gecko-dev/dom/system/nsDeviceSensors.cpp

/* -*- 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 "mozilla/Hal.h"
#include "mozilla/HalSensor.h"

#include "nsContentUtils.h"
#include "nsDeviceSensors.h"

#include "nsPIDOMWindow.h"
#include "nsIScriptObjectPrincipal.h"
#include "mozilla/Preferences.h"
#include "mozilla/StaticPrefs_device.h"
#include "mozilla/Attributes.h"
#include "mozilla/dom/BrowsingContext.h"
#include "mozilla/dom/DeviceLightEvent.h"
#include "mozilla/dom/DeviceOrientationEvent.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/Event.h"
#include "mozilla/ErrorResult.h"

#include <cmath>

using namespace mozilla;
using namespace mozilla::dom;
using namespace hal;

class nsIDOMWindow;

#undef near

#define DEFAULT_SENSOR_POLL 100

static const nsTArray<nsIDOMWindow*>::index_type NoIndex =
    nsTArray<nsIDOMWindow*>::NoIndex;

class nsDeviceSensorData final : public nsIDeviceSensorData {
 public:
  NS_DECL_ISUPPORTS
  NS_DECL_NSIDEVICESENSORDATA

  nsDeviceSensorData(unsigned long type, double x, double y, double z);

 private:
  ~nsDeviceSensorData();

 protected:
  unsigned long mType;
  double mX, mY, mZ;
};

nsDeviceSensorData::nsDeviceSensorData(unsigned long type, double x, double y,
                                       double z)
    : mType(type), mX(x), mY(y), mZ(z) {}

NS_INTERFACE_MAP_BEGIN(nsDeviceSensorData)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDeviceSensorData)
NS_INTERFACE_MAP_END

NS_IMPL_ADDREF(nsDeviceSensorData)
NS_IMPL_RELEASE(nsDeviceSensorData)

nsDeviceSensorData::~nsDeviceSensorData() = default;

NS_IMETHODIMP nsDeviceSensorData::GetType(uint32_t* aType) {
  NS_ENSURE_ARG_POINTER(aType);
  *aType = mType;
  return NS_OK;
}

NS_IMETHODIMP nsDeviceSensorData::GetX(double* aX) {
  NS_ENSURE_ARG_POINTER(aX);
  *aX = mX;
  return NS_OK;
}

NS_IMETHODIMP nsDeviceSensorData::GetY(double* aY) {
  NS_ENSURE_ARG_POINTER(aY);
  *aY = mY;
  return NS_OK;
}

NS_IMETHODIMP nsDeviceSensorData::GetZ(double* aZ) {
  NS_ENSURE_ARG_POINTER(aZ);
  *aZ = mZ;
  return NS_OK;
}

NS_IMPL_ISUPPORTS(nsDeviceSensors, nsIDeviceSensors)

nsDeviceSensors::nsDeviceSensors() {
  mLastDOMMotionEventTime = TimeStamp::Now();

  for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
    nsTArray<nsIDOMWindow*>* windows = new nsTArray<nsIDOMWindow*>();
    mWindowListeners.AppendElement(windows);
  }

  mLastDOMMotionEventTime = TimeStamp::Now();
}

nsDeviceSensors::~nsDeviceSensors() {
  for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
    if (IsSensorEnabled(i)) UnregisterSensorObserver((SensorType)i, this);
  }

  for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
    delete mWindowListeners[i];
  }
}

NS_IMETHODIMP nsDeviceSensors::HasWindowListener(uint32_t aType,
                                                 nsIDOMWindow* aWindow,
                                                 bool* aRetVal) {
  if (!IsSensorAllowedByPref(aType, aWindow))
    *aRetVal = false;
  else
    *aRetVal = mWindowListeners[aType]->IndexOf(aWindow) != NoIndex;

  return NS_OK;
}

class DeviceSensorTestEvent : public Runnable {
 public:
  DeviceSensorTestEvent(nsDeviceSensors* aTarget, uint32_t aType)
      : mozilla::Runnable("DeviceSensorTestEvent"),
        mTarget(aTarget),
        mType(aType) {}

  NS_IMETHOD Run() override {
    SensorData sensorData;
    sensorData.sensor() = static_cast<SensorType>(mType);
    sensorData.timestamp() = PR_Now();
    sensorData.values().AppendElement(0.5f);
    sensorData.values().AppendElement(0.5f);
    sensorData.values().AppendElement(0.5f);
    sensorData.values().AppendElement(0.5f);
    mTarget->Notify(sensorData);
    return NS_OK;
  }

 private:
  RefPtr<nsDeviceSensors> mTarget;
  uint32_t mType;
};

NS_IMETHODIMP nsDeviceSensors::AddWindowListener(uint32_t aType,
                                                 nsIDOMWindow* aWindow) {
  if (!IsSensorAllowedByPref(aType, aWindow)) return NS_OK;

  if (mWindowListeners[aType]->IndexOf(aWindow) != NoIndex) return NS_OK;

  if (!IsSensorEnabled(aType)) {
    RegisterSensorObserver((SensorType)aType, this);
  }

  mWindowListeners[aType]->AppendElement(aWindow);

  if (StaticPrefs::device_sensors_test_events()) {
    nsCOMPtr<nsIRunnable> event = new DeviceSensorTestEvent(this, aType);
    NS_DispatchToCurrentThread(event);
  }

  return NS_OK;
}

NS_IMETHODIMP nsDeviceSensors::RemoveWindowListener(uint32_t aType,
                                                    nsIDOMWindow* aWindow) {
  if (mWindowListeners[aType]->IndexOf(aWindow) == NoIndex) return NS_OK;

  mWindowListeners[aType]->RemoveElement(aWindow);

  if (mWindowListeners[aType]->Length() == 0)
    UnregisterSensorObserver((SensorType)aType, this);

  return NS_OK;
}

NS_IMETHODIMP nsDeviceSensors::RemoveWindowAsListener(nsIDOMWindow* aWindow) {
  for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
    RemoveWindowListener((SensorType)i, aWindow);
  }
  return NS_OK;
}

static bool WindowCannotReceiveSensorEvent(nsPIDOMWindowInner* aWindow) {
  // Check to see if this window is in the background.
  if (!aWindow || !aWindow->IsCurrentInnerWindow()) {
    return true;
  }

  nsPIDOMWindowOuter* windowOuter = aWindow->GetOuterWindow();
  BrowsingContext* topBC = aWindow->GetBrowsingContext()->Top();
  if (windowOuter->IsBackground() || !topBC->GetIsActiveBrowserWindow()) {
    return true;
  }

  // Check to see if this window is a cross-origin iframe:
  if (!topBC->IsInProcess()) {
    return true;
  }

  nsCOMPtr<nsIScriptObjectPrincipal> sop = do_QueryInterface(aWindow);
  nsCOMPtr<nsIScriptObjectPrincipal> topSop =
      do_QueryInterface(topBC->GetDOMWindow());
  if (!sop || !topSop) {
    return true;
  }

  nsIPrincipal* principal = sop->GetPrincipal();
  nsIPrincipal* topPrincipal = topSop->GetPrincipal();
  if (!principal || !topPrincipal) {
    return true;
  }

  return !principal->Subsumes(topPrincipal);
}

// Holds the device orientation in Euler angle degrees (azimuth, pitch, roll).
struct Orientation {
  enum OrientationReference { kRelative = 0, kAbsolute };

  static Orientation RadToDeg(const Orientation& aOrient) {
    const static double kRadToDeg = 180.0 / M_PI;
    return {aOrient.alpha * kRadToDeg, aOrient.beta * kRadToDeg,
            aOrient.gamma * kRadToDeg};
  }

  double alpha;
  double beta;
  double gamma;
};

static Orientation RotationVectorToOrientation(double aX, double aY, double aZ,
                                               double aW) {
  double mat[9];

  mat[0] = 1 - 2 * aY * aY - 2 * aZ * aZ;
  mat[1] = 2 * aX * aY - 2 * aZ * aW;
  mat[2] = 2 * aX * aZ + 2 * aY * aW;

  mat[3] = 2 * aX * aY + 2 * aZ * aW;
  mat[4] = 1 - 2 * aX * aX - 2 * aZ * aZ;
  mat[5] = 2 * aY * aZ - 2 * aX * aW;

  mat[6] = 2 * aX * aZ - 2 * aY * aW;
  mat[7] = 2 * aY * aZ + 2 * aX * aW;
  mat[8] = 1 - 2 * aX * aX - 2 * aY * aY;

  Orientation orient;

  if (mat[8] > 0) {
    orient.alpha = atan2(-mat[1], mat[4]);
    orient.beta = asin(mat[7]);
    orient.gamma = atan2(-mat[6], mat[8]);
  } else if (mat[8] < 0) {
    orient.alpha = atan2(mat[1], -mat[4]);
    orient.beta = -asin(mat[7]);
    orient.beta += (orient.beta >= 0) ? -M_PI : M_PI;
    orient.gamma = atan2(mat[6], -mat[8]);
  } else {
    if (mat[6] > 0) {
      orient.alpha = atan2(-mat[1], mat[4]);
      orient.beta = asin(mat[7]);
      orient.gamma = -M_PI_2;
    } else if (mat[6] < 0) {
      orient.alpha = atan2(mat[1], -mat[4]);
      orient.beta = -asin(mat[7]);
      orient.beta += (orient.beta >= 0) ? -M_PI : M_PI;
      orient.gamma = -M_PI_2;
    } else {
      orient.alpha = atan2(mat[3], mat[0]);
      orient.beta = (mat[7] > 0) ? M_PI_2 : -M_PI_2;
      orient.gamma = 0;
    }
  }

  if (orient.alpha < 0) {
    orient.alpha += 2 * M_PI;
  }

  return Orientation::RadToDeg(orient);
}

void nsDeviceSensors::Notify(const mozilla::hal::SensorData& aSensorData) {
  uint32_t type = aSensorData.sensor();

  const nsTArray<float>& values = aSensorData.values();
  size_t len = values.Length();
  double x = len > 0 ? values[0] : 0.0;
  double y = len > 1 ? values[1] : 0.0;
  double z = len > 2 ? values[2] : 0.0;
  double w = len > 3 ? values[3] : 0.0;
  PRTime timestamp = aSensorData.timestamp();

  nsCOMArray<nsIDOMWindow> windowListeners;
  for (uint32_t i = 0; i < mWindowListeners[type]->Length(); i++) {
    windowListeners.AppendObject(mWindowListeners[type]->SafeElementAt(i));
  }

  for (uint32_t i = windowListeners.Count(); i > 0;) {
    --i;

    nsCOMPtr<nsPIDOMWindowInner> pwindow =
        do_QueryInterface(windowListeners[i]);
    if (WindowCannotReceiveSensorEvent(pwindow)) {
      continue;
    }

    if (nsCOMPtr<Document> doc = pwindow->GetDoc()) {
      nsCOMPtr<mozilla::dom::EventTarget> target =
          do_QueryInterface(windowListeners[i]);
      if (type == nsIDeviceSensorData::TYPE_ACCELERATION ||
          type == nsIDeviceSensorData::TYPE_LINEAR_ACCELERATION ||
          type == nsIDeviceSensorData::TYPE_GYROSCOPE) {
        FireDOMMotionEvent(doc, target, type, timestamp, x, y, z);
      } else if (type == nsIDeviceSensorData::TYPE_ORIENTATION) {
        FireDOMOrientationEvent(target, x, y, z, Orientation::kAbsolute);
      } else if (type == nsIDeviceSensorData::TYPE_ROTATION_VECTOR) {
        const Orientation orient = RotationVectorToOrientation(x, y, z, w);
        FireDOMOrientationEvent(target, orient.alpha, orient.beta, orient.gamma,
                                Orientation::kAbsolute);
      } else if (type == nsIDeviceSensorData::TYPE_GAME_ROTATION_VECTOR) {
        const Orientation orient = RotationVectorToOrientation(x, y, z, w);
        FireDOMOrientationEvent(target, orient.alpha, orient.beta, orient.gamma,
                                Orientation::kRelative);
      } else if (type == nsIDeviceSensorData::TYPE_LIGHT) {
        FireDOMLightEvent(target, x);
      }
    }
  }
}

void nsDeviceSensors::FireDOMLightEvent(mozilla::dom::EventTarget* aTarget,
                                        double aValue) {
  DeviceLightEventInit init;
  init.mBubbles = true;
  init.mCancelable = false;
  init.mValue = round(aValue);
  RefPtr<DeviceLightEvent> event =
      DeviceLightEvent::Constructor(aTarget, u"devicelight"_ns, init);

  event->SetTrusted(true);

  aTarget->DispatchEvent(*event);
}

void nsDeviceSensors::FireDOMOrientationEvent(EventTarget* aTarget,
                                              double aAlpha, double aBeta,
                                              double aGamma, bool aIsAbsolute) {
  DeviceOrientationEventInit init;
  init.mBubbles = true;
  init.mCancelable = false;
  init.mAlpha.SetValue(aAlpha);
  init.mBeta.SetValue(aBeta);
  init.mGamma.SetValue(aGamma);
  init.mAbsolute = aIsAbsolute;

  auto Dispatch = [&](EventTarget* aEventTarget, const nsAString& aType) {
    RefPtr<DeviceOrientationEvent> event =
        DeviceOrientationEvent::Constructor(aEventTarget, aType, init);
    event->SetTrusted(true);
    aEventTarget->DispatchEvent(*event);
  };

  Dispatch(aTarget, aIsAbsolute ? u"absolutedeviceorientation"_ns
                                : u"deviceorientation"_ns);

  // This is used to determine whether relative events have been dispatched
  // during the current session, in which case we don't dispatch the additional
  // compatibility events.
  static bool sIsDispatchingRelativeEvents = false;
  sIsDispatchingRelativeEvents = sIsDispatchingRelativeEvents || !aIsAbsolute;

  // Android devices with SENSOR_GAME_ROTATION_VECTOR support dispatch
  // relative events for "deviceorientation" by default, while other platforms
  // and devices without such support dispatch absolute events by default.
  if (aIsAbsolute && !sIsDispatchingRelativeEvents) {
    // For absolute events on devices without support for relative events,
    // we need to additionally dispatch type "deviceorientation" to keep
    // backwards-compatibility.
    Dispatch(aTarget, u"deviceorientation"_ns);
  }
}

void nsDeviceSensors::FireDOMMotionEvent(Document* doc, EventTarget* target,
                                         uint32_t type, PRTime timestamp,
                                         double x, double y, double z) {
  // Attempt to coalesce events
  TimeDuration sensorPollDuration =
      TimeDuration::FromMilliseconds(DEFAULT_SENSOR_POLL);
  bool fireEvent =
      (TimeStamp::Now() > mLastDOMMotionEventTime + sensorPollDuration) ||
      StaticPrefs::device_sensors_test_events();

  switch (type) {
    case nsIDeviceSensorData::TYPE_LINEAR_ACCELERATION:
      if (!mLastAcceleration) {
        mLastAcceleration.emplace();
      }
      mLastAcceleration->mX.SetValue(x);
      mLastAcceleration->mY.SetValue(y);
      mLastAcceleration->mZ.SetValue(z);
      break;
    case nsIDeviceSensorData::TYPE_ACCELERATION:
      if (!mLastAccelerationIncludingGravity) {
        mLastAccelerationIncludingGravity.emplace();
      }
      mLastAccelerationIncludingGravity->mX.SetValue(x);
      mLastAccelerationIncludingGravity->mY.SetValue(y);
      mLastAccelerationIncludingGravity->mZ.SetValue(z);
      break;
    case nsIDeviceSensorData::TYPE_GYROSCOPE:
      if (!mLastRotationRate) {
        mLastRotationRate.emplace();
      }
      mLastRotationRate->mAlpha.SetValue(x);
      mLastRotationRate->mBeta.SetValue(y);
      mLastRotationRate->mGamma.SetValue(z);
      break;
  }

  if (fireEvent) {
    if (!mLastAcceleration) {
      mLastAcceleration.emplace();
    }
    if (!mLastAccelerationIncludingGravity) {
      mLastAccelerationIncludingGravity.emplace();
    }
    if (!mLastRotationRate) {
      mLastRotationRate.emplace();
    }
  } else if (!mLastAcceleration || !mLastAccelerationIncludingGravity ||
             !mLastRotationRate) {
    return;
  }

  IgnoredErrorResult ignored;
  RefPtr<Event> event =
      doc->CreateEvent(u"DeviceMotionEvent"_ns, CallerType::System, ignored);
  if (!event) {
    return;
  }

  DeviceMotionEvent* me = static_cast<DeviceMotionEvent*>(event.get());

  me->InitDeviceMotionEvent(
      u"devicemotion"_ns, true, false, *mLastAcceleration,
      *mLastAccelerationIncludingGravity, *mLastRotationRate,
      Nullable<double>(DEFAULT_SENSOR_POLL), Nullable<uint64_t>(timestamp));

  event->SetTrusted(true);

  target->DispatchEvent(*event);

  mLastRotationRate.reset();
  mLastAccelerationIncludingGravity.reset();
  mLastAcceleration.reset();
  mLastDOMMotionEventTime = TimeStamp::Now();
}

bool nsDeviceSensors::IsSensorAllowedByPref(uint32_t aType,
                                            nsIDOMWindow* aWindow) {
  // checks "device.sensors.enabled" master pref
  if (!StaticPrefs::device_sensors_enabled()) {
    return false;
  }

  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(aWindow);
  nsCOMPtr<Document> doc;
  if (window) {
    doc = window->GetExtantDoc();
  }

  switch (aType) {
    case nsIDeviceSensorData::TYPE_LINEAR_ACCELERATION:
    case nsIDeviceSensorData::TYPE_ACCELERATION:
    case nsIDeviceSensorData::TYPE_GYROSCOPE:
      // checks "device.sensors.motion.enabled" pref
      if (!StaticPrefs::device_sensors_motion_enabled()) {
        return false;
      } else if (doc) {
        doc->WarnOnceAbout(DeprecatedOperations::eMotionEvent);
      }
      break;
    case nsIDeviceSensorData::TYPE_GAME_ROTATION_VECTOR:
    case nsIDeviceSensorData::TYPE_ORIENTATION:
    case nsIDeviceSensorData::TYPE_ROTATION_VECTOR:
      // checks "device.sensors.orientation.enabled" pref
      if (!StaticPrefs::device_sensors_orientation_enabled()) {
        return false;
      } else if (doc) {
        doc->WarnOnceAbout(DeprecatedOperations::eOrientationEvent);
      }
      break;
    case nsIDeviceSensorData::TYPE_LIGHT:
      // checks "device.sensors.ambientLight.enabled" pref
      if (!StaticPrefs::device_sensors_ambientLight_enabled()) {
        return false;
      } else if (doc) {
        doc->WarnOnceAbout(DeprecatedOperations::eAmbientLightEvent, true);
      }
      break;
    default:
      MOZ_ASSERT_UNREACHABLE("Device sensor type not recognised");
      return false;
  }

  if (!window) {
    return true;
  }

  nsCOMPtr<nsIScriptObjectPrincipal> soPrincipal = do_QueryInterface(window);
  return !nsContentUtils::ShouldResistFingerprinting(
      soPrincipal->GetPrincipal());
}