1 files changed, 702 insertions, 0 deletions
diff --git a/layout/base/AccessibleCaretEventHub.cpp b/layout/base/AccessibleCaretEventHub.cpp
new file mode 100644
index 0000000000..d9cd91d866
--- /dev/null
+++ b/layout/base/AccessibleCaretEventHub.cpp
@@ -0,0 +1,702 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=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 http://mozilla.org/MPL/2.0/. */
+
+#include "AccessibleCaretEventHub.h"
+
+#include "AccessibleCaretLogger.h"
+#include "AccessibleCaretManager.h"
+
+#include "mozilla/AutoRestore.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/StaticPrefs_layout.h"
+#include "mozilla/StaticPrefs_ui.h"
+#include "mozilla/TextEvents.h"
+#include "mozilla/TouchEvents.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/MouseEventBinding.h"
+#include "mozilla/dom/Selection.h"
+#include "nsCanvasFrame.h"
+#include "nsDocShell.h"
+#include "nsFocusManager.h"
+#include "nsFrameSelection.h"
+#include "nsITimer.h"
+#include "nsLayoutUtils.h"
+#include "nsPresContext.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+namespace mozilla {
+
+#undef AC_LOG
+#define AC_LOG(message, ...) \
+  AC_LOG_BASE("AccessibleCaretEventHub (%p): " message, this, ##__VA_ARGS__);
+
+#undef AC_LOGV
+#define AC_LOGV(message, ...) \
+  AC_LOGV_BASE("AccessibleCaretEventHub (%p): " message, this, ##__VA_ARGS__);
+
+NS_IMPL_ISUPPORTS(AccessibleCaretEventHub, nsIReflowObserver, nsIScrollObserver,
+                  nsISupportsWeakReference);
+
+// -----------------------------------------------------------------------------
+// NoActionState
+//
+class AccessibleCaretEventHub::NoActionState
+    : public AccessibleCaretEventHub::State {
+ public:
+  const char* Name() const override { return "NoActionState"; }
+
+  MOZ_CAN_RUN_SCRIPT
+  nsEventStatus OnPress(AccessibleCaretEventHub* aContext,
+                        const nsPoint& aPoint, int32_t aTouchId,
+                        EventClassID aEventClass) override {
+    nsEventStatus rv = nsEventStatus_eIgnore;
+
+    if (NS_SUCCEEDED(aContext->mManager->PressCaret(aPoint, aEventClass))) {
+      aContext->SetState(AccessibleCaretEventHub::PressCaretState());
+      rv = nsEventStatus_eConsumeNoDefault;
+    } else {
+      aContext->SetState(AccessibleCaretEventHub::PressNoCaretState());
+    }
+
+    aContext->mPressPoint = aPoint;
+    aContext->mActiveTouchId = aTouchId;
+
+    return rv;
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnScrollStart(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnScrollStart();
+    aContext->SetState(AccessibleCaretEventHub::ScrollState());
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnScrollPositionChanged(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnScrollPositionChanged();
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnSelectionChanged(AccessibleCaretEventHub* aContext, Document* aDoc,
+                          dom::Selection* aSel, int16_t aReason) override {
+    aContext->mManager->OnSelectionChanged(aDoc, aSel, aReason);
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnBlur(AccessibleCaretEventHub* aContext,
+              bool aIsLeavingDocument) override {
+    aContext->mManager->OnBlur();
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnReflow(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnReflow();
+  }
+
+  void Enter(AccessibleCaretEventHub* aContext) override {
+    aContext->mPressPoint = nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);
+    aContext->mActiveTouchId = kInvalidTouchId;
+  }
+};
+
+// -----------------------------------------------------------------------------
+// PressCaretState: Because we've pressed on the caret, always consume the
+// event, both real and synthesized, so that other event handling code won't
+// have a chance to do something else to interrupt caret dragging.
+//
+class AccessibleCaretEventHub::PressCaretState
+    : public AccessibleCaretEventHub::State {
+ public:
+  const char* Name() const override { return "PressCaretState"; }
+
+  MOZ_CAN_RUN_SCRIPT
+  nsEventStatus OnMove(AccessibleCaretEventHub* aContext, const nsPoint& aPoint,
+                       WidgetMouseEvent::Reason aReason) override {
+    if (aReason == WidgetMouseEvent::eReal &&
+        aContext->MoveDistanceIsLarge(aPoint)) {
+      if (NS_SUCCEEDED(aContext->mManager->DragCaret(aPoint))) {
+        aContext->SetState(AccessibleCaretEventHub::DragCaretState());
+      }
+    }
+
+    return nsEventStatus_eConsumeNoDefault;
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  nsEventStatus OnRelease(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->ReleaseCaret();
+    aContext->mManager->TapCaret(aContext->mPressPoint);
+    aContext->SetState(AccessibleCaretEventHub::NoActionState());
+
+    return nsEventStatus_eConsumeNoDefault;
+  }
+
+  nsEventStatus OnLongTap(AccessibleCaretEventHub* aContext,
+                          const nsPoint& aPoint) override {
+    return nsEventStatus_eConsumeNoDefault;
+  }
+};
+
+// -----------------------------------------------------------------------------
+// DragCaretState: Because we've pressed on the caret, always consume the event,
+// both real and synthesized, so that other event handling code won't have a
+// chance to do something else to interrupt caret dragging.
+//
+class AccessibleCaretEventHub::DragCaretState
+    : public AccessibleCaretEventHub::State {
+ public:
+  const char* Name() const override { return "DragCaretState"; }
+
+  MOZ_CAN_RUN_SCRIPT
+  nsEventStatus OnMove(AccessibleCaretEventHub* aContext, const nsPoint& aPoint,
+                       WidgetMouseEvent::Reason aReason) override {
+    if (aReason == WidgetMouseEvent::eReal) {
+      aContext->mManager->DragCaret(aPoint);
+    }
+
+    return nsEventStatus_eConsumeNoDefault;
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  nsEventStatus OnRelease(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->ReleaseCaret();
+    aContext->SetState(AccessibleCaretEventHub::NoActionState());
+
+    return nsEventStatus_eConsumeNoDefault;
+  }
+};
+
+// -----------------------------------------------------------------------------
+// PressNoCaretState
+//
+class AccessibleCaretEventHub::PressNoCaretState
+    : public AccessibleCaretEventHub::State {
+ public:
+  const char* Name() const override { return "PressNoCaretState"; }
+
+  nsEventStatus OnMove(AccessibleCaretEventHub* aContext, const nsPoint& aPoint,
+                       WidgetMouseEvent::Reason aReason) override {
+    if (aContext->MoveDistanceIsLarge(aPoint)) {
+      aContext->SetState(AccessibleCaretEventHub::NoActionState());
+    }
+
+    return nsEventStatus_eIgnore;
+  }
+
+  nsEventStatus OnRelease(AccessibleCaretEventHub* aContext) override {
+    aContext->SetState(AccessibleCaretEventHub::NoActionState());
+
+    return nsEventStatus_eIgnore;
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  nsEventStatus OnLongTap(AccessibleCaretEventHub* aContext,
+                          const nsPoint& aPoint) override {
+    aContext->SetState(AccessibleCaretEventHub::LongTapState());
+
+    return aContext->GetState()->OnLongTap(aContext, aPoint);
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnScrollStart(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnScrollStart();
+    aContext->SetState(AccessibleCaretEventHub::ScrollState());
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnBlur(AccessibleCaretEventHub* aContext,
+              bool aIsLeavingDocument) override {
+    aContext->mManager->OnBlur();
+    if (aIsLeavingDocument) {
+      aContext->SetState(AccessibleCaretEventHub::NoActionState());
+    }
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnSelectionChanged(AccessibleCaretEventHub* aContext, Document* aDoc,
+                          dom::Selection* aSel, int16_t aReason) override {
+    aContext->mManager->OnSelectionChanged(aDoc, aSel, aReason);
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnReflow(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnReflow();
+  }
+
+  void Enter(AccessibleCaretEventHub* aContext) override {
+    aContext->LaunchLongTapInjector();
+  }
+
+  void Leave(AccessibleCaretEventHub* aContext) override {
+    aContext->CancelLongTapInjector();
+  }
+};
+
+// -----------------------------------------------------------------------------
+// ScrollState
+//
+class AccessibleCaretEventHub::ScrollState
+    : public AccessibleCaretEventHub::State {
+ public:
+  const char* Name() const override { return "ScrollState"; }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnScrollEnd(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnScrollEnd();
+    aContext->SetState(AccessibleCaretEventHub::NoActionState());
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnScrollPositionChanged(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnScrollPositionChanged();
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnBlur(AccessibleCaretEventHub* aContext,
+              bool aIsLeavingDocument) override {
+    aContext->mManager->OnBlur();
+    if (aIsLeavingDocument) {
+      aContext->SetState(AccessibleCaretEventHub::NoActionState());
+    }
+  }
+};
+
+// -----------------------------------------------------------------------------
+// LongTapState
+//
+class AccessibleCaretEventHub::LongTapState
+    : public AccessibleCaretEventHub::State {
+ public:
+  const char* Name() const override { return "LongTapState"; }
+
+  MOZ_CAN_RUN_SCRIPT
+  nsEventStatus OnLongTap(AccessibleCaretEventHub* aContext,
+                          const nsPoint& aPoint) override {
+    // In general text selection is lower-priority than the context menu. If
+    // we consume this long-press event, then it prevents the context menu from
+    // showing up on desktop Firefox (because that happens on long-tap-up, if
+    // the long-tap was not cancelled). So we return eIgnore instead.
+    aContext->mManager->SelectWordOrShortcut(aPoint);
+    return nsEventStatus_eIgnore;
+  }
+
+  nsEventStatus OnRelease(AccessibleCaretEventHub* aContext) override {
+    aContext->SetState(AccessibleCaretEventHub::NoActionState());
+
+    // Do not consume the release since the press is not consumed in
+    // PressNoCaretState either.
+    return nsEventStatus_eIgnore;
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnScrollStart(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnScrollStart();
+    aContext->SetState(AccessibleCaretEventHub::ScrollState());
+  }
+
+  MOZ_CAN_RUN_SCRIPT
+  void OnReflow(AccessibleCaretEventHub* aContext) override {
+    aContext->mManager->OnReflow();
+  }
+};
+
+// -----------------------------------------------------------------------------
+// Implementation of AccessibleCaretEventHub methods
+//
+AccessibleCaretEventHub::State* AccessibleCaretEventHub::GetState() const {
+  return mState;
+}
+
+void AccessibleCaretEventHub::SetState(State* aState) {
+  MOZ_ASSERT(aState);
+
+  AC_LOG("%s -> %s", mState->Name(), aState->Name());
+
+  mState->Leave(this);
+  mState = aState;
+  mState->Enter(this);
+}
+
+MOZ_IMPL_STATE_CLASS_GETTER(NoActionState)
+MOZ_IMPL_STATE_CLASS_GETTER(PressCaretState)
+MOZ_IMPL_STATE_CLASS_GETTER(DragCaretState)
+MOZ_IMPL_STATE_CLASS_GETTER(PressNoCaretState)
+MOZ_IMPL_STATE_CLASS_GETTER(ScrollState)
+MOZ_IMPL_STATE_CLASS_GETTER(LongTapState)
+
+AccessibleCaretEventHub::AccessibleCaretEventHub(PresShell* aPresShell)
+    : mPresShell(aPresShell) {}
+
+void AccessibleCaretEventHub::Init() {
+  if (mInitialized || !mPresShell) {
+    return;
+  }
+
+  // Without nsAutoScriptBlocker, the script might be run after constructing
+  // mFirstCaret in AccessibleCaretManager's constructor, which might destructs
+  // the whole frame tree. Therefore we'll fail to construct mSecondCaret
+  // because we cannot get root frame or canvas frame from mPresShell to inject
+  // anonymous content. To avoid that, we protect Init() by nsAutoScriptBlocker.
+  // To reproduce, run "./mach crashtest layout/base/crashtests/897852.html"
+  // without the following scriptBlocker.
+  nsAutoScriptBlocker scriptBlocker;
+
+  nsPresContext* presContext = mPresShell->GetPresContext();
+  MOZ_ASSERT(presContext, "PresContext should be given in PresShell::Init()");
+
+  nsDocShell* docShell = presContext->GetDocShell();
+  if (!docShell) {
+    return;
+  }
+
+  docShell->AddWeakReflowObserver(this);
+  docShell->AddWeakScrollObserver(this);
+
+  mDocShell = static_cast<nsDocShell*>(docShell);
+
+  if (StaticPrefs::layout_accessiblecaret_use_long_tap_injector()) {
+    mLongTapInjectorTimer = NS_NewTimer();
+  }
+
+  mManager = MakeUnique<AccessibleCaretManager>(mPresShell);
+
+  mInitialized = true;
+}
+
+void AccessibleCaretEventHub::Terminate() {
+  if (!mInitialized) {
+    return;
+  }
+
+  if (mDocShell) {
+    mDocShell->RemoveWeakReflowObserver(this);
+    mDocShell->RemoveWeakScrollObserver(this);
+  }
+
+  if (mLongTapInjectorTimer) {
+    mLongTapInjectorTimer->Cancel();
+  }
+
+  mManager->Terminate();
+  mPresShell = nullptr;
+  mInitialized = false;
+}
+
+nsEventStatus AccessibleCaretEventHub::HandleEvent(WidgetEvent* aEvent) {
+  nsEventStatus status = nsEventStatus_eIgnore;
+
+  if (!mInitialized) {
+    return status;
+  }
+
+  MOZ_ASSERT(mRefCnt.get() > 1, "Expect caller holds us as well!");
+
+  switch (aEvent->mClass) {
+    case eMouseEventClass:
+      status = HandleMouseEvent(aEvent->AsMouseEvent());
+      break;
+
+    case eTouchEventClass:
+      status = HandleTouchEvent(aEvent->AsTouchEvent());
+      break;
+
+    case eKeyboardEventClass:
+      status = HandleKeyboardEvent(aEvent->AsKeyboardEvent());
+      break;
+
+    default:
+      MOZ_ASSERT_UNREACHABLE(
+          "PresShell should've filtered unwanted event classes!");
+      break;
+  }
+
+  return status;
+}
+
+nsEventStatus AccessibleCaretEventHub::HandleMouseEvent(
+    WidgetMouseEvent* aEvent) {
+  nsEventStatus rv = nsEventStatus_eIgnore;
+
+  if (aEvent->mButton != MouseButton::ePrimary) {
+    return rv;
+  }
+
+  int32_t id =
+      (mActiveTouchId == kInvalidTouchId ? kDefaultTouchId : mActiveTouchId);
+  nsPoint point = GetMouseEventPosition(aEvent);
+
+  if (aEvent->mMessage == eMouseDown || aEvent->mMessage == eMouseUp ||
+      aEvent->mMessage == eMouseClick ||
+      aEvent->mMessage == eMouseDoubleClick ||
+      aEvent->mMessage == eMouseLongTap) {
+    // Don't reset the source on mouse movement since that can
+    // happen anytime, even randomly during a touch sequence.
+    mManager->SetLastInputSource(aEvent->mInputSource);
+  }
+
+  switch (aEvent->mMessage) {
+    case eMouseDown:
+      AC_LOGV("Before eMouseDown, state: %s", mState->Name());
+      rv = mState->OnPress(this, point, id, eMouseEventClass);
+      AC_LOGV("After eMouseDown, state: %s, consume: %d", mState->Name(), rv);
+      break;
+
+    case eMouseMove:
+      AC_LOGV("Before eMouseMove, state: %s", mState->Name());
+      // The mouse move events synthesized from the touch move events can have
+      // wrong point (bug 1549355). Workaround it by ignoring the events when
+      // dragging the caret because the caret doesn't really need them.
+      rv = mState->OnMove(this, point, aEvent->mReason);
+      AC_LOGV("After eMouseMove, state: %s, consume: %d", mState->Name(), rv);
+      break;
+
+    case eMouseUp:
+      AC_LOGV("Before eMouseUp, state: %s", mState->Name());
+      rv = mState->OnRelease(this);
+      AC_LOGV("After eMouseUp, state: %s, consume: %d", mState->Name(), rv);
+      break;
+
+    case eMouseLongTap:
+      AC_LOGV("Before eMouseLongTap, state: %s", mState->Name());
+      rv = mState->OnLongTap(this, point);
+      AC_LOGV("After eMouseLongTap, state: %s, consume: %d", mState->Name(),
+              rv);
+      break;
+
+    default:
+      break;
+  }
+
+  return rv;
+}
+
+nsEventStatus AccessibleCaretEventHub::HandleTouchEvent(
+    WidgetTouchEvent* aEvent) {
+  if (aEvent->mTouches.IsEmpty()) {
+    AC_LOG("%s: Receive a touch event without any touch data!", __FUNCTION__);
+    return nsEventStatus_eIgnore;
+  }
+
+  nsEventStatus rv = nsEventStatus_eIgnore;
+
+  int32_t id =
+      (mActiveTouchId == kInvalidTouchId ? aEvent->mTouches[0]->Identifier()
+                                         : mActiveTouchId);
+  nsPoint point = GetTouchEventPosition(aEvent, id);
+
+  mManager->SetLastInputSource(MouseEvent_Binding::MOZ_SOURCE_TOUCH);
+
+  switch (aEvent->mMessage) {
+    case eTouchStart:
+      AC_LOGV("Before eTouchStart, state: %s", mState->Name());
+      rv = mState->OnPress(this, point, id, eTouchEventClass);
+      AC_LOGV("After eTouchStart, state: %s, consume: %d", mState->Name(), rv);
+      break;
+
+    case eTouchMove:
+      AC_LOGV("Before eTouchMove, state: %s", mState->Name());
+      // There is no synthesized touch move event.
+      rv = mState->OnMove(this, point, WidgetMouseEvent::eReal);
+      AC_LOGV("After eTouchMove, state: %s, consume: %d", mState->Name(), rv);
+      break;
+
+    case eTouchEnd:
+      AC_LOGV("Before eTouchEnd, state: %s", mState->Name());
+      rv = mState->OnRelease(this);
+      AC_LOGV("After eTouchEnd, state: %s, consume: %d", mState->Name(), rv);
+      break;
+
+    case eTouchCancel:
+      AC_LOGV("Got eTouchCancel, state: %s", mState->Name());
+      // Do nothing since we don't really care eTouchCancel anyway.
+      break;
+
+    default:
+      break;
+  }
+
+  return rv;
+}
+
+nsEventStatus AccessibleCaretEventHub::HandleKeyboardEvent(
+    WidgetKeyboardEvent* aEvent) {
+  mManager->SetLastInputSource(MouseEvent_Binding::MOZ_SOURCE_KEYBOARD);
+
+  switch (aEvent->mMessage) {
+    case eKeyUp:
+      AC_LOGV("eKeyUp, state: %s", mState->Name());
+      mManager->OnKeyboardEvent();
+      break;
+
+    case eKeyDown:
+      AC_LOGV("eKeyDown, state: %s", mState->Name());
+      mManager->OnKeyboardEvent();
+      break;
+
+    case eKeyPress:
+      AC_LOGV("eKeyPress, state: %s", mState->Name());
+      mManager->OnKeyboardEvent();
+      break;
+
+    default:
+      break;
+  }
+
+  return nsEventStatus_eIgnore;
+}
+
+bool AccessibleCaretEventHub::MoveDistanceIsLarge(const nsPoint& aPoint) const {
+  nsPoint delta = aPoint - mPressPoint;
+  return NS_hypot(delta.x, delta.y) >
+         AppUnitsPerCSSPixel() * kMoveStartToleranceInPixel;
+}
+
+void AccessibleCaretEventHub::LaunchLongTapInjector() {
+  if (!mLongTapInjectorTimer) {
+    return;
+  }
+
+  int32_t longTapDelay = StaticPrefs::ui_click_hold_context_menus_delay();
+  mLongTapInjectorTimer->InitWithNamedFuncCallback(
+      FireLongTap, this, longTapDelay, nsITimer::TYPE_ONE_SHOT,
+      "AccessibleCaretEventHub::LaunchLongTapInjector");
+}
+
+void AccessibleCaretEventHub::CancelLongTapInjector() {
+  if (!mLongTapInjectorTimer) {
+    return;
+  }
+
+  mLongTapInjectorTimer->Cancel();
+}
+
+/* static */
+void AccessibleCaretEventHub::FireLongTap(nsITimer* aTimer,
+                                          void* aAccessibleCaretEventHub) {
+  RefPtr<AccessibleCaretEventHub> self =
+      static_cast<AccessibleCaretEventHub*>(aAccessibleCaretEventHub);
+  self->mState->OnLongTap(self, self->mPressPoint);
+}
+
+NS_IMETHODIMP
+AccessibleCaretEventHub::Reflow(DOMHighResTimeStamp aStart,
+                                DOMHighResTimeStamp aEnd) {
+  if (!mInitialized) {
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(mRefCnt.get() > 1, "Expect caller holds us as well!");
+
+  if (mIsInReflowCallback) {
+    return NS_OK;
+  }
+
+  AutoRestore<bool> autoRestoreIsInReflowCallback(mIsInReflowCallback);
+  mIsInReflowCallback = true;
+
+  AC_LOG("%s, state: %s", __FUNCTION__, mState->Name());
+  mState->OnReflow(this);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AccessibleCaretEventHub::ReflowInterruptible(DOMHighResTimeStamp aStart,
+                                             DOMHighResTimeStamp aEnd) {
+  // Defer the error checking to Reflow().
+  return Reflow(aStart, aEnd);
+}
+
+void AccessibleCaretEventHub::AsyncPanZoomStarted() {
+  if (!mInitialized) {
+    return;
+  }
+
+  MOZ_ASSERT(mRefCnt.get() > 1, "Expect caller holds us as well!");
+
+  AC_LOG("%s, state: %s", __FUNCTION__, mState->Name());
+  mState->OnScrollStart(this);
+}
+
+void AccessibleCaretEventHub::AsyncPanZoomStopped() {
+  if (!mInitialized) {
+    return;
+  }
+
+  MOZ_ASSERT(mRefCnt.get() > 1, "Expect caller holds us as well!");
+
+  AC_LOG("%s, state: %s", __FUNCTION__, mState->Name());
+  mState->OnScrollEnd(this);
+}
+
+void AccessibleCaretEventHub::ScrollPositionChanged() {
+  if (!mInitialized) {
+    return;
+  }
+
+  MOZ_ASSERT(mRefCnt.get() > 1, "Expect caller holds us as well!");
+
+  AC_LOG("%s, state: %s", __FUNCTION__, mState->Name());
+  mState->OnScrollPositionChanged(this);
+}
+
+void AccessibleCaretEventHub::OnSelectionChange(Document* aDoc,
+                                                dom::Selection* aSel,
+                                                int16_t aReason) {
+  if (!mInitialized) {
+    return;
+  }
+
+  MOZ_ASSERT(mRefCnt.get() > 1, "Expect caller holds us as well!");
+
+  AC_LOG("%s, state: %s, reason: %d", __FUNCTION__, mState->Name(), aReason);
+
+  // XXX Here we may be in a hot path.  So, if we could avoid this virtual call,
+  //     we should do so.
+  mState->OnSelectionChanged(this, aDoc, aSel, aReason);
+}
+
+bool AccessibleCaretEventHub::ShouldDisableApz() const {
+  return mManager && mManager->ShouldDisableApz();
+}
+
+void AccessibleCaretEventHub::NotifyBlur(bool aIsLeavingDocument) {
+  if (!mInitialized) {
+    return;
+  }
+
+  MOZ_ASSERT(mRefCnt.get() > 1, "Expect caller holds us as well!");
+
+  AC_LOG("%s, state: %s", __FUNCTION__, mState->Name());
+  mState->OnBlur(this, aIsLeavingDocument);
+}
+
+nsPoint AccessibleCaretEventHub::GetTouchEventPosition(
+    WidgetTouchEvent* aEvent, int32_t aIdentifier) const {
+  for (dom::Touch* touch : aEvent->mTouches) {
+    if (touch->Identifier() == aIdentifier) {
+      LayoutDeviceIntPoint touchIntPoint = touch->mRefPoint;
+
+      // Get event coordinate relative to root frame.
+      nsIFrame* rootFrame = mPresShell->GetRootFrame();
+      return nsLayoutUtils::GetEventCoordinatesRelativeTo(
+          aEvent, touchIntPoint, RelativeTo{rootFrame});
+    }
+  }
+  return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);
+}
+
+nsPoint AccessibleCaretEventHub::GetMouseEventPosition(
+    WidgetMouseEvent* aEvent) const {
+  LayoutDeviceIntPoint mouseIntPoint = aEvent->AsGUIEvent()->mRefPoint;
+
+  // Get event coordinate relative to root frame.
+  nsIFrame* rootFrame = mPresShell->GetRootFrame();
+  return nsLayoutUtils::GetEventCoordinatesRelativeTo(aEvent, mouseIntPoint,
+                                                      RelativeTo{rootFrame});
+}
+
+}  // namespace mozilla