1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.hardware;
18 
19 import android.annotation.SystemApi;
20 import android.annotation.SystemService;
21 import android.compat.annotation.UnsupportedAppUsage;
22 import android.content.Context;
23 import android.os.Build;
24 import android.os.Handler;
25 import android.os.MemoryFile;
26 import android.util.Log;
27 import android.util.SparseArray;
28 
29 import java.util.ArrayList;
30 import java.util.Collections;
31 import java.util.List;
32 
33 /**
34  * <p>
35  * SensorManager lets you access the device's {@link android.hardware.Sensor
36  * sensors}.
37  * </p>
38  * <p>
39  * Always make sure to disable sensors you don't need, especially when your
40  * activity is paused. Failing to do so can drain the battery in just a few
41  * hours. Note that the system will <i>not</i> disable sensors automatically when
42  * the screen turns off.
43  * </p>
44  * <p class="note">
45  * Note: Don't use this mechanism with a Trigger Sensor, have a look
46  * at {@link TriggerEventListener}. {@link Sensor#TYPE_SIGNIFICANT_MOTION}
47  * is an example of a trigger sensor.
48  * </p>
49  * <pre class="prettyprint">
50  * public class SensorActivity extends Activity implements SensorEventListener {
51  *     private final SensorManager mSensorManager;
52  *     private final Sensor mAccelerometer;
53  *
54  *     public SensorActivity() {
55  *         mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
56  *         mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
57  *     }
58  *
59  *     protected void onResume() {
60  *         super.onResume();
61  *         mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
62  *     }
63  *
64  *     protected void onPause() {
65  *         super.onPause();
66  *         mSensorManager.unregisterListener(this);
67  *     }
68  *
69  *     public void onAccuracyChanged(Sensor sensor, int accuracy) {
70  *     }
71  *
72  *     public void onSensorChanged(SensorEvent event) {
73  *     }
74  * }
75  * </pre>
76  *
77  * @see SensorEventListener
78  * @see SensorEvent
79  * @see Sensor
80  *
81  */
82 @SystemService(Context.SENSOR_SERVICE)
83 public abstract class SensorManager {
84     /** @hide */
85     protected static final String TAG = "SensorManager";
86 
87     private static final float[] sTempMatrix = new float[16];
88 
89     // Cached lists of sensors by type.  Guarded by mSensorListByType.
90     private final SparseArray<List<Sensor>> mSensorListByType =
91             new SparseArray<List<Sensor>>();
92 
93     // Legacy sensor manager implementation.  Guarded by mSensorListByType during initialization.
94     private LegacySensorManager mLegacySensorManager;
95 
96     /* NOTE: sensor IDs must be a power of 2 */
97 
98     /**
99      * A constant describing an orientation sensor. See
100      * {@link android.hardware.SensorListener SensorListener} for more details.
101      *
102      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
103      */
104     @Deprecated
105     public static final int SENSOR_ORIENTATION = 1 << 0;
106 
107     /**
108      * A constant describing an accelerometer. See
109      * {@link android.hardware.SensorListener SensorListener} for more details.
110      *
111      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
112      */
113     @Deprecated
114     public static final int SENSOR_ACCELEROMETER = 1 << 1;
115 
116     /**
117      * A constant describing a temperature sensor See
118      * {@link android.hardware.SensorListener SensorListener} for more details.
119      *
120      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
121      */
122     @Deprecated
123     public static final int SENSOR_TEMPERATURE = 1 << 2;
124 
125     /**
126      * A constant describing a magnetic sensor See
127      * {@link android.hardware.SensorListener SensorListener} for more details.
128      *
129      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
130      */
131     @Deprecated
132     public static final int SENSOR_MAGNETIC_FIELD = 1 << 3;
133 
134     /**
135      * A constant describing an ambient light sensor See
136      * {@link android.hardware.SensorListener SensorListener} for more details.
137      *
138      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
139      */
140     @Deprecated
141     public static final int SENSOR_LIGHT = 1 << 4;
142 
143     /**
144      * A constant describing a proximity sensor See
145      * {@link android.hardware.SensorListener SensorListener} for more details.
146      *
147      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
148      */
149     @Deprecated
150     public static final int SENSOR_PROXIMITY = 1 << 5;
151 
152     /**
153      * A constant describing a Tricorder See
154      * {@link android.hardware.SensorListener SensorListener} for more details.
155      *
156      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
157      */
158     @Deprecated
159     public static final int SENSOR_TRICORDER = 1 << 6;
160 
161     /**
162      * A constant describing an orientation sensor. See
163      * {@link android.hardware.SensorListener SensorListener} for more details.
164      *
165      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
166      */
167     @Deprecated
168     public static final int SENSOR_ORIENTATION_RAW = 1 << 7;
169 
170     /**
171      * A constant that includes all sensors
172      *
173      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
174      */
175     @Deprecated
176     public static final int SENSOR_ALL = 0x7F;
177 
178     /**
179      * Smallest sensor ID
180      *
181      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
182      */
183     @Deprecated
184     public static final int SENSOR_MIN = SENSOR_ORIENTATION;
185 
186     /**
187      * Largest sensor ID
188      *
189      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
190      */
191     @Deprecated
192     public static final int SENSOR_MAX = ((SENSOR_ALL + 1) >> 1);
193 
194 
195     /**
196      * Index of the X value in the array returned by
197      * {@link android.hardware.SensorListener#onSensorChanged}
198      *
199      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
200      */
201     @Deprecated
202     public static final int DATA_X = 0;
203 
204     /**
205      * Index of the Y value in the array returned by
206      * {@link android.hardware.SensorListener#onSensorChanged}
207      *
208      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
209      */
210     @Deprecated
211     public static final int DATA_Y = 1;
212 
213     /**
214      * Index of the Z value in the array returned by
215      * {@link android.hardware.SensorListener#onSensorChanged}
216      *
217      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
218      */
219     @Deprecated
220     public static final int DATA_Z = 2;
221 
222     /**
223      * Offset to the untransformed values in the array returned by
224      * {@link android.hardware.SensorListener#onSensorChanged}
225      *
226      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
227      */
228     @Deprecated
229     public static final int RAW_DATA_INDEX = 3;
230 
231     /**
232      * Index of the untransformed X value in the array returned by
233      * {@link android.hardware.SensorListener#onSensorChanged}
234      *
235      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
236      */
237     @Deprecated
238     public static final int RAW_DATA_X = 3;
239 
240     /**
241      * Index of the untransformed Y value in the array returned by
242      * {@link android.hardware.SensorListener#onSensorChanged}
243      *
244      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
245      */
246     @Deprecated
247     public static final int RAW_DATA_Y = 4;
248 
249     /**
250      * Index of the untransformed Z value in the array returned by
251      * {@link android.hardware.SensorListener#onSensorChanged}
252      *
253      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
254      */
255     @Deprecated
256     public static final int RAW_DATA_Z = 5;
257 
258     /** Standard gravity (g) on Earth. This value is equivalent to 1G */
259     public static final float STANDARD_GRAVITY = 9.80665f;
260 
261     /** Sun's gravity in SI units (m/s^2) */
262     public static final float GRAVITY_SUN             = 275.0f;
263     /** Mercury's gravity in SI units (m/s^2) */
264     public static final float GRAVITY_MERCURY         = 3.70f;
265     /** Venus' gravity in SI units (m/s^2) */
266     public static final float GRAVITY_VENUS           = 8.87f;
267     /** Earth's gravity in SI units (m/s^2) */
268     public static final float GRAVITY_EARTH           = 9.80665f;
269     /** The Moon's gravity in SI units (m/s^2) */
270     public static final float GRAVITY_MOON            = 1.6f;
271     /** Mars' gravity in SI units (m/s^2) */
272     public static final float GRAVITY_MARS            = 3.71f;
273     /** Jupiter's gravity in SI units (m/s^2) */
274     public static final float GRAVITY_JUPITER         = 23.12f;
275     /** Saturn's gravity in SI units (m/s^2) */
276     public static final float GRAVITY_SATURN          = 8.96f;
277     /** Uranus' gravity in SI units (m/s^2) */
278     public static final float GRAVITY_URANUS          = 8.69f;
279     /** Neptune's gravity in SI units (m/s^2) */
280     public static final float GRAVITY_NEPTUNE         = 11.0f;
281     /** Pluto's gravity in SI units (m/s^2) */
282     public static final float GRAVITY_PLUTO           = 0.6f;
283     /** Gravity (estimate) on the first Death Star in Empire units (m/s^2) */
284     public static final float GRAVITY_DEATH_STAR_I    = 0.000000353036145f;
285     /** Gravity on the island */
286     public static final float GRAVITY_THE_ISLAND      = 4.815162342f;
287 
288 
289     /** Maximum magnetic field on Earth's surface */
290     public static final float MAGNETIC_FIELD_EARTH_MAX = 60.0f;
291     /** Minimum magnetic field on Earth's surface */
292     public static final float MAGNETIC_FIELD_EARTH_MIN = 30.0f;
293 
294 
295     /** Standard atmosphere, or average sea-level pressure in hPa (millibar) */
296     public static final float PRESSURE_STANDARD_ATMOSPHERE = 1013.25f;
297 
298 
299     /** Maximum luminance of sunlight in lux */
300     public static final float LIGHT_SUNLIGHT_MAX = 120000.0f;
301     /** luminance of sunlight in lux */
302     public static final float LIGHT_SUNLIGHT     = 110000.0f;
303     /** luminance in shade in lux */
304     public static final float LIGHT_SHADE        = 20000.0f;
305     /** luminance under an overcast sky in lux */
306     public static final float LIGHT_OVERCAST     = 10000.0f;
307     /** luminance at sunrise in lux */
308     public static final float LIGHT_SUNRISE      = 400.0f;
309     /** luminance under a cloudy sky in lux */
310     public static final float LIGHT_CLOUDY       = 100.0f;
311     /** luminance at night with full moon in lux */
312     public static final float LIGHT_FULLMOON     = 0.25f;
313     /** luminance at night with no moon in lux*/
314     public static final float LIGHT_NO_MOON      = 0.001f;
315 
316 
317     /** get sensor data as fast as possible */
318     public static final int SENSOR_DELAY_FASTEST = 0;
319     /** rate suitable for games */
320     public static final int SENSOR_DELAY_GAME = 1;
321     /** rate suitable for the user interface  */
322     public static final int SENSOR_DELAY_UI = 2;
323     /** rate (default) suitable for screen orientation changes */
324     public static final int SENSOR_DELAY_NORMAL = 3;
325 
326 
327     /**
328       * The values returned by this sensor cannot be trusted because the sensor
329       * had no contact with what it was measuring (for example, the heart rate
330       * monitor is not in contact with the user).
331       */
332     public static final int SENSOR_STATUS_NO_CONTACT = -1;
333 
334     /**
335      * The values returned by this sensor cannot be trusted, calibration is
336      * needed or the environment doesn't allow readings
337      */
338     public static final int SENSOR_STATUS_UNRELIABLE = 0;
339 
340     /**
341      * This sensor is reporting data with low accuracy, calibration with the
342      * environment is needed
343      */
344     public static final int SENSOR_STATUS_ACCURACY_LOW = 1;
345 
346     /**
347      * This sensor is reporting data with an average level of accuracy,
348      * calibration with the environment may improve the readings
349      */
350     public static final int SENSOR_STATUS_ACCURACY_MEDIUM = 2;
351 
352     /** This sensor is reporting data with maximum accuracy */
353     public static final int SENSOR_STATUS_ACCURACY_HIGH = 3;
354 
355     /** see {@link #remapCoordinateSystem} */
356     public static final int AXIS_X = 1;
357     /** see {@link #remapCoordinateSystem} */
358     public static final int AXIS_Y = 2;
359     /** see {@link #remapCoordinateSystem} */
360     public static final int AXIS_Z = 3;
361     /** see {@link #remapCoordinateSystem} */
362     public static final int AXIS_MINUS_X = AXIS_X | 0x80;
363     /** see {@link #remapCoordinateSystem} */
364     public static final int AXIS_MINUS_Y = AXIS_Y | 0x80;
365     /** see {@link #remapCoordinateSystem} */
366     public static final int AXIS_MINUS_Z = AXIS_Z | 0x80;
367 
368 
369     /**
370      * {@hide}
371      */
372     @UnsupportedAppUsage
SensorManager()373     public SensorManager() {
374     }
375 
376     /**
377      * Gets the full list of sensors that are available.
378      * @hide
379      */
getFullSensorList()380     protected abstract List<Sensor> getFullSensorList();
381 
382     /**
383      * Gets the full list of dynamic sensors that are available.
384      * @hide
385      */
getFullDynamicSensorList()386     protected abstract List<Sensor> getFullDynamicSensorList();
387 
388     /**
389      * @return available sensors.
390      * @deprecated This method is deprecated, use
391      *             {@link SensorManager#getSensorList(int)} instead
392      */
393     @Deprecated
getSensors()394     public int getSensors() {
395         return getLegacySensorManager().getSensors();
396     }
397 
398     /**
399      * Use this method to get the list of available sensors of a certain type.
400      * Make multiple calls to get sensors of different types or use
401      * {@link android.hardware.Sensor#TYPE_ALL Sensor.TYPE_ALL} to get all the
402      * sensors.
403      *
404      * <p class="note">
405      * NOTE: Both wake-up and non wake-up sensors matching the given type are
406      * returned. Check {@link Sensor#isWakeUpSensor()} to know the wake-up properties
407      * of the returned {@link Sensor}.
408      * </p>
409      *
410      * @param type
411      *        of sensors requested
412      *
413      * @return a list of sensors matching the asked type.
414      *
415      * @see #getDefaultSensor(int)
416      * @see Sensor
417      */
getSensorList(int type)418     public List<Sensor> getSensorList(int type) {
419         // cache the returned lists the first time
420         List<Sensor> list;
421         final List<Sensor> fullList = getFullSensorList();
422         synchronized (mSensorListByType) {
423             list = mSensorListByType.get(type);
424             if (list == null) {
425                 if (type == Sensor.TYPE_ALL) {
426                     list = fullList;
427                 } else {
428                     list = new ArrayList<Sensor>();
429                     for (Sensor i : fullList) {
430                         if (i.getType() == type) {
431                             list.add(i);
432                         }
433                     }
434                 }
435                 list = Collections.unmodifiableList(list);
436                 mSensorListByType.append(type, list);
437             }
438         }
439         return list;
440     }
441 
442     /**
443      * Use this method to get a list of available dynamic sensors of a certain type.
444      * Make multiple calls to get sensors of different types or use
445      * {@link android.hardware.Sensor#TYPE_ALL Sensor.TYPE_ALL} to get all dynamic sensors.
446      *
447      * <p class="note">
448      * NOTE: Both wake-up and non wake-up sensors matching the given type are
449      * returned. Check {@link Sensor#isWakeUpSensor()} to know the wake-up properties
450      * of the returned {@link Sensor}.
451      * </p>
452      *
453      * @param type of sensors requested
454      *
455      * @return a list of dynamic sensors matching the requested type.
456      *
457      * @see Sensor
458      */
getDynamicSensorList(int type)459     public List<Sensor> getDynamicSensorList(int type) {
460         // cache the returned lists the first time
461         final List<Sensor> fullList = getFullDynamicSensorList();
462         if (type == Sensor.TYPE_ALL) {
463             return Collections.unmodifiableList(fullList);
464         } else {
465             List<Sensor> list = new ArrayList();
466             for (Sensor i : fullList) {
467                 if (i.getType() == type) {
468                     list.add(i);
469                 }
470             }
471             return Collections.unmodifiableList(list);
472         }
473     }
474 
475     /**
476      * Use this method to get the default sensor for a given type. Note that the
477      * returned sensor could be a composite sensor, and its data could be
478      * averaged or filtered. If you need to access the raw sensors use
479      * {@link SensorManager#getSensorList(int) getSensorList}.
480      *
481      * @param type
482      *         of sensors requested
483      *
484      * @return the default sensor matching the requested type if one exists and the application
485      *         has the necessary permissions, or null otherwise.
486      *
487      * @see #getSensorList(int)
488      * @see Sensor
489      */
getDefaultSensor(int type)490     public Sensor getDefaultSensor(int type) {
491         // TODO: need to be smarter, for now, just return the 1st sensor
492         List<Sensor> l = getSensorList(type);
493         boolean wakeUpSensor = false;
494         // For the following sensor types, return a wake-up sensor. These types are by default
495         // defined as wake-up sensors. For the rest of the SDK defined sensor types return a
496         // non_wake-up version.
497         if (type == Sensor.TYPE_PROXIMITY || type == Sensor.TYPE_SIGNIFICANT_MOTION
498                 || type == Sensor.TYPE_TILT_DETECTOR || type == Sensor.TYPE_WAKE_GESTURE
499                 || type == Sensor.TYPE_GLANCE_GESTURE || type == Sensor.TYPE_PICK_UP_GESTURE
500                 || type == Sensor.TYPE_WRIST_TILT_GESTURE
501                 || type == Sensor.TYPE_DYNAMIC_SENSOR_META || type == Sensor.TYPE_HINGE_ANGLE) {
502             wakeUpSensor = true;
503         }
504 
505         for (Sensor sensor : l) {
506             if (sensor.isWakeUpSensor() == wakeUpSensor) return sensor;
507         }
508         return null;
509     }
510 
511     /**
512      * Return a Sensor with the given type and wakeUp properties. If multiple sensors of this
513      * type exist, any one of them may be returned.
514      * <p>
515      * For example,
516      * <ul>
517      *     <li>getDefaultSensor({@link Sensor#TYPE_ACCELEROMETER}, true) returns a wake-up
518      *     accelerometer sensor if it exists. </li>
519      *     <li>getDefaultSensor({@link Sensor#TYPE_PROXIMITY}, false) returns a non wake-up
520      *     proximity sensor if it exists. </li>
521      *     <li>getDefaultSensor({@link Sensor#TYPE_PROXIMITY}, true) returns a wake-up proximity
522      *     sensor which is the same as the Sensor returned by {@link #getDefaultSensor(int)}. </li>
523      * </ul>
524      * </p>
525      * <p class="note">
526      * Note: Sensors like {@link Sensor#TYPE_PROXIMITY} and {@link Sensor#TYPE_SIGNIFICANT_MOTION}
527      * are declared as wake-up sensors by default.
528      * </p>
529      * @param type
530      *        type of sensor requested
531      * @param wakeUp
532      *        flag to indicate whether the Sensor is a wake-up or non wake-up sensor.
533      * @return the default sensor matching the requested type and wakeUp properties if one exists
534      *         and the application has the necessary permissions, or null otherwise.
535      * @see Sensor#isWakeUpSensor()
536      */
getDefaultSensor(int type, boolean wakeUp)537     public Sensor getDefaultSensor(int type, boolean wakeUp) {
538         List<Sensor> l = getSensorList(type);
539         for (Sensor sensor : l) {
540             if (sensor.isWakeUpSensor() == wakeUp) {
541                 return sensor;
542             }
543         }
544         return null;
545     }
546 
547     /**
548      * Registers a listener for given sensors.
549      *
550      * @deprecated This method is deprecated, use
551      *             {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
552      *             instead.
553      *
554      * @param listener
555      *        sensor listener object
556      *
557      * @param sensors
558      *        a bit masks of the sensors to register to
559      *
560      * @return <code>true</code> if the sensor is supported and successfully
561      *         enabled
562      */
563     @Deprecated
registerListener(SensorListener listener, int sensors)564     public boolean registerListener(SensorListener listener, int sensors) {
565         return registerListener(listener, sensors, SENSOR_DELAY_NORMAL);
566     }
567 
568     /**
569      * Registers a SensorListener for given sensors.
570      *
571      * @deprecated This method is deprecated, use
572      *             {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
573      *             instead.
574      *
575      * @param listener
576      *        sensor listener object
577      *
578      * @param sensors
579      *        a bit masks of the sensors to register to
580      *
581      * @param rate
582      *        rate of events. This is only a hint to the system. events may be
583      *        received faster or slower than the specified rate. Usually events
584      *        are received faster. The value must be one of
585      *        {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
586      *        {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}.
587      *
588      * @return <code>true</code> if the sensor is supported and successfully
589      *         enabled
590      */
591     @Deprecated
registerListener(SensorListener listener, int sensors, int rate)592     public boolean registerListener(SensorListener listener, int sensors, int rate) {
593         return getLegacySensorManager().registerListener(listener, sensors, rate);
594     }
595 
596     /**
597      * Unregisters a listener for all sensors.
598      *
599      * @deprecated This method is deprecated, use
600      *             {@link SensorManager#unregisterListener(SensorEventListener)}
601      *             instead.
602      *
603      * @param listener
604      *        a SensorListener object
605      */
606     @Deprecated
unregisterListener(SensorListener listener)607     public void unregisterListener(SensorListener listener) {
608         unregisterListener(listener, SENSOR_ALL | SENSOR_ORIENTATION_RAW);
609     }
610 
611     /**
612      * Unregisters a listener for the sensors with which it is registered.
613      *
614      * @deprecated This method is deprecated, use
615      *             {@link SensorManager#unregisterListener(SensorEventListener, Sensor)}
616      *             instead.
617      *
618      * @param listener
619      *        a SensorListener object
620      *
621      * @param sensors
622      *        a bit masks of the sensors to unregister from
623      */
624     @Deprecated
unregisterListener(SensorListener listener, int sensors)625     public void unregisterListener(SensorListener listener, int sensors) {
626         getLegacySensorManager().unregisterListener(listener, sensors);
627     }
628 
629     /**
630      * Unregisters a listener for the sensors with which it is registered.
631      *
632      * <p class="note"></p>
633      * Note: Don't use this method with a one shot trigger sensor such as
634      * {@link Sensor#TYPE_SIGNIFICANT_MOTION}.
635      * Use {@link #cancelTriggerSensor(TriggerEventListener, Sensor)} instead.
636      * </p>
637      *
638      * @param listener
639      *        a SensorEventListener object
640      *
641      * @param sensor
642      *        the sensor to unregister from
643      *
644      * @see #unregisterListener(SensorEventListener)
645      * @see #registerListener(SensorEventListener, Sensor, int)
646      */
unregisterListener(SensorEventListener listener, Sensor sensor)647     public void unregisterListener(SensorEventListener listener, Sensor sensor) {
648         if (listener == null || sensor == null) {
649             return;
650         }
651 
652         unregisterListenerImpl(listener, sensor);
653     }
654 
655     /**
656      * Unregisters a listener for all sensors.
657      *
658      * @param listener
659      *        a SensorListener object
660      *
661      * @see #unregisterListener(SensorEventListener, Sensor)
662      * @see #registerListener(SensorEventListener, Sensor, int)
663      *
664      */
unregisterListener(SensorEventListener listener)665     public void unregisterListener(SensorEventListener listener) {
666         if (listener == null) {
667             return;
668         }
669 
670         unregisterListenerImpl(listener, null);
671     }
672 
673     /** @hide */
unregisterListenerImpl(SensorEventListener listener, Sensor sensor)674     protected abstract void unregisterListenerImpl(SensorEventListener listener, Sensor sensor);
675 
676     /**
677      * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
678      * sensor at the given sampling frequency.
679      * <p>
680      * The events will be delivered to the provided {@code SensorEventListener} as soon as they are
681      * available. To reduce the power consumption, applications can use
682      * {@link #registerListener(SensorEventListener, Sensor, int, int)} instead and specify a
683      * positive non-zero maximum reporting latency.
684      * </p>
685      * <p>
686      * In the case of non-wake-up sensors, the events are only delivered while the Application
687      * Processor (AP) is not in suspend mode. See {@link Sensor#isWakeUpSensor()} for more details.
688      * To ensure delivery of events from non-wake-up sensors even when the screen is OFF, the
689      * application registering to the sensor must hold a partial wake-lock to keep the AP awake,
690      * otherwise some events might be lost while the AP is asleep. Note that although events might
691      * be lost while the AP is asleep, the sensor will still consume power if it is not explicitly
692      * deactivated by the application. Applications must unregister their {@code
693      * SensorEventListener}s in their activity's {@code onPause()} method to avoid consuming power
694      * while the device is inactive.  See {@link #registerListener(SensorEventListener, Sensor, int,
695      * int)} for more details on hardware FIFO (queueing) capabilities and when some sensor events
696      * might be lost.
697      * </p>
698      * <p>
699      * In the case of wake-up sensors, each event generated by the sensor will cause the AP to
700      * wake-up, ensuring that each event can be delivered. Because of this, registering to a wake-up
701      * sensor has very significant power implications. Call {@link Sensor#isWakeUpSensor()} to check
702      * whether a sensor is a wake-up sensor. See
703      * {@link #registerListener(SensorEventListener, Sensor, int, int)} for information on how to
704      * reduce the power impact of registering to wake-up sensors.
705      * </p>
706      * <p class="note">
707      * Note: Don't use this method with one-shot trigger sensors such as
708      * {@link Sensor#TYPE_SIGNIFICANT_MOTION}. Use
709      * {@link #requestTriggerSensor(TriggerEventListener, Sensor)} instead. Use
710      * {@link Sensor#getReportingMode()} to obtain the reporting mode of a given sensor.
711      * </p>
712      *
713      * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object.
714      * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
715      * @param samplingPeriodUs The rate {@link android.hardware.SensorEvent sensor events} are
716      *            delivered at. This is only a hint to the system. Events may be received faster or
717      *            slower than the specified rate. Usually events are received faster. The value must
718      *            be one of {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
719      *            {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST} or, the desired delay
720      *            between events in microseconds. Specifying the delay in microseconds only works
721      *            from Android 2.3 (API level 9) onwards. For earlier releases, you must use one of
722      *            the {@code SENSOR_DELAY_*} constants.
723      * @return <code>true</code> if the sensor is supported and successfully enabled.
724      * @see #registerListener(SensorEventListener, Sensor, int, Handler)
725      * @see #unregisterListener(SensorEventListener)
726      * @see #unregisterListener(SensorEventListener, Sensor)
727      */
registerListener(SensorEventListener listener, Sensor sensor, int samplingPeriodUs)728     public boolean registerListener(SensorEventListener listener, Sensor sensor,
729             int samplingPeriodUs) {
730         return registerListener(listener, sensor, samplingPeriodUs, null);
731     }
732 
733     /**
734      * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
735      * sensor at the given sampling frequency and the given maximum reporting latency.
736      * <p>
737      * This function is similar to {@link #registerListener(SensorEventListener, Sensor, int)} but
738      * it allows events to stay temporarily in the hardware FIFO (queue) before being delivered. The
739      * events can be stored in the hardware FIFO up to {@code maxReportLatencyUs} microseconds. Once
740      * one of the events in the FIFO needs to be reported, all of the events in the FIFO are
741      * reported sequentially. This means that some events will be reported before the maximum
742      * reporting latency has elapsed.
743      * </p><p>
744      * When {@code maxReportLatencyUs} is 0, the call is equivalent to a call to
745      * {@link #registerListener(SensorEventListener, Sensor, int)}, as it requires the events to be
746      * delivered as soon as possible.
747      * </p><p>
748      * When {@code sensor.maxFifoEventCount()} is 0, the sensor does not use a FIFO, so the call
749      * will also be equivalent to {@link #registerListener(SensorEventListener, Sensor, int)}.
750      * </p><p>
751      * Setting {@code maxReportLatencyUs} to a positive value allows to reduce the number of
752      * interrupts the AP (Application Processor) receives, hence reducing power consumption, as the
753      * AP can switch to a lower power state while the sensor is capturing the data. This is
754      * especially important when registering to wake-up sensors, for which each interrupt causes the
755      * AP to wake up if it was in suspend mode. See {@link Sensor#isWakeUpSensor()} for more
756      * information on wake-up sensors.
757      * </p>
758      * <p class="note">
759      * </p>
760      * Note: Don't use this method with one-shot trigger sensors such as
761      * {@link Sensor#TYPE_SIGNIFICANT_MOTION}. Use
762      * {@link #requestTriggerSensor(TriggerEventListener, Sensor)} instead. </p>
763      *
764      * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
765      *            that will receive the sensor events. If the application is interested in receiving
766      *            flush complete notifications, it should register with
767      *            {@link android.hardware.SensorEventListener SensorEventListener2} instead.
768      * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
769      * @param samplingPeriodUs The desired delay between two consecutive events in microseconds.
770      *            This is only a hint to the system. Events may be received faster or slower than
771      *            the specified rate. Usually events are received faster. Can be one of
772      *            {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
773      *            {@link #SENSOR_DELAY_GAME}, {@link #SENSOR_DELAY_FASTEST} or the delay in
774      *            microseconds.
775      * @param maxReportLatencyUs Maximum time in microseconds that events can be delayed before
776      *            being reported to the application. A large value allows reducing the power
777      *            consumption associated with the sensor. If maxReportLatencyUs is set to zero,
778      *            events are delivered as soon as they are available, which is equivalent to calling
779      *            {@link #registerListener(SensorEventListener, Sensor, int)}.
780      * @return <code>true</code> if the sensor is supported and successfully enabled.
781      * @see #registerListener(SensorEventListener, Sensor, int)
782      * @see #unregisterListener(SensorEventListener)
783      * @see #flush(SensorEventListener)
784      */
registerListener(SensorEventListener listener, Sensor sensor, int samplingPeriodUs, int maxReportLatencyUs)785     public boolean registerListener(SensorEventListener listener, Sensor sensor,
786             int samplingPeriodUs, int maxReportLatencyUs) {
787         int delay = getDelay(samplingPeriodUs);
788         return registerListenerImpl(listener, sensor, delay, null, maxReportLatencyUs, 0);
789     }
790 
791     /**
792      * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
793      * sensor. Events are delivered in continuous mode as soon as they are available. To reduce the
794      * power consumption, applications can use
795      * {@link #registerListener(SensorEventListener, Sensor, int, int)} instead and specify a
796      * positive non-zero maximum reporting latency.
797      * <p class="note">
798      * </p>
799      * Note: Don't use this method with a one shot trigger sensor such as
800      * {@link Sensor#TYPE_SIGNIFICANT_MOTION}. Use
801      * {@link #requestTriggerSensor(TriggerEventListener, Sensor)} instead. </p>
802      *
803      * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object.
804      * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
805      * @param samplingPeriodUs The rate {@link android.hardware.SensorEvent sensor events} are
806      *            delivered at. This is only a hint to the system. Events may be received faster or
807      *            slower than the specified rate. Usually events are received faster. The value must
808      *            be one of {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
809      *            {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST} or, the desired
810      *            delay between events in microseconds. Specifying the delay in microseconds only
811      *            works from Android 2.3 (API level 9) onwards. For earlier releases, you must use
812      *            one of the {@code SENSOR_DELAY_*} constants.
813      * @param handler The {@link android.os.Handler Handler} the {@link android.hardware.SensorEvent
814      *            sensor events} will be delivered to.
815      * @return <code>true</code> if the sensor is supported and successfully enabled.
816      * @see #registerListener(SensorEventListener, Sensor, int)
817      * @see #unregisterListener(SensorEventListener)
818      * @see #unregisterListener(SensorEventListener, Sensor)
819      */
registerListener(SensorEventListener listener, Sensor sensor, int samplingPeriodUs, Handler handler)820     public boolean registerListener(SensorEventListener listener, Sensor sensor,
821             int samplingPeriodUs, Handler handler) {
822         int delay = getDelay(samplingPeriodUs);
823         return registerListenerImpl(listener, sensor, delay, handler, 0, 0);
824     }
825 
826     /**
827      * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
828      * sensor at the given sampling frequency and the given maximum reporting latency.
829      *
830      * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
831      *            that will receive the sensor events. If the application is interested in receiving
832      *            flush complete notifications, it should register with
833      *            {@link android.hardware.SensorEventListener SensorEventListener2} instead.
834      * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
835      * @param samplingPeriodUs The desired delay between two consecutive events in microseconds.
836      *            This is only a hint to the system. Events may be received faster or slower than
837      *            the specified rate. Usually events are received faster. Can be one of
838      *            {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
839      *            {@link #SENSOR_DELAY_GAME}, {@link #SENSOR_DELAY_FASTEST} or the delay in
840      *            microseconds.
841      * @param maxReportLatencyUs Maximum time in microseconds that events can be delayed before
842      *            being reported to the application. A large value allows reducing the power
843      *            consumption associated with the sensor. If maxReportLatencyUs is set to zero,
844      *            events are delivered as soon as they are available, which is equivalent to calling
845      *            {@link #registerListener(SensorEventListener, Sensor, int)}.
846      * @param handler The {@link android.os.Handler Handler} the {@link android.hardware.SensorEvent
847      *            sensor events} will be delivered to.
848      * @return <code>true</code> if the sensor is supported and successfully enabled.
849      * @see #registerListener(SensorEventListener, Sensor, int, int)
850      */
registerListener(SensorEventListener listener, Sensor sensor, int samplingPeriodUs, int maxReportLatencyUs, Handler handler)851     public boolean registerListener(SensorEventListener listener, Sensor sensor,
852             int samplingPeriodUs, int maxReportLatencyUs, Handler handler) {
853         int delayUs = getDelay(samplingPeriodUs);
854         return registerListenerImpl(listener, sensor, delayUs, handler, maxReportLatencyUs, 0);
855     }
856 
857     /** @hide */
registerListenerImpl(SensorEventListener listener, Sensor sensor, int delayUs, Handler handler, int maxReportLatencyUs, int reservedFlags)858     protected abstract boolean registerListenerImpl(SensorEventListener listener, Sensor sensor,
859             int delayUs, Handler handler, int maxReportLatencyUs, int reservedFlags);
860 
861 
862     /**
863      * Flushes the FIFO of all the sensors registered for this listener. If there are events
864      * in the FIFO of the sensor, they are returned as if the maxReportLantecy of the FIFO has
865      * expired. Events are returned in the usual way through the SensorEventListener.
866      * This call doesn't affect the maxReportLantecy for this sensor. This call is asynchronous and
867      * returns immediately.
868      * {@link android.hardware.SensorEventListener2#onFlushCompleted onFlushCompleted} is called
869      * after all the events in the batch at the time of calling this method have been delivered
870      * successfully. If the hardware doesn't support flush, it still returns true and a trivial
871      * flush complete event is sent after the current event for all the clients registered for this
872      * sensor.
873      *
874      * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
875      *        which was previously used in a registerListener call.
876      * @return <code>true</code> if the flush is initiated successfully on all the sensors
877      *         registered for this listener, false if no sensor is previously registered for this
878      *         listener or flush on one of the sensors fails.
879      * @see #registerListener(SensorEventListener, Sensor, int, int)
880      * @throws IllegalArgumentException when listener is null.
881      */
flush(SensorEventListener listener)882     public boolean flush(SensorEventListener listener) {
883         return flushImpl(listener);
884     }
885 
886     /** @hide */
flushImpl(SensorEventListener listener)887     protected abstract boolean flushImpl(SensorEventListener listener);
888 
889 
890     /**
891      * Create a sensor direct channel backed by shared memory wrapped in MemoryFile object.
892      *
893      * The resulting channel can be used for delivering sensor events to native code, other
894      * processes, GPU/DSP or other co-processors without CPU intervention. This is the recommanded
895      * for high performance sensor applications that use high sensor rates (e.g. greater than 200Hz)
896      * and cares about sensor event latency.
897      *
898      * Use the returned {@link android.hardware.SensorDirectChannel} object to configure direct
899      * report of sensor events. After use, call {@link android.hardware.SensorDirectChannel#close()}
900      * to free up resource in sensor system associated with the direct channel.
901      *
902      * @param mem A {@link android.os.MemoryFile} shared memory object.
903      * @return A {@link android.hardware.SensorDirectChannel} object.
904      * @throws NullPointerException when mem is null.
905      * @throws UncheckedIOException if not able to create channel.
906      * @see SensorDirectChannel#close()
907      */
createDirectChannel(MemoryFile mem)908     public SensorDirectChannel createDirectChannel(MemoryFile mem) {
909         return createDirectChannelImpl(mem, null);
910     }
911 
912     /**
913      * Create a sensor direct channel backed by shared memory wrapped in HardwareBuffer object.
914      *
915      * The resulting channel can be used for delivering sensor events to native code, other
916      * processes, GPU/DSP or other co-processors without CPU intervention. This is the recommanded
917      * for high performance sensor applications that use high sensor rates (e.g. greater than 200Hz)
918      * and cares about sensor event latency.
919      *
920      * Use the returned {@link android.hardware.SensorDirectChannel} object to configure direct
921      * report of sensor events. After use, call {@link android.hardware.SensorDirectChannel#close()}
922      * to free up resource in sensor system associated with the direct channel.
923      *
924      * @param mem A {@link android.hardware.HardwareBuffer} shared memory object.
925      * @return A {@link android.hardware.SensorDirectChannel} object.
926      * @throws NullPointerException when mem is null.
927      * @throws UncheckedIOException if not able to create channel.
928      * @see SensorDirectChannel#close()
929      */
createDirectChannel(HardwareBuffer mem)930     public SensorDirectChannel createDirectChannel(HardwareBuffer mem) {
931         return createDirectChannelImpl(null, mem);
932     }
933 
934     /** @hide */
createDirectChannelImpl( MemoryFile memoryFile, HardwareBuffer hardwareBuffer)935     protected abstract SensorDirectChannel createDirectChannelImpl(
936             MemoryFile memoryFile, HardwareBuffer hardwareBuffer);
937 
938     /** @hide */
destroyDirectChannel(SensorDirectChannel channel)939     void destroyDirectChannel(SensorDirectChannel channel) {
940         destroyDirectChannelImpl(channel);
941     }
942 
943     /** @hide */
destroyDirectChannelImpl(SensorDirectChannel channel)944     protected abstract void destroyDirectChannelImpl(SensorDirectChannel channel);
945 
946     /** @hide */
configureDirectChannelImpl( SensorDirectChannel channel, Sensor s, int rate)947     protected abstract int configureDirectChannelImpl(
948             SensorDirectChannel channel, Sensor s, int rate);
949 
950     /**
951      * Used for receiving notifications from the SensorManager when dynamic sensors are connected or
952      * disconnected.
953      */
954     public abstract static class DynamicSensorCallback {
955         /**
956          * Called when there is a dynamic sensor being connected to the system.
957          *
958          * @param sensor the newly connected sensor. See {@link android.hardware.Sensor Sensor}.
959          */
onDynamicSensorConnected(Sensor sensor)960         public void onDynamicSensorConnected(Sensor sensor) {}
961 
962         /**
963          * Called when there is a dynamic sensor being disconnected from the system.
964          *
965          * @param sensor the disconnected sensor. See {@link android.hardware.Sensor Sensor}.
966          */
onDynamicSensorDisconnected(Sensor sensor)967         public void onDynamicSensorDisconnected(Sensor sensor) {}
968     }
969 
970 
971     /**
972      * Add a {@link android.hardware.SensorManager.DynamicSensorCallback
973      * DynamicSensorCallback} to receive dynamic sensor connection callbacks. Repeat
974      * registration with the already registered callback object will have no additional effect.
975      *
976      * @param callback An object that implements the
977      *        {@link android.hardware.SensorManager.DynamicSensorCallback
978      *        DynamicSensorCallback}
979      *        interface for receiving callbacks.
980      * @see #registerDynamicSensorCallback(DynamicSensorCallback, Handler)
981      *
982      * @throws IllegalArgumentException when callback is null.
983      */
registerDynamicSensorCallback(DynamicSensorCallback callback)984     public void registerDynamicSensorCallback(DynamicSensorCallback callback) {
985         registerDynamicSensorCallback(callback, null);
986     }
987 
988     /**
989      * Add a {@link android.hardware.SensorManager.DynamicSensorCallback
990      * DynamicSensorCallback} to receive dynamic sensor connection callbacks. Repeat
991      * registration with the already registered callback object will have no additional effect.
992      *
993      * @param callback An object that implements the
994      *        {@link android.hardware.SensorManager.DynamicSensorCallback
995      *        DynamicSensorCallback} interface for receiving callbacks.
996      * @param handler The {@link android.os.Handler Handler} the {@link
997      *        android.hardware.SensorManager.DynamicSensorCallback
998      *        sensor connection events} will be delivered to.
999      *
1000      * @throws IllegalArgumentException when callback is null.
1001      */
registerDynamicSensorCallback( DynamicSensorCallback callback, Handler handler)1002     public void registerDynamicSensorCallback(
1003             DynamicSensorCallback callback, Handler handler) {
1004         registerDynamicSensorCallbackImpl(callback, handler);
1005     }
1006 
1007     /**
1008      * Remove a {@link android.hardware.SensorManager.DynamicSensorCallback
1009      * DynamicSensorCallback} to stop sending dynamic sensor connection events to that
1010      * callback.
1011      *
1012      * @param callback An object that implements the
1013      *        {@link android.hardware.SensorManager.DynamicSensorCallback
1014      *        DynamicSensorCallback}
1015      *        interface for receiving callbacks.
1016      */
unregisterDynamicSensorCallback(DynamicSensorCallback callback)1017     public void unregisterDynamicSensorCallback(DynamicSensorCallback callback) {
1018         unregisterDynamicSensorCallbackImpl(callback);
1019     }
1020 
1021     /**
1022      * Tell if dynamic sensor discovery feature is supported by system.
1023      *
1024      * @return <code>true</code> if dynamic sensor discovery is supported, <code>false</code>
1025      * otherwise.
1026      */
isDynamicSensorDiscoverySupported()1027     public boolean isDynamicSensorDiscoverySupported() {
1028         List<Sensor> sensors = getSensorList(Sensor.TYPE_DYNAMIC_SENSOR_META);
1029         return sensors.size() > 0;
1030     }
1031 
1032     /** @hide */
registerDynamicSensorCallbackImpl( DynamicSensorCallback callback, Handler handler)1033     protected abstract void registerDynamicSensorCallbackImpl(
1034             DynamicSensorCallback callback, Handler handler);
1035 
1036     /** @hide */
unregisterDynamicSensorCallbackImpl( DynamicSensorCallback callback)1037     protected abstract void unregisterDynamicSensorCallbackImpl(
1038             DynamicSensorCallback callback);
1039 
1040     /**
1041      * <p>
1042      * Computes the inclination matrix <b>I</b> as well as the rotation matrix
1043      * <b>R</b> transforming a vector from the device coordinate system to the
1044      * world's coordinate system which is defined as a direct orthonormal basis,
1045      * where:
1046      * </p>
1047      *
1048      * <ul>
1049      * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to
1050      * the ground at the device's current location and roughly points East).</li>
1051      * <li>Y is tangential to the ground at the device's current location and
1052      * points towards the magnetic North Pole.</li>
1053      * <li>Z points towards the sky and is perpendicular to the ground.</li>
1054      * </ul>
1055      *
1056      * <p>
1057      * <center><img src="../../../images/axis_globe.png"
1058      * alt="World coordinate-system diagram." border="0" /></center>
1059      * </p>
1060      *
1061      * <p>
1062      * <hr>
1063      * <p>
1064      * By definition:
1065      * <p>
1066      * [0 0 g] = <b>R</b> * <b>gravity</b> (g = magnitude of gravity)
1067      * <p>
1068      * [0 m 0] = <b>I</b> * <b>R</b> * <b>geomagnetic</b> (m = magnitude of
1069      * geomagnetic field)
1070      * <p>
1071      * <b>R</b> is the identity matrix when the device is aligned with the
1072      * world's coordinate system, that is, when the device's X axis points
1073      * toward East, the Y axis points to the North Pole and the device is facing
1074      * the sky.
1075      *
1076      * <p>
1077      * <b>I</b> is a rotation matrix transforming the geomagnetic vector into
1078      * the same coordinate space as gravity (the world's coordinate space).
1079      * <b>I</b> is a simple rotation around the X axis. The inclination angle in
1080      * radians can be computed with {@link #getInclination}.
1081      * <hr>
1082      *
1083      * <p>
1084      * Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending
1085      * on the length of the passed array:
1086      * <p>
1087      * <u>If the array length is 16:</u>
1088      *
1089      * <pre>
1090      *   /  M[ 0]   M[ 1]   M[ 2]   M[ 3]  \
1091      *   |  M[ 4]   M[ 5]   M[ 6]   M[ 7]  |
1092      *   |  M[ 8]   M[ 9]   M[10]   M[11]  |
1093      *   \  M[12]   M[13]   M[14]   M[15]  /
1094      *</pre>
1095      *
1096      * This matrix is ready to be used by OpenGL ES's
1097      * {@link javax.microedition.khronos.opengles.GL10#glLoadMatrixf(float[], int)
1098      * glLoadMatrixf(float[], int)}.
1099      * <p>
1100      * Note that because OpenGL matrices are column-major matrices you must
1101      * transpose the matrix before using it. However, since the matrix is a
1102      * rotation matrix, its transpose is also its inverse, conveniently, it is
1103      * often the inverse of the rotation that is needed for rendering; it can
1104      * therefore be used with OpenGL ES directly.
1105      * <p>
1106      * Also note that the returned matrices always have this form:
1107      *
1108      * <pre>
1109      *   /  M[ 0]   M[ 1]   M[ 2]   0  \
1110      *   |  M[ 4]   M[ 5]   M[ 6]   0  |
1111      *   |  M[ 8]   M[ 9]   M[10]   0  |
1112      *   \      0       0       0   1  /
1113      *</pre>
1114      *
1115      * <p>
1116      * <u>If the array length is 9:</u>
1117      *
1118      * <pre>
1119      *   /  M[ 0]   M[ 1]   M[ 2]  \
1120      *   |  M[ 3]   M[ 4]   M[ 5]  |
1121      *   \  M[ 6]   M[ 7]   M[ 8]  /
1122      *</pre>
1123      *
1124      * <hr>
1125      * <p>
1126      * The inverse of each matrix can be computed easily by taking its
1127      * transpose.
1128      *
1129      * <p>
1130      * The matrices returned by this function are meaningful only when the
1131      * device is not free-falling and it is not close to the magnetic north. If
1132      * the device is accelerating, or placed into a strong magnetic field, the
1133      * returned matrices may be inaccurate.
1134      *
1135      * @param R
1136      *        is an array of 9 floats holding the rotation matrix <b>R</b> when
1137      *        this function returns. R can be null.
1138      *        <p>
1139      *
1140      * @param I
1141      *        is an array of 9 floats holding the rotation matrix <b>I</b> when
1142      *        this function returns. I can be null.
1143      *        <p>
1144      *
1145      * @param gravity
1146      *        is an array of 3 floats containing the gravity vector expressed in
1147      *        the device's coordinate. You can simply use the
1148      *        {@link android.hardware.SensorEvent#values values} returned by a
1149      *        {@link android.hardware.SensorEvent SensorEvent} of a
1150      *        {@link android.hardware.Sensor Sensor} of type
1151      *        {@link android.hardware.Sensor#TYPE_ACCELEROMETER
1152      *        TYPE_ACCELEROMETER}.
1153      *        <p>
1154      *
1155      * @param geomagnetic
1156      *        is an array of 3 floats containing the geomagnetic vector
1157      *        expressed in the device's coordinate. You can simply use the
1158      *        {@link android.hardware.SensorEvent#values values} returned by a
1159      *        {@link android.hardware.SensorEvent SensorEvent} of a
1160      *        {@link android.hardware.Sensor Sensor} of type
1161      *        {@link android.hardware.Sensor#TYPE_MAGNETIC_FIELD
1162      *        TYPE_MAGNETIC_FIELD}.
1163      *
1164      * @return <code>true</code> on success, <code>false</code> on failure (for
1165      *         instance, if the device is in free fall). Free fall is defined as
1166      *         condition when the magnitude of the gravity is less than 1/10 of
1167      *         the nominal value. On failure the output matrices are not modified.
1168      *
1169      * @see #getInclination(float[])
1170      * @see #getOrientation(float[], float[])
1171      * @see #remapCoordinateSystem(float[], int, int, float[])
1172      */
1173 
getRotationMatrix(float[] R, float[] I, float[] gravity, float[] geomagnetic)1174     public static boolean getRotationMatrix(float[] R, float[] I,
1175             float[] gravity, float[] geomagnetic) {
1176         // TODO: move this to native code for efficiency
1177         float Ax = gravity[0];
1178         float Ay = gravity[1];
1179         float Az = gravity[2];
1180 
1181         final float normsqA = (Ax * Ax + Ay * Ay + Az * Az);
1182         final float g = 9.81f;
1183         final float freeFallGravitySquared = 0.01f * g * g;
1184         if (normsqA < freeFallGravitySquared) {
1185             // gravity less than 10% of normal value
1186             return false;
1187         }
1188 
1189         final float Ex = geomagnetic[0];
1190         final float Ey = geomagnetic[1];
1191         final float Ez = geomagnetic[2];
1192         float Hx = Ey * Az - Ez * Ay;
1193         float Hy = Ez * Ax - Ex * Az;
1194         float Hz = Ex * Ay - Ey * Ax;
1195         final float normH = (float) Math.sqrt(Hx * Hx + Hy * Hy + Hz * Hz);
1196 
1197         if (normH < 0.1f) {
1198             // device is close to free fall (or in space?), or close to
1199             // magnetic north pole. Typical values are  > 100.
1200             return false;
1201         }
1202         final float invH = 1.0f / normH;
1203         Hx *= invH;
1204         Hy *= invH;
1205         Hz *= invH;
1206         final float invA = 1.0f / (float) Math.sqrt(Ax * Ax + Ay * Ay + Az * Az);
1207         Ax *= invA;
1208         Ay *= invA;
1209         Az *= invA;
1210         final float Mx = Ay * Hz - Az * Hy;
1211         final float My = Az * Hx - Ax * Hz;
1212         final float Mz = Ax * Hy - Ay * Hx;
1213         if (R != null) {
1214             if (R.length == 9) {
1215                 R[0] = Hx;     R[1] = Hy;     R[2] = Hz;
1216                 R[3] = Mx;     R[4] = My;     R[5] = Mz;
1217                 R[6] = Ax;     R[7] = Ay;     R[8] = Az;
1218             } else if (R.length == 16) {
1219                 R[0]  = Hx;    R[1]  = Hy;    R[2]  = Hz;   R[3]  = 0;
1220                 R[4]  = Mx;    R[5]  = My;    R[6]  = Mz;   R[7]  = 0;
1221                 R[8]  = Ax;    R[9]  = Ay;    R[10] = Az;   R[11] = 0;
1222                 R[12] = 0;     R[13] = 0;     R[14] = 0;    R[15] = 1;
1223             }
1224         }
1225         if (I != null) {
1226             // compute the inclination matrix by projecting the geomagnetic
1227             // vector onto the Z (gravity) and X (horizontal component
1228             // of geomagnetic vector) axes.
1229             final float invE = 1.0f / (float) Math.sqrt(Ex * Ex + Ey * Ey + Ez * Ez);
1230             final float c = (Ex * Mx + Ey * My + Ez * Mz) * invE;
1231             final float s = (Ex * Ax + Ey * Ay + Ez * Az) * invE;
1232             if (I.length == 9) {
1233                 I[0] = 1;     I[1] = 0;     I[2] = 0;
1234                 I[3] = 0;     I[4] = c;     I[5] = s;
1235                 I[6] = 0;     I[7] = -s;     I[8] = c;
1236             } else if (I.length == 16) {
1237                 I[0] = 1;     I[1] = 0;     I[2] = 0;
1238                 I[4] = 0;     I[5] = c;     I[6] = s;
1239                 I[8] = 0;     I[9] = -s;     I[10] = c;
1240                 I[3] = I[7] = I[11] = I[12] = I[13] = I[14] = 0;
1241                 I[15] = 1;
1242             }
1243         }
1244         return true;
1245     }
1246 
1247     /**
1248      * Computes the geomagnetic inclination angle in radians from the
1249      * inclination matrix <b>I</b> returned by {@link #getRotationMatrix}.
1250      *
1251      * @param I
1252      *        inclination matrix see {@link #getRotationMatrix}.
1253      *
1254      * @return The geomagnetic inclination angle in radians.
1255      *
1256      * @see #getRotationMatrix(float[], float[], float[], float[])
1257      * @see #getOrientation(float[], float[])
1258      * @see GeomagneticField
1259      *
1260      */
getInclination(float[] I)1261     public static float getInclination(float[] I) {
1262         if (I.length == 9) {
1263             return (float) Math.atan2(I[5], I[4]);
1264         } else {
1265             return (float) Math.atan2(I[6], I[5]);
1266         }
1267     }
1268 
1269     /**
1270      * <p>
1271      * Rotates the supplied rotation matrix so it is expressed in a different
1272      * coordinate system. This is typically used when an application needs to
1273      * compute the three orientation angles of the device (see
1274      * {@link #getOrientation}) in a different coordinate system.
1275      * </p>
1276      *
1277      * <p>
1278      * When the rotation matrix is used for drawing (for instance with OpenGL
1279      * ES), it usually <b>doesn't need</b> to be transformed by this function,
1280      * unless the screen is physically rotated, in which case you can use
1281      * {@link android.view.Display#getRotation() Display.getRotation()} to
1282      * retrieve the current rotation of the screen. Note that because the user
1283      * is generally free to rotate their screen, you often should consider the
1284      * rotation in deciding the parameters to use here.
1285      * </p>
1286      *
1287      * <p>
1288      * <u>Examples:</u>
1289      * <p>
1290      *
1291      * <ul>
1292      * <li>Using the camera (Y axis along the camera's axis) for an augmented
1293      * reality application where the rotation angles are needed:</li>
1294      *
1295      * <p>
1296      * <ul>
1297      * <code>remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);</code>
1298      * </ul>
1299      * </p>
1300      *
1301      * <li>Using the device as a mechanical compass when rotation is
1302      * {@link android.view.Surface#ROTATION_90 Surface.ROTATION_90}:</li>
1303      *
1304      * <p>
1305      * <ul>
1306      * <code>remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);</code>
1307      * </ul>
1308      * </p>
1309      *
1310      * Beware of the above example. This call is needed only to account for a
1311      * rotation from its natural orientation when calculating the rotation
1312      * angles (see {@link #getOrientation}). If the rotation matrix is also used
1313      * for rendering, it may not need to be transformed, for instance if your
1314      * {@link android.app.Activity Activity} is running in landscape mode.
1315      * </ul>
1316      *
1317      * <p>
1318      * Since the resulting coordinate system is orthonormal, only two axes need
1319      * to be specified.
1320      *
1321      * @param inR
1322      *        the rotation matrix to be transformed. Usually it is the matrix
1323      *        returned by {@link #getRotationMatrix}.
1324      *
1325      * @param X
1326      *        defines the axis of the new cooridinate system that coincide with the X axis of the
1327      *        original coordinate system.
1328      *
1329      * @param Y
1330      *        defines the axis of the new cooridinate system that coincide with the Y axis of the
1331      *        original coordinate system.
1332      *
1333      * @param outR
1334      *        the transformed rotation matrix. inR and outR should not be the same
1335      *        array.
1336      *
1337      * @return <code>true</code> on success. <code>false</code> if the input
1338      *         parameters are incorrect, for instance if X and Y define the same
1339      *         axis. Or if inR and outR don't have the same length.
1340      *
1341      * @see #getRotationMatrix(float[], float[], float[], float[])
1342      */
1343 
remapCoordinateSystem(float[] inR, int X, int Y, float[] outR)1344     public static boolean remapCoordinateSystem(float[] inR, int X, int Y, float[] outR) {
1345         if (inR == outR) {
1346             final float[] temp = sTempMatrix;
1347             synchronized (temp) {
1348                 // we don't expect to have a lot of contention
1349                 if (remapCoordinateSystemImpl(inR, X, Y, temp)) {
1350                     final int size = outR.length;
1351                     for (int i = 0; i < size; i++) {
1352                         outR[i] = temp[i];
1353                     }
1354                     return true;
1355                 }
1356             }
1357         }
1358         return remapCoordinateSystemImpl(inR, X, Y, outR);
1359     }
1360 
remapCoordinateSystemImpl(float[] inR, int X, int Y, float[] outR)1361     private static boolean remapCoordinateSystemImpl(float[] inR, int X, int Y, float[] outR) {
1362         /*
1363          * X and Y define a rotation matrix 'r':
1364          *
1365          *  (X==1)?((X&0x80)?-1:1):0    (X==2)?((X&0x80)?-1:1):0    (X==3)?((X&0x80)?-1:1):0
1366          *  (Y==1)?((Y&0x80)?-1:1):0    (Y==2)?((Y&0x80)?-1:1):0    (Y==3)?((X&0x80)?-1:1):0
1367          *                              r[0] ^ r[1]
1368          *
1369          * where the 3rd line is the vector product of the first 2 lines
1370          *
1371          */
1372 
1373         final int length = outR.length;
1374         if (inR.length != length) {
1375             return false;   // invalid parameter
1376         }
1377         if ((X & 0x7C) != 0 || (Y & 0x7C) != 0) {
1378             return false;   // invalid parameter
1379         }
1380         if (((X & 0x3) == 0) || ((Y & 0x3) == 0)) {
1381             return false;   // no axis specified
1382         }
1383         if ((X & 0x3) == (Y & 0x3)) {
1384             return false;   // same axis specified
1385         }
1386 
1387         // Z is "the other" axis, its sign is either +/- sign(X)*sign(Y)
1388         // this can be calculated by exclusive-or'ing X and Y; except for
1389         // the sign inversion (+/-) which is calculated below.
1390         int Z = X ^ Y;
1391 
1392         // extract the axis (remove the sign), offset in the range 0 to 2.
1393         final int x = (X & 0x3) - 1;
1394         final int y = (Y & 0x3) - 1;
1395         final int z = (Z & 0x3) - 1;
1396 
1397         // compute the sign of Z (whether it needs to be inverted)
1398         final int axis_y = (z + 1) % 3;
1399         final int axis_z = (z + 2) % 3;
1400         if (((x ^ axis_y) | (y ^ axis_z)) != 0) {
1401             Z ^= 0x80;
1402         }
1403 
1404         final boolean sx = (X >= 0x80);
1405         final boolean sy = (Y >= 0x80);
1406         final boolean sz = (Z >= 0x80);
1407 
1408         // Perform R * r, in avoiding actual muls and adds.
1409         final int rowLength = ((length == 16) ? 4 : 3);
1410         for (int j = 0; j < 3; j++) {
1411             final int offset = j * rowLength;
1412             for (int i = 0; i < 3; i++) {
1413                 if (x == i)   outR[offset + i] = sx ? -inR[offset + 0] : inR[offset + 0];
1414                 if (y == i)   outR[offset + i] = sy ? -inR[offset + 1] : inR[offset + 1];
1415                 if (z == i)   outR[offset + i] = sz ? -inR[offset + 2] : inR[offset + 2];
1416             }
1417         }
1418         if (length == 16) {
1419             outR[3] = outR[7] = outR[11] = outR[12] = outR[13] = outR[14] = 0;
1420             outR[15] = 1;
1421         }
1422         return true;
1423     }
1424 
1425     /**
1426      * Computes the device's orientation based on the rotation matrix.
1427      * <p>
1428      * When it returns, the array values are as follows:
1429      * <ul>
1430      * <li>values[0]: <i>Azimuth</i>, angle of rotation about the -z axis.
1431      *                This value represents the angle between the device's y
1432      *                axis and the magnetic north pole. When facing north, this
1433      *                angle is 0, when facing south, this angle is &pi;.
1434      *                Likewise, when facing east, this angle is &pi;/2, and
1435      *                when facing west, this angle is -&pi;/2. The range of
1436      *                values is -&pi; to &pi;.</li>
1437      * <li>values[1]: <i>Pitch</i>, angle of rotation about the x axis.
1438      *                This value represents the angle between a plane parallel
1439      *                to the device's screen and a plane parallel to the ground.
1440      *                Assuming that the bottom edge of the device faces the
1441      *                user and that the screen is face-up, tilting the top edge
1442      *                of the device toward the ground creates a positive pitch
1443      *                angle. The range of values is -&pi; to &pi;.</li>
1444      * <li>values[2]: <i>Roll</i>, angle of rotation about the y axis. This
1445      *                value represents the angle between a plane perpendicular
1446      *                to the device's screen and a plane perpendicular to the
1447      *                ground. Assuming that the bottom edge of the device faces
1448      *                the user and that the screen is face-up, tilting the left
1449      *                edge of the device toward the ground creates a positive
1450      *                roll angle. The range of values is -&pi;/2 to &pi;/2.</li>
1451      * </ul>
1452      * <p>
1453      * Applying these three rotations in the azimuth, pitch, roll order
1454      * transforms an identity matrix to the rotation matrix passed into this
1455      * method. Also, note that all three orientation angles are expressed in
1456      * <b>radians</b>.
1457      *
1458      * @param R
1459      *        rotation matrix see {@link #getRotationMatrix}.
1460      *
1461      * @param values
1462      *        an array of 3 floats to hold the result.
1463      *
1464      * @return The array values passed as argument.
1465      *
1466      * @see #getRotationMatrix(float[], float[], float[], float[])
1467      * @see GeomagneticField
1468      */
getOrientation(float[] R, float[] values)1469     public static float[] getOrientation(float[] R, float[] values) {
1470         /*
1471          * 4x4 (length=16) case:
1472          *   /  R[ 0]   R[ 1]   R[ 2]   0  \
1473          *   |  R[ 4]   R[ 5]   R[ 6]   0  |
1474          *   |  R[ 8]   R[ 9]   R[10]   0  |
1475          *   \      0       0       0   1  /
1476          *
1477          * 3x3 (length=9) case:
1478          *   /  R[ 0]   R[ 1]   R[ 2]  \
1479          *   |  R[ 3]   R[ 4]   R[ 5]  |
1480          *   \  R[ 6]   R[ 7]   R[ 8]  /
1481          *
1482          */
1483         if (R.length == 9) {
1484             values[0] = (float) Math.atan2(R[1], R[4]);
1485             values[1] = (float) Math.asin(-R[7]);
1486             values[2] = (float) Math.atan2(-R[6], R[8]);
1487         } else {
1488             values[0] = (float) Math.atan2(R[1], R[5]);
1489             values[1] = (float) Math.asin(-R[9]);
1490             values[2] = (float) Math.atan2(-R[8], R[10]);
1491         }
1492 
1493         return values;
1494     }
1495 
1496     /**
1497      * Computes the Altitude in meters from the atmospheric pressure and the
1498      * pressure at sea level.
1499      * <p>
1500      * Typically the atmospheric pressure is read from a
1501      * {@link Sensor#TYPE_PRESSURE} sensor. The pressure at sea level must be
1502      * known, usually it can be retrieved from airport databases in the
1503      * vicinity. If unknown, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE}
1504      * as an approximation, but absolute altitudes won't be accurate.
1505      * </p>
1506      * <p>
1507      * To calculate altitude differences, you must calculate the difference
1508      * between the altitudes at both points. If you don't know the altitude
1509      * as sea level, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} instead,
1510      * which will give good results considering the range of pressure typically
1511      * involved.
1512      * </p>
1513      * <p>
1514      * <code><ul>
1515      *  float altitude_difference =
1516      *      getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2)
1517      *      - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1);
1518      * </ul></code>
1519      * </p>
1520      *
1521      * @param p0 pressure at sea level
1522      * @param p atmospheric pressure
1523      * @return Altitude in meters
1524      */
getAltitude(float p0, float p)1525     public static float getAltitude(float p0, float p) {
1526         final float coef = 1.0f / 5.255f;
1527         return 44330.0f * (1.0f - (float) Math.pow(p / p0, coef));
1528     }
1529 
1530     /** Helper function to compute the angle change between two rotation matrices.
1531      *  Given a current rotation matrix (R) and a previous rotation matrix
1532      *  (prevR) computes the intrinsic rotation around the z, x, and y axes which
1533      *  transforms prevR to R.
1534      *  outputs a 3 element vector containing the z, x, and y angle
1535      *  change at indexes 0, 1, and 2 respectively.
1536      * <p> Each input matrix is either as a 3x3 or 4x4 row-major matrix
1537      * depending on the length of the passed array:
1538      * <p>If the array length is 9, then the array elements represent this matrix
1539      * <pre>
1540      *   /  R[ 0]   R[ 1]   R[ 2]   \
1541      *   |  R[ 3]   R[ 4]   R[ 5]   |
1542      *   \  R[ 6]   R[ 7]   R[ 8]   /
1543      *</pre>
1544      * <p>If the array length is 16, then the array elements represent this matrix
1545      * <pre>
1546      *   /  R[ 0]   R[ 1]   R[ 2]   R[ 3]  \
1547      *   |  R[ 4]   R[ 5]   R[ 6]   R[ 7]  |
1548      *   |  R[ 8]   R[ 9]   R[10]   R[11]  |
1549      *   \  R[12]   R[13]   R[14]   R[15]  /
1550      *</pre>
1551      *
1552      * See {@link #getOrientation} for more detailed definition of the output.
1553      *
1554      * @param R current rotation matrix
1555      * @param prevR previous rotation matrix
1556      * @param angleChange an an array of floats (z, x, and y) in which the angle change
1557      *        (in radians) is stored
1558      */
1559 
getAngleChange(float[] angleChange, float[] R, float[] prevR)1560     public static void getAngleChange(float[] angleChange, float[] R, float[] prevR) {
1561         float rd1 = 0, rd4 = 0, rd6 = 0, rd7 = 0, rd8 = 0;
1562         float ri0 = 0, ri1 = 0, ri2 = 0, ri3 = 0, ri4 = 0, ri5 = 0, ri6 = 0, ri7 = 0, ri8 = 0;
1563         float pri0 = 0, pri1 = 0, pri2 = 0, pri3 = 0, pri4 = 0;
1564         float pri5 = 0, pri6 = 0, pri7 = 0, pri8 = 0;
1565 
1566         if (R.length == 9) {
1567             ri0 = R[0];
1568             ri1 = R[1];
1569             ri2 = R[2];
1570             ri3 = R[3];
1571             ri4 = R[4];
1572             ri5 = R[5];
1573             ri6 = R[6];
1574             ri7 = R[7];
1575             ri8 = R[8];
1576         } else if (R.length == 16) {
1577             ri0 = R[0];
1578             ri1 = R[1];
1579             ri2 = R[2];
1580             ri3 = R[4];
1581             ri4 = R[5];
1582             ri5 = R[6];
1583             ri6 = R[8];
1584             ri7 = R[9];
1585             ri8 = R[10];
1586         }
1587 
1588         if (prevR.length == 9) {
1589             pri0 = prevR[0];
1590             pri1 = prevR[1];
1591             pri2 = prevR[2];
1592             pri3 = prevR[3];
1593             pri4 = prevR[4];
1594             pri5 = prevR[5];
1595             pri6 = prevR[6];
1596             pri7 = prevR[7];
1597             pri8 = prevR[8];
1598         } else if (prevR.length == 16) {
1599             pri0 = prevR[0];
1600             pri1 = prevR[1];
1601             pri2 = prevR[2];
1602             pri3 = prevR[4];
1603             pri4 = prevR[5];
1604             pri5 = prevR[6];
1605             pri6 = prevR[8];
1606             pri7 = prevR[9];
1607             pri8 = prevR[10];
1608         }
1609 
1610         // calculate the parts of the rotation difference matrix we need
1611         // rd[i][j] = pri[0][i] * ri[0][j] + pri[1][i] * ri[1][j] + pri[2][i] * ri[2][j];
1612 
1613         rd1 = pri0 * ri1 + pri3 * ri4 + pri6 * ri7; //rd[0][1]
1614         rd4 = pri1 * ri1 + pri4 * ri4 + pri7 * ri7; //rd[1][1]
1615         rd6 = pri2 * ri0 + pri5 * ri3 + pri8 * ri6; //rd[2][0]
1616         rd7 = pri2 * ri1 + pri5 * ri4 + pri8 * ri7; //rd[2][1]
1617         rd8 = pri2 * ri2 + pri5 * ri5 + pri8 * ri8; //rd[2][2]
1618 
1619         angleChange[0] = (float) Math.atan2(rd1, rd4);
1620         angleChange[1] = (float) Math.asin(-rd7);
1621         angleChange[2] = (float) Math.atan2(-rd6, rd8);
1622 
1623     }
1624 
1625     /** Helper function to convert a rotation vector to a rotation matrix.
1626      *  Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a
1627      *  9  or 16 element rotation matrix in the array R.  R must have length 9 or 16.
1628      *  If R.length == 9, the following matrix is returned:
1629      * <pre>
1630      *   /  R[ 0]   R[ 1]   R[ 2]   \
1631      *   |  R[ 3]   R[ 4]   R[ 5]   |
1632      *   \  R[ 6]   R[ 7]   R[ 8]   /
1633      *</pre>
1634      * If R.length == 16, the following matrix is returned:
1635      * <pre>
1636      *   /  R[ 0]   R[ 1]   R[ 2]   0  \
1637      *   |  R[ 4]   R[ 5]   R[ 6]   0  |
1638      *   |  R[ 8]   R[ 9]   R[10]   0  |
1639      *   \  0       0       0       1  /
1640      *</pre>
1641      *  @param rotationVector the rotation vector to convert
1642      *  @param R an array of floats in which to store the rotation matrix
1643      */
getRotationMatrixFromVector(float[] R, float[] rotationVector)1644     public static void getRotationMatrixFromVector(float[] R, float[] rotationVector) {
1645 
1646         float q0;
1647         float q1 = rotationVector[0];
1648         float q2 = rotationVector[1];
1649         float q3 = rotationVector[2];
1650 
1651         if (rotationVector.length >= 4) {
1652             q0 = rotationVector[3];
1653         } else {
1654             q0 = 1 - q1 * q1 - q2 * q2 - q3 * q3;
1655             q0 = (q0 > 0) ? (float) Math.sqrt(q0) : 0;
1656         }
1657 
1658         float sq_q1 = 2 * q1 * q1;
1659         float sq_q2 = 2 * q2 * q2;
1660         float sq_q3 = 2 * q3 * q3;
1661         float q1_q2 = 2 * q1 * q2;
1662         float q3_q0 = 2 * q3 * q0;
1663         float q1_q3 = 2 * q1 * q3;
1664         float q2_q0 = 2 * q2 * q0;
1665         float q2_q3 = 2 * q2 * q3;
1666         float q1_q0 = 2 * q1 * q0;
1667 
1668         if (R.length == 9) {
1669             R[0] = 1 - sq_q2 - sq_q3;
1670             R[1] = q1_q2 - q3_q0;
1671             R[2] = q1_q3 + q2_q0;
1672 
1673             R[3] = q1_q2 + q3_q0;
1674             R[4] = 1 - sq_q1 - sq_q3;
1675             R[5] = q2_q3 - q1_q0;
1676 
1677             R[6] = q1_q3 - q2_q0;
1678             R[7] = q2_q3 + q1_q0;
1679             R[8] = 1 - sq_q1 - sq_q2;
1680         } else if (R.length == 16) {
1681             R[0] = 1 - sq_q2 - sq_q3;
1682             R[1] = q1_q2 - q3_q0;
1683             R[2] = q1_q3 + q2_q0;
1684             R[3] = 0.0f;
1685 
1686             R[4] = q1_q2 + q3_q0;
1687             R[5] = 1 - sq_q1 - sq_q3;
1688             R[6] = q2_q3 - q1_q0;
1689             R[7] = 0.0f;
1690 
1691             R[8] = q1_q3 - q2_q0;
1692             R[9] = q2_q3 + q1_q0;
1693             R[10] = 1 - sq_q1 - sq_q2;
1694             R[11] = 0.0f;
1695 
1696             R[12] = R[13] = R[14] = 0.0f;
1697             R[15] = 1.0f;
1698         }
1699     }
1700 
1701     /** Helper function to convert a rotation vector to a normalized quaternion.
1702      *  Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized
1703      *  quaternion in the array Q.  The quaternion is stored as [w, x, y, z]
1704      *  @param rv the rotation vector to convert
1705      *  @param Q an array of floats in which to store the computed quaternion
1706      */
getQuaternionFromVector(float[] Q, float[] rv)1707     public static void getQuaternionFromVector(float[] Q, float[] rv) {
1708         if (rv.length >= 4) {
1709             Q[0] = rv[3];
1710         } else {
1711             Q[0] = 1 - rv[0] * rv[0] - rv[1] * rv[1] - rv[2] * rv[2];
1712             Q[0] = (Q[0] > 0) ? (float) Math.sqrt(Q[0]) : 0;
1713         }
1714         Q[1] = rv[0];
1715         Q[2] = rv[1];
1716         Q[3] = rv[2];
1717     }
1718 
1719     /**
1720      * Requests receiving trigger events for a trigger sensor.
1721      *
1722      * <p>
1723      * When the sensor detects a trigger event condition, such as significant motion in
1724      * the case of the {@link Sensor#TYPE_SIGNIFICANT_MOTION}, the provided trigger listener
1725      * will be invoked once and then its request to receive trigger events will be canceled.
1726      * To continue receiving trigger events, the application must request to receive trigger
1727      * events again.
1728      * </p>
1729      *
1730      * @param listener The listener on which the
1731      *        {@link TriggerEventListener#onTrigger(TriggerEvent)} will be delivered.
1732      * @param sensor The sensor to be enabled.
1733      *
1734      * @return true if the sensor was successfully enabled.
1735      *
1736      * @throws IllegalArgumentException when sensor is null or not a trigger sensor.
1737      */
requestTriggerSensor(TriggerEventListener listener, Sensor sensor)1738     public boolean requestTriggerSensor(TriggerEventListener listener, Sensor sensor) {
1739         return requestTriggerSensorImpl(listener, sensor);
1740     }
1741 
1742     /**
1743      * @hide
1744      */
requestTriggerSensorImpl(TriggerEventListener listener, Sensor sensor)1745     protected abstract boolean requestTriggerSensorImpl(TriggerEventListener listener,
1746             Sensor sensor);
1747 
1748     /**
1749      * Cancels receiving trigger events for a trigger sensor.
1750      *
1751      * <p>
1752      * Note that a Trigger sensor will be auto disabled if
1753      * {@link TriggerEventListener#onTrigger(TriggerEvent)} has triggered.
1754      * This method is provided in case the user wants to explicitly cancel the request
1755      * to receive trigger events.
1756      * </p>
1757      *
1758      * @param listener The listener on which the
1759      *        {@link TriggerEventListener#onTrigger(TriggerEvent)}
1760      *        is delivered.It should be the same as the one used
1761      *        in {@link #requestTriggerSensor(TriggerEventListener, Sensor)}
1762      * @param sensor The sensor for which the trigger request should be canceled.
1763      *        If null, it cancels receiving trigger for all sensors associated
1764      *        with the listener.
1765      *
1766      * @return true if successfully canceled.
1767      *
1768      * @throws IllegalArgumentException when sensor is a trigger sensor.
1769      */
cancelTriggerSensor(TriggerEventListener listener, Sensor sensor)1770     public boolean cancelTriggerSensor(TriggerEventListener listener, Sensor sensor) {
1771         return cancelTriggerSensorImpl(listener, sensor, true);
1772     }
1773 
1774     /**
1775      * @hide
1776      */
cancelTriggerSensorImpl(TriggerEventListener listener, Sensor sensor, boolean disable)1777     protected abstract boolean cancelTriggerSensorImpl(TriggerEventListener listener,
1778             Sensor sensor, boolean disable);
1779 
1780 
1781     /**
1782      * For testing purposes only. Not for third party applications.
1783      *
1784      * Initialize data injection mode and create a client for data injection. SensorService should
1785      * already be operating in DATA_INJECTION mode for this call succeed. To set SensorService into
1786      * DATA_INJECTION mode "adb shell dumpsys sensorservice data_injection" needs to be called
1787      * through adb. Typically this is done using a host side test.  This mode is expected to be used
1788      * only for testing purposes. If the HAL is set to data injection mode, it will ignore the input
1789      * from physical sensors and read sensor data that is injected from the test application. This
1790      * mode is used for testing vendor implementations for various algorithms like Rotation Vector,
1791      * Significant Motion, Step Counter etc. Not all HALs support DATA_INJECTION. This method will
1792      * fail in those cases. Once this method succeeds, the test can call
1793      * {@link injectSensorData(Sensor, float[], int, long)} to inject sensor data into the HAL.
1794      *
1795      * @param enable True to initialize a client in DATA_INJECTION mode.
1796      *               False to clean up the native resources.
1797      *
1798      * @return true if the HAL supports data injection and false
1799      *         otherwise.
1800      * @hide
1801      */
1802     @SystemApi
initDataInjection(boolean enable)1803     public boolean initDataInjection(boolean enable) {
1804         return initDataInjectionImpl(enable);
1805     }
1806 
1807     /**
1808      * @hide
1809      */
initDataInjectionImpl(boolean enable)1810     protected abstract boolean initDataInjectionImpl(boolean enable);
1811 
1812     /**
1813      * For testing purposes only. Not for third party applications.
1814      *
1815      * This method is used to inject raw sensor data into the HAL.  Call {@link
1816      * initDataInjection(boolean)} before this method to set the HAL in data injection mode. This
1817      * method should be called only if a previous call to initDataInjection has been successful and
1818      * the HAL and SensorService are already opreating in data injection mode.
1819      *
1820      * @param sensor The sensor to inject.
1821      * @param values Sensor values to inject. The length of this
1822      *               array must be exactly equal to the number of
1823      *               values reported by the sensor type.
1824      * @param accuracy Accuracy of the sensor.
1825      * @param timestamp Sensor timestamp associated with the event.
1826      *
1827      * @return boolean True if the data injection succeeds, false
1828      *         otherwise.
1829      * @throws IllegalArgumentException when the sensor is null,
1830      *         data injection is not supported by the sensor, values
1831      *         are null, incorrect number of values for the sensor,
1832      *         sensor accuracy is incorrect or timestamps are
1833      *         invalid.
1834      * @hide
1835      */
1836     @SystemApi
injectSensorData(Sensor sensor, float[] values, int accuracy, long timestamp)1837     public boolean injectSensorData(Sensor sensor, float[] values, int accuracy,
1838                 long timestamp) {
1839         if (sensor == null) {
1840             throw new IllegalArgumentException("sensor cannot be null");
1841         }
1842         if (!sensor.isDataInjectionSupported()) {
1843             throw new IllegalArgumentException("sensor does not support data injection");
1844         }
1845         if (values == null) {
1846             throw new IllegalArgumentException("sensor data cannot be null");
1847         }
1848         int expectedNumValues = Sensor.getMaxLengthValuesArray(sensor, Build.VERSION_CODES.M);
1849         if (values.length != expectedNumValues) {
1850             throw new  IllegalArgumentException("Wrong number of values for sensor "
1851                     + sensor.getName() + " actual=" + values.length + " expected="
1852                     + expectedNumValues);
1853         }
1854         if (accuracy < SENSOR_STATUS_NO_CONTACT || accuracy > SENSOR_STATUS_ACCURACY_HIGH) {
1855             throw new IllegalArgumentException("Invalid sensor accuracy");
1856         }
1857         if (timestamp <= 0) {
1858             throw new IllegalArgumentException("Negative or zero sensor timestamp");
1859         }
1860         return injectSensorDataImpl(sensor, values, accuracy, timestamp);
1861     }
1862 
1863     /**
1864      * @hide
1865      */
injectSensorDataImpl(Sensor sensor, float[] values, int accuracy, long timestamp)1866     protected abstract boolean injectSensorDataImpl(Sensor sensor, float[] values, int accuracy,
1867                 long timestamp);
1868 
getLegacySensorManager()1869     private LegacySensorManager getLegacySensorManager() {
1870         synchronized (mSensorListByType) {
1871             if (mLegacySensorManager == null) {
1872                 Log.i(TAG, "This application is using deprecated SensorManager API which will "
1873                         + "be removed someday.  Please consider switching to the new API.");
1874                 mLegacySensorManager = new LegacySensorManager(this);
1875             }
1876             return mLegacySensorManager;
1877         }
1878     }
1879 
getDelay(int rate)1880     private static int getDelay(int rate) {
1881         int delay = -1;
1882         switch (rate) {
1883             case SENSOR_DELAY_FASTEST:
1884                 delay = 0;
1885                 break;
1886             case SENSOR_DELAY_GAME:
1887                 delay = 20000;
1888                 break;
1889             case SENSOR_DELAY_UI:
1890                 delay = 66667;
1891                 break;
1892             case SENSOR_DELAY_NORMAL:
1893                 delay = 200000;
1894                 break;
1895             default:
1896                 delay = rate;
1897                 break;
1898         }
1899         return delay;
1900     }
1901 
1902     /** @hide */
setOperationParameter(SensorAdditionalInfo parameter)1903     public boolean setOperationParameter(SensorAdditionalInfo parameter) {
1904         return setOperationParameterImpl(parameter);
1905     }
1906 
1907     /** @hide */
setOperationParameterImpl(SensorAdditionalInfo parameter)1908     protected abstract boolean setOperationParameterImpl(SensorAdditionalInfo parameter);
1909 }
1910