gecko-dev/widget/InputData.cpp

/* -*- 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 "InputData.h"

#include "mozilla/dom/Touch.h"
#include "nsDebug.h"
#include "nsThreadUtils.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/TouchEvents.h"
#include "UnitTransforms.h"

namespace mozilla {

using namespace dom;

InputData::~InputData()
{
}

InputData::InputData(InputType aInputType)
  : mInputType(aInputType)
  , mTime(0)
  , modifiers(0)
{
}

InputData::InputData(InputType aInputType, uint32_t aTime, TimeStamp aTimeStamp,
                     Modifiers aModifiers)
  : mInputType(aInputType)
  , mTime(aTime)
  , mTimeStamp(aTimeStamp)
  , modifiers(aModifiers)
{
}

SingleTouchData::SingleTouchData(int32_t aIdentifier, ScreenIntPoint aScreenPoint,
                                 ScreenSize aRadius, float aRotationAngle,
                                 float aForce)
  : mIdentifier(aIdentifier)
  , mScreenPoint(aScreenPoint)
  , mRadius(aRadius)
  , mRotationAngle(aRotationAngle)
  , mForce(aForce)
{
}

SingleTouchData::SingleTouchData(int32_t aIdentifier,
                                 ParentLayerPoint aLocalScreenPoint,
                                 ScreenSize aRadius, float aRotationAngle,
                                 float aForce)
  : mIdentifier(aIdentifier)
  , mLocalScreenPoint(aLocalScreenPoint)
  , mRadius(aRadius)
  , mRotationAngle(aRotationAngle)
  , mForce(aForce)
{
}

SingleTouchData::SingleTouchData()
{
}

already_AddRefed<Touch> SingleTouchData::ToNewDOMTouch() const
{
  MOZ_ASSERT(NS_IsMainThread(),
             "Can only create dom::Touch instances on main thread");
  RefPtr<Touch> touch = new Touch(mIdentifier,
                                  LayoutDeviceIntPoint::Truncate(mScreenPoint.x, mScreenPoint.y),
                                  LayoutDeviceIntPoint::Truncate(mRadius.width, mRadius.height),
                                  mRotationAngle,
                                  mForce);
  return touch.forget();
}

MultiTouchInput::MultiTouchInput(MultiTouchType aType, uint32_t aTime,
                                 TimeStamp aTimeStamp, Modifiers aModifiers)
  : InputData(MULTITOUCH_INPUT, aTime, aTimeStamp, aModifiers)
  , mType(aType)
  , mHandledByAPZ(false)
{
}

MultiTouchInput::MultiTouchInput()
  : InputData(MULTITOUCH_INPUT)
  , mHandledByAPZ(false)
{
}

MultiTouchInput::MultiTouchInput(const MultiTouchInput& aOther)
  : InputData(MULTITOUCH_INPUT, aOther.mTime, aOther.mTimeStamp, aOther.modifiers)
  , mType(aOther.mType)
  , mHandledByAPZ(aOther.mHandledByAPZ)
{
  mTouches.AppendElements(aOther.mTouches);
}

MultiTouchInput::MultiTouchInput(const WidgetTouchEvent& aTouchEvent)
  : InputData(MULTITOUCH_INPUT, aTouchEvent.mTime, aTouchEvent.mTimeStamp,
              aTouchEvent.mModifiers)
  , mHandledByAPZ(aTouchEvent.mFlags.mHandledByAPZ)
{
  MOZ_ASSERT(NS_IsMainThread(),
             "Can only copy from WidgetTouchEvent on main thread");

  switch (aTouchEvent.mMessage) {
    case eTouchStart:
      mType = MULTITOUCH_START;
      break;
    case eTouchMove:
      mType = MULTITOUCH_MOVE;
      break;
    case eTouchEnd:
      mType = MULTITOUCH_END;
      break;
    case eTouchCancel:
      mType = MULTITOUCH_CANCEL;
      break;
    default:
      MOZ_ASSERT_UNREACHABLE("Did not assign a type to a MultiTouchInput");
      break;
  }

  for (size_t i = 0; i < aTouchEvent.mTouches.Length(); i++) {
    const Touch* domTouch = aTouchEvent.mTouches[i];

    // Extract data from weird interfaces.
    int32_t identifier = domTouch->Identifier();
    int32_t radiusX = domTouch->RadiusX();
    int32_t radiusY = domTouch->RadiusY();
    float rotationAngle = domTouch->RotationAngle();
    float force = domTouch->Force();

    SingleTouchData data(identifier,
                         ViewAs<ScreenPixel>(domTouch->mRefPoint,
                                             PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent),
                         ScreenSize(radiusX, radiusY),
                         rotationAngle,
                         force);

    mTouches.AppendElement(data);
  }
}

MultiTouchInput::MultiTouchInput(const WidgetMouseEvent& aMouseEvent)
  : InputData(MULTITOUCH_INPUT, aMouseEvent.mTime, aMouseEvent.mTimeStamp,
              aMouseEvent.mModifiers)
  , mHandledByAPZ(aMouseEvent.mFlags.mHandledByAPZ)
{
  MOZ_ASSERT(NS_IsMainThread(),
             "Can only copy from WidgetMouseEvent on main thread");
  switch (aMouseEvent.mMessage) {
  case eMouseDown:
    mType = MULTITOUCH_START;
    break;
  case eMouseMove:
    mType = MULTITOUCH_MOVE;
    break;
  case eMouseUp:
    mType = MULTITOUCH_END;
    break;
  // The mouse pointer has been interrupted in an implementation-specific
  // manner, such as a synchronous event or action cancelling the touch, or a
  // touch point leaving the document window and going into a non-document
  // area capable of handling user interactions.
  case eMouseExitFromWidget:
    mType = MULTITOUCH_CANCEL;
    break;
  default:
    NS_WARNING("Did not assign a type to a MultiTouchInput");
    break;
  }

  mTouches.AppendElement(SingleTouchData(0,
                                         ViewAs<ScreenPixel>(aMouseEvent.mRefPoint,
                                                             PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent),
                                         ScreenSize(1, 1),
                                         180.0f,
                                         1.0f));
}

void
MultiTouchInput::Translate(const ScreenPoint& aTranslation)
{
  const int32_t xTranslation = (int32_t)(aTranslation.x + 0.5f);
  const int32_t yTranslation = (int32_t)(aTranslation.y + 0.5f);

  for (auto iter = mTouches.begin(); iter != mTouches.end(); iter++) {
    iter->mScreenPoint.MoveBy(xTranslation, yTranslation);
  }
}

WidgetTouchEvent
MultiTouchInput::ToWidgetTouchEvent(nsIWidget* aWidget) const
{
  MOZ_ASSERT(NS_IsMainThread(),
             "Can only convert To WidgetTouchEvent on main thread");

  EventMessage touchEventMessage = eVoidEvent;
  switch (mType) {
  case MULTITOUCH_START:
    touchEventMessage = eTouchStart;
    break;
  case MULTITOUCH_MOVE:
    touchEventMessage = eTouchMove;
    break;
  case MULTITOUCH_END:
    touchEventMessage = eTouchEnd;
    break;
  case MULTITOUCH_CANCEL:
    touchEventMessage = eTouchCancel;
    break;
  default:
    MOZ_ASSERT_UNREACHABLE("Did not assign a type to WidgetTouchEvent in MultiTouchInput");
    break;
  }

  WidgetTouchEvent event(true, touchEventMessage, aWidget);
  if (touchEventMessage == eVoidEvent) {
    return event;
  }

  event.mModifiers = this->modifiers;
  event.mTime = this->mTime;
  event.mTimeStamp = this->mTimeStamp;
  event.mFlags.mHandledByAPZ = mHandledByAPZ;

  for (size_t i = 0; i < mTouches.Length(); i++) {
    *event.mTouches.AppendElement() = mTouches[i].ToNewDOMTouch();
  }

  return event;
}

WidgetMouseEvent
MultiTouchInput::ToWidgetMouseEvent(nsIWidget* aWidget) const
{
  MOZ_ASSERT(NS_IsMainThread(),
             "Can only convert To WidgetMouseEvent on main thread");

  EventMessage mouseEventMessage = eVoidEvent;
  switch (mType) {
    case MultiTouchInput::MULTITOUCH_START:
      mouseEventMessage = eMouseDown;
      break;
    case MultiTouchInput::MULTITOUCH_MOVE:
      mouseEventMessage = eMouseMove;
      break;
    case MultiTouchInput::MULTITOUCH_CANCEL:
    case MultiTouchInput::MULTITOUCH_END:
      mouseEventMessage = eMouseUp;
      break;
    default:
      MOZ_ASSERT_UNREACHABLE("Did not assign a type to WidgetMouseEvent");
      break;
  }

  WidgetMouseEvent event(true, mouseEventMessage, aWidget,
                         WidgetMouseEvent::eReal, WidgetMouseEvent::eNormal);

  const SingleTouchData& firstTouch = mTouches[0];
  event.mRefPoint.x = firstTouch.mScreenPoint.x;
  event.mRefPoint.y = firstTouch.mScreenPoint.y;

  event.mTime = mTime;
  event.button = WidgetMouseEvent::eLeftButton;
  event.inputSource = nsIDOMMouseEvent::MOZ_SOURCE_TOUCH;
  event.mModifiers = modifiers;
  event.mFlags.mHandledByAPZ = mHandledByAPZ;

  if (mouseEventMessage != eMouseMove) {
    event.mClickCount = 1;
  }

  return event;
}

int32_t
MultiTouchInput::IndexOfTouch(int32_t aTouchIdentifier)
{
  for (size_t i = 0; i < mTouches.Length(); i++) {
    if (mTouches[i].mIdentifier == aTouchIdentifier) {
      return (int32_t)i;
    }
  }
  return -1;
}

bool
MultiTouchInput::TransformToLocal(const ScreenToParentLayerMatrix4x4& aTransform)
{
  for (size_t i = 0; i < mTouches.Length(); i++) {
    Maybe<ParentLayerIntPoint> point = UntransformBy(aTransform, mTouches[i].mScreenPoint);
    if (!point) { 
      return false;
    }
    mTouches[i].mLocalScreenPoint = *point;
  }
  return true;
}

MouseInput::MouseInput()
  : InputData(MOUSE_INPUT)
  , mType(MOUSE_NONE)
  , mButtonType(NONE)
  , mInputSource(0)
  , mButtons(0)
  , mHandledByAPZ(false)
{
}

MouseInput::MouseInput(MouseType aType, ButtonType aButtonType,
                       uint16_t aInputSource, int16_t aButtons,
                       const ScreenPoint& aPoint, uint32_t aTime,
                       TimeStamp aTimeStamp, Modifiers aModifiers)
  : InputData(MOUSE_INPUT, aTime, aTimeStamp, aModifiers)
  , mType(aType)
  , mButtonType(aButtonType)
  , mInputSource(aInputSource)
  , mButtons(aButtons)
  , mOrigin(aPoint)
  , mHandledByAPZ(false)
{
}

MouseInput::MouseInput(const WidgetMouseEventBase& aMouseEvent)
  : InputData(MOUSE_INPUT, aMouseEvent.mTime, aMouseEvent.mTimeStamp,
              aMouseEvent.mModifiers)
  , mType(MOUSE_NONE)
  , mButtonType(NONE)
  , mInputSource(aMouseEvent.inputSource)
  , mButtons(aMouseEvent.buttons)
  , mHandledByAPZ(aMouseEvent.mFlags.mHandledByAPZ)
{
  MOZ_ASSERT(NS_IsMainThread(),
             "Can only copy from WidgetTouchEvent on main thread");

  mButtonType = NONE;

  switch (aMouseEvent.button) {
    case WidgetMouseEventBase::eLeftButton:
      mButtonType = MouseInput::LEFT_BUTTON;
      break;
    case WidgetMouseEventBase::eMiddleButton:
      mButtonType = MouseInput::MIDDLE_BUTTON;
      break;
    case WidgetMouseEventBase::eRightButton:
      mButtonType = MouseInput::RIGHT_BUTTON;
      break;
  }

  switch (aMouseEvent.mMessage) {
    case eMouseMove:
      mType = MOUSE_MOVE;
      break;
    case eMouseUp:
      mType = MOUSE_UP;
      break;
    case eMouseDown:
      mType = MOUSE_DOWN;
      break;
    case eDragStart:
      mType = MOUSE_DRAG_START;
      break;
    case eDragEnd:
      mType = MOUSE_DRAG_END;
      break;
    case eMouseEnterIntoWidget:
      mType = MOUSE_WIDGET_ENTER;
      break;
    case eMouseExitFromWidget:
      mType = MOUSE_WIDGET_EXIT;
      break;
    default:
      MOZ_ASSERT_UNREACHABLE("Mouse event type not supported");
      break;
  }

  mOrigin =
    ScreenPoint(ViewAs<ScreenPixel>(aMouseEvent.mRefPoint,
      PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent));
}

bool
MouseInput::IsLeftButton() const
{
  return mButtonType == LEFT_BUTTON;
}

bool
MouseInput::TransformToLocal(const ScreenToParentLayerMatrix4x4& aTransform)
{
  Maybe<ParentLayerPoint> point = UntransformBy(aTransform, mOrigin);
  if (!point) {
    return false;
  }
  mLocalOrigin = *point;

  return true;
}

WidgetMouseEvent
MouseInput::ToWidgetMouseEvent(nsIWidget* aWidget) const
{
  MOZ_ASSERT(NS_IsMainThread(),
             "Can only convert To WidgetTouchEvent on main thread");

  EventMessage msg = eVoidEvent;
  uint32_t clickCount = 0;
  switch (mType) {
    case MOUSE_MOVE:
      msg = eMouseMove;
      break;
    case MOUSE_UP:
      msg = eMouseUp;
      clickCount = 1;
      break;
    case MOUSE_DOWN:
      msg = eMouseDown;
      clickCount = 1;
      break;
    case MOUSE_DRAG_START:
      msg = eDragStart;
      break;
    case MOUSE_DRAG_END:
      msg = eDragEnd;
      break;
    case MOUSE_WIDGET_ENTER:
      msg = eMouseEnterIntoWidget;
      break;
    case MOUSE_WIDGET_EXIT:
      msg = eMouseExitFromWidget;
      break;
    default:
      MOZ_ASSERT_UNREACHABLE("Did not assign a type to WidgetMouseEvent in MouseInput");
      break;
  }

  WidgetMouseEvent event(true, msg, aWidget, WidgetMouseEvent::eReal, WidgetMouseEvent::eNormal);

  if (msg == eVoidEvent) {
    return event;
  }

  switch (mButtonType) {
    case MouseInput::LEFT_BUTTON:
      event.button = WidgetMouseEventBase::eLeftButton;
      break;
    case MouseInput::MIDDLE_BUTTON:
      event.button = WidgetMouseEventBase::eMiddleButton;
      break;
    case MouseInput::RIGHT_BUTTON:
      event.button = WidgetMouseEventBase::eRightButton;
      break;
    case MouseInput::NONE:
    default:
      break;
  }

  event.buttons = mButtons;
  event.mModifiers = modifiers;
  event.mTime = mTime;
  event.mTimeStamp = mTimeStamp;
  event.mFlags.mHandledByAPZ = mHandledByAPZ;
  event.mRefPoint =
    RoundedToInt(ViewAs<LayoutDevicePixel>(mOrigin,
      PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent));
  event.mClickCount = clickCount;
  event.inputSource = mInputSource;
  event.mIgnoreRootScrollFrame = true;

  return event;
}

PanGestureInput::PanGestureInput()
  : InputData(PANGESTURE_INPUT)
  , mLineOrPageDeltaX(0)
  , mLineOrPageDeltaY(0)
  , mUserDeltaMultiplierX(1.0)
  , mUserDeltaMultiplierY(1.0)
  , mHandledByAPZ(false)
  , mFollowedByMomentum(false)
  , mRequiresContentResponseIfCannotScrollHorizontallyInStartDirection(false)
{
}

PanGestureInput::PanGestureInput(PanGestureType aType, uint32_t aTime,
                                 TimeStamp aTimeStamp,
                                 const ScreenPoint& aPanStartPoint,
                                 const ScreenPoint& aPanDisplacement,
                                 Modifiers aModifiers)
  : InputData(PANGESTURE_INPUT, aTime, aTimeStamp, aModifiers)
  , mType(aType)
  , mPanStartPoint(aPanStartPoint)
  , mPanDisplacement(aPanDisplacement)
  , mLineOrPageDeltaX(0)
  , mLineOrPageDeltaY(0)
  , mUserDeltaMultiplierX(1.0)
  , mUserDeltaMultiplierY(1.0)
  , mHandledByAPZ(false)
  , mFollowedByMomentum(false)
  , mRequiresContentResponseIfCannotScrollHorizontallyInStartDirection(false)
{
}

bool
PanGestureInput::IsMomentum() const
{
  switch (mType) {
    case PanGestureInput::PANGESTURE_MOMENTUMSTART:
    case PanGestureInput::PANGESTURE_MOMENTUMPAN:
    case PanGestureInput::PANGESTURE_MOMENTUMEND:
      return true;
    default:
      return false;
  }
}

WidgetWheelEvent
PanGestureInput::ToWidgetWheelEvent(nsIWidget* aWidget) const
{
  WidgetWheelEvent wheelEvent(true, eWheel, aWidget);
  wheelEvent.mModifiers = this->modifiers;
  wheelEvent.mTime = mTime;
  wheelEvent.mTimeStamp = mTimeStamp;
  wheelEvent.mRefPoint =
    RoundedToInt(ViewAs<LayoutDevicePixel>(mPanStartPoint,
      PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent));
  wheelEvent.buttons = 0;
  wheelEvent.mDeltaMode = nsIDOMWheelEvent::DOM_DELTA_PIXEL;
  wheelEvent.mMayHaveMomentum = true; // pan inputs may have momentum
  wheelEvent.mIsMomentum = IsMomentum();
  wheelEvent.mLineOrPageDeltaX = mLineOrPageDeltaX;
  wheelEvent.mLineOrPageDeltaY = mLineOrPageDeltaY;
  wheelEvent.mDeltaX = mPanDisplacement.x;
  wheelEvent.mDeltaY = mPanDisplacement.y;
  wheelEvent.mFlags.mHandledByAPZ = mHandledByAPZ;
  return wheelEvent;
}

bool
PanGestureInput::TransformToLocal(const ScreenToParentLayerMatrix4x4& aTransform)
{ 
  Maybe<ParentLayerPoint> panStartPoint = UntransformBy(aTransform, mPanStartPoint);
  if (!panStartPoint) {
    return false;
  }
  mLocalPanStartPoint = *panStartPoint;
  
  Maybe<ParentLayerPoint> panDisplacement = UntransformVector(aTransform, mPanDisplacement, mPanStartPoint);
  if (!panDisplacement) {
    return false;
  }
  mLocalPanDisplacement = *panDisplacement;
  return true;
}

ScreenPoint
PanGestureInput::UserMultipliedPanDisplacement() const
{
  return ScreenPoint(mPanDisplacement.x * mUserDeltaMultiplierX,
                     mPanDisplacement.y * mUserDeltaMultiplierY);
}

ParentLayerPoint
PanGestureInput::UserMultipliedLocalPanDisplacement() const
{
  return ParentLayerPoint(mLocalPanDisplacement.x * mUserDeltaMultiplierX,
                          mLocalPanDisplacement.y * mUserDeltaMultiplierY);
}

PinchGestureInput::PinchGestureInput()
  : InputData(PINCHGESTURE_INPUT)
{
}

PinchGestureInput::PinchGestureInput(PinchGestureType aType, uint32_t aTime,
                                     TimeStamp aTimeStamp,
                                     const ParentLayerPoint& aLocalFocusPoint,
                                     ParentLayerCoord aCurrentSpan,
                                     ParentLayerCoord aPreviousSpan,
                                     Modifiers aModifiers)
  : InputData(PINCHGESTURE_INPUT, aTime, aTimeStamp, aModifiers)
  , mType(aType)
  , mLocalFocusPoint(aLocalFocusPoint)
  , mCurrentSpan(aCurrentSpan)
  , mPreviousSpan(aPreviousSpan)
{
}

bool
PinchGestureInput::TransformToLocal(const ScreenToParentLayerMatrix4x4& aTransform)
{ 
  Maybe<ParentLayerPoint> point = UntransformBy(aTransform, mFocusPoint);
  if (!point) {
    return false;
  }
  mLocalFocusPoint = *point;
  return true;
}

TapGestureInput::TapGestureInput()
  : InputData(TAPGESTURE_INPUT)
{
}

TapGestureInput::TapGestureInput(TapGestureType aType, uint32_t aTime,
                                 TimeStamp aTimeStamp,
                                 const ScreenIntPoint& aPoint,
                                 Modifiers aModifiers)
  : InputData(TAPGESTURE_INPUT, aTime, aTimeStamp, aModifiers)
  , mType(aType)
  , mPoint(aPoint)
{
}

TapGestureInput::TapGestureInput(TapGestureType aType, uint32_t aTime,
                                 TimeStamp aTimeStamp,
                                 const ParentLayerPoint& aLocalPoint,
                                 Modifiers aModifiers)
  : InputData(TAPGESTURE_INPUT, aTime, aTimeStamp, aModifiers)
  , mType(aType)
  , mLocalPoint(aLocalPoint)
{
}

bool
TapGestureInput::TransformToLocal(const ScreenToParentLayerMatrix4x4& aTransform)
{
  Maybe<ParentLayerIntPoint> point = UntransformBy(aTransform, mPoint);
  if (!point) {
    return false;
  }
  mLocalPoint = *point;
  return true;
}

ScrollWheelInput::ScrollWheelInput()
  : InputData(SCROLLWHEEL_INPUT)
  , mHandledByAPZ(false)
  , mLineOrPageDeltaX(0)
  , mLineOrPageDeltaY(0)
  , mScrollSeriesNumber(0)
  , mUserDeltaMultiplierX(1.0)
  , mUserDeltaMultiplierY(1.0)
  , mMayHaveMomentum(false)
  , mIsMomentum(false)
{
}

ScrollWheelInput::ScrollWheelInput(uint32_t aTime, TimeStamp aTimeStamp,
                                   Modifiers aModifiers, ScrollMode aScrollMode,
                                   ScrollDeltaType aDeltaType,
                                   const ScreenPoint& aOrigin, double aDeltaX,
                                   double aDeltaY,
                                   bool aAllowToOverrideSystemScrollSpeed)
  : InputData(SCROLLWHEEL_INPUT, aTime, aTimeStamp, aModifiers)
  , mDeltaType(aDeltaType)
  , mScrollMode(aScrollMode)
  , mOrigin(aOrigin)
  , mHandledByAPZ(false)
  , mDeltaX(aDeltaX)
  , mDeltaY(aDeltaY)
  , mLineOrPageDeltaX(0)
  , mLineOrPageDeltaY(0)
  , mScrollSeriesNumber(0)
  , mUserDeltaMultiplierX(1.0)
  , mUserDeltaMultiplierY(1.0)
  , mMayHaveMomentum(false)
  , mIsMomentum(false)
  , mAllowToOverrideSystemScrollSpeed(aAllowToOverrideSystemScrollSpeed)
{
}

ScrollWheelInput::ScrollWheelInput(const WidgetWheelEvent& aWheelEvent)
  : InputData(SCROLLWHEEL_INPUT, aWheelEvent.mTime, aWheelEvent.mTimeStamp,
              aWheelEvent.mModifiers)
  , mDeltaType(DeltaTypeForDeltaMode(aWheelEvent.mDeltaMode))
  , mScrollMode(SCROLLMODE_INSTANT)
  , mHandledByAPZ(aWheelEvent.mFlags.mHandledByAPZ)
  , mDeltaX(aWheelEvent.mDeltaX)
  , mDeltaY(aWheelEvent.mDeltaY)
  , mLineOrPageDeltaX(aWheelEvent.mLineOrPageDeltaX)
  , mLineOrPageDeltaY(aWheelEvent.mLineOrPageDeltaY)
  , mScrollSeriesNumber(0)
  , mUserDeltaMultiplierX(1.0)
  , mUserDeltaMultiplierY(1.0)
  , mMayHaveMomentum(aWheelEvent.mMayHaveMomentum)
  , mIsMomentum(aWheelEvent.mIsMomentum)
  , mAllowToOverrideSystemScrollSpeed(
      aWheelEvent.mAllowToOverrideSystemScrollSpeed)
{
  mOrigin =
    ScreenPoint(ViewAs<ScreenPixel>(aWheelEvent.mRefPoint,
      PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent));
}

ScrollWheelInput::ScrollDeltaType
ScrollWheelInput::DeltaTypeForDeltaMode(uint32_t aDeltaMode)
{
  switch (aDeltaMode) {
  case nsIDOMWheelEvent::DOM_DELTA_LINE:
    return SCROLLDELTA_LINE;
  case nsIDOMWheelEvent::DOM_DELTA_PAGE:
    return SCROLLDELTA_PAGE;
  case nsIDOMWheelEvent::DOM_DELTA_PIXEL:
    return SCROLLDELTA_PIXEL;
  default:
    MOZ_CRASH();
  }
  return SCROLLDELTA_LINE;
}

uint32_t
ScrollWheelInput::DeltaModeForDeltaType(ScrollDeltaType aDeltaType)
{
  switch (aDeltaType) {
  case ScrollWheelInput::SCROLLDELTA_LINE:
    return nsIDOMWheelEvent::DOM_DELTA_LINE;
  case ScrollWheelInput::SCROLLDELTA_PAGE:
    return nsIDOMWheelEvent::DOM_DELTA_PAGE;
  case ScrollWheelInput::SCROLLDELTA_PIXEL:
  default:
    return nsIDOMWheelEvent::DOM_DELTA_PIXEL;
  }
}

nsIScrollableFrame::ScrollUnit
ScrollWheelInput::ScrollUnitForDeltaType(ScrollDeltaType aDeltaType)
{
  switch (aDeltaType) {
  case SCROLLDELTA_LINE:
    return nsIScrollableFrame::LINES;
  case SCROLLDELTA_PAGE:
    return nsIScrollableFrame::PAGES;
  case SCROLLDELTA_PIXEL:
    return nsIScrollableFrame::DEVICE_PIXELS;
  default:
    MOZ_CRASH();
  }
  return nsIScrollableFrame::LINES;
}

WidgetWheelEvent
ScrollWheelInput::ToWidgetWheelEvent(nsIWidget* aWidget) const
{
  WidgetWheelEvent wheelEvent(true, eWheel, aWidget);
  wheelEvent.mModifiers = this->modifiers;
  wheelEvent.mTime = mTime;
  wheelEvent.mTimeStamp = mTimeStamp;
  wheelEvent.mRefPoint =
    RoundedToInt(ViewAs<LayoutDevicePixel>(mOrigin,
      PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent));
  wheelEvent.buttons = 0;
  wheelEvent.mDeltaMode = DeltaModeForDeltaType(mDeltaType);
  wheelEvent.mMayHaveMomentum = mMayHaveMomentum;
  wheelEvent.mIsMomentum = mIsMomentum;
  wheelEvent.mDeltaX = mDeltaX;
  wheelEvent.mDeltaY = mDeltaY;
  wheelEvent.mLineOrPageDeltaX = mLineOrPageDeltaX;
  wheelEvent.mLineOrPageDeltaY = mLineOrPageDeltaY;
  wheelEvent.mAllowToOverrideSystemScrollSpeed =
    mAllowToOverrideSystemScrollSpeed;
  wheelEvent.mFlags.mHandledByAPZ = mHandledByAPZ;
  return wheelEvent;
}

bool
ScrollWheelInput::TransformToLocal(const ScreenToParentLayerMatrix4x4& aTransform)
{
  Maybe<ParentLayerPoint> point = UntransformBy(aTransform, mOrigin);
  if (!point) {
    return false;
  }
  mLocalOrigin = *point;
  return true;
}

bool
ScrollWheelInput::IsCustomizedByUserPrefs() const
{
  return mUserDeltaMultiplierX != 1.0 ||
         mUserDeltaMultiplierY != 1.0;
}

} // namespace mozilla