Success Criterion 2.5.4 - Level A
Motion Actuation
Ensure an alternative is provided for motion-triggered actions and make it possible to disable them. Users with limited hand function might not be able to shake their device. On the other hand, users with spasms might accidentally trigger actions.
Impact
For users with (temporarily) limited hand function, shaking is often not possible. Make sure that these functions can also be activated in another way.
Movement in a wheelchair or spasms can unintentionally activate functions. Make sure that these functions can be turned off.
Check
“Is an alternative option available for motion-triggered functions?“
This can be tested without assistive technologies.
Solution
Add alternatives for motion activated actions
On Android, the SensorManager can be used in combination with SensorEventListener to detect movement.
An event through sensors should not be the only way to trigger actions. Make sure to provide a second way, such as a button, to trigger the same action.
class SensorActivity : AppCompatActivity(), SensorEventListener {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val sensorManager = getSystemService(Context.SENSOR_SERVICE) as SensorManager
val sensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
sensorManager.registerListener(this, sensor, SensorManager.SENSOR_DELAY_NORMAL)
}
override fun onSensorChanged(event: SensorEvent?) {
// Add alternative
}
}