1 files changed, 868 insertions, 0 deletions
diff --git a/gfx/layers/apz/src/InputBlockState.cpp b/gfx/layers/apz/src/InputBlockState.cpp
new file mode 100644
index 000000000..f1310c031
--- /dev/null
+++ b/gfx/layers/apz/src/InputBlockState.cpp
@@ -0,0 +1,868 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et 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 "InputBlockState.h"
+#include "AsyncPanZoomController.h"         // for AsyncPanZoomController
+#include "AsyncScrollBase.h"                // for kScrollSeriesTimeoutMs
+#include "gfxPrefs.h"                       // for gfxPrefs
+#include "mozilla/MouseEvents.h"
+#include "mozilla/SizePrintfMacros.h"       // for PRIuSIZE
+#include "mozilla/Telemetry.h"              // for Telemetry
+#include "mozilla/layers/APZCTreeManager.h" // for AllowedTouchBehavior
+#include "OverscrollHandoffState.h"
+#include "QueuedInput.h"
+
+#define TBS_LOG(...)
+// #define TBS_LOG(...) printf_stderr("TBS: " __VA_ARGS__)
+
+namespace mozilla {
+namespace layers {
+
+static uint64_t sBlockCounter = InputBlockState::NO_BLOCK_ID + 1;
+
+InputBlockState::InputBlockState(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                 bool aTargetConfirmed)
+  : mTargetApzc(aTargetApzc)
+  , mTargetConfirmed(aTargetConfirmed ? TargetConfirmationState::eConfirmed
+                                      : TargetConfirmationState::eUnconfirmed)
+  , mBlockId(sBlockCounter++)
+  , mTransformToApzc(aTargetApzc->GetTransformToThis())
+{
+  // We should never be constructed with a nullptr target.
+  MOZ_ASSERT(mTargetApzc);
+  mOverscrollHandoffChain = mTargetApzc->BuildOverscrollHandoffChain();
+}
+
+bool
+InputBlockState::SetConfirmedTargetApzc(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                        TargetConfirmationState aState,
+                                        InputData* aFirstInput)
+{
+  MOZ_ASSERT(aState == TargetConfirmationState::eConfirmed
+          || aState == TargetConfirmationState::eTimedOut);
+
+  if (mTargetConfirmed == TargetConfirmationState::eTimedOut &&
+      aState == TargetConfirmationState::eConfirmed) {
+    // The main thread finally responded. We had already timed out the
+    // confirmation, but we want to update the state internally so that we
+    // can record the time for telemetry purposes.
+    mTargetConfirmed = TargetConfirmationState::eTimedOutAndMainThreadResponded;
+  }
+  if (mTargetConfirmed != TargetConfirmationState::eUnconfirmed) {
+    return false;
+  }
+  mTargetConfirmed = aState;
+
+  TBS_LOG("%p got confirmed target APZC %p\n", this, mTargetApzc.get());
+  if (mTargetApzc == aTargetApzc) {
+    // The confirmed target is the same as the tentative one, so we're done.
+    return true;
+  }
+
+  TBS_LOG("%p replacing unconfirmed target %p with real target %p\n",
+      this, mTargetApzc.get(), aTargetApzc.get());
+
+  UpdateTargetApzc(aTargetApzc);
+  return true;
+}
+
+void
+InputBlockState::UpdateTargetApzc(const RefPtr<AsyncPanZoomController>& aTargetApzc)
+{
+  // note that aTargetApzc MAY be null here.
+  mTargetApzc = aTargetApzc;
+  mTransformToApzc = aTargetApzc ? aTargetApzc->GetTransformToThis() : ScreenToParentLayerMatrix4x4();
+  mOverscrollHandoffChain = (mTargetApzc ? mTargetApzc->BuildOverscrollHandoffChain() : nullptr);
+}
+
+const RefPtr<AsyncPanZoomController>&
+InputBlockState::GetTargetApzc() const
+{
+  return mTargetApzc;
+}
+
+const RefPtr<const OverscrollHandoffChain>&
+InputBlockState::GetOverscrollHandoffChain() const
+{
+  return mOverscrollHandoffChain;
+}
+
+uint64_t
+InputBlockState::GetBlockId() const
+{
+  return mBlockId;
+}
+
+bool
+InputBlockState::IsTargetConfirmed() const
+{
+  return mTargetConfirmed != TargetConfirmationState::eUnconfirmed;
+}
+
+bool
+InputBlockState::HasReceivedRealConfirmedTarget() const
+{
+  return mTargetConfirmed == TargetConfirmationState::eConfirmed ||
+         mTargetConfirmed == TargetConfirmationState::eTimedOutAndMainThreadResponded;
+}
+
+bool
+InputBlockState::IsDownchainOf(AsyncPanZoomController* aA, AsyncPanZoomController* aB) const
+{
+  if (aA == aB) {
+    return true;
+  }
+
+  bool seenA = false;
+  for (size_t i = 0; i < mOverscrollHandoffChain->Length(); ++i) {
+    AsyncPanZoomController* apzc = mOverscrollHandoffChain->GetApzcAtIndex(i);
+    if (apzc == aB) {
+      return seenA;
+    }
+    if (apzc == aA) {
+      seenA = true;
+    }
+  }
+  return false;
+}
+
+
+void
+InputBlockState::SetScrolledApzc(AsyncPanZoomController* aApzc)
+{
+  // An input block should only have one scrolled APZC.
+  MOZ_ASSERT(!mScrolledApzc || (gfxPrefs::APZAllowImmediateHandoff() ? IsDownchainOf(mScrolledApzc, aApzc) : mScrolledApzc == aApzc));
+
+  mScrolledApzc = aApzc;
+}
+
+AsyncPanZoomController*
+InputBlockState::GetScrolledApzc() const
+{
+  return mScrolledApzc;
+}
+
+bool
+InputBlockState::IsDownchainOfScrolledApzc(AsyncPanZoomController* aApzc) const
+{
+  MOZ_ASSERT(aApzc && mScrolledApzc);
+
+  return IsDownchainOf(mScrolledApzc, aApzc);
+}
+
+CancelableBlockState::CancelableBlockState(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                           bool aTargetConfirmed)
+  : InputBlockState(aTargetApzc, aTargetConfirmed)
+  , mPreventDefault(false)
+  , mContentResponded(false)
+  , mContentResponseTimerExpired(false)
+{
+}
+
+bool
+CancelableBlockState::SetContentResponse(bool aPreventDefault)
+{
+  if (mContentResponded) {
+    return false;
+  }
+  TBS_LOG("%p got content response %d with timer expired %d\n",
+    this, aPreventDefault, mContentResponseTimerExpired);
+  mPreventDefault = aPreventDefault;
+  mContentResponded = true;
+  return true;
+}
+
+void
+CancelableBlockState::StartContentResponseTimer()
+{
+  MOZ_ASSERT(mContentResponseTimer.IsNull());
+  mContentResponseTimer = TimeStamp::Now();
+}
+
+bool
+CancelableBlockState::TimeoutContentResponse()
+{
+  if (mContentResponseTimerExpired) {
+    return false;
+  }
+  TBS_LOG("%p got content timer expired with response received %d\n",
+    this, mContentResponded);
+  if (!mContentResponded) {
+    mPreventDefault = false;
+  }
+  mContentResponseTimerExpired = true;
+  return true;
+}
+
+bool
+CancelableBlockState::IsContentResponseTimerExpired() const
+{
+  return mContentResponseTimerExpired;
+}
+
+bool
+CancelableBlockState::IsDefaultPrevented() const
+{
+  MOZ_ASSERT(mContentResponded || mContentResponseTimerExpired);
+  return mPreventDefault;
+}
+
+bool
+CancelableBlockState::HasReceivedAllContentNotifications() const
+{
+  return HasReceivedRealConfirmedTarget() && mContentResponded;
+}
+
+bool
+CancelableBlockState::IsReadyForHandling() const
+{
+  if (!IsTargetConfirmed()) {
+    return false;
+  }
+  return mContentResponded || mContentResponseTimerExpired;
+}
+
+void
+CancelableBlockState::DispatchEvent(const InputData& aEvent) const
+{
+  GetTargetApzc()->HandleInputEvent(aEvent, mTransformToApzc);
+}
+
+void
+CancelableBlockState::RecordContentResponseTime()
+{
+  if (!mContentResponseTimer) {
+    // We might get responses from content even though we didn't wait for them.
+    // In that case, ignore the time on them, because they're not relevant for
+    // tuning our timeout value. Also this function might get called multiple
+    // times on the same input block, so we should only record the time from the
+    // first successful call.
+    return;
+  }
+  if (!HasReceivedAllContentNotifications()) {
+    // Not done yet, we'll get called again
+    return;
+  }
+  mozilla::Telemetry::Accumulate(mozilla::Telemetry::CONTENT_RESPONSE_DURATION,
+    (uint32_t)(TimeStamp::Now() - mContentResponseTimer).ToMilliseconds());
+  mContentResponseTimer = TimeStamp();
+}
+
+DragBlockState::DragBlockState(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                               bool aTargetConfirmed,
+                               const MouseInput& aInitialEvent)
+  : CancelableBlockState(aTargetApzc, aTargetConfirmed)
+  , mReceivedMouseUp(false)
+{
+}
+
+bool
+DragBlockState::HasReceivedMouseUp()
+{
+  return mReceivedMouseUp;
+}
+
+void
+DragBlockState::MarkMouseUpReceived()
+{
+  mReceivedMouseUp = true;
+}
+
+void
+DragBlockState::SetDragMetrics(const AsyncDragMetrics& aDragMetrics)
+{
+  mDragMetrics = aDragMetrics;
+}
+
+void
+DragBlockState::DispatchEvent(const InputData& aEvent) const
+{
+  MouseInput mouseInput = aEvent.AsMouseInput();
+  if (!mouseInput.TransformToLocal(mTransformToApzc)) {
+    return;
+  }
+
+  GetTargetApzc()->HandleDragEvent(mouseInput, mDragMetrics);
+}
+
+bool
+DragBlockState::MustStayActive()
+{
+  return !mReceivedMouseUp;
+}
+
+const char*
+DragBlockState::Type()
+{
+  return "drag";
+}
+// This is used to track the current wheel transaction.
+static uint64_t sLastWheelBlockId = InputBlockState::NO_BLOCK_ID;
+
+WheelBlockState::WheelBlockState(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                 bool aTargetConfirmed,
+                                 const ScrollWheelInput& aInitialEvent)
+  : CancelableBlockState(aTargetApzc, aTargetConfirmed)
+  , mScrollSeriesCounter(0)
+  , mTransactionEnded(false)
+{
+  sLastWheelBlockId = GetBlockId();
+
+  if (aTargetConfirmed) {
+    // Find the nearest APZC in the overscroll handoff chain that is scrollable.
+    // If we get a content confirmation later that the apzc is different, then
+    // content should have found a scrollable apzc, so we don't need to handle
+    // that case.
+    RefPtr<AsyncPanZoomController> apzc =
+      mOverscrollHandoffChain->FindFirstScrollable(aInitialEvent);
+
+    // If nothing is scrollable, we don't consider this block as starting a
+    // transaction.
+    if (!apzc) {
+      EndTransaction();
+      return;
+    }
+
+    if (apzc != GetTargetApzc()) {
+      UpdateTargetApzc(apzc);
+    }
+  }
+}
+
+bool
+WheelBlockState::SetContentResponse(bool aPreventDefault)
+{
+  if (aPreventDefault) {
+    EndTransaction();
+  }
+  return CancelableBlockState::SetContentResponse(aPreventDefault);
+}
+
+bool
+WheelBlockState::SetConfirmedTargetApzc(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                        TargetConfirmationState aState,
+                                        InputData* aFirstInput)
+{
+  // The APZC that we find via APZCCallbackHelpers may not be the same APZC
+  // ESM or OverscrollHandoff would have computed. Make sure we get the right
+  // one by looking for the first apzc the next pending event can scroll.
+  RefPtr<AsyncPanZoomController> apzc = aTargetApzc;
+  if (apzc && aFirstInput) {
+    apzc = apzc->BuildOverscrollHandoffChain()->FindFirstScrollable(*aFirstInput);
+  }
+
+  InputBlockState::SetConfirmedTargetApzc(apzc, aState, aFirstInput);
+  return true;
+}
+
+void
+WheelBlockState::Update(ScrollWheelInput& aEvent)
+{
+  // We might not be in a transaction if the block never started in a
+  // transaction - for example, if nothing was scrollable.
+  if (!InTransaction()) {
+    return;
+  }
+
+  // The current "scroll series" is a like a sub-transaction. It has a separate
+  // timeout of 80ms. Since we need to compute wheel deltas at different phases
+  // of a transaction (for example, when it is updated, and later when the
+  // event action is taken), we affix the scroll series counter to the event.
+  // This makes GetScrollWheelDelta() consistent.
+  if (!mLastEventTime.IsNull() &&
+      (aEvent.mTimeStamp - mLastEventTime).ToMilliseconds() > kScrollSeriesTimeoutMs)
+  {
+    mScrollSeriesCounter = 0;
+  }
+  aEvent.mScrollSeriesNumber = ++mScrollSeriesCounter;
+
+  // If we can't scroll in the direction of the wheel event, we don't update
+  // the last move time. This allows us to timeout a transaction even if the
+  // mouse isn't moving.
+  //
+  // We skip this check if the target is not yet confirmed, so that when it is
+  // confirmed, we don't timeout the transaction.
+  RefPtr<AsyncPanZoomController> apzc = GetTargetApzc();
+  if (IsTargetConfirmed() && !apzc->CanScroll(aEvent)) {
+    return;
+  }
+
+  // Update the time of the last known good event, and reset the mouse move
+  // time to null. This will reset the delays on both the general transaction
+  // timeout and the mouse-move-in-frame timeout.
+  mLastEventTime = aEvent.mTimeStamp;
+  mLastMouseMove = TimeStamp();
+}
+
+bool
+WheelBlockState::MustStayActive()
+{
+  return !mTransactionEnded;
+}
+
+const char*
+WheelBlockState::Type()
+{
+  return "scroll wheel";
+}
+
+bool
+WheelBlockState::ShouldAcceptNewEvent() const
+{
+  if (!InTransaction()) {
+    // If we're not in a transaction, start a new one.
+    return false;
+  }
+
+  RefPtr<AsyncPanZoomController> apzc = GetTargetApzc();
+  if (apzc->IsDestroyed()) {
+    return false;
+  }
+
+  return true;
+}
+
+bool
+WheelBlockState::MaybeTimeout(const ScrollWheelInput& aEvent)
+{
+  MOZ_ASSERT(InTransaction());
+
+  if (MaybeTimeout(aEvent.mTimeStamp)) {
+    return true;
+  }
+
+  if (!mLastMouseMove.IsNull()) {
+    // If there's a recent mouse movement, we can time out the transaction early.
+    TimeDuration duration = TimeStamp::Now() - mLastMouseMove;
+    if (duration.ToMilliseconds() >= gfxPrefs::MouseWheelIgnoreMoveDelayMs()) {
+      TBS_LOG("%p wheel transaction timed out after mouse move\n", this);
+      EndTransaction();
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool
+WheelBlockState::MaybeTimeout(const TimeStamp& aTimeStamp)
+{
+  MOZ_ASSERT(InTransaction());
+
+  // End the transaction if the event occurred > 1.5s after the most recently
+  // seen wheel event.
+  TimeDuration duration = aTimeStamp - mLastEventTime;
+  if (duration.ToMilliseconds() < gfxPrefs::MouseWheelTransactionTimeoutMs()) {
+    return false;
+  }
+
+  TBS_LOG("%p wheel transaction timed out\n", this);
+
+  if (gfxPrefs::MouseScrollTestingEnabled()) {
+    RefPtr<AsyncPanZoomController> apzc = GetTargetApzc();
+    apzc->NotifyMozMouseScrollEvent(NS_LITERAL_STRING("MozMouseScrollTransactionTimeout"));
+  }
+
+  EndTransaction();
+  return true;
+}
+
+void
+WheelBlockState::OnMouseMove(const ScreenIntPoint& aPoint)
+{
+  MOZ_ASSERT(InTransaction());
+
+  if (!GetTargetApzc()->Contains(aPoint)) {
+    EndTransaction();
+    return;
+  }
+
+  if (mLastMouseMove.IsNull()) {
+    // If the cursor is moving inside the frame, and it is more than the
+    // ignoremovedelay time since the last scroll operation, we record
+    // this as the most recent mouse movement.
+    TimeStamp now = TimeStamp::Now();
+    TimeDuration duration = now - mLastEventTime;
+    if (duration.ToMilliseconds() >= gfxPrefs::MouseWheelIgnoreMoveDelayMs()) {
+      mLastMouseMove = now;
+    }
+  }
+}
+
+void
+WheelBlockState::UpdateTargetApzc(const RefPtr<AsyncPanZoomController>& aTargetApzc)
+{
+  InputBlockState::UpdateTargetApzc(aTargetApzc);
+
+  // If we found there was no target apzc, then we end the transaction.
+  if (!GetTargetApzc()) {
+    EndTransaction();
+  }
+}
+
+bool
+WheelBlockState::InTransaction() const
+{
+  // We consider a wheel block to be in a transaction if it has a confirmed
+  // target and is the most recent wheel input block to be created.
+  if (GetBlockId() != sLastWheelBlockId) {
+    return false;
+  }
+
+  if (mTransactionEnded) {
+    return false;
+  }
+
+  MOZ_ASSERT(GetTargetApzc());
+  return true;
+}
+
+bool
+WheelBlockState::AllowScrollHandoff() const
+{
+  // If we're in a wheel transaction, we do not allow overscroll handoff until
+  // a new event ends the wheel transaction.
+  return !IsTargetConfirmed() || !InTransaction();
+}
+
+void
+WheelBlockState::EndTransaction()
+{
+  TBS_LOG("%p ending wheel transaction\n", this);
+  mTransactionEnded = true;
+}
+
+PanGestureBlockState::PanGestureBlockState(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                           bool aTargetConfirmed,
+                                           const PanGestureInput& aInitialEvent)
+  : CancelableBlockState(aTargetApzc, aTargetConfirmed)
+  , mInterrupted(false)
+  , mWaitingForContentResponse(false)
+{
+  if (aTargetConfirmed) {
+    // Find the nearest APZC in the overscroll handoff chain that is scrollable.
+    // If we get a content confirmation later that the apzc is different, then
+    // content should have found a scrollable apzc, so we don't need to handle
+    // that case.
+    RefPtr<AsyncPanZoomController> apzc =
+      mOverscrollHandoffChain->FindFirstScrollable(aInitialEvent);
+
+    if (apzc && apzc != GetTargetApzc()) {
+      UpdateTargetApzc(apzc);
+    }
+  }
+}
+
+bool
+PanGestureBlockState::SetConfirmedTargetApzc(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                             TargetConfirmationState aState,
+                                             InputData* aFirstInput)
+{
+  // The APZC that we find via APZCCallbackHelpers may not be the same APZC
+  // ESM or OverscrollHandoff would have computed. Make sure we get the right
+  // one by looking for the first apzc the next pending event can scroll.
+  RefPtr<AsyncPanZoomController> apzc = aTargetApzc;
+  if (apzc && aFirstInput) {
+    RefPtr<AsyncPanZoomController> scrollableApzc =
+      apzc->BuildOverscrollHandoffChain()->FindFirstScrollable(*aFirstInput);
+    if (scrollableApzc) {
+      apzc = scrollableApzc;
+    }
+  }
+
+  InputBlockState::SetConfirmedTargetApzc(apzc, aState, aFirstInput);
+  return true;
+}
+
+bool
+PanGestureBlockState::MustStayActive()
+{
+  return !mInterrupted;
+}
+
+const char*
+PanGestureBlockState::Type()
+{
+  return "pan gesture";
+}
+
+bool
+PanGestureBlockState::SetContentResponse(bool aPreventDefault)
+{
+  if (aPreventDefault) {
+    TBS_LOG("%p setting interrupted flag\n", this);
+    mInterrupted = true;
+  }
+  bool stateChanged = CancelableBlockState::SetContentResponse(aPreventDefault);
+  if (mWaitingForContentResponse) {
+    mWaitingForContentResponse = false;
+    stateChanged = true;
+  }
+  return stateChanged;
+}
+
+bool
+PanGestureBlockState::HasReceivedAllContentNotifications() const
+{
+  return CancelableBlockState::HasReceivedAllContentNotifications()
+      && !mWaitingForContentResponse;
+}
+
+bool
+PanGestureBlockState::IsReadyForHandling() const
+{
+  if (!CancelableBlockState::IsReadyForHandling()) {
+    return false;
+  }
+  return !mWaitingForContentResponse ||
+         IsContentResponseTimerExpired();
+}
+
+bool
+PanGestureBlockState::AllowScrollHandoff() const
+{
+  return false;
+}
+
+void
+PanGestureBlockState::SetNeedsToWaitForContentResponse(bool aWaitForContentResponse)
+{
+  mWaitingForContentResponse = aWaitForContentResponse;
+}
+
+TouchBlockState::TouchBlockState(const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                 bool aTargetConfirmed, TouchCounter& aCounter)
+  : CancelableBlockState(aTargetApzc, aTargetConfirmed)
+  , mAllowedTouchBehaviorSet(false)
+  , mDuringFastFling(false)
+  , mSingleTapOccurred(false)
+  , mInSlop(false)
+  , mTouchCounter(aCounter)
+{
+  TBS_LOG("Creating %p\n", this);
+  if (!gfxPrefs::TouchActionEnabled()) {
+    mAllowedTouchBehaviorSet = true;
+  }
+}
+
+bool
+TouchBlockState::SetAllowedTouchBehaviors(const nsTArray<TouchBehaviorFlags>& aBehaviors)
+{
+  if (mAllowedTouchBehaviorSet) {
+    return false;
+  }
+  TBS_LOG("%p got allowed touch behaviours for %" PRIuSIZE " points\n", this, aBehaviors.Length());
+  mAllowedTouchBehaviors.AppendElements(aBehaviors);
+  mAllowedTouchBehaviorSet = true;
+  return true;
+}
+
+bool
+TouchBlockState::GetAllowedTouchBehaviors(nsTArray<TouchBehaviorFlags>& aOutBehaviors) const
+{
+  if (!mAllowedTouchBehaviorSet) {
+    return false;
+  }
+  aOutBehaviors.AppendElements(mAllowedTouchBehaviors);
+  return true;
+}
+
+void
+TouchBlockState::CopyPropertiesFrom(const TouchBlockState& aOther)
+{
+  TBS_LOG("%p copying properties from %p\n", this, &aOther);
+  if (gfxPrefs::TouchActionEnabled()) {
+    MOZ_ASSERT(aOther.mAllowedTouchBehaviorSet || aOther.IsContentResponseTimerExpired());
+    SetAllowedTouchBehaviors(aOther.mAllowedTouchBehaviors);
+  }
+  mTransformToApzc = aOther.mTransformToApzc;
+}
+
+bool
+TouchBlockState::HasReceivedAllContentNotifications() const
+{
+  return CancelableBlockState::HasReceivedAllContentNotifications()
+      // See comment in TouchBlockState::IsReadyforHandling()
+      && (!gfxPrefs::TouchActionEnabled() || mAllowedTouchBehaviorSet);
+}
+
+bool
+TouchBlockState::IsReadyForHandling() const
+{
+  if (!CancelableBlockState::IsReadyForHandling()) {
+    return false;
+  }
+
+  if (!gfxPrefs::TouchActionEnabled()) {
+    // If TouchActionEnabled() was false when this block was created, then
+    // mAllowedTouchBehaviorSet is guaranteed to the true. However, the pref
+    // may have been flipped to false after the block was created. In that case,
+    // we should eventually get the touch-behaviour notification, or expire the
+    // content response timeout, but we don't really need to wait for those,
+    // since we don't care about the touch-behaviour values any more.
+    return true;
+  }
+
+  return mAllowedTouchBehaviorSet || IsContentResponseTimerExpired();
+}
+
+void
+TouchBlockState::SetDuringFastFling()
+{
+  TBS_LOG("%p setting fast-motion flag\n", this);
+  mDuringFastFling = true;
+}
+
+bool
+TouchBlockState::IsDuringFastFling() const
+{
+  return mDuringFastFling;
+}
+
+void
+TouchBlockState::SetSingleTapOccurred()
+{
+  TBS_LOG("%p setting single-tap-occurred flag\n", this);
+  mSingleTapOccurred = true;
+}
+
+bool
+TouchBlockState::SingleTapOccurred() const
+{
+  return mSingleTapOccurred;
+}
+
+bool
+TouchBlockState::MustStayActive()
+{
+  return true;
+}
+
+const char*
+TouchBlockState::Type()
+{
+  return "touch";
+}
+
+void
+TouchBlockState::DispatchEvent(const InputData& aEvent) const
+{
+  MOZ_ASSERT(aEvent.mInputType == MULTITOUCH_INPUT);
+  mTouchCounter.Update(aEvent.AsMultiTouchInput());
+  CancelableBlockState::DispatchEvent(aEvent);
+}
+
+bool
+TouchBlockState::TouchActionAllowsPinchZoom() const
+{
+  if (!gfxPrefs::TouchActionEnabled()) {
+    return true;
+  }
+  // Pointer events specification requires that all touch points allow zoom.
+  for (size_t i = 0; i < mAllowedTouchBehaviors.Length(); i++) {
+    if (!(mAllowedTouchBehaviors[i] & AllowedTouchBehavior::PINCH_ZOOM)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool
+TouchBlockState::TouchActionAllowsDoubleTapZoom() const
+{
+  if (!gfxPrefs::TouchActionEnabled()) {
+    return true;
+  }
+  for (size_t i = 0; i < mAllowedTouchBehaviors.Length(); i++) {
+    if (!(mAllowedTouchBehaviors[i] & AllowedTouchBehavior::DOUBLE_TAP_ZOOM)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool
+TouchBlockState::TouchActionAllowsPanningX() const
+{
+  if (!gfxPrefs::TouchActionEnabled()) {
+    return true;
+  }
+  if (mAllowedTouchBehaviors.IsEmpty()) {
+    // Default to allowed
+    return true;
+  }
+  TouchBehaviorFlags flags = mAllowedTouchBehaviors[0];
+  return (flags & AllowedTouchBehavior::HORIZONTAL_PAN);
+}
+
+bool
+TouchBlockState::TouchActionAllowsPanningY() const
+{
+  if (!gfxPrefs::TouchActionEnabled()) {
+    return true;
+  }
+  if (mAllowedTouchBehaviors.IsEmpty()) {
+    // Default to allowed
+    return true;
+  }
+  TouchBehaviorFlags flags = mAllowedTouchBehaviors[0];
+  return (flags & AllowedTouchBehavior::VERTICAL_PAN);
+}
+
+bool
+TouchBlockState::TouchActionAllowsPanningXY() const
+{
+  if (!gfxPrefs::TouchActionEnabled()) {
+    return true;
+  }
+  if (mAllowedTouchBehaviors.IsEmpty()) {
+    // Default to allowed
+    return true;
+  }
+  TouchBehaviorFlags flags = mAllowedTouchBehaviors[0];
+  return (flags & AllowedTouchBehavior::HORIZONTAL_PAN)
+      && (flags & AllowedTouchBehavior::VERTICAL_PAN);
+}
+
+bool
+TouchBlockState::UpdateSlopState(const MultiTouchInput& aInput,
+                                 bool aApzcCanConsumeEvents)
+{
+  if (aInput.mType == MultiTouchInput::MULTITOUCH_START) {
+    // this is by definition the first event in this block. If it's the first
+    // touch, then we enter a slop state.
+    mInSlop = (aInput.mTouches.Length() == 1);
+    if (mInSlop) {
+      mSlopOrigin = aInput.mTouches[0].mScreenPoint;
+      TBS_LOG("%p entering slop with origin %s\n", this, Stringify(mSlopOrigin).c_str());
+    }
+    return false;
+  }
+  if (mInSlop) {
+    ScreenCoord threshold = aApzcCanConsumeEvents
+        ? AsyncPanZoomController::GetTouchStartTolerance()
+        : ScreenCoord(gfxPrefs::APZTouchMoveTolerance() * APZCTreeManager::GetDPI());
+    bool stayInSlop = (aInput.mType == MultiTouchInput::MULTITOUCH_MOVE) &&
+        (aInput.mTouches.Length() == 1) &&
+        ((aInput.mTouches[0].mScreenPoint - mSlopOrigin).Length() < threshold);
+    if (!stayInSlop) {
+      // we're out of the slop zone, and will stay out for the remainder of
+      // this block
+      TBS_LOG("%p exiting slop\n", this);
+      mInSlop = false;
+    }
+  }
+  return mInSlop;
+}
+
+uint32_t
+TouchBlockState::GetActiveTouchCount() const
+{
+  return mTouchCounter.GetActiveTouchCount();
+}
+
+} // namespace layers
+} // namespace mozilla