gecko-dev/accessible/base/NotificationController.cpp

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/* -*- 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/. */
#include "NotificationController.h"
#include "DocAccessible-inl.h"
#include "DocAccessibleChild.h"
#include "TextLeafAccessible.h"
#include "TextUpdater.h"
#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/Element.h"
#include "mozilla/Telemetry.h"
using namespace mozilla;
using namespace mozilla::a11y;
////////////////////////////////////////////////////////////////////////////////
// NotificationCollector
////////////////////////////////////////////////////////////////////////////////
NotificationController::NotificationController(DocAccessible* aDocument,
nsIPresShell* aPresShell) :
EventQueue(aDocument), mObservingState(eNotObservingRefresh),
mPresShell(aPresShell)
{
// Schedule initial accessible tree construction.
ScheduleProcessing();
}
NotificationController::~NotificationController()
{
NS_ASSERTION(!mDocument, "Controller wasn't shutdown properly!");
if (mDocument)
Shutdown();
}
////////////////////////////////////////////////////////////////////////////////
// NotificationCollector: AddRef/Release and cycle collection
NS_IMPL_CYCLE_COLLECTING_NATIVE_ADDREF(NotificationController)
NS_IMPL_CYCLE_COLLECTING_NATIVE_RELEASE(NotificationController)
NS_IMPL_CYCLE_COLLECTION_CLASS(NotificationController)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(NotificationController)
if (tmp->mDocument)
tmp->Shutdown();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(NotificationController)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mHangingChildDocuments)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mContentInsertions)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mEvents)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(NotificationController, AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(NotificationController, Release)
////////////////////////////////////////////////////////////////////////////////
// NotificationCollector: public
void
NotificationController::Shutdown()
{
if (mObservingState != eNotObservingRefresh &&
mPresShell->RemoveRefreshObserver(this, Flush_Display)) {
mObservingState = eNotObservingRefresh;
}
// Shutdown handling child documents.
int32_t childDocCount = mHangingChildDocuments.Length();
for (int32_t idx = childDocCount - 1; idx >= 0; idx--) {
if (!mHangingChildDocuments[idx]->IsDefunct())
mHangingChildDocuments[idx]->Shutdown();
}
mHangingChildDocuments.Clear();
mDocument = nullptr;
mPresShell = nullptr;
mTextHash.Clear();
mContentInsertions.Clear();
mNotifications.Clear();
mEvents.Clear();
}
void
NotificationController::ScheduleChildDocBinding(DocAccessible* aDocument)
{
// Schedule child document binding to the tree.
mHangingChildDocuments.AppendElement(aDocument);
ScheduleProcessing();
}
void
NotificationController::ScheduleContentInsertion(Accessible* aContainer,
nsIContent* aStartChildNode,
nsIContent* aEndChildNode)
{
nsRefPtr<ContentInsertion> insertion = new ContentInsertion(mDocument,
aContainer);
if (insertion && insertion->InitChildList(aStartChildNode, aEndChildNode) &&
mContentInsertions.AppendElement(insertion)) {
ScheduleProcessing();
}
}
////////////////////////////////////////////////////////////////////////////////
// NotificationCollector: protected
void
NotificationController::ScheduleProcessing()
{
// If notification flush isn't planed yet start notification flush
// asynchronously (after style and layout).
if (mObservingState == eNotObservingRefresh) {
if (mPresShell->AddRefreshObserver(this, Flush_Display))
mObservingState = eRefreshObserving;
}
}
bool
NotificationController::IsUpdatePending()
{
return mPresShell->IsLayoutFlushObserver() ||
mObservingState == eRefreshProcessingForUpdate ||
mContentInsertions.Length() != 0 || mNotifications.Length() != 0 ||
mTextHash.Count() != 0 ||
!mDocument->HasLoadState(DocAccessible::eTreeConstructed);
}
////////////////////////////////////////////////////////////////////////////////
// NotificationCollector: private
void
NotificationController::WillRefresh(mozilla::TimeStamp aTime)
{
Telemetry::AutoTimer<Telemetry::A11Y_UPDATE_TIME> updateTimer;
// If the document accessible that notification collector was created for is
// now shut down, don't process notifications anymore.
NS_ASSERTION(mDocument,
"The document was shut down while refresh observer is attached!");
if (!mDocument)
return;
if (mObservingState == eRefreshProcessing ||
mObservingState == eRefreshProcessingForUpdate)
return;
// Any generic notifications should be queued if we're processing content
// insertions or generic notifications.
mObservingState = eRefreshProcessingForUpdate;
// Initial accessible tree construction.
if (!mDocument->HasLoadState(DocAccessible::eTreeConstructed)) {
// If document is not bound to parent at this point then the document is not
// ready yet (process notifications later).
if (!mDocument->IsBoundToParent()) {
mObservingState = eRefreshObserving;
return;
}
#ifdef A11Y_LOG
if (logging::IsEnabled(logging::eTree)) {
logging::MsgBegin("TREE", "initial tree created");
logging::Address("document", mDocument);
logging::MsgEnd();
}
#endif
mDocument->DoInitialUpdate();
NS_ASSERTION(mContentInsertions.Length() == 0,
"Pending content insertions while initial accessible tree isn't created!");
}
// Initialize scroll support if needed.
if (!(mDocument->mDocFlags & DocAccessible::eScrollInitialized))
mDocument->AddScrollListener();
// Process content inserted notifications to update the tree. Process other
// notifications like DOM events and then flush event queue. If any new
// notifications are queued during this processing then they will be processed
// on next refresh. If notification processing queues up new events then they
// are processed in this refresh. If events processing queues up new events
// then new events are processed on next refresh.
// Note: notification processing or event handling may shut down the owning
// document accessible.
// Process only currently queued content inserted notifications.
nsTArray<nsRefPtr<ContentInsertion> > contentInsertions;
contentInsertions.SwapElements(mContentInsertions);
uint32_t insertionCount = contentInsertions.Length();
for (uint32_t idx = 0; idx < insertionCount; idx++) {
contentInsertions[idx]->Process();
if (!mDocument)
return;
}
// Process rendered text change notifications.
mTextHash.EnumerateEntries(TextEnumerator, mDocument);
mTextHash.Clear();
// Bind hanging child documents.
uint32_t hangingDocCnt = mHangingChildDocuments.Length();
for (uint32_t idx = 0; idx < hangingDocCnt; idx++) {
DocAccessible* childDoc = mHangingChildDocuments[idx];
if (childDoc->IsDefunct())
continue;
nsIContent* ownerContent = mDocument->DocumentNode()->
FindContentForSubDocument(childDoc->DocumentNode());
if (ownerContent) {
Accessible* outerDocAcc = mDocument->GetAccessible(ownerContent);
if (outerDocAcc && outerDocAcc->AppendChild(childDoc)) {
if (mDocument->AppendChildDocument(childDoc)) {
continue;
}
outerDocAcc->RemoveChild(childDoc);
}
// Failed to bind the child document, destroy it.
childDoc->Shutdown();
}
}
nsTArray<nsRefPtr<DocAccessible>> newChildDocs = Move(mHangingChildDocuments);
// If the document is ready and all its subdocuments are completely loaded
// then process the document load.
if (mDocument->HasLoadState(DocAccessible::eReady) &&
!mDocument->HasLoadState(DocAccessible::eCompletelyLoaded) &&
hangingDocCnt == 0) {
uint32_t childDocCnt = mDocument->ChildDocumentCount(), childDocIdx = 0;
for (; childDocIdx < childDocCnt; childDocIdx++) {
DocAccessible* childDoc = mDocument->GetChildDocumentAt(childDocIdx);
if (!childDoc->HasLoadState(DocAccessible::eCompletelyLoaded))
break;
}
if (childDocIdx == childDocCnt) {
mDocument->ProcessLoad();
if (!mDocument)
return;
}
}
// Process only currently queued generic notifications.
nsTArray < nsRefPtr<Notification> > notifications;
notifications.SwapElements(mNotifications);
uint32_t notificationCount = notifications.Length();
for (uint32_t idx = 0; idx < notificationCount; idx++) {
notifications[idx]->Process();
if (!mDocument)
return;
}
// Process invalidation list of the document after all accessible tree
// modification are done.
mDocument->ProcessInvalidationList();
// If a generic notification occurs after this point then we may be allowed to
// process it synchronously. However we do not want to reenter if fireing
// events causes script to run.
mObservingState = eRefreshProcessing;
ProcessEventQueue();
if (IPCAccessibilityActive()) {
size_t newDocCount = newChildDocs.Length();
for (size_t i = 0; i < newDocCount; i++) {
DocAccessible* childDoc = newChildDocs[i];
DocAccessibleChild* ipcDoc = new DocAccessibleChild(childDoc);
childDoc->SetIPCDoc(ipcDoc);
auto contentChild = dom::ContentChild::GetSingleton();
DocAccessibleChild* parentIPCDoc = mDocument->IPCDoc();
uint64_t id = reinterpret_cast<uintptr_t>(childDoc->Parent()->UniqueID());
contentChild->SendPDocAccessibleConstructor(ipcDoc, parentIPCDoc, id);
}
}
mObservingState = eRefreshObserving;
if (!mDocument)
return;
// Stop further processing if there are no new notifications of any kind or
// events and document load is processed.
if (mContentInsertions.IsEmpty() && mNotifications.IsEmpty() &&
mEvents.IsEmpty() && mTextHash.Count() == 0 &&
mHangingChildDocuments.IsEmpty() &&
mDocument->HasLoadState(DocAccessible::eCompletelyLoaded) &&
mPresShell->RemoveRefreshObserver(this, Flush_Display)) {
mObservingState = eNotObservingRefresh;
}
}
////////////////////////////////////////////////////////////////////////////////
// Notification controller: text leaf accessible text update
PLDHashOperator
NotificationController::TextEnumerator(nsCOMPtrHashKey<nsIContent>* aEntry,
void* aUserArg)
{
DocAccessible* document = static_cast<DocAccessible*>(aUserArg);
nsIContent* textNode = aEntry->GetKey();
Accessible* textAcc = document->GetAccessible(textNode);
// If the text node is not in tree or doesn't have frame then this case should
// have been handled already by content removal notifications.
nsINode* containerNode = textNode->GetParentNode();
if (!containerNode) {
NS_ASSERTION(!textAcc,
"Text node was removed but accessible is kept alive!");
return PL_DHASH_NEXT;
}
nsIFrame* textFrame = textNode->GetPrimaryFrame();
if (!textFrame) {
NS_ASSERTION(!textAcc,
"Text node isn't rendered but accessible is kept alive!");
return PL_DHASH_NEXT;
}
nsIContent* containerElm = containerNode->IsElement() ?
containerNode->AsElement() : nullptr;
nsAutoString text;
textFrame->GetRenderedText(&text);
// Remove text accessible if rendered text is empty.
if (textAcc) {
if (text.IsEmpty()) {
#ifdef A11Y_LOG
if (logging::IsEnabled(logging::eTree | logging::eText)) {
logging::MsgBegin("TREE", "text node lost its content");
logging::Node("container", containerElm);
logging::Node("content", textNode);
logging::MsgEnd();
}
#endif
document->ContentRemoved(containerElm, textNode);
return PL_DHASH_NEXT;
}
// Update text of the accessible and fire text change events.
#ifdef A11Y_LOG
if (logging::IsEnabled(logging::eText)) {
logging::MsgBegin("TEXT", "text may be changed");
logging::Node("container", containerElm);
logging::Node("content", textNode);
logging::MsgEntry("old text '%s'",
NS_ConvertUTF16toUTF8(textAcc->AsTextLeaf()->Text()).get());
logging::MsgEntry("new text: '%s'",
NS_ConvertUTF16toUTF8(text).get());
logging::MsgEnd();
}
#endif
TextUpdater::Run(document, textAcc->AsTextLeaf(), text);
return PL_DHASH_NEXT;
}
// Append an accessible if rendered text is not empty.
if (!text.IsEmpty()) {
#ifdef A11Y_LOG
if (logging::IsEnabled(logging::eTree | logging::eText)) {
logging::MsgBegin("TREE", "text node gains new content");
logging::Node("container", containerElm);
logging::Node("content", textNode);
logging::MsgEnd();
}
#endif
// Make sure the text node is in accessible document still.
Accessible* container = document->GetAccessibleOrContainer(containerNode);
NS_ASSERTION(container,
"Text node having rendered text hasn't accessible document!");
if (container) {
nsTArray<nsCOMPtr<nsIContent> > insertedContents;
insertedContents.AppendElement(textNode);
document->ProcessContentInserted(container, &insertedContents);
}
}
return PL_DHASH_NEXT;
}
////////////////////////////////////////////////////////////////////////////////
// NotificationController: content inserted notification
NotificationController::ContentInsertion::
ContentInsertion(DocAccessible* aDocument, Accessible* aContainer) :
mDocument(aDocument), mContainer(aContainer)
{
}
bool
NotificationController::ContentInsertion::
InitChildList(nsIContent* aStartChildNode, nsIContent* aEndChildNode)
{
bool haveToUpdate = false;
nsIContent* node = aStartChildNode;
while (node != aEndChildNode) {
// Notification triggers for content insertion even if no content was
// actually inserted, check if the given content has a frame to discard
// this case early.
if (node->GetPrimaryFrame()) {
if (mInsertedContent.AppendElement(node))
haveToUpdate = true;
}
node = node->GetNextSibling();
}
return haveToUpdate;
}
NS_IMPL_CYCLE_COLLECTION(NotificationController::ContentInsertion,
mContainer)
NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(NotificationController::ContentInsertion,
AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(NotificationController::ContentInsertion,
Release)
void
NotificationController::ContentInsertion::Process()
{
mDocument->ProcessContentInserted(mContainer, &mInsertedContent);
mDocument = nullptr;
mContainer = nullptr;
mInsertedContent.Clear();
}