interface Event {
};

interface Error {
};

dictionary EventInit {
};

interface Sensor : EventTarget {
  readonly attribute SensorState state;
  readonly attribute SensorReading? reading;
  void start();
  void stop();
  attribute EventHandler onchange;
  attribute EventHandler onstatechange;
  attribute EventHandler onerror;
};

dictionary SensorOptions {
  double? frequency;
};

enum SensorState {
  "idle",
  "activating",
  "active",
  "errored"
};

interface SensorReading {
  readonly attribute DOMHighResTimeStamp timeStamp;
};

[Constructor(DOMString type, SensorReadingEventInit eventInitDict)]
interface SensorReadingEvent : Event {
  readonly attribute SensorReading reading;
};

dictionary SensorReadingEventInit : EventInit {
  SensorReading reading;
};

[Constructor(DOMString type, SensorErrorEventInit errorEventInitDict)]
interface SensorErrorEvent : Event {
  readonly attribute Error error;
};

dictionary SensorErrorEventInit : EventInit {
  Error error;
};

[Constructor(optional SensorOptions sensorOptions)]
interface AmbientLightSensor : Sensor {
  readonly attribute AmbientLightSensorReading? reading;
};

[Constructor(AmbientLightSensorReadingInit ambientLightSensorReadingInit)]
interface AmbientLightSensorReading : SensorReading {
    readonly attribute unrestricted double illuminance;
};

dictionary AmbientLightSensorReadingInit {
  unrestricted double illuminance;
};