Sensors

device/generic_sensor contains the platform-specific parts of the Sensor APIs implementation.

Sensors Mojo interfaces are defined in the public/interfaces subdirectory.

The JS bindings are implemented in third_party/WebKit/Source/modules/sensor.

Platform Support

Support for the SensorTypes defined by the Mojo interface is summarized in this table. An empty cell indicates that the sensor type is not supported on that platform.

SensorTypeAndroidLinuxmacOSWindows
AMBIENT_LIGHTTYPE_LIGHTin_illuminanceAppleLMUControllerSENSOR_TYPE_AMBIENT_LIGHT
PROXIMITY
ACCELEROMETERTYPE_ACCELEROMETERin_accelSMCMotionSensorSENSOR_TYPE_ACCELEROMETER_3D
LINEAR_ACCELEROMETERTYPE_LINEAR_ACCELEROMETER
GYROSCOPETYPE_GYROSCOPEin_anglvelSENSOR_TYPE_GYROMETER_3D
MAGNETOMETERTYPE_MAGNETIC_FIELDin_magnSENSOR_TYPE_COMPASS_3D
PRESSURE
ABSOLUTE_ORIENTATIONTYPE_ROTATION_VECTORSENSOR_TYPE_AGGREGATED_DEVICE_ORIENTATION
RELATIVE_ORIENTATIONTYPE_GAME_ROTATION_VECTOR

Android

Sensors are implemented by passing through values provided by the Sensor class. The values in the “Android” column of the table above correspond to the integer constants from the android.hardware.Sensor used to provide data for a SensorType.

Linux (and Chrome OS)

Sensors are implemented by reading values from the IIO subsystem. The values in the “Linux” column of the table above are the prefix of the sysfs files Chrome searches for to provide data for a SensorType.

macOS

On this platform there is limited support for sensors. The AMBIENT_LIGHT sensor type is provided by interpreting the value that can be read from the LMU. The ACCELEROMETER sensor type is provided by interpreting the value that can be read from the SMCMotionSensor.

Windows

Sensors are implemented by passing through values provided by the Sensor API. The values in the “Windows” column of the table above correspond to the names of the sensor type GUIDs used to provide data for a SensorType.

Testing

Sensors platform unit tests are located in the current directory and its subdirectories.

The sensors unit tests file for Android is android/junit/src/org/chromium/device/sensors/PlatformSensorAndProviderTest.java.

Sensors browser tests are located in content/test/data/generic_sensor.

Design Documents

Please refer to the design documentation for more details.