virtual mozilla::ipc::IPCResult RecvHideEvent(const uint64_t& aRootID,
const bool& aFromUser) override;
mozilla::ipc::IPCResult RecvStateChangeEvent(const uint64_t& aID,
const uint64_t& aState,
const bool& aEnabled) final;
mozilla::ipc::IPCResult RecvCaretMoveEvent(
const uint64_t& aID,
#if defined(XP_WIN)
const LayoutDeviceIntRect& aCaretRect,
const int32_t& aOffset, const bool& aIsSelectionCollapsed,
const bool& aIsAtEndOfLine, const int32_t& aGranularity) final;
virtual mozilla::ipc::IPCResult RecvTextChangeEvent(
const uint64_t& aID, const nsAString& aStr, const int32_t& aStart,
const uint32_t& aLen, const bool& aIsInsert,
const bool& aFromUser) override;
#if defined(XP_WIN)
virtual mozilla::ipc::IPCResult RecvSyncTextChangeEvent(
const uint64_t& aID, const nsAString& aStr, const int32_t& aStart,
const uint32_t& aLen, const bool& aIsInsert,
const bool& aFromUser) override;
virtual mozilla::ipc::IPCResult RecvFocusEvent(
const uint64_t& aID, const LayoutDeviceIntRect& aCaretRect) override;
#endif // defined(XP_WIN)
virtual mozilla::ipc::IPCResult RecvSelectionEvent(
const uint64_t& aID, const uint64_t& aWidgetID,
const uint32_t& aType) override;
virtual mozilla::ipc::IPCResult RecvVirtualCursorChangeEvent(
const uint64_t& aID, const uint64_t& aOldPositionID,
const int32_t& aOldStartOffset, const int32_t& aOldEndOffset,
const uint64_t& aNewPositionID, const int32_t& aNewStartOffset,
const int32_t& aNewEndOffset, const int16_t& aReason,
const int16_t& aBoundaryType, const bool& aFromUser) override;
virtual mozilla::ipc::IPCResult RecvScrollingEvent(
const uint64_t& aID, const uint64_t& aType, const uint32_t& aScrollX,
const uint32_t& aScrollY, const uint32_t& aMaxScrollX,
const uint32_t& aMaxScrollY) override;
virtual mozilla::ipc::IPCResult RecvCache(
const mozilla::a11y::CacheUpdateType& aUpdateType,
nsTArray<CacheData>&& aData, const bool& aFinal) override;
virtual mozilla::ipc::IPCResult RecvSelectedAccessiblesChanged(
nsTArray<uint64_t>&& aSelectedIDs,
nsTArray<uint64_t>&& aUnselectedIDs) override;
virtual mozilla::ipc::IPCResult RecvAccessiblesWillMove(
nsTArray<uint64_t>&& aIDs) override;
#if !defined(XP_WIN)
virtual mozilla::ipc::IPCResult RecvAnnouncementEvent(
const uint64_t& aID, const nsAString& aAnnouncement,
const uint16_t& aPriority) override;
virtual mozilla::ipc::IPCResult RecvTextSelectionChangeEvent(
const uint64_t& aID, nsTArray<TextRangeData>&& aSelection) override;
mozilla::ipc::IPCResult RecvRoleChangedEvent(const a11y::role& aRole) final;
virtual mozilla::ipc::IPCResult RecvBindChildDoc(
PDocAccessibleParent* aChildDoc, const uint64_t& aID) override;
void Unbind() {
if (DocAccessibleParent* parent = ParentDoc()) {
virtual mozilla::ipc::IPCResult RecvShutdown() override;
void Destroy();
virtual void ActorDestroy(ActorDestroyReason aWhy) override;
* Return the main processes representation of the parent document (if any)
* of the document this object represents.
DocAccessibleParent* ParentDoc() const;
static const uint64_t kNoParentDoc = UINT64_MAX;
* Called when a document in a content process notifies the main process of a
* new child document.
* Although this is called internally for OOP child documents, these should be
* added via the BrowserBridgeParent version of this method, as the parent id
* might not exist yet in that case.
ipc::IPCResult AddChildDoc(DocAccessibleParent* aChildDoc, uint64_t aParentID,
bool aCreating = true);
* Called when a document in a content process notifies the main process of a
* new OOP child document.
ipc::IPCResult AddChildDoc(dom::BrowserBridgeParent* aBridge);
void RemovePendingOOPChildDoc(dom::BrowserBridgeParent* aBridge) {
* Called when the document in the content process this object represents
* notifies the main process a child document has been removed.
void RemoveChildDoc(DocAccessibleParent* aChildDoc) {
RemoteAccessible* parent = aChildDoc->RemoteParent();
if (parent) {
DebugOnly<bool> result = mChildDocs.RemoveElement(aChildDoc->mActorID);
aChildDoc->mParentDoc = kNoParentDoc;
void RemoveAccessible(RemoteAccessible* aAccessible) {
* Return the accessible for given id.
RemoteAccessible* GetAccessible(uintptr_t aID) {
if (!aID) return this;
ProxyEntry* e = mAccessibles.GetEntry(aID);
return e ? e->mProxy : nullptr;
const RemoteAccessible* GetAccessible(uintptr_t aID) const {
return const_cast<DocAccessibleParent*>(this)->GetAccessible(aID);
size_t ChildDocCount() const { return mChildDocs.Length(); }
const DocAccessibleParent* ChildDocAt(size_t aIdx) const {
return const_cast<DocAccessibleParent*>(this)->ChildDocAt(aIdx);
DocAccessibleParent* ChildDocAt(size_t aIdx) {
return LiveDocs().Get(mChildDocs[aIdx]);
#if defined(XP_WIN)
void MaybeInitWindowEmulation();
* Note that an OuterDocAccessible can be created before the
* DocAccessibleParent or vice versa. Therefore, this must be conditionally
* called when either of these is created.
* @param aOuterDoc The OuterDocAccessible to be returned as the parent of
* this document.
void SendParentCOMProxy(Accessible* aOuterDoc);
* Set emulated native window handle for a document.
* @param aWindowHandle emulated native window handle
void SetEmulatedWindowHandle(HWND aWindowHandle);
HWND GetEmulatedWindowHandle() const { return mEmulatedWindowHandle; }
#if !defined(XP_WIN)
virtual mozilla::ipc::IPCResult RecvBatch(
const uint64_t& aBatchType, nsTArray<BatchData>&& aData) override;
virtual bool DeallocPDocAccessiblePlatformExtParent(
PDocAccessiblePlatformExtParent* aActor) override;
virtual PDocAccessiblePlatformExtParent*
AllocPDocAccessiblePlatformExtParent() override;
DocAccessiblePlatformExtParent* GetPlatformExtension();
// Accessible
virtual Accessible* Parent() const override {
if (IsTopLevel()) {
return OuterDocOfRemoteBrowser();
return RemoteParent();
virtual int32_t IndexInParent() const override {
if (IsTopLevel() && OuterDocOfRemoteBrowser()) {
// An OuterDoc can only have 1 child.
return 0;
return RemoteAccessible::IndexInParent();
* Get the focused Accessible in this document, if any.
RemoteAccessible* GetFocusedAcc() const {
return const_cast<DocAccessibleParent*>(this)->GetAccessible(mFocus);
* Get the HyperText Accessible containing the caret and the offset of the
* caret within. If there is no caret in this document, returns
* {nullptr, -1}.
std::pair<RemoteAccessible*, int32_t> GetCaret() const {
if (mCaretOffset == -1) {
return {nullptr, -1};
RemoteAccessible* acc =
if (!acc) {
return {nullptr, -1};
return {acc, mCaretOffset};
bool IsCaretAtEndOfLine() const { return mIsCaretAtEndOfLine; }
virtual void SelectionRanges(nsTArray<TextRange>* aRanges) const override;
void URL(nsAString& aURL) const;
// Tracks cached reverse relations (ie. those not set explicitly by an
// attribute like aria-labelledby) for accessibles in this doc. This map is of
// the form: {accID, {relationType, [targetAccID, targetAccID, ...]}}
nsTHashMap<uint64_t, nsTHashMap<uint64_t, nsTArray<uint64_t>>>
class ProxyEntry : public PLDHashEntryHdr {
explicit ProxyEntry(const void*) : mProxy(nullptr) {}
ProxyEntry(ProxyEntry&& aOther) : mProxy(aOther.mProxy) {
aOther.mProxy = nullptr;
~ProxyEntry() { delete mProxy; }
typedef uint64_t KeyType;
typedef const void* KeyTypePointer;
bool KeyEquals(const void* aKey) const {
return mProxy->ID() == (uint64_t)aKey;
static const void* KeyToPointer(uint64_t aKey) { return (void*)aKey; }
static PLDHashNumber HashKey(const void* aKey) { return (uint64_t)aKey; }
enum { ALLOW_MEMMOVE = true };
RemoteAccessible* mProxy;
uint32_t AddSubtree(RemoteAccessible* aParent,
const nsTArray<AccessibleData>& aNewTree, uint32_t aIdx,
uint32_t aIdxInParent);
[[nodiscard]] bool CheckDocTree() const;
xpcAccessibleGeneric* GetXPCAccessible(RemoteAccessible* aProxy);
void FireEvent(RemoteAccessible* aAcc, const uint32_t& aType);
* If this Accessible is being moved, prepare it for reuse. Otherwise, it is
* being removed, so shut it down.
void ShutdownOrPrepareForMove(RemoteAccessible* aAcc);
nsTArray<uint64_t> mChildDocs;
uint64_t mParentDoc;
#if defined(XP_WIN)
// The handle associated with the emulated window that contains this document
HWND mEmulatedWindowHandle;
# if defined(MOZ_SANDBOX)
mscom::PreservedStreamPtr mParentProxyStream;
mscom::PreservedStreamPtr mDocProxyStream;
mscom::PreservedStreamPtr mTopLevelDocProxyStream;
# endif // defined(MOZ_SANDBOX)
#endif // defined(XP_WIN)
* Conceptually this is a map from IDs to proxies, but we store the ID in the
* proxy object so we can't use a real map.
nsTHashtable<ProxyEntry> mAccessibles;
nsTHashSet<uint64_t> mMovingIDs;
uint64_t mActorID;
bool mTopLevel;
bool mTopLevelInContentProcess;
bool mShutdown;
RefPtr<dom::CanonicalBrowsingContext> mBrowsingContext;
nsTHashSet<RefPtr<dom::BrowserBridgeParent>> mPendingOOPChildDocs;
uint64_t mFocus;
uint64_t mCaretId;
int32_t mCaretOffset;
bool mIsCaretAtEndOfLine;
nsTArray<TextRangeData> mTextSelections;
static uint64_t sMaxDocID;
static nsTHashMap<nsUint64HashKey, DocAccessibleParent*>& LiveDocs() {
static nsTHashMap<nsUint64HashKey, DocAccessibleParent*> sLiveDocs;
return sLiveDocs;
} // namespace a11y
} // namespace mozilla