/* -*- 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 "GestureEventListener.h"
#include <algorithm>                 // for max
#include <math.h>                    // for fabsf
#include <stddef.h>                  // for size_t
#include "AsyncPanZoomController.h"  // for AsyncPanZoomController
#include "InputBlockState.h"         // for TouchBlockState
#include "base/task.h"               // for CancelableTask, etc
#include "InputBlockState.h"         // for TouchBlockState
#include "mozilla/StaticPrefs_apz.h"
#include "mozilla/StaticPrefs_ui.h"
#include "nsDebug.h"      // for NS_WARNING
#include "nsMathUtils.h"  // for NS_hypot

static mozilla::LazyLogModule sApzGelLog("apz.gesture");
#define GEL_LOG(...) MOZ_LOG(sApzGelLog, LogLevel::Debug, (__VA_ARGS__))

namespace mozilla {
namespace layers {

/**
 * Amount of span or focus change needed to take us from the
 * GESTURE_WAITING_PINCH state to the GESTURE_PINCH state. This is measured as
 * either a change in distance between the fingers used to compute the span
 * ratio, or the a change in position of the focus point between the two
 * fingers.
 */
static const float PINCH_START_THRESHOLD = 35.0f;

/**
 * Determines how fast a one touch pinch zooms in and out. The greater the
 * value, the faster it zooms.
 */
static const float ONE_TOUCH_PINCH_SPEED = 0.005f;

static bool sLongTapEnabled = true;

static ScreenPoint GetCurrentFocus(const MultiTouchInput& aEvent) {
  const ScreenPoint& firstTouch = aEvent.mTouches[0].mScreenPoint;
  const ScreenPoint& secondTouch = aEvent.mTouches[1].mScreenPoint;
  return (firstTouch + secondTouch) / 2;
}

static ScreenCoord GetCurrentSpan(const MultiTouchInput& aEvent) {
  const ScreenPoint& firstTouch = aEvent.mTouches[0].mScreenPoint;
  const ScreenPoint& secondTouch = aEvent.mTouches[1].mScreenPoint;
  ScreenPoint delta = secondTouch - firstTouch;
  return delta.Length();
}

ScreenCoord GestureEventListener::GetYSpanFromGestureStartPoint() {
  // use the position that began the one-touch-pinch gesture rather
  // mTouchStartPosition
  const ScreenPoint start = mOneTouchPinchStartPosition;
  const ScreenPoint& current = mTouches[0].mScreenPoint;
  return current.y - start.y;
}

static TapGestureInput CreateTapEvent(const MultiTouchInput& aTouch,
                                      TapGestureInput::TapGestureType aType) {
  return TapGestureInput(aType, aTouch.mTimeStamp,
                         aTouch.mTouches[0].mScreenPoint, aTouch.modifiers);
}

GestureEventListener::GestureEventListener(
    AsyncPanZoomController* aAsyncPanZoomController)
    : mAsyncPanZoomController(aAsyncPanZoomController),
      mState(GESTURE_NONE),
      mSpanChange(0.0f),
      mPreviousSpan(0.0f),
      mFocusChange(0.0f),
      mLastTouchInput(MultiTouchInput::MULTITOUCH_START, 0, TimeStamp(), 0),
      mLastTapInput(MultiTouchInput::MULTITOUCH_START, 0, TimeStamp(), 0),
      mLongTapTimeoutTask(nullptr),
      mMaxTapTimeoutTask(nullptr) {}

GestureEventListener::~GestureEventListener() = default;

nsEventStatus GestureEventListener::HandleInputEvent(
    const MultiTouchInput& aEvent) {
  GEL_LOG("Receiving event type %d with %zu touches in state %d\n",
          aEvent.mType, aEvent.mTouches.Length(), mState);

  nsEventStatus rv = nsEventStatus_eIgnore;

  // Cache the current event since it may become the single or long tap that we
  // send.
  mLastTouchInput = aEvent;

  switch (aEvent.mType) {
    case MultiTouchInput::MULTITOUCH_START:
      mTouches.Clear();
      // Cache every touch.
      for (size_t i = 0; i < aEvent.mTouches.Length(); i++) {
        mTouches.AppendElement(aEvent.mTouches[i]);
      }

      if (aEvent.mTouches.Length() == 1) {
        rv = HandleInputTouchSingleStart();
      } else {
        rv = HandleInputTouchMultiStart();
      }
      break;
    case MultiTouchInput::MULTITOUCH_MOVE:
      // Update the screen points of the cached touches.
      for (size_t i = 0; i < aEvent.mTouches.Length(); i++) {
        for (size_t j = 0; j < mTouches.Length(); j++) {
          if (aEvent.mTouches[i].mIdentifier == mTouches[j].mIdentifier) {
            mTouches[j].mScreenPoint = aEvent.mTouches[i].mScreenPoint;
            mTouches[j].mLocalScreenPoint =
                aEvent.mTouches[i].mLocalScreenPoint;
          }
        }
      }
      rv = HandleInputTouchMove();
      break;
    case MultiTouchInput::MULTITOUCH_END:
      // Remove the cache of the touch that ended.
      for (size_t i = 0; i < aEvent.mTouches.Length(); i++) {
        for (size_t j = 0; j < mTouches.Length(); j++) {
          if (aEvent.mTouches[i].mIdentifier == mTouches[j].mIdentifier) {
            mTouches.RemoveElementAt(j);
            break;
          }
        }
      }

      rv = HandleInputTouchEnd();
      break;
    case MultiTouchInput::MULTITOUCH_CANCEL:
      mTouches.Clear();
      rv = HandleInputTouchCancel();
      break;
  }

  return rv;
}

int32_t GestureEventListener::GetLastTouchIdentifier() const {
  if (mTouches.Length() != 1) {
    NS_WARNING(
        "GetLastTouchIdentifier() called when last touch event "
        "did not have one touch");
  }
  return mTouches.IsEmpty() ? -1 : mTouches[0].mIdentifier;
}

/* static */
void GestureEventListener::SetLongTapEnabled(bool aLongTapEnabled) {
  sLongTapEnabled = aLongTapEnabled;
}

/* static */
bool GestureEventListener::IsLongTapEnabled() { return sLongTapEnabled; }

void GestureEventListener::EnterFirstSingleTouchDown() {
  SetState(GESTURE_FIRST_SINGLE_TOUCH_DOWN);
  mTouchStartPosition = mLastTouchInput.mTouches[0].mScreenPoint;
  mTouchStartOffset = mLastTouchInput.mScreenOffset;

  if (sLongTapEnabled) {
    CreateLongTapTimeoutTask();
  }
  CreateMaxTapTimeoutTask();
}

nsEventStatus GestureEventListener::HandleInputTouchSingleStart() {
  switch (mState) {
    case GESTURE_NONE:
      EnterFirstSingleTouchDown();
      break;
    case GESTURE_FIRST_SINGLE_TOUCH_UP:
      if (SecondTapIsFar()) {
        // If the second tap goes down far away from the first, then bail out
        // of any gesture that includes the first tap.
        CancelLongTapTimeoutTask();
        CancelMaxTapTimeoutTask();
        mSingleTapSent = Nothing();

        // But still allow the second tap to participate in a gesture
        // (e.g. lead to a single tap, or a double tap if an additional
        // tap occurs near the same location).
        EnterFirstSingleTouchDown();
      } else {
        // Otherwise, reset the touch start position so that, if this turns into
        // a one-touch-pinch gesture, it uses the second tap's down position as
        // the focus, rather than the first tap's.
        mTouchStartPosition = mLastTouchInput.mTouches[0].mScreenPoint;
        mTouchStartOffset = mLastTouchInput.mScreenOffset;
        SetState(GESTURE_SECOND_SINGLE_TOUCH_DOWN);
      }
      break;
    default:
      NS_WARNING("Unhandled state upon single touch start");
      SetState(GESTURE_NONE);
      break;
  }

  return nsEventStatus_eIgnore;
}

nsEventStatus GestureEventListener::HandleInputTouchMultiStart() {
  nsEventStatus rv = nsEventStatus_eIgnore;

  switch (mState) {
    case GESTURE_NONE:
      SetState(GESTURE_MULTI_TOUCH_DOWN);
      break;
    case GESTURE_FIRST_SINGLE_TOUCH_DOWN:
      CancelLongTapTimeoutTask();
      CancelMaxTapTimeoutTask();
      SetState(GESTURE_MULTI_TOUCH_DOWN);
      // Prevent APZC::OnTouchStart() from handling MULTITOUCH_START event
      rv = nsEventStatus_eConsumeNoDefault;
      break;
    case GESTURE_FIRST_SINGLE_TOUCH_MAX_TAP_DOWN:
      CancelLongTapTimeoutTask();
      SetState(GESTURE_MULTI_TOUCH_DOWN);
      // Prevent APZC::OnTouchStart() from handling MULTITOUCH_START event
      rv = nsEventStatus_eConsumeNoDefault;
      break;
    case GESTURE_FIRST_SINGLE_TOUCH_UP:
    case GESTURE_SECOND_SINGLE_TOUCH_DOWN:
      // Cancel wait for double tap
      CancelMaxTapTimeoutTask();
      MOZ_ASSERT(mSingleTapSent.isSome());
      if (!mSingleTapSent.value()) {
        TriggerSingleTapConfirmedEvent();
      }
      mSingleTapSent = Nothing();
      SetState(GESTURE_MULTI_TOUCH_DOWN);
      // Prevent APZC::OnTouchStart() from handling MULTITOUCH_START event
      rv = nsEventStatus_eConsumeNoDefault;
      break;
    case GESTURE_LONG_TOUCH_DOWN:
      SetState(GESTURE_MULTI_TOUCH_DOWN);
      break;
    case GESTURE_MULTI_TOUCH_DOWN:
    case GESTURE_PINCH:
      // Prevent APZC::OnTouchStart() from handling MULTITOUCH_START event
      rv = nsEventStatus_eConsumeNoDefault;
      break;
    default:
      NS_WARNING("Unhandled state upon multitouch start");
      SetState(GESTURE_NONE);
      break;
  }

  return rv;
}

bool GestureEventListener::MoveDistanceExceeds(ScreenCoord aThreshold) const {
  ExternalPoint start = AsyncPanZoomController::ToExternalPoint(
      mTouchStartOffset, mTouchStartPosition);
  ExternalPoint end = AsyncPanZoomController::ToExternalPoint(
      mLastTouchInput.mScreenOffset, mLastTouchInput.mTouches[0].mScreenPoint);
  return (start - end).Length() > aThreshold;
}

bool GestureEventListener::MoveDistanceIsLarge() const {
  return MoveDistanceExceeds(mAsyncPanZoomController->GetTouchStartTolerance());
}

bool GestureEventListener::SecondTapIsFar() const {
  // Allow a little more room here, because the is actually lifting their finger
  // off the screen before replacing it, and that tends to have more error than
  // wiggling the finger while on the screen.
  return MoveDistanceExceeds(mAsyncPanZoomController->GetSecondTapTolerance());
}

nsEventStatus GestureEventListener::HandleInputTouchMove() {
  nsEventStatus rv = nsEventStatus_eIgnore;

  switch (mState) {
    case GESTURE_NONE:
      // Ignore this input signal as the corresponding events get handled by
      // APZC
      break;

    case GESTURE_LONG_TOUCH_DOWN:
      if (MoveDistanceIsLarge()) {
        // So that we don't fire a long-tap-up if the user moves around after a
        // long-tap
        SetState(GESTURE_NONE);
      }
      break;

    case GESTURE_FIRST_SINGLE_TOUCH_DOWN:
    case GESTURE_FIRST_SINGLE_TOUCH_MAX_TAP_DOWN: {
      // If we move too much, bail out of the tap.
      if (MoveDistanceIsLarge()) {
        CancelLongTapTimeoutTask();
        CancelMaxTapTimeoutTask();
        mSingleTapSent = Nothing();
        SetState(GESTURE_NONE);
      }
      break;
    }

    // The user has performed a double tap, but not lifted her finger.
    case GESTURE_SECOND_SINGLE_TOUCH_DOWN: {
      // If touch has moved noticeably (within StaticPrefs::apz_max_tap_time()),
      // change state.
      if (MoveDistanceIsLarge()) {
        CancelLongTapTimeoutTask();
        CancelMaxTapTimeoutTask();
        mSingleTapSent = Nothing();
        if (!StaticPrefs::apz_one_touch_pinch_enabled()) {
          // If the one-touch-pinch feature is disabled, bail out of the double-
          // tap gesture instead.
          SetState(GESTURE_NONE);
          break;
        }

        SetState(GESTURE_ONE_TOUCH_PINCH);

        ScreenCoord currentSpan = 1.0f;
        ScreenPoint currentFocus = mTouchStartPosition;

        // save the position that the one-touch-pinch gesture actually begins
        mOneTouchPinchStartPosition = mLastTouchInput.mTouches[0].mScreenPoint;

        PinchGestureInput pinchEvent(
            PinchGestureInput::PINCHGESTURE_START, PinchGestureInput::ONE_TOUCH,
            mLastTouchInput.mTimeStamp, mLastTouchInput.mScreenOffset,
            currentFocus, currentSpan, currentSpan, mLastTouchInput.modifiers);

        rv = mAsyncPanZoomController->HandleGestureEvent(pinchEvent);

        mPreviousSpan = currentSpan;
        mPreviousFocus = currentFocus;
      }
      break;
    }

    case GESTURE_MULTI_TOUCH_DOWN: {
      if (mLastTouchInput.mTouches.Length() < 2) {
        NS_WARNING(
            "Wrong input: less than 2 moving points in "
            "GESTURE_MULTI_TOUCH_DOWN state");
        break;
      }

      ScreenCoord currentSpan = GetCurrentSpan(mLastTouchInput);
      ScreenPoint currentFocus = GetCurrentFocus(mLastTouchInput);

      mSpanChange += fabsf(currentSpan - mPreviousSpan);
      mFocusChange += (currentFocus - mPreviousFocus).Length();
      if (mSpanChange > PINCH_START_THRESHOLD ||
          mFocusChange > PINCH_START_THRESHOLD) {
        SetState(GESTURE_PINCH);
        PinchGestureInput pinchEvent(
            PinchGestureInput::PINCHGESTURE_START, PinchGestureInput::TOUCH,
            mLastTouchInput.mTimeStamp, mLastTouchInput.mScreenOffset,
            currentFocus, currentSpan, currentSpan, mLastTouchInput.modifiers);

        rv = mAsyncPanZoomController->HandleGestureEvent(pinchEvent);
      } else {
        // Prevent APZC::OnTouchMove from processing a move event when two
        // touches are active
        rv = nsEventStatus_eConsumeNoDefault;
      }

      mPreviousSpan = currentSpan;
      mPreviousFocus = currentFocus;
      break;
    }

    case GESTURE_PINCH: {
      if (mLastTouchInput.mTouches.Length() < 2) {
        NS_WARNING(
            "Wrong input: less than 2 moving points in GESTURE_PINCH state");
        // Prevent APZC::OnTouchMove() from handling this wrong input
        rv = nsEventStatus_eConsumeNoDefault;
        break;
      }

      ScreenCoord currentSpan = GetCurrentSpan(mLastTouchInput);

      PinchGestureInput pinchEvent(
          PinchGestureInput::PINCHGESTURE_SCALE, PinchGestureInput::TOUCH,
          mLastTouchInput.mTimeStamp, mLastTouchInput.mScreenOffset,
          GetCurrentFocus(mLastTouchInput), currentSpan, mPreviousSpan,
          mLastTouchInput.modifiers);

      rv = mAsyncPanZoomController->HandleGestureEvent(pinchEvent);
      mPreviousSpan = currentSpan;

      break;
    }

    case GESTURE_ONE_TOUCH_PINCH: {
      ScreenCoord currentSpan = GetYSpanFromGestureStartPoint();
      float effectiveSpan =
          1.0f + (fabsf(currentSpan.value) * ONE_TOUCH_PINCH_SPEED);
      ScreenPoint currentFocus = mTouchStartPosition;

      // Invert zoom.
      if (currentSpan.value < 0) {
        effectiveSpan = 1.0f / effectiveSpan;
      }

      PinchGestureInput pinchEvent(
          PinchGestureInput::PINCHGESTURE_SCALE, PinchGestureInput::ONE_TOUCH,
          mLastTouchInput.mTimeStamp, mLastTouchInput.mScreenOffset,
          currentFocus, effectiveSpan, mPreviousSpan,
          mLastTouchInput.modifiers);

      rv = mAsyncPanZoomController->HandleGestureEvent(pinchEvent);
      mPreviousSpan = effectiveSpan;

      break;
    }

    default:
      NS_WARNING("Unhandled state upon touch move");
      SetState(GESTURE_NONE);
      break;
  }

  return rv;
}

nsEventStatus GestureEventListener::HandleInputTouchEnd() {
  // We intentionally do not pass apzc return statuses up since
  // it may cause apzc stay in the touching state even after
  // gestures are completed (please see Bug 1013378 for reference).

  nsEventStatus rv = nsEventStatus_eIgnore;

  switch (mState) {
    case GESTURE_NONE:
      // GEL doesn't have a dedicated state for PANNING handled in APZC thus
      // ignore.
      break;

    case GESTURE_FIRST_SINGLE_TOUCH_DOWN: {
      CancelLongTapTimeoutTask();
      CancelMaxTapTimeoutTask();
      nsEventStatus tapupStatus = mAsyncPanZoomController->HandleGestureEvent(
          CreateTapEvent(mLastTouchInput, TapGestureInput::TAPGESTURE_UP));
      mSingleTapSent = Some(tapupStatus != nsEventStatus_eIgnore);
      SetState(GESTURE_FIRST_SINGLE_TOUCH_UP);
      CreateMaxTapTimeoutTask();
      break;
    }

    case GESTURE_SECOND_SINGLE_TOUCH_DOWN: {
      CancelMaxTapTimeoutTask();
      MOZ_ASSERT(mSingleTapSent.isSome());
      mAsyncPanZoomController->HandleGestureEvent(CreateTapEvent(
          mLastTouchInput, mSingleTapSent.value()
                               ? TapGestureInput::TAPGESTURE_SECOND
                               : TapGestureInput::TAPGESTURE_DOUBLE));
      mSingleTapSent = Nothing();
      SetState(GESTURE_NONE);
      break;
    }

    case GESTURE_FIRST_SINGLE_TOUCH_MAX_TAP_DOWN:
      CancelLongTapTimeoutTask();
      SetState(GESTURE_NONE);
      TriggerSingleTapConfirmedEvent();
      break;

    case GESTURE_LONG_TOUCH_DOWN: {
      SetState(GESTURE_NONE);
      mAsyncPanZoomController->HandleGestureEvent(
          CreateTapEvent(mLastTouchInput, TapGestureInput::TAPGESTURE_LONG_UP));
      break;
    }

    case GESTURE_MULTI_TOUCH_DOWN:
      if (mTouches.Length() < 2) {
        SetState(GESTURE_NONE);
      }
      break;

    case GESTURE_PINCH:
      if (mTouches.Length() < 2) {
        SetState(GESTURE_NONE);
        PinchGestureInput::PinchGestureType type =
            PinchGestureInput::PINCHGESTURE_END;
        ScreenPoint point;
        if (mTouches.Length() == 1) {
          // As user still keeps one finger down the event's focus point should
          // contain meaningful data.
          type = PinchGestureInput::PINCHGESTURE_FINGERLIFTED;
          point = mTouches[0].mScreenPoint;
        }
        PinchGestureInput pinchEvent(type, PinchGestureInput::TOUCH,
                                     mLastTouchInput.mTimeStamp,
                                     mLastTouchInput.mScreenOffset, point, 1.0f,
                                     1.0f, mLastTouchInput.modifiers);
        mAsyncPanZoomController->HandleGestureEvent(pinchEvent);
      }

      rv = nsEventStatus_eConsumeNoDefault;

      break;

    case GESTURE_ONE_TOUCH_PINCH: {
      SetState(GESTURE_NONE);
      PinchGestureInput pinchEvent(
          PinchGestureInput::PINCHGESTURE_END, PinchGestureInput::ONE_TOUCH,
          mLastTouchInput.mTimeStamp, mLastTouchInput.mScreenOffset,
          ScreenPoint(), 1.0f, 1.0f, mLastTouchInput.modifiers);
      mAsyncPanZoomController->HandleGestureEvent(pinchEvent);

      rv = nsEventStatus_eConsumeNoDefault;

      break;
    }

    default:
      NS_WARNING("Unhandled state upon touch end");
      SetState(GESTURE_NONE);
      break;
  }

  return rv;
}

nsEventStatus GestureEventListener::HandleInputTouchCancel() {
  mSingleTapSent = Nothing();
  SetState(GESTURE_NONE);
  CancelMaxTapTimeoutTask();
  CancelLongTapTimeoutTask();
  return nsEventStatus_eIgnore;
}

void GestureEventListener::HandleInputTimeoutLongTap() {
  GEL_LOG("Running long-tap timeout task in state %d\n", mState);

  mLongTapTimeoutTask = nullptr;

  switch (mState) {
    case GESTURE_FIRST_SINGLE_TOUCH_DOWN:
      // just in case MaxTapTime > ContextMenuDelay cancel MaxTap timer
      // and fall through
      CancelMaxTapTimeoutTask();
      [[fallthrough]];
    case GESTURE_FIRST_SINGLE_TOUCH_MAX_TAP_DOWN: {
      SetState(GESTURE_LONG_TOUCH_DOWN);
      mAsyncPanZoomController->HandleGestureEvent(
          CreateTapEvent(mLastTouchInput, TapGestureInput::TAPGESTURE_LONG));
      break;
    }
    default:
      NS_WARNING("Unhandled state upon long tap timeout");
      SetState(GESTURE_NONE);
      break;
  }
}

void GestureEventListener::HandleInputTimeoutMaxTap(bool aDuringFastFling) {
  GEL_LOG("Running max-tap timeout task in state %d\n", mState);

  mMaxTapTimeoutTask = nullptr;

  if (mState == GESTURE_FIRST_SINGLE_TOUCH_DOWN) {
    SetState(GESTURE_FIRST_SINGLE_TOUCH_MAX_TAP_DOWN);
  } else if (mState == GESTURE_FIRST_SINGLE_TOUCH_UP ||
             mState == GESTURE_SECOND_SINGLE_TOUCH_DOWN) {
    MOZ_ASSERT(mSingleTapSent.isSome());
    if (!aDuringFastFling && !mSingleTapSent.value()) {
      TriggerSingleTapConfirmedEvent();
    }
    mSingleTapSent = Nothing();
    SetState(GESTURE_NONE);
  } else {
    NS_WARNING("Unhandled state upon MAX_TAP timeout");
    SetState(GESTURE_NONE);
  }
}

void GestureEventListener::TriggerSingleTapConfirmedEvent() {
  mAsyncPanZoomController->HandleGestureEvent(
      CreateTapEvent(mLastTapInput, TapGestureInput::TAPGESTURE_CONFIRMED));
}

void GestureEventListener::SetState(GestureState aState) {
  mState = aState;

  if (mState == GESTURE_NONE) {
    mSpanChange = 0.0f;
    mPreviousSpan = 0.0f;
    mFocusChange = 0.0f;
  } else if (mState == GESTURE_MULTI_TOUCH_DOWN) {
    mPreviousSpan = GetCurrentSpan(mLastTouchInput);
    mPreviousFocus = GetCurrentFocus(mLastTouchInput);
  }
}

void GestureEventListener::CancelLongTapTimeoutTask() {
  if (mState == GESTURE_SECOND_SINGLE_TOUCH_DOWN) {
    // being in this state means the task has been canceled already
    return;
  }

  if (mLongTapTimeoutTask) {
    mLongTapTimeoutTask->Cancel();
    mLongTapTimeoutTask = nullptr;
  }
}

void GestureEventListener::CreateLongTapTimeoutTask() {
  RefPtr<CancelableRunnable> task = NewCancelableRunnableMethod(
      "layers::GestureEventListener::HandleInputTimeoutLongTap", this,
      &GestureEventListener::HandleInputTimeoutLongTap);

  mLongTapTimeoutTask = task;

  TouchBlockState* block =
      mAsyncPanZoomController->GetInputQueue()->GetCurrentTouchBlock();
  MOZ_ASSERT(block);
  long alreadyElapsed =
      static_cast<long>(block->GetTimeSinceBlockStart().ToMilliseconds());
  long remainingDelay =
      StaticPrefs::ui_click_hold_context_menus_delay() - alreadyElapsed;
  mAsyncPanZoomController->PostDelayedTask(task.forget(),
                                           std::max(0L, remainingDelay));
}

void GestureEventListener::CancelMaxTapTimeoutTask() {
  if (mState == GESTURE_FIRST_SINGLE_TOUCH_MAX_TAP_DOWN) {
    // being in this state means the timer has just been triggered
    return;
  }

  if (mMaxTapTimeoutTask) {
    mMaxTapTimeoutTask->Cancel();
    mMaxTapTimeoutTask = nullptr;
  }
}

void GestureEventListener::CreateMaxTapTimeoutTask() {
  mLastTapInput = mLastTouchInput;

  TouchBlockState* block =
      mAsyncPanZoomController->GetInputQueue()->GetCurrentTouchBlock();
  MOZ_ASSERT(block);
  RefPtr<CancelableRunnable> task = NewCancelableRunnableMethod<bool>(
      "layers::GestureEventListener::HandleInputTimeoutMaxTap", this,
      &GestureEventListener::HandleInputTimeoutMaxTap,
      block->IsDuringFastFling());

  mMaxTapTimeoutTask = task;

  long alreadyElapsed =
      static_cast<long>(block->GetTimeSinceBlockStart().ToMilliseconds());
  long remainingDelay = StaticPrefs::apz_max_tap_time() - alreadyElapsed;
  mAsyncPanZoomController->PostDelayedTask(task.forget(),
                                           std::max(0L, remainingDelay));
}

}  // namespace layers
}  // namespace mozilla