TalkBackPreferencesActivity.java 文件源码

/**
 * Ensure that the proximity sensor setting does not appear on devices
 * without a proximity sensor.
 */
private void checkProximitySupport() {
    Activity activity = getActivity();
    if (activity == null) {
        return;
    }

    final SensorManager manager = (SensorManager) activity.getSystemService(SENSOR_SERVICE);
    final Sensor proximity = manager.getDefaultSensor(Sensor.TYPE_PROXIMITY);

    if (proximity != null) {
        return;
    }

    final PreferenceGroup category = (PreferenceGroup) findPreferenceByResId(
            R.string.pref_category_when_to_speak_key);
    final TwoStatePreference prefProximity =
            (TwoStatePreference) findPreferenceByResId(R.string.pref_proximity_key);

    if (prefProximity != null) {
        prefProximity.setChecked(false);
        category.removePreference(prefProximity);
    }
}