https://source.android.com/ 
/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.hardware;

import android.annotation.SystemApi;
import android.annotation.SystemService;
import android.content.Context;
import android.os.Build;
import android.os.Handler;
import android.os.MemoryFile;
import android.util.Log;
import android.util.SparseArray;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;


 SensorManager lets you access the device's 
sensors. 



Always make sure to disable sensors you don't need, especially when your
activity is paused. Failing to do so can drain the battery in just a few
hours. Note that the system will not disable sensors automatically when
the screen turns off.



 Note: Don't use this mechanism with a Trigger Sensor, have a look at TriggerEventListener. Sensor.TYPE_SIGNIFICANT_MOTION is an example of a trigger sensor. 


public class SensorActivity extends Activity implements SensorEventListener {
    private final SensorManager mSensorManager;
    private final Sensor mAccelerometer;
    public SensorActivity() {
        mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
        mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
    }
    protected void onResume() {
        super.onResume();
        mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
    }
    protected void onPause() {
        super.onPause();
        mSensorManager.unregisterListener(this);
    }
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
    }
    public void onSensorChanged(SensorEvent event) {
    }
}



See Also:
/**
 * <p>
 * SensorManager lets you access the device's {@link android.hardware.Sensor
 * sensors}.
 * </p>
 * <p>
 * Always make sure to disable sensors you don't need, especially when your
 * activity is paused. Failing to do so can drain the battery in just a few
 * hours. Note that the system will <i>not</i> disable sensors automatically when
 * the screen turns off.
 * </p>
 * <p class="note">
 * Note: Don't use this mechanism with a Trigger Sensor, have a look
 * at {@link TriggerEventListener}. {@link Sensor#TYPE_SIGNIFICANT_MOTION}
 * is an example of a trigger sensor.
 * </p>
 * <pre class="prettyprint">
 * public class SensorActivity extends Activity implements SensorEventListener {
 *     private final SensorManager mSensorManager;
 *     private final Sensor mAccelerometer;
 *
 *     public SensorActivity() {
 *         mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
 *         mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
 *     }
 *
 *     protected void onResume() {
 *         super.onResume();
 *         mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
 *     }
 *
 *     protected void onPause() {
 *         super.onPause();
 *         mSensorManager.unregisterListener(this);
 *     }
 *
 *     public void onAccuracyChanged(Sensor sensor, int accuracy) {
 *     }
 *
 *     public void onSensorChanged(SensorEvent event) {
 *     }
 * }
 * </pre>
 *
 * @see SensorEventListener
 * @see SensorEvent
 * @see Sensor
 *
 */
@SystemService(Context.SENSOR_SERVICE)
public abstract class SensorManager {
    
@hide
/** @hide */
    protected static final String TAG = "SensorManager";

    private static final float[] sTempMatrix = new float[16];

    // Cached lists of sensors by type.  Guarded by mSensorListByType.
    private final SparseArray<List<Sensor>> mSensorListByType =
            new SparseArray<List<Sensor>>();

    // Legacy sensor manager implementation.  Guarded by mSensorListByType during initialization.
    private LegacySensorManager mLegacySensorManager;

    /* NOTE: sensor IDs must be a power of 2 */

    
A constant describing an orientation sensor. See SensorListener for more details. 
Deprecated:use Sensor instead.
/**
     * A constant describing an orientation sensor. See
     * {@link android.hardware.SensorListener SensorListener} for more details.
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_ORIENTATION = 1 << 0;

    
A constant describing an accelerometer. See SensorListener for more details. 
Deprecated:use Sensor instead.
/**
     * A constant describing an accelerometer. See
     * {@link android.hardware.SensorListener SensorListener} for more details.
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_ACCELEROMETER = 1 << 1;

    
A constant describing a temperature sensor See SensorListener for more details. 
Deprecated:use Sensor instead.
/**
     * A constant describing a temperature sensor See
     * {@link android.hardware.SensorListener SensorListener} for more details.
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_TEMPERATURE = 1 << 2;

    
A constant describing a magnetic sensor See SensorListener for more details. 
Deprecated:use Sensor instead.
/**
     * A constant describing a magnetic sensor See
     * {@link android.hardware.SensorListener SensorListener} for more details.
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_MAGNETIC_FIELD = 1 << 3;

    
A constant describing an ambient light sensor See SensorListener for more details. 
Deprecated:use Sensor instead.
/**
     * A constant describing an ambient light sensor See
     * {@link android.hardware.SensorListener SensorListener} for more details.
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_LIGHT = 1 << 4;

    
A constant describing a proximity sensor See SensorListener for more details. 
Deprecated:use Sensor instead.
/**
     * A constant describing a proximity sensor See
     * {@link android.hardware.SensorListener SensorListener} for more details.
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_PROXIMITY = 1 << 5;

    
A constant describing a Tricorder See SensorListener for more details. 
Deprecated:use Sensor instead.
/**
     * A constant describing a Tricorder See
     * {@link android.hardware.SensorListener SensorListener} for more details.
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_TRICORDER = 1 << 6;

    
A constant describing an orientation sensor. See SensorListener for more details. 
Deprecated:use Sensor instead.
/**
     * A constant describing an orientation sensor. See
     * {@link android.hardware.SensorListener SensorListener} for more details.
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_ORIENTATION_RAW = 1 << 7;

    
A constant that includes all sensors

Deprecated:use Sensor instead.
/**
     * A constant that includes all sensors
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_ALL = 0x7F;

    
Smallest sensor ID

Deprecated:use Sensor instead.
/**
     * Smallest sensor ID
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_MIN = SENSOR_ORIENTATION;

    
Largest sensor ID

Deprecated:use Sensor instead.
/**
     * Largest sensor ID
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int SENSOR_MAX = ((SENSOR_ALL + 1) >> 1);


    
Index of the X value in the array returned by SensorListener.onSensorChanged 
Deprecated:use Sensor instead.
/**
     * Index of the X value in the array returned by
     * {@link android.hardware.SensorListener#onSensorChanged}
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int DATA_X = 0;

    
Index of the Y value in the array returned by SensorListener.onSensorChanged 
Deprecated:use Sensor instead.
/**
     * Index of the Y value in the array returned by
     * {@link android.hardware.SensorListener#onSensorChanged}
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int DATA_Y = 1;

    
Index of the Z value in the array returned by SensorListener.onSensorChanged 
Deprecated:use Sensor instead.
/**
     * Index of the Z value in the array returned by
     * {@link android.hardware.SensorListener#onSensorChanged}
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int DATA_Z = 2;

    
Offset to the untransformed values in the array returned by SensorListener.onSensorChanged 
Deprecated:use Sensor instead.
/**
     * Offset to the untransformed values in the array returned by
     * {@link android.hardware.SensorListener#onSensorChanged}
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int RAW_DATA_INDEX = 3;

    
Index of the untransformed X value in the array returned by SensorListener.onSensorChanged 
Deprecated:use Sensor instead.
/**
     * Index of the untransformed X value in the array returned by
     * {@link android.hardware.SensorListener#onSensorChanged}
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int RAW_DATA_X = 3;

    
Index of the untransformed Y value in the array returned by SensorListener.onSensorChanged 
Deprecated:use Sensor instead.
/**
     * Index of the untransformed Y value in the array returned by
     * {@link android.hardware.SensorListener#onSensorChanged}
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int RAW_DATA_Y = 4;

    
Index of the untransformed Z value in the array returned by SensorListener.onSensorChanged 
Deprecated:use Sensor instead.
/**
     * Index of the untransformed Z value in the array returned by
     * {@link android.hardware.SensorListener#onSensorChanged}
     *
     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
     */
    @Deprecated
    public static final int RAW_DATA_Z = 5;

    
Standard gravity (g) on Earth. This value is equivalent to 1G 
/** Standard gravity (g) on Earth. This value is equivalent to 1G */
    public static final float STANDARD_GRAVITY = 9.80665f;

    
Sun's gravity in SI units (m/s^2) 
/** Sun's gravity in SI units (m/s^2) */
    public static final float GRAVITY_SUN             = 275.0f;
    
Mercury's gravity in SI units (m/s^2) 
/** Mercury's gravity in SI units (m/s^2) */
    public static final float GRAVITY_MERCURY         = 3.70f;
    
Venus' gravity in SI units (m/s^2) 
/** Venus' gravity in SI units (m/s^2) */
    public static final float GRAVITY_VENUS           = 8.87f;
    
Earth's gravity in SI units (m/s^2) 
/** Earth's gravity in SI units (m/s^2) */
    public static final float GRAVITY_EARTH           = 9.80665f;
    
The Moon's gravity in SI units (m/s^2) 
/** The Moon's gravity in SI units (m/s^2) */
    public static final float GRAVITY_MOON            = 1.6f;
    
Mars' gravity in SI units (m/s^2) 
/** Mars' gravity in SI units (m/s^2) */
    public static final float GRAVITY_MARS            = 3.71f;
    
Jupiter's gravity in SI units (m/s^2) 
/** Jupiter's gravity in SI units (m/s^2) */
    public static final float GRAVITY_JUPITER         = 23.12f;
    
Saturn's gravity in SI units (m/s^2) 
/** Saturn's gravity in SI units (m/s^2) */
    public static final float GRAVITY_SATURN          = 8.96f;
    
Uranus' gravity in SI units (m/s^2) 
/** Uranus' gravity in SI units (m/s^2) */
    public static final float GRAVITY_URANUS          = 8.69f;
    
Neptune's gravity in SI units (m/s^2) 
/** Neptune's gravity in SI units (m/s^2) */
    public static final float GRAVITY_NEPTUNE         = 11.0f;
    
Pluto's gravity in SI units (m/s^2) 
/** Pluto's gravity in SI units (m/s^2) */
    public static final float GRAVITY_PLUTO           = 0.6f;
    
Gravity (estimate) on the first Death Star in Empire units (m/s^2) 
/** Gravity (estimate) on the first Death Star in Empire units (m/s^2) */
    public static final float GRAVITY_DEATH_STAR_I    = 0.000000353036145f;
    
Gravity on the island 
/** Gravity on the island */
    public static final float GRAVITY_THE_ISLAND      = 4.815162342f;


    
Maximum magnetic field on Earth's surface 
/** Maximum magnetic field on Earth's surface */
    public static final float MAGNETIC_FIELD_EARTH_MAX = 60.0f;
    
Minimum magnetic field on Earth's surface 
/** Minimum magnetic field on Earth's surface */
    public static final float MAGNETIC_FIELD_EARTH_MIN = 30.0f;


    
Standard atmosphere, or average sea-level pressure in hPa (millibar) 
/** Standard atmosphere, or average sea-level pressure in hPa (millibar) */
    public static final float PRESSURE_STANDARD_ATMOSPHERE = 1013.25f;


    
Maximum luminance of sunlight in lux 
/** Maximum luminance of sunlight in lux */
    public static final float LIGHT_SUNLIGHT_MAX = 120000.0f;
    
luminance of sunlight in lux 
/** luminance of sunlight in lux */
    public static final float LIGHT_SUNLIGHT     = 110000.0f;
    
luminance in shade in lux 
/** luminance in shade in lux */
    public static final float LIGHT_SHADE        = 20000.0f;
    
luminance under an overcast sky in lux 
/** luminance under an overcast sky in lux */
    public static final float LIGHT_OVERCAST     = 10000.0f;
    
luminance at sunrise in lux 
/** luminance at sunrise in lux */
    public static final float LIGHT_SUNRISE      = 400.0f;
    
luminance under a cloudy sky in lux 
/** luminance under a cloudy sky in lux */
    public static final float LIGHT_CLOUDY       = 100.0f;
    
luminance at night with full moon in lux 
/** luminance at night with full moon in lux */
    public static final float LIGHT_FULLMOON     = 0.25f;
    
luminance at night with no moon in lux
/** luminance at night with no moon in lux*/
    public static final float LIGHT_NO_MOON      = 0.001f;


    
get sensor data as fast as possible 
/** get sensor data as fast as possible */
    public static final int SENSOR_DELAY_FASTEST = 0;
    
rate suitable for games 
/** rate suitable for games */
    public static final int SENSOR_DELAY_GAME = 1;
    
rate suitable for the user interface  
/** rate suitable for the user interface  */
    public static final int SENSOR_DELAY_UI = 2;
    
rate (default) suitable for screen orientation changes 
/** rate (default) suitable for screen orientation changes */
    public static final int SENSOR_DELAY_NORMAL = 3;


    
The values returned by this sensor cannot be trusted because the sensor
had no contact with what it was measuring (for example, the heart rate
monitor is not in contact with the user).

/**
      * The values returned by this sensor cannot be trusted because the sensor
      * had no contact with what it was measuring (for example, the heart rate
      * monitor is not in contact with the user).
      */
    public static final int SENSOR_STATUS_NO_CONTACT = -1;

    
The values returned by this sensor cannot be trusted, calibration is
needed or the environment doesn't allow readings

/**
     * The values returned by this sensor cannot be trusted, calibration is
     * needed or the environment doesn't allow readings
     */
    public static final int SENSOR_STATUS_UNRELIABLE = 0;

    
This sensor is reporting data with low accuracy, calibration with the
environment is needed

/**
     * This sensor is reporting data with low accuracy, calibration with the
     * environment is needed
     */
    public static final int SENSOR_STATUS_ACCURACY_LOW = 1;

    
This sensor is reporting data with an average level of accuracy,
calibration with the environment may improve the readings

/**
     * This sensor is reporting data with an average level of accuracy,
     * calibration with the environment may improve the readings
     */
    public static final int SENSOR_STATUS_ACCURACY_MEDIUM = 2;

    
This sensor is reporting data with maximum accuracy 
/** This sensor is reporting data with maximum accuracy */
    public static final int SENSOR_STATUS_ACCURACY_HIGH = 3;

    /** see {@link #remapCoordinateSystem} */
    public static final int AXIS_X = 1;
    /** see {@link #remapCoordinateSystem} */
    public static final int AXIS_Y = 2;
    /** see {@link #remapCoordinateSystem} */
    public static final int AXIS_Z = 3;
    /** see {@link #remapCoordinateSystem} */
    public static final int AXIS_MINUS_X = AXIS_X | 0x80;
    /** see {@link #remapCoordinateSystem} */
    public static final int AXIS_MINUS_Y = AXIS_Y | 0x80;
    /** see {@link #remapCoordinateSystem} */
    public static final int AXIS_MINUS_Z = AXIS_Z | 0x80;


    
{@hide}

/**
     * {@hide}
     */
    public SensorManager() {
    }

    
Gets the full list of sensors that are available.

@hide
/**
     * Gets the full list of sensors that are available.
     * @hide
     */
    protected abstract List<Sensor> getFullSensorList();

    
Gets the full list of dynamic sensors that are available.

@hide
/**
     * Gets the full list of dynamic sensors that are available.
     * @hide
     */
    protected abstract List<Sensor> getFullDynamicSensorList();

    
Returns:available sensors.
Deprecated:This method is deprecated, use getSensorList(int) instead
/**
     * @return available sensors.
     * @deprecated This method is deprecated, use
     *             {@link SensorManager#getSensorList(int)} instead
     */
    @Deprecated
    public int getSensors() {
        return getLegacySensorManager().getSensors();
    }

    
Use this method to get the list of available sensors of a certain type. Make multiple calls to get sensors of different types or use Sensor.TYPE_ALL to get all the sensors. 
 NOTE: Both wake-up and non wake-up sensors matching the given type are returned. Check Sensor.isWakeUpSensor() to know the wake-up properties of the returned Sensor. 


Params:
  • type – 
       of sensors requested
See Also:
Returns:a list of sensors matching the asked type.
/**
     * Use this method to get the list of available sensors of a certain type.
     * Make multiple calls to get sensors of different types or use
     * {@link android.hardware.Sensor#TYPE_ALL Sensor.TYPE_ALL} to get all the
     * sensors.
     *
     * <p class="note">
     * NOTE: Both wake-up and non wake-up sensors matching the given type are
     * returned. Check {@link Sensor#isWakeUpSensor()} to know the wake-up properties
     * of the returned {@link Sensor}.
     * </p>
     *
     * @param type
     *        of sensors requested
     *
     * @return a list of sensors matching the asked type.
     *
     * @see #getDefaultSensor(int)
     * @see Sensor
     */
    public List<Sensor> getSensorList(int type) {
        // cache the returned lists the first time
        List<Sensor> list;
        final List<Sensor> fullList = getFullSensorList();
        synchronized (mSensorListByType) {
            list = mSensorListByType.get(type);
            if (list == null) {
                if (type == Sensor.TYPE_ALL) {
                    list = fullList;
                } else {
                    list = new ArrayList<Sensor>();
                    for (Sensor i : fullList) {
                        if (i.getType() == type) {
                            list.add(i);
                        }
                    }
                }
                list = Collections.unmodifiableList(list);
                mSensorListByType.append(type, list);
            }
        }
        return list;
    }

    
Use this method to get a list of available dynamic sensors of a certain type. Make multiple calls to get sensors of different types or use Sensor.TYPE_ALL to get all dynamic sensors. 
 NOTE: Both wake-up and non wake-up sensors matching the given type are returned. Check Sensor.isWakeUpSensor() to know the wake-up properties of the returned Sensor. 


Params:
  • type – of sensors requested
See Also:
Returns:a list of dynamic sensors matching the requested type.
/**
     * Use this method to get a list of available dynamic sensors of a certain type.
     * Make multiple calls to get sensors of different types or use
     * {@link android.hardware.Sensor#TYPE_ALL Sensor.TYPE_ALL} to get all dynamic sensors.
     *
     * <p class="note">
     * NOTE: Both wake-up and non wake-up sensors matching the given type are
     * returned. Check {@link Sensor#isWakeUpSensor()} to know the wake-up properties
     * of the returned {@link Sensor}.
     * </p>
     *
     * @param type of sensors requested
     *
     * @return a list of dynamic sensors matching the requested type.
     *
     * @see Sensor
     */
    public List<Sensor> getDynamicSensorList(int type) {
        // cache the returned lists the first time
        final List<Sensor> fullList = getFullDynamicSensorList();
        if (type == Sensor.TYPE_ALL) {
            return Collections.unmodifiableList(fullList);
        } else {
            List<Sensor> list = new ArrayList();
            for (Sensor i : fullList) {
                if (i.getType() == type) {
                    list.add(i);
                }
            }
            return Collections.unmodifiableList(list);
        }
    }

    
Use this method to get the default sensor for a given type. Note that the returned sensor could be a composite sensor, and its data could be averaged or filtered. If you need to access the raw sensors use getSensorList. 
Params:
  • type – 
        of sensors requested
See Also:
Returns:the default sensor matching the requested type if one exists and the application
        has the necessary permissions, or null otherwise.
/**
     * Use this method to get the default sensor for a given type. Note that the
     * returned sensor could be a composite sensor, and its data could be
     * averaged or filtered. If you need to access the raw sensors use
     * {@link SensorManager#getSensorList(int) getSensorList}.
     *
     * @param type
     *         of sensors requested
     *
     * @return the default sensor matching the requested type if one exists and the application
     *         has the necessary permissions, or null otherwise.
     *
     * @see #getSensorList(int)
     * @see Sensor
     */
    public Sensor getDefaultSensor(int type) {
        // TODO: need to be smarter, for now, just return the 1st sensor
        List<Sensor> l = getSensorList(type);
        boolean wakeUpSensor = false;
        // For the following sensor types, return a wake-up sensor. These types are by default
        // defined as wake-up sensors. For the rest of the SDK defined sensor types return a
        // non_wake-up version.
        if (type == Sensor.TYPE_PROXIMITY || type == Sensor.TYPE_SIGNIFICANT_MOTION
                || type == Sensor.TYPE_TILT_DETECTOR || type == Sensor.TYPE_WAKE_GESTURE
                || type == Sensor.TYPE_GLANCE_GESTURE || type == Sensor.TYPE_PICK_UP_GESTURE
                || type == Sensor.TYPE_WRIST_TILT_GESTURE
                || type == Sensor.TYPE_DYNAMIC_SENSOR_META) {
            wakeUpSensor = true;
        }

        for (Sensor sensor : l) {
            if (sensor.isWakeUpSensor() == wakeUpSensor) return sensor;
        }
        return null;
    }

    
Return a Sensor with the given type and wakeUp properties. If multiple sensors of this
type exist, any one of them may be returned.


For example,





 Note: Sensors like Sensor.TYPE_PROXIMITY and Sensor.TYPE_SIGNIFICANT_MOTION are declared as wake-up sensors by default. 


Params:
  • type – 
       type of sensor requested
  • wakeUp – 
       flag to indicate whether the Sensor is a wake-up or non wake-up sensor.
See Also:
Returns:the default sensor matching the requested type and wakeUp properties if one exists
        and the application has the necessary permissions, or null otherwise.
/**
     * Return a Sensor with the given type and wakeUp properties. If multiple sensors of this
     * type exist, any one of them may be returned.
     * <p>
     * For example,
     * <ul>
     *     <li>getDefaultSensor({@link Sensor#TYPE_ACCELEROMETER}, true) returns a wake-up
     *     accelerometer sensor if it exists. </li>
     *     <li>getDefaultSensor({@link Sensor#TYPE_PROXIMITY}, false) returns a non wake-up
     *     proximity sensor if it exists. </li>
     *     <li>getDefaultSensor({@link Sensor#TYPE_PROXIMITY}, true) returns a wake-up proximity
     *     sensor which is the same as the Sensor returned by {@link #getDefaultSensor(int)}. </li>
     * </ul>
     * </p>
     * <p class="note">
     * Note: Sensors like {@link Sensor#TYPE_PROXIMITY} and {@link Sensor#TYPE_SIGNIFICANT_MOTION}
     * are declared as wake-up sensors by default.
     * </p>
     * @param type
     *        type of sensor requested
     * @param wakeUp
     *        flag to indicate whether the Sensor is a wake-up or non wake-up sensor.
     * @return the default sensor matching the requested type and wakeUp properties if one exists
     *         and the application has the necessary permissions, or null otherwise.
     * @see Sensor#isWakeUpSensor()
     */
    public Sensor getDefaultSensor(int type, boolean wakeUp) {
        List<Sensor> l = getSensorList(type);
        for (Sensor sensor : l) {
            if (sensor.isWakeUpSensor() == wakeUp) {
                return sensor;
            }
        }
        return null;
    }

    
Registers a listener for given sensors.

Params:
  • listener – 
       sensor listener object
  • sensors – 
       a bit masks of the sensors to register to
Deprecated:This method is deprecated, use registerListener(SensorEventListener, Sensor, int) instead.
Returns:true if the sensor is supported and successfully
        enabled
/**
     * Registers a listener for given sensors.
     *
     * @deprecated This method is deprecated, use
     *             {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
     *             instead.
     *
     * @param listener
     *        sensor listener object
     *
     * @param sensors
     *        a bit masks of the sensors to register to
     *
     * @return <code>true</code> if the sensor is supported and successfully
     *         enabled
     */
    @Deprecated
    public boolean registerListener(SensorListener listener, int sensors) {
        return registerListener(listener, sensors, SENSOR_DELAY_NORMAL);
    }

    
Registers a SensorListener for given sensors.

Params:
  • listener – 
       sensor listener object
  • sensors – 
       a bit masks of the sensors to register to
  • rate –  rate of events. This is only a hint to the system. events may be received faster or slower than the specified rate. Usually events are received faster. The value must be one of SENSOR_DELAY_NORMAL, SENSOR_DELAY_UI, SENSOR_DELAY_GAME, or SENSOR_DELAY_FASTEST.
Deprecated:This method is deprecated, use registerListener(SensorEventListener, Sensor, int) instead.
Returns:true if the sensor is supported and successfully
        enabled
/**
     * Registers a SensorListener for given sensors.
     *
     * @deprecated This method is deprecated, use
     *             {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
     *             instead.
     *
     * @param listener
     *        sensor listener object
     *
     * @param sensors
     *        a bit masks of the sensors to register to
     *
     * @param rate
     *        rate of events. This is only a hint to the system. events may be
     *        received faster or slower than the specified rate. Usually events
     *        are received faster. The value must be one of
     *        {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
     *        {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}.
     *
     * @return <code>true</code> if the sensor is supported and successfully
     *         enabled
     */
    @Deprecated
    public boolean registerListener(SensorListener listener, int sensors, int rate) {
        return getLegacySensorManager().registerListener(listener, sensors, rate);
    }

    
Unregisters a listener for all sensors.

Params:
  • listener – 
       a SensorListener object
Deprecated:This method is deprecated, use unregisterListener(SensorEventListener) instead.
/**
     * Unregisters a listener for all sensors.
     *
     * @deprecated This method is deprecated, use
     *             {@link SensorManager#unregisterListener(SensorEventListener)}
     *             instead.
     *
     * @param listener
     *        a SensorListener object
     */
    @Deprecated
    public void unregisterListener(SensorListener listener) {
        unregisterListener(listener, SENSOR_ALL | SENSOR_ORIENTATION_RAW);
    }

    
Unregisters a listener for the sensors with which it is registered.

Params:
  • listener – 
       a SensorListener object
  • sensors – 
       a bit masks of the sensors to unregister from
Deprecated:This method is deprecated, use unregisterListener(SensorEventListener, Sensor) instead.
/**
     * Unregisters a listener for the sensors with which it is registered.
     *
     * @deprecated This method is deprecated, use
     *             {@link SensorManager#unregisterListener(SensorEventListener, Sensor)}
     *             instead.
     *
     * @param listener
     *        a SensorListener object
     *
     * @param sensors
     *        a bit masks of the sensors to unregister from
     */
    @Deprecated
    public void unregisterListener(SensorListener listener, int sensors) {
        getLegacySensorManager().unregisterListener(listener, sensors);
    }

    
Unregisters a listener for the sensors with which it is registered.

 Note: Don't use this method with a one shot trigger sensor such as Sensor.TYPE_SIGNIFICANT_MOTION. Use cancelTriggerSensor(TriggerEventListener, Sensor) instead. 


Params:
  • listener – 
       a SensorEventListener object
  • sensor – 
       the sensor to unregister from
See Also:
/**
     * Unregisters a listener for the sensors with which it is registered.
     *
     * <p class="note"></p>
     * Note: Don't use this method with a one shot trigger sensor such as
     * {@link Sensor#TYPE_SIGNIFICANT_MOTION}.
     * Use {@link #cancelTriggerSensor(TriggerEventListener, Sensor)} instead.
     * </p>
     *
     * @param listener
     *        a SensorEventListener object
     *
     * @param sensor
     *        the sensor to unregister from
     *
     * @see #unregisterListener(SensorEventListener)
     * @see #registerListener(SensorEventListener, Sensor, int)
     */
    public void unregisterListener(SensorEventListener listener, Sensor sensor) {
        if (listener == null || sensor == null) {
            return;
        }

        unregisterListenerImpl(listener, sensor);
    }

    
Unregisters a listener for all sensors.

Params:
  • listener – 
       a SensorListener object
See Also:
/**
     * Unregisters a listener for all sensors.
     *
     * @param listener
     *        a SensorListener object
     *
     * @see #unregisterListener(SensorEventListener, Sensor)
     * @see #registerListener(SensorEventListener, Sensor, int)
     *
     */
    public void unregisterListener(SensorEventListener listener) {
        if (listener == null) {
            return;
        }

        unregisterListenerImpl(listener, null);
    }

    
@hide
/** @hide */
    protected abstract void unregisterListenerImpl(SensorEventListener listener, Sensor sensor);

    
Registers a SensorEventListener for the given sensor at the given sampling frequency. 
 The events will be delivered to the provided SensorEventListener as soon as they are available. To reduce the power consumption, applications can use registerListener(SensorEventListener, Sensor, int, int) instead and specify a positive non-zero maximum reporting latency. 


 In the case of non-wake-up sensors, the events are only delivered while the Application Processor (AP) is not in suspend mode. See Sensor.isWakeUpSensor() for more details. To ensure delivery of events from non-wake-up sensors even when the screen is OFF, the application registering to the sensor must hold a partial wake-lock to keep the AP awake, otherwise some events might be lost while the AP is asleep. Note that although events might be lost while the AP is asleep, the sensor will still consume power if it is not explicitly deactivated by the application. Applications must unregister their 
SensorEventListeners in their activity's onPause() method to avoid consuming power while the device is inactive. See registerListener(SensorEventListener, Sensor, int, int) for more details on hardware FIFO (queueing) capabilities and when some sensor events might be lost. 


 In the case of wake-up sensors, each event generated by the sensor will cause the AP to wake-up, ensuring that each event can be delivered. Because of this, registering to a wake-up sensor has very significant power implications. Call Sensor.isWakeUpSensor() to check whether a sensor is a wake-up sensor. See registerListener(SensorEventListener, Sensor, int, int) for information on how to reduce the power impact of registering to wake-up sensors. 


 Note: Don't use this method with one-shot trigger sensors such as Sensor.TYPE_SIGNIFICANT_MOTION. Use requestTriggerSensor(TriggerEventListener, Sensor) instead. Use Sensor.getReportingMode() to obtain the reporting mode of a given sensor. 


Params:
  • listener – A SensorEventListener object.
  • sensor – The Sensor to register to.
  • samplingPeriodUs – The rate sensor events are delivered at. This is only a hint to the system. Events may be received faster or slower than the specified rate. Usually events are received faster. The value must be one of SENSOR_DELAY_NORMAL, SENSOR_DELAY_UI, SENSOR_DELAY_GAME, or SENSOR_DELAY_FASTEST or, the desired delay between events in microseconds. Specifying the delay in microseconds only works from Android 2.3 (API level 9) onwards. For earlier releases, you must use one of the SENSOR_DELAY_* constants.
See Also:
Returns:true if the sensor is supported and successfully enabled.
/**
     * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
     * sensor at the given sampling frequency.
     * <p>
     * The events will be delivered to the provided {@code SensorEventListener} as soon as they are
     * available. To reduce the power consumption, applications can use
     * {@link #registerListener(SensorEventListener, Sensor, int, int)} instead and specify a
     * positive non-zero maximum reporting latency.
     * </p>
     * <p>
     * In the case of non-wake-up sensors, the events are only delivered while the Application
     * Processor (AP) is not in suspend mode. See {@link Sensor#isWakeUpSensor()} for more details.
     * To ensure delivery of events from non-wake-up sensors even when the screen is OFF, the
     * application registering to the sensor must hold a partial wake-lock to keep the AP awake,
     * otherwise some events might be lost while the AP is asleep. Note that although events might
     * be lost while the AP is asleep, the sensor will still consume power if it is not explicitly
     * deactivated by the application. Applications must unregister their {@code
     * SensorEventListener}s in their activity's {@code onPause()} method to avoid consuming power
     * while the device is inactive.  See {@link #registerListener(SensorEventListener, Sensor, int,
     * int)} for more details on hardware FIFO (queueing) capabilities and when some sensor events
     * might be lost.
     * </p>
     * <p>
     * In the case of wake-up sensors, each event generated by the sensor will cause the AP to
     * wake-up, ensuring that each event can be delivered. Because of this, registering to a wake-up
     * sensor has very significant power implications. Call {@link Sensor#isWakeUpSensor()} to check
     * whether a sensor is a wake-up sensor. See
     * {@link #registerListener(SensorEventListener, Sensor, int, int)} for information on how to
     * reduce the power impact of registering to wake-up sensors.
     * </p>
     * <p class="note">
     * Note: Don't use this method with one-shot trigger sensors such as
     * {@link Sensor#TYPE_SIGNIFICANT_MOTION}. Use
     * {@link #requestTriggerSensor(TriggerEventListener, Sensor)} instead. Use
     * {@link Sensor#getReportingMode()} to obtain the reporting mode of a given sensor.
     * </p>
     *
     * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object.
     * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
     * @param samplingPeriodUs The rate {@link android.hardware.SensorEvent sensor events} are
     *            delivered at. This is only a hint to the system. Events may be received faster or
     *            slower than the specified rate. Usually events are received faster. The value must
     *            be one of {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
     *            {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST} or, the desired delay
     *            between events in microseconds. Specifying the delay in microseconds only works
     *            from Android 2.3 (API level 9) onwards. For earlier releases, you must use one of
     *            the {@code SENSOR_DELAY_*} constants.
     * @return <code>true</code> if the sensor is supported and successfully enabled.
     * @see #registerListener(SensorEventListener, Sensor, int, Handler)
     * @see #unregisterListener(SensorEventListener)
     * @see #unregisterListener(SensorEventListener, Sensor)
     */
    public boolean registerListener(SensorEventListener listener, Sensor sensor,
            int samplingPeriodUs) {
        return registerListener(listener, sensor, samplingPeriodUs, null);
    }

    
Registers a SensorEventListener for the given sensor at the given sampling frequency and the given maximum reporting latency. 
 This function is similar to registerListener(SensorEventListener, Sensor, int) but it allows events to stay temporarily in the hardware FIFO (queue) before being delivered. The events can be stored in the hardware FIFO up to maxReportLatencyUs microseconds. Once one of the events in the FIFO needs to be reported, all of the events in the FIFO are reported sequentially. This means that some events will be reported before the maximum reporting latency has elapsed. 
 When maxReportLatencyUs is 0, the call is equivalent to a call to registerListener(SensorEventListener, Sensor, int), as it requires the events to be delivered as soon as possible. 
 When sensor.maxFifoEventCount() is 0, the sensor does not use a FIFO, so the call will also be equivalent to registerListener(SensorEventListener, Sensor, int). 
 Setting maxReportLatencyUs to a positive value allows to reduce the number of interrupts the AP (Application Processor) receives, hence reducing power consumption, as the AP can switch to a lower power state while the sensor is capturing the data. This is especially important when registering to wake-up sensors, for which each interrupt causes the AP to wake up if it was in suspend mode. See Sensor.isWakeUpSensor() for more information on wake-up sensors. 




 Note: Don't use this method with one-shot trigger sensors such as Sensor.TYPE_SIGNIFICANT_MOTION. Use requestTriggerSensor(TriggerEventListener, Sensor) instead. 


Params:
  • listener – A SensorEventListener object that will receive the sensor events. If the application is interested in receiving flush complete notifications, it should register with SensorEventListener2 instead.
  • sensor – The Sensor to register to.
  • samplingPeriodUs – The desired delay between two consecutive events in microseconds. This is only a hint to the system. Events may be received faster or slower than the specified rate. Usually events are received faster. Can be one of SENSOR_DELAY_NORMAL, SENSOR_DELAY_UI, SENSOR_DELAY_GAME, SENSOR_DELAY_FASTEST or the delay in microseconds.
  • maxReportLatencyUs – Maximum time in microseconds that events can be delayed before being reported to the application. A large value allows reducing the power consumption associated with the sensor. If maxReportLatencyUs is set to zero, events are delivered as soon as they are available, which is equivalent to calling registerListener(SensorEventListener, Sensor, int).
See Also:
Returns:true if the sensor is supported and successfully enabled.
/**
     * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
     * sensor at the given sampling frequency and the given maximum reporting latency.
     * <p>
     * This function is similar to {@link #registerListener(SensorEventListener, Sensor, int)} but
     * it allows events to stay temporarily in the hardware FIFO (queue) before being delivered. The
     * events can be stored in the hardware FIFO up to {@code maxReportLatencyUs} microseconds. Once
     * one of the events in the FIFO needs to be reported, all of the events in the FIFO are
     * reported sequentially. This means that some events will be reported before the maximum
     * reporting latency has elapsed.
     * </p><p>
     * When {@code maxReportLatencyUs} is 0, the call is equivalent to a call to
     * {@link #registerListener(SensorEventListener, Sensor, int)}, as it requires the events to be
     * delivered as soon as possible.
     * </p><p>
     * When {@code sensor.maxFifoEventCount()} is 0, the sensor does not use a FIFO, so the call
     * will also be equivalent to {@link #registerListener(SensorEventListener, Sensor, int)}.
     * </p><p>
     * Setting {@code maxReportLatencyUs} to a positive value allows to reduce the number of
     * interrupts the AP (Application Processor) receives, hence reducing power consumption, as the
     * AP can switch to a lower power state while the sensor is capturing the data. This is
     * especially important when registering to wake-up sensors, for which each interrupt causes the
     * AP to wake up if it was in suspend mode. See {@link Sensor#isWakeUpSensor()} for more
     * information on wake-up sensors.
     * </p>
     * <p class="note">
     * </p>
     * Note: Don't use this method with one-shot trigger sensors such as
     * {@link Sensor#TYPE_SIGNIFICANT_MOTION}. Use
     * {@link #requestTriggerSensor(TriggerEventListener, Sensor)} instead. </p>
     *
     * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
     *            that will receive the sensor events. If the application is interested in receiving
     *            flush complete notifications, it should register with
     *            {@link android.hardware.SensorEventListener SensorEventListener2} instead.
     * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
     * @param samplingPeriodUs The desired delay between two consecutive events in microseconds.
     *            This is only a hint to the system. Events may be received faster or slower than
     *            the specified rate. Usually events are received faster. Can be one of
     *            {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
     *            {@link #SENSOR_DELAY_GAME}, {@link #SENSOR_DELAY_FASTEST} or the delay in
     *            microseconds.
     * @param maxReportLatencyUs Maximum time in microseconds that events can be delayed before
     *            being reported to the application. A large value allows reducing the power
     *            consumption associated with the sensor. If maxReportLatencyUs is set to zero,
     *            events are delivered as soon as they are available, which is equivalent to calling
     *            {@link #registerListener(SensorEventListener, Sensor, int)}.
     * @return <code>true</code> if the sensor is supported and successfully enabled.
     * @see #registerListener(SensorEventListener, Sensor, int)
     * @see #unregisterListener(SensorEventListener)
     * @see #flush(SensorEventListener)
     */
    public boolean registerListener(SensorEventListener listener, Sensor sensor,
            int samplingPeriodUs, int maxReportLatencyUs) {
        int delay = getDelay(samplingPeriodUs);
        return registerListenerImpl(listener, sensor, delay, null, maxReportLatencyUs, 0);
    }

    
Registers a SensorEventListener for the given sensor. Events are delivered in continuous mode as soon as they are available. To reduce the power consumption, applications can use registerListener(SensorEventListener, Sensor, int, int) instead and specify a positive non-zero maximum reporting latency. 


 Note: Don't use this method with a one shot trigger sensor such as Sensor.TYPE_SIGNIFICANT_MOTION. Use requestTriggerSensor(TriggerEventListener, Sensor) instead. 


Params:
  • listener – A SensorEventListener object.
  • sensor – The Sensor to register to.
  • samplingPeriodUs – The rate sensor events are delivered at. This is only a hint to the system. Events may be received faster or slower than the specified rate. Usually events are received faster. The value must be one of SENSOR_DELAY_NORMAL, SENSOR_DELAY_UI, SENSOR_DELAY_GAME, or SENSOR_DELAY_FASTEST or, the desired delay between events in microseconds. Specifying the delay in microseconds only works from Android 2.3 (API level 9) onwards. For earlier releases, you must use one of the SENSOR_DELAY_* constants.
  • handler – The Handler the 
           sensor events will be delivered to.
See Also:
Returns:true if the sensor is supported and successfully enabled.
/**
     * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
     * sensor. Events are delivered in continuous mode as soon as they are available. To reduce the
     * power consumption, applications can use
     * {@link #registerListener(SensorEventListener, Sensor, int, int)} instead and specify a
     * positive non-zero maximum reporting latency.
     * <p class="note">
     * </p>
     * Note: Don't use this method with a one shot trigger sensor such as
     * {@link Sensor#TYPE_SIGNIFICANT_MOTION}. Use
     * {@link #requestTriggerSensor(TriggerEventListener, Sensor)} instead. </p>
     *
     * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object.
     * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
     * @param samplingPeriodUs The rate {@link android.hardware.SensorEvent sensor events} are
     *            delivered at. This is only a hint to the system. Events may be received faster or
     *            slower than the specified rate. Usually events are received faster. The value must
     *            be one of {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
     *            {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST} or, the desired
     *            delay between events in microseconds. Specifying the delay in microseconds only
     *            works from Android 2.3 (API level 9) onwards. For earlier releases, you must use
     *            one of the {@code SENSOR_DELAY_*} constants.
     * @param handler The {@link android.os.Handler Handler} the {@link android.hardware.SensorEvent
     *            sensor events} will be delivered to.
     * @return <code>true</code> if the sensor is supported and successfully enabled.
     * @see #registerListener(SensorEventListener, Sensor, int)
     * @see #unregisterListener(SensorEventListener)
     * @see #unregisterListener(SensorEventListener, Sensor)
     */
    public boolean registerListener(SensorEventListener listener, Sensor sensor,
            int samplingPeriodUs, Handler handler) {
        int delay = getDelay(samplingPeriodUs);
        return registerListenerImpl(listener, sensor, delay, handler, 0, 0);
    }

    
Registers a SensorEventListener for the given sensor at the given sampling frequency and the given maximum reporting latency. 
Params:
  • listener – A SensorEventListener object that will receive the sensor events. If the application is interested in receiving flush complete notifications, it should register with SensorEventListener2 instead.
  • sensor – The Sensor to register to.
  • samplingPeriodUs – The desired delay between two consecutive events in microseconds. This is only a hint to the system. Events may be received faster or slower than the specified rate. Usually events are received faster. Can be one of SENSOR_DELAY_NORMAL, SENSOR_DELAY_UI, SENSOR_DELAY_GAME, SENSOR_DELAY_FASTEST or the delay in microseconds.
  • maxReportLatencyUs – Maximum time in microseconds that events can be delayed before being reported to the application. A large value allows reducing the power consumption associated with the sensor. If maxReportLatencyUs is set to zero, events are delivered as soon as they are available, which is equivalent to calling registerListener(SensorEventListener, Sensor, int).
  • handler – The Handler the 
           sensor events will be delivered to.
See Also:
Returns:true if the sensor is supported and successfully enabled.
/**
     * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
     * sensor at the given sampling frequency and the given maximum reporting latency.
     *
     * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
     *            that will receive the sensor events. If the application is interested in receiving
     *            flush complete notifications, it should register with
     *            {@link android.hardware.SensorEventListener SensorEventListener2} instead.
     * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
     * @param samplingPeriodUs The desired delay between two consecutive events in microseconds.
     *            This is only a hint to the system. Events may be received faster or slower than
     *            the specified rate. Usually events are received faster. Can be one of
     *            {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
     *            {@link #SENSOR_DELAY_GAME}, {@link #SENSOR_DELAY_FASTEST} or the delay in
     *            microseconds.
     * @param maxReportLatencyUs Maximum time in microseconds that events can be delayed before
     *            being reported to the application. A large value allows reducing the power
     *            consumption associated with the sensor. If maxReportLatencyUs is set to zero,
     *            events are delivered as soon as they are available, which is equivalent to calling
     *            {@link #registerListener(SensorEventListener, Sensor, int)}.
     * @param handler The {@link android.os.Handler Handler} the {@link android.hardware.SensorEvent
     *            sensor events} will be delivered to.
     * @return <code>true</code> if the sensor is supported and successfully enabled.
     * @see #registerListener(SensorEventListener, Sensor, int, int)
     */
    public boolean registerListener(SensorEventListener listener, Sensor sensor,
            int samplingPeriodUs, int maxReportLatencyUs, Handler handler) {
        int delayUs = getDelay(samplingPeriodUs);
        return registerListenerImpl(listener, sensor, delayUs, handler, maxReportLatencyUs, 0);
    }

    
@hide
/** @hide */
    protected abstract boolean registerListenerImpl(SensorEventListener listener, Sensor sensor,
            int delayUs, Handler handler, int maxReportLatencyUs, int reservedFlags);


    
Flushes the FIFO of all the sensors registered for this listener. If there are events in the FIFO of the sensor, they are returned as if the maxReportLantecy of the FIFO has expired. Events are returned in the usual way through the SensorEventListener. This call doesn't affect the maxReportLantecy for this sensor. This call is asynchronous and returns immediately. onFlushCompleted is called after all the events in the batch at the time of calling this method have been delivered successfully. If the hardware doesn't support flush, it still returns true and a trivial flush complete event is sent after the current event for all the clients registered for this sensor. 
Params:
  • listener – A SensorEventListener object which was previously used in a registerListener call.
Throws:
See Also:
Returns:true if the flush is initiated successfully on all the sensors
        registered for this listener, false if no sensor is previously registered for this
        listener or flush on one of the sensors fails.
/**
     * Flushes the FIFO of all the sensors registered for this listener. If there are events
     * in the FIFO of the sensor, they are returned as if the maxReportLantecy of the FIFO has
     * expired. Events are returned in the usual way through the SensorEventListener.
     * This call doesn't affect the maxReportLantecy for this sensor. This call is asynchronous and
     * returns immediately.
     * {@link android.hardware.SensorEventListener2#onFlushCompleted onFlushCompleted} is called
     * after all the events in the batch at the time of calling this method have been delivered
     * successfully. If the hardware doesn't support flush, it still returns true and a trivial
     * flush complete event is sent after the current event for all the clients registered for this
     * sensor.
     *
     * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
     *        which was previously used in a registerListener call.
     * @return <code>true</code> if the flush is initiated successfully on all the sensors
     *         registered for this listener, false if no sensor is previously registered for this
     *         listener or flush on one of the sensors fails.
     * @see #registerListener(SensorEventListener, Sensor, int, int)
     * @throws IllegalArgumentException when listener is null.
     */
    public boolean flush(SensorEventListener listener) {
        return flushImpl(listener);
    }

    
@hide
/** @hide */
    protected abstract boolean flushImpl(SensorEventListener listener);


    
Create a sensor direct channel backed by shared memory wrapped in MemoryFile object. The resulting channel can be used for delivering sensor events to native code, other processes, GPU/DSP or other co-processors without CPU intervention. This is the recommanded for high performance sensor applications that use high sensor rates (e.g. greater than 200Hz) and cares about sensor event latency. Use the returned SensorDirectChannel object to configure direct report of sensor events. After use, call SensorDirectChannel.close() to free up resource in sensor system associated with the direct channel. 
Params:
Throws:
See Also:
Returns:A SensorDirectChannel object.
/**
     * Create a sensor direct channel backed by shared memory wrapped in MemoryFile object.
     *
     * The resulting channel can be used for delivering sensor events to native code, other
     * processes, GPU/DSP or other co-processors without CPU intervention. This is the recommanded
     * for high performance sensor applications that use high sensor rates (e.g. greater than 200Hz)
     * and cares about sensor event latency.
     *
     * Use the returned {@link android.hardware.SensorDirectChannel} object to configure direct
     * report of sensor events. After use, call {@link android.hardware.SensorDirectChannel#close()}
     * to free up resource in sensor system associated with the direct channel.
     *
     * @param mem A {@link android.os.MemoryFile} shared memory object.
     * @return A {@link android.hardware.SensorDirectChannel} object.
     * @throws NullPointerException when mem is null.
     * @throws UncheckedIOException if not able to create channel.
     * @see SensorDirectChannel#close()
     * @see #configureDirectChannel(SensorDirectChannel, Sensor, int)
     */
    public SensorDirectChannel createDirectChannel(MemoryFile mem) {
        return createDirectChannelImpl(mem, null);
    }

    
Create a sensor direct channel backed by shared memory wrapped in HardwareBuffer object. The resulting channel can be used for delivering sensor events to native code, other processes, GPU/DSP or other co-processors without CPU intervention. This is the recommanded for high performance sensor applications that use high sensor rates (e.g. greater than 200Hz) and cares about sensor event latency. Use the returned SensorDirectChannel object to configure direct report of sensor events. After use, call SensorDirectChannel.close() to free up resource in sensor system associated with the direct channel. 
Params:
Throws:
See Also:
Returns:A SensorDirectChannel object.
/**
     * Create a sensor direct channel backed by shared memory wrapped in HardwareBuffer object.
     *
     * The resulting channel can be used for delivering sensor events to native code, other
     * processes, GPU/DSP or other co-processors without CPU intervention. This is the recommanded
     * for high performance sensor applications that use high sensor rates (e.g. greater than 200Hz)
     * and cares about sensor event latency.
     *
     * Use the returned {@link android.hardware.SensorDirectChannel} object to configure direct
     * report of sensor events. After use, call {@link android.hardware.SensorDirectChannel#close()}
     * to free up resource in sensor system associated with the direct channel.
     *
     * @param mem A {@link android.hardware.HardwareBuffer} shared memory object.
     * @return A {@link android.hardware.SensorDirectChannel} object.
     * @throws NullPointerException when mem is null.
     * @throws UncheckedIOException if not able to create channel.
     * @see SensorDirectChannel#close()
     * @see #configureDirectChannel(SensorDirectChannel, Sensor, int)
     */
    public SensorDirectChannel createDirectChannel(HardwareBuffer mem) {
        return createDirectChannelImpl(null, mem);
    }

    
@hide
/** @hide */
    protected abstract SensorDirectChannel createDirectChannelImpl(
            MemoryFile memoryFile, HardwareBuffer hardwareBuffer);

    
@hide
/** @hide */
    void destroyDirectChannel(SensorDirectChannel channel) {
        destroyDirectChannelImpl(channel);
    }

    
@hide
/** @hide */
    protected abstract void destroyDirectChannelImpl(SensorDirectChannel channel);

    
@removed
/** @removed */
    @Deprecated
    public int configureDirectChannel(SensorDirectChannel channel, Sensor sensor, int rateLevel) {
        return configureDirectChannelImpl(channel, sensor, rateLevel);
    }

    
@hide
/** @hide */
    protected abstract int configureDirectChannelImpl(
            SensorDirectChannel channel, Sensor s, int rate);

    
Used for receiving notifications from the SensorManager when dynamic sensors are connected or
disconnected.

/**
     * Used for receiving notifications from the SensorManager when dynamic sensors are connected or
     * disconnected.
     */
    public abstract static class DynamicSensorCallback {
        
Called when there is a dynamic sensor being connected to the system.

Params:
  • sensor – the newly connected sensor. See Sensor.
/**
         * Called when there is a dynamic sensor being connected to the system.
         *
         * @param sensor the newly connected sensor. See {@link android.hardware.Sensor Sensor}.
         */
        public void onDynamicSensorConnected(Sensor sensor) {}

        
Called when there is a dynamic sensor being disconnected from the system.

Params:
  • sensor – the disconnected sensor. See Sensor.
/**
         * Called when there is a dynamic sensor being disconnected from the system.
         *
         * @param sensor the disconnected sensor. See {@link android.hardware.Sensor Sensor}.
         */
        public void onDynamicSensorDisconnected(Sensor sensor) {}
    }


    
Add a 
DynamicSensorCallback to receive dynamic sensor connection callbacks. Repeat registration with the already registered callback object will have no additional effect. 
Params:
Throws:
See Also:
  • addDynamicSensorCallback(DynamicSensorCallback, Handler)
/**
     * Add a {@link android.hardware.SensorManager.DynamicSensorCallback
     * DynamicSensorCallback} to receive dynamic sensor connection callbacks. Repeat
     * registration with the already registered callback object will have no additional effect.
     *
     * @param callback An object that implements the
     *        {@link android.hardware.SensorManager.DynamicSensorCallback
     *        DynamicSensorCallback}
     *        interface for receiving callbacks.
     * @see #addDynamicSensorCallback(DynamicSensorCallback, Handler)
     *
     * @throws IllegalArgumentException when callback is null.
     */
    public void registerDynamicSensorCallback(DynamicSensorCallback callback) {
        registerDynamicSensorCallback(callback, null);
    }

    
Add a 
DynamicSensorCallback to receive dynamic sensor connection callbacks. Repeat registration with the already registered callback object will have no additional effect. 
Params:
Throws:
/**
     * Add a {@link android.hardware.SensorManager.DynamicSensorCallback
     * DynamicSensorCallback} to receive dynamic sensor connection callbacks. Repeat
     * registration with the already registered callback object will have no additional effect.
     *
     * @param callback An object that implements the
     *        {@link android.hardware.SensorManager.DynamicSensorCallback
     *        DynamicSensorCallback} interface for receiving callbacks.
     * @param handler The {@link android.os.Handler Handler} the {@link
     *        android.hardware.SensorManager.DynamicSensorCallback
     *        sensor connection events} will be delivered to.
     *
     * @throws IllegalArgumentException when callback is null.
     */
    public void registerDynamicSensorCallback(
            DynamicSensorCallback callback, Handler handler) {
        registerDynamicSensorCallbackImpl(callback, handler);
    }

    
Remove a 
DynamicSensorCallback to stop sending dynamic sensor connection events to that callback. 
Params:
/**
     * Remove a {@link android.hardware.SensorManager.DynamicSensorCallback
     * DynamicSensorCallback} to stop sending dynamic sensor connection events to that
     * callback.
     *
     * @param callback An object that implements the
     *        {@link android.hardware.SensorManager.DynamicSensorCallback
     *        DynamicSensorCallback}
     *        interface for receiving callbacks.
     */
    public void unregisterDynamicSensorCallback(DynamicSensorCallback callback) {
        unregisterDynamicSensorCallbackImpl(callback);
    }

    
Tell if dynamic sensor discovery feature is supported by system.

Returns:true if dynamic sensor discovery is supported, false
otherwise.
/**
     * Tell if dynamic sensor discovery feature is supported by system.
     *
     * @return <code>true</code> if dynamic sensor discovery is supported, <code>false</code>
     * otherwise.
     */
    public boolean isDynamicSensorDiscoverySupported() {
        List<Sensor> sensors = getSensorList(Sensor.TYPE_DYNAMIC_SENSOR_META);
        return sensors.size() > 0;
    }

    
@hide
/** @hide */
    protected abstract void registerDynamicSensorCallbackImpl(
            DynamicSensorCallback callback, Handler handler);

    
@hide
/** @hide */
    protected abstract void unregisterDynamicSensorCallbackImpl(
            DynamicSensorCallback callback);

    

Computes the inclination matrix I as well as the rotation matrix
R transforming a vector from the device coordinate system to the
world's coordinate system which is defined as a direct orthonormal basis,
where:



    

  • X is defined as the vector product Y.Z (It is tangential to
the ground at the device's current location and roughly points East).
    • 

  • Y is tangential to the ground at the device's current location and
points towards the magnetic North Pole.
    • 

  • Z points towards the sky and is perpendicular to the ground.
    • 














By definition:


[0 0 g] = R * gravity (g = magnitude of gravity)


[0 m 0] = I * R * geomagnetic (m = magnitude of
geomagnetic field)


R is the identity matrix when the device is aligned with the
world's coordinate system, that is, when the device's X axis points
toward East, the Y axis points to the North Pole and the device is facing
the sky.


I is a rotation matrix transforming the geomagnetic vector into
the same coordinate space as gravity (the world's coordinate space).
I is a simple rotation around the X axis. The inclination angle in radians can be computed with getInclination. 



Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending
on the length of the passed array:


If the array length is 16:

  /  M[ 0]   M[ 1]   M[ 2]   M[ 3]  \
  |  M[ 4]   M[ 5]   M[ 6]   M[ 7]  |
  |  M[ 8]   M[ 9]   M[10]   M[11]  |
  \  M[12]   M[13]   M[14]   M[15]  /

 This matrix is ready to be used by OpenGL ES's 
glLoadMatrixf(float[], int). 

Note that because OpenGL matrices are column-major matrices you must
transpose the matrix before using it. However, since the matrix is a
rotation matrix, its transpose is also its inverse, conveniently, it is
often the inverse of the rotation that is needed for rendering; it can
therefore be used with OpenGL ES directly.


Also note that the returned matrices always have this form:

  /  M[ 0]   M[ 1]   M[ 2]   0  \
  |  M[ 4]   M[ 5]   M[ 6]   0  |
  |  M[ 8]   M[ 9]   M[10]   0  |
  \      0       0       0   1  /




If the array length is 9:

  /  M[ 0]   M[ 1]   M[ 2]  \
  |  M[ 3]   M[ 4]   M[ 5]  |
  \  M[ 6]   M[ 7]   M[ 8]  /






The inverse of each matrix can be computed easily by taking its
transpose.


The matrices returned by this function are meaningful only when the
device is not free-falling and it is not close to the magnetic north. If
the device is accelerating, or placed into a strong magnetic field, the
returned matrices may be inaccurate.

Params:
  • R – 
       is an array of 9 floats holding the rotation matrix R when
       this function returns. R can be null.
       
  • I – 
       is an array of 9 floats holding the rotation matrix I when
       this function returns. I can be null.
       
  • gravity –  is an array of 3 floats containing the gravity vector expressed in the device's coordinate. You can simply use the values returned by a SensorEvent of a Sensor of type 
       TYPE_ACCELEROMETER. 
  • geomagnetic –  is an array of 3 floats containing the geomagnetic vector expressed in the device's coordinate. You can simply use the values returned by a SensorEvent of a Sensor of type 
       TYPE_MAGNETIC_FIELD.
See Also:
Returns:true on success, false on failure (for
        instance, if the device is in free fall). Free fall is defined as
        condition when the magnitude of the gravity is less than 1/10 of
        the nominal value. On failure the output matrices are not modified.
/**
     * <p>
     * Computes the inclination matrix <b>I</b> as well as the rotation matrix
     * <b>R</b> transforming a vector from the device coordinate system to the
     * world's coordinate system which is defined as a direct orthonormal basis,
     * where:
     * </p>
     *
     * <ul>
     * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to
     * the ground at the device's current location and roughly points East).</li>
     * <li>Y is tangential to the ground at the device's current location and
     * points towards the magnetic North Pole.</li>
     * <li>Z points towards the sky and is perpendicular to the ground.</li>
     * </ul>
     *
     * <p>
     * <center><img src="../../../images/axis_globe.png"
     * alt="World coordinate-system diagram." border="0" /></center>
     * </p>
     *
     * <p>
     * <hr>
     * <p>
     * By definition:
     * <p>
     * [0 0 g] = <b>R</b> * <b>gravity</b> (g = magnitude of gravity)
     * <p>
     * [0 m 0] = <b>I</b> * <b>R</b> * <b>geomagnetic</b> (m = magnitude of
     * geomagnetic field)
     * <p>
     * <b>R</b> is the identity matrix when the device is aligned with the
     * world's coordinate system, that is, when the device's X axis points
     * toward East, the Y axis points to the North Pole and the device is facing
     * the sky.
     *
     * <p>
     * <b>I</b> is a rotation matrix transforming the geomagnetic vector into
     * the same coordinate space as gravity (the world's coordinate space).
     * <b>I</b> is a simple rotation around the X axis. The inclination angle in
     * radians can be computed with {@link #getInclination}.
     * <hr>
     *
     * <p>
     * Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending
     * on the length of the passed array:
     * <p>
     * <u>If the array length is 16:</u>
     *
     * <pre>
     *   /  M[ 0]   M[ 1]   M[ 2]   M[ 3]  \
     *   |  M[ 4]   M[ 5]   M[ 6]   M[ 7]  |
     *   |  M[ 8]   M[ 9]   M[10]   M[11]  |
     *   \  M[12]   M[13]   M[14]   M[15]  /
     *</pre>
     *
     * This matrix is ready to be used by OpenGL ES's
     * {@link javax.microedition.khronos.opengles.GL10#glLoadMatrixf(float[], int)
     * glLoadMatrixf(float[], int)}.
     * <p>
     * Note that because OpenGL matrices are column-major matrices you must
     * transpose the matrix before using it. However, since the matrix is a
     * rotation matrix, its transpose is also its inverse, conveniently, it is
     * often the inverse of the rotation that is needed for rendering; it can
     * therefore be used with OpenGL ES directly.
     * <p>
     * Also note that the returned matrices always have this form:
     *
     * <pre>
     *   /  M[ 0]   M[ 1]   M[ 2]   0  \
     *   |  M[ 4]   M[ 5]   M[ 6]   0  |
     *   |  M[ 8]   M[ 9]   M[10]   0  |
     *   \      0       0       0   1  /
     *</pre>
     *
     * <p>
     * <u>If the array length is 9:</u>
     *
     * <pre>
     *   /  M[ 0]   M[ 1]   M[ 2]  \
     *   |  M[ 3]   M[ 4]   M[ 5]  |
     *   \  M[ 6]   M[ 7]   M[ 8]  /
     *</pre>
     *
     * <hr>
     * <p>
     * The inverse of each matrix can be computed easily by taking its
     * transpose.
     *
     * <p>
     * The matrices returned by this function are meaningful only when the
     * device is not free-falling and it is not close to the magnetic north. If
     * the device is accelerating, or placed into a strong magnetic field, the
     * returned matrices may be inaccurate.
     *
     * @param R
     *        is an array of 9 floats holding the rotation matrix <b>R</b> when
     *        this function returns. R can be null.
     *        <p>
     *
     * @param I
     *        is an array of 9 floats holding the rotation matrix <b>I</b> when
     *        this function returns. I can be null.
     *        <p>
     *
     * @param gravity
     *        is an array of 3 floats containing the gravity vector expressed in
     *        the device's coordinate. You can simply use the
     *        {@link android.hardware.SensorEvent#values values} returned by a
     *        {@link android.hardware.SensorEvent SensorEvent} of a
     *        {@link android.hardware.Sensor Sensor} of type
     *        {@link android.hardware.Sensor#TYPE_ACCELEROMETER
     *        TYPE_ACCELEROMETER}.
     *        <p>
     *
     * @param geomagnetic
     *        is an array of 3 floats containing the geomagnetic vector
     *        expressed in the device's coordinate. You can simply use the
     *        {@link android.hardware.SensorEvent#values values} returned by a
     *        {@link android.hardware.SensorEvent SensorEvent} of a
     *        {@link android.hardware.Sensor Sensor} of type
     *        {@link android.hardware.Sensor#TYPE_MAGNETIC_FIELD
     *        TYPE_MAGNETIC_FIELD}.
     *
     * @return <code>true</code> on success, <code>false</code> on failure (for
     *         instance, if the device is in free fall). Free fall is defined as
     *         condition when the magnitude of the gravity is less than 1/10 of
     *         the nominal value. On failure the output matrices are not modified.
     *
     * @see #getInclination(float[])
     * @see #getOrientation(float[], float[])
     * @see #remapCoordinateSystem(float[], int, int, float[])
     */

    public static boolean getRotationMatrix(float[] R, float[] I,
            float[] gravity, float[] geomagnetic) {
        // TODO: move this to native code for efficiency
        float Ax = gravity[0];
        float Ay = gravity[1];
        float Az = gravity[2];

        final float normsqA = (Ax * Ax + Ay * Ay + Az * Az);
        final float g = 9.81f;
        final float freeFallGravitySquared = 0.01f * g * g;
        if (normsqA < freeFallGravitySquared) {
            // gravity less than 10% of normal value
            return false;
        }

        final float Ex = geomagnetic[0];
        final float Ey = geomagnetic[1];
        final float Ez = geomagnetic[2];
        float Hx = Ey * Az - Ez * Ay;
        float Hy = Ez * Ax - Ex * Az;
        float Hz = Ex * Ay - Ey * Ax;
        final float normH = (float) Math.sqrt(Hx * Hx + Hy * Hy + Hz * Hz);

        if (normH < 0.1f) {
            // device is close to free fall (or in space?), or close to
            // magnetic north pole. Typical values are  > 100.
            return false;
        }
        final float invH = 1.0f / normH;
        Hx *= invH;
        Hy *= invH;
        Hz *= invH;
        final float invA = 1.0f / (float) Math.sqrt(Ax * Ax + Ay * Ay + Az * Az);
        Ax *= invA;
        Ay *= invA;
        Az *= invA;
        final float Mx = Ay * Hz - Az * Hy;
        final float My = Az * Hx - Ax * Hz;
        final float Mz = Ax * Hy - Ay * Hx;
        if (R != null) {
            if (R.length == 9) {
                R[0] = Hx;     R[1] = Hy;     R[2] = Hz;
                R[3] = Mx;     R[4] = My;     R[5] = Mz;
                R[6] = Ax;     R[7] = Ay;     R[8] = Az;
            } else if (R.length == 16) {
                R[0]  = Hx;    R[1]  = Hy;    R[2]  = Hz;   R[3]  = 0;
                R[4]  = Mx;    R[5]  = My;    R[6]  = Mz;   R[7]  = 0;
                R[8]  = Ax;    R[9]  = Ay;    R[10] = Az;   R[11] = 0;
                R[12] = 0;     R[13] = 0;     R[14] = 0;    R[15] = 1;
            }
        }
        if (I != null) {
            // compute the inclination matrix by projecting the geomagnetic
            // vector onto the Z (gravity) and X (horizontal component
            // of geomagnetic vector) axes.
            final float invE = 1.0f / (float) Math.sqrt(Ex * Ex + Ey * Ey + Ez * Ez);
            final float c = (Ex * Mx + Ey * My + Ez * Mz) * invE;
            final float s = (Ex * Ax + Ey * Ay + Ez * Az) * invE;
            if (I.length == 9) {
                I[0] = 1;     I[1] = 0;     I[2] = 0;
                I[3] = 0;     I[4] = c;     I[5] = s;
                I[6] = 0;     I[7] = -s;     I[8] = c;
            } else if (I.length == 16) {
                I[0] = 1;     I[1] = 0;     I[2] = 0;
                I[4] = 0;     I[5] = c;     I[6] = s;
                I[8] = 0;     I[9] = -s;     I[10] = c;
                I[3] = I[7] = I[11] = I[12] = I[13] = I[14] = 0;
                I[15] = 1;
            }
        }
        return true;
    }

    
Computes the geomagnetic inclination angle in radians from the
inclination matrix I returned by getRotationMatrix. 
Params:
See Also:
Returns:The geomagnetic inclination angle in radians.
/**
     * Computes the geomagnetic inclination angle in radians from the
     * inclination matrix <b>I</b> returned by {@link #getRotationMatrix}.
     *
     * @param I
     *        inclination matrix see {@link #getRotationMatrix}.
     *
     * @return The geomagnetic inclination angle in radians.
     *
     * @see #getRotationMatrix(float[], float[], float[], float[])
     * @see #getOrientation(float[], float[])
     * @see GeomagneticField
     *
     */
    public static float getInclination(float[] I) {
        if (I.length == 9) {
            return (float) Math.atan2(I[5], I[4]);
        } else {
            return (float) Math.atan2(I[6], I[5]);
        }
    }

    
 Rotates the supplied rotation matrix so it is expressed in a different coordinate system. This is typically used when an application needs to compute the three orientation angles of the device (see getOrientation) in a different coordinate system. 



When the rotation matrix is used for drawing (for instance with OpenGL
ES), it usually doesn't need to be transformed by this function, unless the screen is physically rotated, in which case you can use Display.getRotation() to retrieve the current rotation of the screen. Note that because the user is generally free to rotate their screen, you often should consider the rotation in deciding the parameters to use here. 



Examples:



    

  • Using the camera (Y axis along the camera's axis) for an augmented
reality application where the rotation angles are needed:
    • 

    

      
remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);

    

    

  • Using the device as a mechanical compass when rotation is Surface.ROTATION_90:
    • 

    

      
remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);

    

     Beware of the above example. This call is needed only to account for a rotation from its natural orientation when calculating the rotation angles (see getOrientation). If the rotation matrix is also used for rendering, it may not need to be transformed, for instance if your Activity is running in landscape mode. 



Since the resulting coordinate system is orthonormal, only two axes need
to be specified.

Params:
  • inR –  the rotation matrix to be transformed. Usually it is the matrix returned by getRotationMatrix.
  • X – 
       defines the axis of the new cooridinate system that coincide with the X axis of the
       original coordinate system.
  • Y – 
       defines the axis of the new cooridinate system that coincide with the Y axis of the
       original coordinate system.
  • outR – 
       the transformed rotation matrix. inR and outR should not be the same
       array.
See Also:
Returns:true on success. false if the input
        parameters are incorrect, for instance if X and Y define the same
        axis. Or if inR and outR don't have the same length.
/**
     * <p>
     * Rotates the supplied rotation matrix so it is expressed in a different
     * coordinate system. This is typically used when an application needs to
     * compute the three orientation angles of the device (see
     * {@link #getOrientation}) in a different coordinate system.
     * </p>
     *
     * <p>
     * When the rotation matrix is used for drawing (for instance with OpenGL
     * ES), it usually <b>doesn't need</b> to be transformed by this function,
     * unless the screen is physically rotated, in which case you can use
     * {@link android.view.Display#getRotation() Display.getRotation()} to
     * retrieve the current rotation of the screen. Note that because the user
     * is generally free to rotate their screen, you often should consider the
     * rotation in deciding the parameters to use here.
     * </p>
     *
     * <p>
     * <u>Examples:</u>
     * <p>
     *
     * <ul>
     * <li>Using the camera (Y axis along the camera's axis) for an augmented
     * reality application where the rotation angles are needed:</li>
     *
     * <p>
     * <ul>
     * <code>remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);</code>
     * </ul>
     * </p>
     *
     * <li>Using the device as a mechanical compass when rotation is
     * {@link android.view.Surface#ROTATION_90 Surface.ROTATION_90}:</li>
     *
     * <p>
     * <ul>
     * <code>remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);</code>
     * </ul>
     * </p>
     *
     * Beware of the above example. This call is needed only to account for a
     * rotation from its natural orientation when calculating the rotation
     * angles (see {@link #getOrientation}). If the rotation matrix is also used
     * for rendering, it may not need to be transformed, for instance if your
     * {@link android.app.Activity Activity} is running in landscape mode.
     * </ul>
     *
     * <p>
     * Since the resulting coordinate system is orthonormal, only two axes need
     * to be specified.
     *
     * @param inR
     *        the rotation matrix to be transformed. Usually it is the matrix
     *        returned by {@link #getRotationMatrix}.
     *
     * @param X
     *        defines the axis of the new cooridinate system that coincide with the X axis of the
     *        original coordinate system.
     *
     * @param Y
     *        defines the axis of the new cooridinate system that coincide with the Y axis of the
     *        original coordinate system.
     *
     * @param outR
     *        the transformed rotation matrix. inR and outR should not be the same
     *        array.
     *
     * @return <code>true</code> on success. <code>false</code> if the input
     *         parameters are incorrect, for instance if X and Y define the same
     *         axis. Or if inR and outR don't have the same length.
     *
     * @see #getRotationMatrix(float[], float[], float[], float[])
     */

    public static boolean remapCoordinateSystem(float[] inR, int X, int Y, float[] outR) {
        if (inR == outR) {
            final float[] temp = sTempMatrix;
            synchronized (temp) {
                // we don't expect to have a lot of contention
                if (remapCoordinateSystemImpl(inR, X, Y, temp)) {
                    final int size = outR.length;
                    for (int i = 0; i < size; i++) {
                        outR[i] = temp[i];
                    }
                    return true;
                }
            }
        }
        return remapCoordinateSystemImpl(inR, X, Y, outR);
    }

    private static boolean remapCoordinateSystemImpl(float[] inR, int X, int Y, float[] outR) {
        /*
         * X and Y define a rotation matrix 'r':
         *
         *  (X==1)?((X&0x80)?-1:1):0    (X==2)?((X&0x80)?-1:1):0    (X==3)?((X&0x80)?-1:1):0
         *  (Y==1)?((Y&0x80)?-1:1):0    (Y==2)?((Y&0x80)?-1:1):0    (Y==3)?((X&0x80)?-1:1):0
         *                              r[0] ^ r[1]
         *
         * where the 3rd line is the vector product of the first 2 lines
         *
         */

        final int length = outR.length;
        if (inR.length != length) {
            return false;   // invalid parameter
        }
        if ((X & 0x7C) != 0 || (Y & 0x7C) != 0) {
            return false;   // invalid parameter
        }
        if (((X & 0x3) == 0) || ((Y & 0x3) == 0)) {
            return false;   // no axis specified
        }
        if ((X & 0x3) == (Y & 0x3)) {
            return false;   // same axis specified
        }

        // Z is "the other" axis, its sign is either +/- sign(X)*sign(Y)
        // this can be calculated by exclusive-or'ing X and Y; except for
        // the sign inversion (+/-) which is calculated below.
        int Z = X ^ Y;

        // extract the axis (remove the sign), offset in the range 0 to 2.
        final int x = (X & 0x3) - 1;
        final int y = (Y & 0x3) - 1;
        final int z = (Z & 0x3) - 1;

        // compute the sign of Z (whether it needs to be inverted)
        final int axis_y = (z + 1) % 3;
        final int axis_z = (z + 2) % 3;
        if (((x ^ axis_y) | (y ^ axis_z)) != 0) {
            Z ^= 0x80;
        }

        final boolean sx = (X >= 0x80);
        final boolean sy = (Y >= 0x80);
        final boolean sz = (Z >= 0x80);

        // Perform R * r, in avoiding actual muls and adds.
        final int rowLength = ((length == 16) ? 4 : 3);
        for (int j = 0; j < 3; j++) {
            final int offset = j * rowLength;
            for (int i = 0; i < 3; i++) {
                if (x == i)   outR[offset + i] = sx ? -inR[offset + 0] : inR[offset + 0];
                if (y == i)   outR[offset + i] = sy ? -inR[offset + 1] : inR[offset + 1];
                if (z == i)   outR[offset + i] = sz ? -inR[offset + 2] : inR[offset + 2];
            }
        }
        if (length == 16) {
            outR[3] = outR[7] = outR[11] = outR[12] = outR[13] = outR[14] = 0;
            outR[15] = 1;
        }
        return true;
    }

    
Computes the device's orientation based on the rotation matrix.


When it returns, the array values are as follows:

    

  • values[0]: Azimuth, angle of rotation about the -z axis.
               This value represents the angle between the device's y
               axis and the magnetic north pole. When facing north, this
               angle is 0, when facing south, this angle is π.
               Likewise, when facing east, this angle is π/2, and
               when facing west, this angle is -π/2. The range of
               values is -π to π.
    • 

  • values[1]: Pitch, angle of rotation about the x axis.
               This value represents the angle between a plane parallel
               to the device's screen and a plane parallel to the ground.
               Assuming that the bottom edge of the device faces the
               user and that the screen is face-up, tilting the top edge
               of the device toward the ground creates a positive pitch
               angle. The range of values is -π to π.
    • 

  • values[2]: Roll, angle of rotation about the y axis. This
               value represents the angle between a plane perpendicular
               to the device's screen and a plane perpendicular to the
               ground. Assuming that the bottom edge of the device faces
               the user and that the screen is face-up, tilting the left
               edge of the device toward the ground creates a positive
               roll angle. The range of values is -π/2 to π/2.
    • 




Applying these three rotations in the azimuth, pitch, roll order
transforms an identity matrix to the rotation matrix passed into this
method. Also, note that all three orientation angles are expressed in
radians.

Params:
  • R –  rotation matrix see getRotationMatrix.
  • values – 
       an array of 3 floats to hold the result.
See Also:
Returns:The array values passed as argument.
/**
     * Computes the device's orientation based on the rotation matrix.
     * <p>
     * When it returns, the array values are as follows:
     * <ul>
     * <li>values[0]: <i>Azimuth</i>, angle of rotation about the -z axis.
     *                This value represents the angle between the device's y
     *                axis and the magnetic north pole. When facing north, this
     *                angle is 0, when facing south, this angle is &pi;.
     *                Likewise, when facing east, this angle is &pi;/2, and
     *                when facing west, this angle is -&pi;/2. The range of
     *                values is -&pi; to &pi;.</li>
     * <li>values[1]: <i>Pitch</i>, angle of rotation about the x axis.
     *                This value represents the angle between a plane parallel
     *                to the device's screen and a plane parallel to the ground.
     *                Assuming that the bottom edge of the device faces the
     *                user and that the screen is face-up, tilting the top edge
     *                of the device toward the ground creates a positive pitch
     *                angle. The range of values is -&pi; to &pi;.</li>
     * <li>values[2]: <i>Roll</i>, angle of rotation about the y axis. This
     *                value represents the angle between a plane perpendicular
     *                to the device's screen and a plane perpendicular to the
     *                ground. Assuming that the bottom edge of the device faces
     *                the user and that the screen is face-up, tilting the left
     *                edge of the device toward the ground creates a positive
     *                roll angle. The range of values is -&pi;/2 to &pi;/2.</li>
     * </ul>
     * <p>
     * Applying these three rotations in the azimuth, pitch, roll order
     * transforms an identity matrix to the rotation matrix passed into this
     * method. Also, note that all three orientation angles are expressed in
     * <b>radians</b>.
     *
     * @param R
     *        rotation matrix see {@link #getRotationMatrix}.
     *
     * @param values
     *        an array of 3 floats to hold the result.
     *
     * @return The array values passed as argument.
     *
     * @see #getRotationMatrix(float[], float[], float[], float[])
     * @see GeomagneticField
     */
    public static float[] getOrientation(float[] R, float[] values) {
        /*
         * 4x4 (length=16) case:
         *   /  R[ 0]   R[ 1]   R[ 2]   0  \
         *   |  R[ 4]   R[ 5]   R[ 6]   0  |
         *   |  R[ 8]   R[ 9]   R[10]   0  |
         *   \      0       0       0   1  /
         *
         * 3x3 (length=9) case:
         *   /  R[ 0]   R[ 1]   R[ 2]  \
         *   |  R[ 3]   R[ 4]   R[ 5]  |
         *   \  R[ 6]   R[ 7]   R[ 8]  /
         *
         */
        if (R.length == 9) {
            values[0] = (float) Math.atan2(R[1], R[4]);
            values[1] = (float) Math.asin(-R[7]);
            values[2] = (float) Math.atan2(-R[6], R[8]);
        } else {
            values[0] = (float) Math.atan2(R[1], R[5]);
            values[1] = (float) Math.asin(-R[9]);
            values[2] = (float) Math.atan2(-R[8], R[10]);
        }

        return values;
    }

    
Computes the Altitude in meters from the atmospheric pressure and the
pressure at sea level.

 Typically the atmospheric pressure is read from a Sensor.TYPE_PRESSURE sensor. The pressure at sea level must be known, usually it can be retrieved from airport databases in the vicinity. If unknown, you can use PRESSURE_STANDARD_ATMOSPHERE as an approximation, but absolute altitudes won't be accurate. 


 To calculate altitude differences, you must calculate the difference between the altitudes at both points. If you don't know the altitude as sea level, you can use PRESSURE_STANDARD_ATMOSPHERE instead, which will give good results considering the range of pressure typically involved. 




    
 float altitude_difference =
     getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2)
     - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1);





Params:
  • p0 – pressure at sea level
  • p – atmospheric pressure
Returns:Altitude in meters
/**
     * Computes the Altitude in meters from the atmospheric pressure and the
     * pressure at sea level.
     * <p>
     * Typically the atmospheric pressure is read from a
     * {@link Sensor#TYPE_PRESSURE} sensor. The pressure at sea level must be
     * known, usually it can be retrieved from airport databases in the
     * vicinity. If unknown, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE}
     * as an approximation, but absolute altitudes won't be accurate.
     * </p>
     * <p>
     * To calculate altitude differences, you must calculate the difference
     * between the altitudes at both points. If you don't know the altitude
     * as sea level, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} instead,
     * which will give good results considering the range of pressure typically
     * involved.
     * </p>
     * <p>
     * <code><ul>
     *  float altitude_difference =
     *      getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2)
     *      - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1);
     * </ul></code>
     * </p>
     *
     * @param p0 pressure at sea level
     * @param p atmospheric pressure
     * @return Altitude in meters
     */
    public static float getAltitude(float p0, float p) {
        final float coef = 1.0f / 5.255f;
        return 44330.0f * (1.0f - (float) Math.pow(p / p0, coef));
    }

    
Helper function to compute the angle change between two rotation matrices.
 Given a current rotation matrix (R) and a previous rotation matrix
 (prevR) computes the intrinsic rotation around the z, x, and y axes which
 transforms prevR to R.
 outputs a 3 element vector containing the z, x, and y angle
 change at indexes 0, 1, and 2 respectively.

 Each input matrix is either as a 3x3 or 4x4 row-major matrix
depending on the length of the passed array:

If the array length is 9, then the array elements represent this matrix

  /  R[ 0]   R[ 1]   R[ 2]   \
  |  R[ 3]   R[ 4]   R[ 5]   |
  \  R[ 6]   R[ 7]   R[ 8]   /



If the array length is 16, then the array elements represent this matrix

  /  R[ 0]   R[ 1]   R[ 2]   R[ 3]  \
  |  R[ 4]   R[ 5]   R[ 6]   R[ 7]  |
  |  R[ 8]   R[ 9]   R[10]   R[11]  |
  \  R[12]   R[13]   R[14]   R[15]  /

 See getOrientation for more detailed definition of the output. 
Params:
  • R – current rotation matrix
  • prevR – previous rotation matrix
  • angleChange – an an array of floats (z, x, and y) in which the angle change
       (in radians) is stored
/** Helper function to compute the angle change between two rotation matrices.
     *  Given a current rotation matrix (R) and a previous rotation matrix
     *  (prevR) computes the intrinsic rotation around the z, x, and y axes which
     *  transforms prevR to R.
     *  outputs a 3 element vector containing the z, x, and y angle
     *  change at indexes 0, 1, and 2 respectively.
     * <p> Each input matrix is either as a 3x3 or 4x4 row-major matrix
     * depending on the length of the passed array:
     * <p>If the array length is 9, then the array elements represent this matrix
     * <pre>
     *   /  R[ 0]   R[ 1]   R[ 2]   \
     *   |  R[ 3]   R[ 4]   R[ 5]   |
     *   \  R[ 6]   R[ 7]   R[ 8]   /
     *</pre>
     * <p>If the array length is 16, then the array elements represent this matrix
     * <pre>
     *   /  R[ 0]   R[ 1]   R[ 2]   R[ 3]  \
     *   |  R[ 4]   R[ 5]   R[ 6]   R[ 7]  |
     *   |  R[ 8]   R[ 9]   R[10]   R[11]  |
     *   \  R[12]   R[13]   R[14]   R[15]  /
     *</pre>
     *
     * See {@link #getOrientation} for more detailed definition of the output.
     *
     * @param R current rotation matrix
     * @param prevR previous rotation matrix
     * @param angleChange an an array of floats (z, x, and y) in which the angle change
     *        (in radians) is stored
     */

    public static void getAngleChange(float[] angleChange, float[] R, float[] prevR) {
        float rd1 = 0, rd4 = 0, rd6 = 0, rd7 = 0, rd8 = 0;
        float ri0 = 0, ri1 = 0, ri2 = 0, ri3 = 0, ri4 = 0, ri5 = 0, ri6 = 0, ri7 = 0, ri8 = 0;
        float pri0 = 0, pri1 = 0, pri2 = 0, pri3 = 0, pri4 = 0;
        float pri5 = 0, pri6 = 0, pri7 = 0, pri8 = 0;

        if (R.length == 9) {
            ri0 = R[0];
            ri1 = R[1];
            ri2 = R[2];
            ri3 = R[3];
            ri4 = R[4];
            ri5 = R[5];
            ri6 = R[6];
            ri7 = R[7];
            ri8 = R[8];
        } else if (R.length == 16) {
            ri0 = R[0];
            ri1 = R[1];
            ri2 = R[2];
            ri3 = R[4];
            ri4 = R[5];
            ri5 = R[6];
            ri6 = R[8];
            ri7 = R[9];
            ri8 = R[10];
        }

        if (prevR.length == 9) {
            pri0 = prevR[0];
            pri1 = prevR[1];
            pri2 = prevR[2];
            pri3 = prevR[3];
            pri4 = prevR[4];
            pri5 = prevR[5];
            pri6 = prevR[6];
            pri7 = prevR[7];
            pri8 = prevR[8];
        } else if (prevR.length == 16) {
            pri0 = prevR[0];
            pri1 = prevR[1];
            pri2 = prevR[2];
            pri3 = prevR[4];
            pri4 = prevR[5];
            pri5 = prevR[6];
            pri6 = prevR[8];
            pri7 = prevR[9];
            pri8 = prevR[10];
        }

        // calculate the parts of the rotation difference matrix we need
        // rd[i][j] = pri[0][i] * ri[0][j] + pri[1][i] * ri[1][j] + pri[2][i] * ri[2][j];

        rd1 = pri0 * ri1 + pri3 * ri4 + pri6 * ri7; //rd[0][1]
        rd4 = pri1 * ri1 + pri4 * ri4 + pri7 * ri7; //rd[1][1]
        rd6 = pri2 * ri0 + pri5 * ri3 + pri8 * ri6; //rd[2][0]
        rd7 = pri2 * ri1 + pri5 * ri4 + pri8 * ri7; //rd[2][1]
        rd8 = pri2 * ri2 + pri5 * ri5 + pri8 * ri8; //rd[2][2]

        angleChange[0] = (float) Math.atan2(rd1, rd4);
        angleChange[1] = (float) Math.asin(-rd7);
        angleChange[2] = (float) Math.atan2(-rd6, rd8);

    }

    
Helper function to convert a rotation vector to a rotation matrix.
 Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a
 9  or 16 element rotation matrix in the array R.  R must have length 9 or 16.
 If R.length == 9, the following matrix is returned:

  /  R[ 0]   R[ 1]   R[ 2]   \
  |  R[ 3]   R[ 4]   R[ 5]   |
  \  R[ 6]   R[ 7]   R[ 8]   /


If R.length == 16, the following matrix is returned:

  /  R[ 0]   R[ 1]   R[ 2]   0  \
  |  R[ 4]   R[ 5]   R[ 6]   0  |
  |  R[ 8]   R[ 9]   R[10]   0  |
  \  0       0       0       1  /


 @param rotationVector the rotation vector to convert
 @param R an array of floats in which to store the rotation matrix

/** Helper function to convert a rotation vector to a rotation matrix.
     *  Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a
     *  9  or 16 element rotation matrix in the array R.  R must have length 9 or 16.
     *  If R.length == 9, the following matrix is returned:
     * <pre>
     *   /  R[ 0]   R[ 1]   R[ 2]   \
     *   |  R[ 3]   R[ 4]   R[ 5]   |
     *   \  R[ 6]   R[ 7]   R[ 8]   /
     *</pre>
     * If R.length == 16, the following matrix is returned:
     * <pre>
     *   /  R[ 0]   R[ 1]   R[ 2]   0  \
     *   |  R[ 4]   R[ 5]   R[ 6]   0  |
     *   |  R[ 8]   R[ 9]   R[10]   0  |
     *   \  0       0       0       1  /
     *</pre>
     *  @param rotationVector the rotation vector to convert
     *  @param R an array of floats in which to store the rotation matrix
     */
    public static void getRotationMatrixFromVector(float[] R, float[] rotationVector) {

        float q0;
        float q1 = rotationVector[0];
        float q2 = rotationVector[1];
        float q3 = rotationVector[2];

        if (rotationVector.length >= 4) {
            q0 = rotationVector[3];
        } else {
            q0 = 1 - q1 * q1 - q2 * q2 - q3 * q3;
            q0 = (q0 > 0) ? (float) Math.sqrt(q0) : 0;
        }

        float sq_q1 = 2 * q1 * q1;
        float sq_q2 = 2 * q2 * q2;
        float sq_q3 = 2 * q3 * q3;
        float q1_q2 = 2 * q1 * q2;
        float q3_q0 = 2 * q3 * q0;
        float q1_q3 = 2 * q1 * q3;
        float q2_q0 = 2 * q2 * q0;
        float q2_q3 = 2 * q2 * q3;
        float q1_q0 = 2 * q1 * q0;

        if (R.length == 9) {
            R[0] = 1 - sq_q2 - sq_q3;
            R[1] = q1_q2 - q3_q0;
            R[2] = q1_q3 + q2_q0;

            R[3] = q1_q2 + q3_q0;
            R[4] = 1 - sq_q1 - sq_q3;
            R[5] = q2_q3 - q1_q0;

            R[6] = q1_q3 - q2_q0;
            R[7] = q2_q3 + q1_q0;
            R[8] = 1 - sq_q1 - sq_q2;
        } else if (R.length == 16) {
            R[0] = 1 - sq_q2 - sq_q3;
            R[1] = q1_q2 - q3_q0;
            R[2] = q1_q3 + q2_q0;
            R[3] = 0.0f;

            R[4] = q1_q2 + q3_q0;
            R[5] = 1 - sq_q1 - sq_q3;
            R[6] = q2_q3 - q1_q0;
            R[7] = 0.0f;

            R[8] = q1_q3 - q2_q0;
            R[9] = q2_q3 + q1_q0;
            R[10] = 1 - sq_q1 - sq_q2;
            R[11] = 0.0f;

            R[12] = R[13] = R[14] = 0.0f;
            R[15] = 1.0f;
        }
    }

    
Helper function to convert a rotation vector to a normalized quaternion.
 Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized
 quaternion in the array Q.  The quaternion is stored as [w, x, y, z]
 @param rv the rotation vector to convert
 @param Q an array of floats in which to store the computed quaternion

/** Helper function to convert a rotation vector to a normalized quaternion.
     *  Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized
     *  quaternion in the array Q.  The quaternion is stored as [w, x, y, z]
     *  @param rv the rotation vector to convert
     *  @param Q an array of floats in which to store the computed quaternion
     */
    public static void getQuaternionFromVector(float[] Q, float[] rv) {
        if (rv.length >= 4) {
            Q[0] = rv[3];
        } else {
            Q[0] = 1 - rv[0] * rv[0] - rv[1] * rv[1] - rv[2] * rv[2];
            Q[0] = (Q[0] > 0) ? (float) Math.sqrt(Q[0]) : 0;
        }
        Q[1] = rv[0];
        Q[2] = rv[1];
        Q[3] = rv[2];
    }

    
Requests receiving trigger events for a trigger sensor.

 When the sensor detects a trigger event condition, such as significant motion in the case of the Sensor.TYPE_SIGNIFICANT_MOTION, the provided trigger listener will be invoked once and then its request to receive trigger events will be canceled. To continue receiving trigger events, the application must request to receive trigger events again. 


Params:
Throws:
Returns:true if the sensor was successfully enabled.
/**
     * Requests receiving trigger events for a trigger sensor.
     *
     * <p>
     * When the sensor detects a trigger event condition, such as significant motion in
     * the case of the {@link Sensor#TYPE_SIGNIFICANT_MOTION}, the provided trigger listener
     * will be invoked once and then its request to receive trigger events will be canceled.
     * To continue receiving trigger events, the application must request to receive trigger
     * events again.
     * </p>
     *
     * @param listener The listener on which the
     *        {@link TriggerEventListener#onTrigger(TriggerEvent)} will be delivered.
     * @param sensor The sensor to be enabled.
     *
     * @return true if the sensor was successfully enabled.
     *
     * @throws IllegalArgumentException when sensor is null or not a trigger sensor.
     */
    public boolean requestTriggerSensor(TriggerEventListener listener, Sensor sensor) {
        return requestTriggerSensorImpl(listener, sensor);
    }

    
@hide
/**
     * @hide
     */
    protected abstract boolean requestTriggerSensorImpl(TriggerEventListener listener,
            Sensor sensor);

    
Cancels receiving trigger events for a trigger sensor.

 Note that a Trigger sensor will be auto disabled if TriggerEventListener.onTrigger(TriggerEvent) has triggered. This method is provided in case the user wants to explicitly cancel the request to receive trigger events. 


Params:
Throws:
Returns:true if successfully canceled.
/**
     * Cancels receiving trigger events for a trigger sensor.
     *
     * <p>
     * Note that a Trigger sensor will be auto disabled if
     * {@link TriggerEventListener#onTrigger(TriggerEvent)} has triggered.
     * This method is provided in case the user wants to explicitly cancel the request
     * to receive trigger events.
     * </p>
     *
     * @param listener The listener on which the
     *        {@link TriggerEventListener#onTrigger(TriggerEvent)}
     *        is delivered.It should be the same as the one used
     *        in {@link #requestTriggerSensor(TriggerEventListener, Sensor)}
     * @param sensor The sensor for which the trigger request should be canceled.
     *        If null, it cancels receiving trigger for all sensors associated
     *        with the listener.
     *
     * @return true if successfully canceled.
     *
     * @throws IllegalArgumentException when sensor is a trigger sensor.
     */
    public boolean cancelTriggerSensor(TriggerEventListener listener, Sensor sensor) {
        return cancelTriggerSensorImpl(listener, sensor, true);
    }

    
@hide
/**
     * @hide
     */
    protected abstract boolean cancelTriggerSensorImpl(TriggerEventListener listener,
            Sensor sensor, boolean disable);


    
For testing purposes only. Not for third party applications. Initialize data injection mode and create a client for data injection. SensorService should already be operating in DATA_INJECTION mode for this call succeed. To set SensorService into DATA_INJECTION mode "adb shell dumpsys sensorservice data_injection" needs to be called through adb. Typically this is done using a host side test. This mode is expected to be used only for testing purposes. If the HAL is set to data injection mode, it will ignore the input from physical sensors and read sensor data that is injected from the test application. This mode is used for testing vendor implementations for various algorithms like Rotation Vector, Significant Motion, Step Counter etc. Not all HALs support DATA_INJECTION. This method will fail in those cases. Once this method succeeds, the test can call injectSensorData(Sensor, float[], int, long) to inject sensor data into the HAL. 
Params:
  • enable – True to initialize a client in DATA_INJECTION mode.
              False to clean up the native resources.
Returns:true if the HAL supports data injection and false
        otherwise.
@hide
/**
     * For testing purposes only. Not for third party applications.
     *
     * Initialize data injection mode and create a client for data injection. SensorService should
     * already be operating in DATA_INJECTION mode for this call succeed. To set SensorService into
     * DATA_INJECTION mode "adb shell dumpsys sensorservice data_injection" needs to be called
     * through adb. Typically this is done using a host side test.  This mode is expected to be used
     * only for testing purposes. If the HAL is set to data injection mode, it will ignore the input
     * from physical sensors and read sensor data that is injected from the test application. This
     * mode is used for testing vendor implementations for various algorithms like Rotation Vector,
     * Significant Motion, Step Counter etc. Not all HALs support DATA_INJECTION. This method will
     * fail in those cases. Once this method succeeds, the test can call
     * {@link injectSensorData(Sensor, float[], int, long)} to inject sensor data into the HAL.
     *
     * @param enable True to initialize a client in DATA_INJECTION mode.
     *               False to clean up the native resources.
     *
     * @return true if the HAL supports data injection and false
     *         otherwise.
     * @hide
     */
    @SystemApi
    public boolean initDataInjection(boolean enable) {
        return initDataInjectionImpl(enable);
    }

    
@hide
/**
     * @hide
     */
    protected abstract boolean initDataInjectionImpl(boolean enable);

    
For testing purposes only. Not for third party applications. This method is used to inject raw sensor data into the HAL. Call 
     * initDataInjection(boolean) before this method to set the HAL in data injection mode. This method should be called only if a previous call to initDataInjection has been successful and the HAL and SensorService are already opreating in data injection mode. 
Params:
  • sensor – The sensor to inject.
  • values – Sensor values to inject. The length of this
              array must be exactly equal to the number of
              values reported by the sensor type.
  • accuracy – Accuracy of the sensor.
  • timestamp – Sensor timestamp associated with the event.
Throws:
  • IllegalArgumentException – when the sensor is null,
        data injection is not supported by the sensor, values
        are null, incorrect number of values for the sensor,
        sensor accuracy is incorrect or timestamps are
        invalid.
Returns:boolean True if the data injection succeeds, false
        otherwise.
@hide
/**
     * For testing purposes only. Not for third party applications.
     *
     * This method is used to inject raw sensor data into the HAL.  Call {@link
     * initDataInjection(boolean)} before this method to set the HAL in data injection mode. This
     * method should be called only if a previous call to initDataInjection has been successful and
     * the HAL and SensorService are already opreating in data injection mode.
     *
     * @param sensor The sensor to inject.
     * @param values Sensor values to inject. The length of this
     *               array must be exactly equal to the number of
     *               values reported by the sensor type.
     * @param accuracy Accuracy of the sensor.
     * @param timestamp Sensor timestamp associated with the event.
     *
     * @return boolean True if the data injection succeeds, false
     *         otherwise.
     * @throws IllegalArgumentException when the sensor is null,
     *         data injection is not supported by the sensor, values
     *         are null, incorrect number of values for the sensor,
     *         sensor accuracy is incorrect or timestamps are
     *         invalid.
     * @hide
     */
    @SystemApi
    public boolean injectSensorData(Sensor sensor, float[] values, int accuracy,
                long timestamp) {
        if (sensor == null) {
            throw new IllegalArgumentException("sensor cannot be null");
        }
        if (!sensor.isDataInjectionSupported()) {
            throw new IllegalArgumentException("sensor does not support data injection");
        }
        if (values == null) {
            throw new IllegalArgumentException("sensor data cannot be null");
        }
        int expectedNumValues = Sensor.getMaxLengthValuesArray(sensor, Build.VERSION_CODES.M);
        if (values.length != expectedNumValues) {
            throw new  IllegalArgumentException("Wrong number of values for sensor "
                    + sensor.getName() + " actual=" + values.length + " expected="
                    + expectedNumValues);
        }
        if (accuracy < SENSOR_STATUS_NO_CONTACT || accuracy > SENSOR_STATUS_ACCURACY_HIGH) {
            throw new IllegalArgumentException("Invalid sensor accuracy");
        }
        if (timestamp <= 0) {
            throw new IllegalArgumentException("Negative or zero sensor timestamp");
        }
        return injectSensorDataImpl(sensor, values, accuracy, timestamp);
    }

    
@hide
/**
     * @hide
     */
    protected abstract boolean injectSensorDataImpl(Sensor sensor, float[] values, int accuracy,
                long timestamp);

    private LegacySensorManager getLegacySensorManager() {
        synchronized (mSensorListByType) {
            if (mLegacySensorManager == null) {
                Log.i(TAG, "This application is using deprecated SensorManager API which will "
                        + "be removed someday.  Please consider switching to the new API.");
                mLegacySensorManager = new LegacySensorManager(this);
            }
            return mLegacySensorManager;
        }
    }

    private static int getDelay(int rate) {
        int delay = -1;
        switch (rate) {
            case SENSOR_DELAY_FASTEST:
                delay = 0;
                break;
            case SENSOR_DELAY_GAME:
                delay = 20000;
                break;
            case SENSOR_DELAY_UI:
                delay = 66667;
                break;
            case SENSOR_DELAY_NORMAL:
                delay = 200000;
                break;
            default:
                delay = rate;
                break;
        }
        return delay;
    }

    
@hide
/** @hide */
    public boolean setOperationParameter(SensorAdditionalInfo parameter) {
        return setOperationParameterImpl(parameter);
    }

    
@hide
/** @hide */
    protected abstract boolean setOperationParameterImpl(SensorAdditionalInfo parameter);
}