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
17package android.hardware;
18
19import android.os.Handler;
20import android.util.Log;
21import android.util.SparseArray;
22
23import java.util.ArrayList;
24import java.util.Collections;
25import java.util.List;
26
27/**
28 * <p>
29 * SensorManager lets you access the device's {@link android.hardware.Sensor
30 * sensors}. Get an instance of this class by calling
31 * {@link android.content.Context#getSystemService(java.lang.String)
32 * Context.getSystemService()} with the argument
33 * {@link android.content.Context#SENSOR_SERVICE}.
34 * </p>
35 * <p>
36 * Always make sure to disable sensors you don't need, especially when your
37 * activity is paused. Failing to do so can drain the battery in just a few
38 * hours. Note that the system will <i>not</i> disable sensors automatically when
39 * the screen turns off.
40 * </p>
41 * <p class="note">
42 * Note: Don't use this mechanism with a Trigger Sensor, have a look
43 * at {@link TriggerEventListener}. {@link Sensor#TYPE_SIGNIFICANT_MOTION}
44 * is an example of a trigger sensor.
45 * </p>
46 * <pre class="prettyprint">
47 * public class SensorActivity extends Activity, implements SensorEventListener {
48 *     private final SensorManager mSensorManager;
49 *     private final Sensor mAccelerometer;
50 *
51 *     public SensorActivity() {
52 *         mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
53 *         mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
54 *     }
55 *
56 *     protected void onResume() {
57 *         super.onResume();
58 *         mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
59 *     }
60 *
61 *     protected void onPause() {
62 *         super.onPause();
63 *         mSensorManager.unregisterListener(this);
64 *     }
65 *
66 *     public void onAccuracyChanged(Sensor sensor, int accuracy) {
67 *     }
68 *
69 *     public void onSensorChanged(SensorEvent event) {
70 *     }
71 * }
72 * </pre>
73 *
74 * @see SensorEventListener
75 * @see SensorEvent
76 * @see Sensor
77 *
78 */
79public abstract class SensorManager {
80    /** @hide */
81    protected static final String TAG = "SensorManager";
82
83    private static final float[] mTempMatrix = new float[16];
84
85    // Cached lists of sensors by type.  Guarded by mSensorListByType.
86    private final SparseArray<List<Sensor>> mSensorListByType =
87            new SparseArray<List<Sensor>>();
88
89    // Legacy sensor manager implementation.  Guarded by mSensorListByType during initialization.
90    private LegacySensorManager mLegacySensorManager;
91
92    /* NOTE: sensor IDs must be a power of 2 */
93
94    /**
95     * A constant describing an orientation sensor. See
96     * {@link android.hardware.SensorListener SensorListener} for more details.
97     *
98     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
99     */
100    @Deprecated
101    public static final int SENSOR_ORIENTATION = 1 << 0;
102
103    /**
104     * A constant describing an accelerometer. See
105     * {@link android.hardware.SensorListener SensorListener} for more details.
106     *
107     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
108     */
109    @Deprecated
110    public static final int SENSOR_ACCELEROMETER = 1 << 1;
111
112    /**
113     * A constant describing a temperature sensor See
114     * {@link android.hardware.SensorListener SensorListener} for more details.
115     *
116     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
117     */
118    @Deprecated
119    public static final int SENSOR_TEMPERATURE = 1 << 2;
120
121    /**
122     * A constant describing a magnetic sensor See
123     * {@link android.hardware.SensorListener SensorListener} for more details.
124     *
125     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
126     */
127    @Deprecated
128    public static final int SENSOR_MAGNETIC_FIELD = 1 << 3;
129
130    /**
131     * A constant describing an ambient light sensor See
132     * {@link android.hardware.SensorListener SensorListener} for more details.
133     *
134     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
135     */
136    @Deprecated
137    public static final int SENSOR_LIGHT = 1 << 4;
138
139    /**
140     * A constant describing a proximity sensor See
141     * {@link android.hardware.SensorListener SensorListener} for more details.
142     *
143     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
144     */
145    @Deprecated
146    public static final int SENSOR_PROXIMITY = 1 << 5;
147
148    /**
149     * A constant describing a Tricorder See
150     * {@link android.hardware.SensorListener SensorListener} for more details.
151     *
152     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
153     */
154    @Deprecated
155    public static final int SENSOR_TRICORDER = 1 << 6;
156
157    /**
158     * A constant describing an orientation sensor. See
159     * {@link android.hardware.SensorListener SensorListener} for more details.
160     *
161     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
162     */
163    @Deprecated
164    public static final int SENSOR_ORIENTATION_RAW = 1 << 7;
165
166    /**
167     * A constant that includes all sensors
168     *
169     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
170     */
171    @Deprecated
172    public static final int SENSOR_ALL = 0x7F;
173
174    /**
175     * Smallest sensor ID
176     *
177     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
178     */
179    @Deprecated
180    public static final int SENSOR_MIN = SENSOR_ORIENTATION;
181
182    /**
183     * Largest sensor ID
184     *
185     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
186     */
187    @Deprecated
188    public static final int SENSOR_MAX = ((SENSOR_ALL + 1)>>1);
189
190
191    /**
192     * Index of the X value in the array returned by
193     * {@link android.hardware.SensorListener#onSensorChanged}
194     *
195     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
196     */
197    @Deprecated
198    public static final int DATA_X = 0;
199
200    /**
201     * Index of the Y value in the array returned by
202     * {@link android.hardware.SensorListener#onSensorChanged}
203     *
204     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
205     */
206    @Deprecated
207    public static final int DATA_Y = 1;
208
209    /**
210     * Index of the Z value in the array returned by
211     * {@link android.hardware.SensorListener#onSensorChanged}
212     *
213     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
214     */
215    @Deprecated
216    public static final int DATA_Z = 2;
217
218    /**
219     * Offset to the untransformed values in the array returned by
220     * {@link android.hardware.SensorListener#onSensorChanged}
221     *
222     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
223     */
224    @Deprecated
225    public static final int RAW_DATA_INDEX = 3;
226
227    /**
228     * Index of the untransformed X value in the array returned by
229     * {@link android.hardware.SensorListener#onSensorChanged}
230     *
231     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
232     */
233    @Deprecated
234    public static final int RAW_DATA_X = 3;
235
236    /**
237     * Index of the untransformed Y value in the array returned by
238     * {@link android.hardware.SensorListener#onSensorChanged}
239     *
240     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
241     */
242    @Deprecated
243    public static final int RAW_DATA_Y = 4;
244
245    /**
246     * Index of the untransformed Z value in the array returned by
247     * {@link android.hardware.SensorListener#onSensorChanged}
248     *
249     * @deprecated use {@link android.hardware.Sensor Sensor} instead.
250     */
251    @Deprecated
252    public static final int RAW_DATA_Z = 5;
253
254    /** Standard gravity (g) on Earth. This value is equivalent to 1G */
255    public static final float STANDARD_GRAVITY = 9.80665f;
256
257    /** Sun's gravity in SI units (m/s^2) */
258    public static final float GRAVITY_SUN             = 275.0f;
259    /** Mercury's gravity in SI units (m/s^2) */
260    public static final float GRAVITY_MERCURY         = 3.70f;
261    /** Venus' gravity in SI units (m/s^2) */
262    public static final float GRAVITY_VENUS           = 8.87f;
263    /** Earth's gravity in SI units (m/s^2) */
264    public static final float GRAVITY_EARTH           = 9.80665f;
265    /** The Moon's gravity in SI units (m/s^2) */
266    public static final float GRAVITY_MOON            = 1.6f;
267    /** Mars' gravity in SI units (m/s^2) */
268    public static final float GRAVITY_MARS            = 3.71f;
269    /** Jupiter's gravity in SI units (m/s^2) */
270    public static final float GRAVITY_JUPITER         = 23.12f;
271    /** Saturn's gravity in SI units (m/s^2) */
272    public static final float GRAVITY_SATURN          = 8.96f;
273    /** Uranus' gravity in SI units (m/s^2) */
274    public static final float GRAVITY_URANUS          = 8.69f;
275    /** Neptune's gravity in SI units (m/s^2) */
276    public static final float GRAVITY_NEPTUNE         = 11.0f;
277    /** Pluto's gravity in SI units (m/s^2) */
278    public static final float GRAVITY_PLUTO           = 0.6f;
279    /** Gravity (estimate) on the first Death Star in Empire units (m/s^2) */
280    public static final float GRAVITY_DEATH_STAR_I    = 0.000000353036145f;
281    /** Gravity on the island */
282    public static final float GRAVITY_THE_ISLAND      = 4.815162342f;
283
284
285    /** Maximum magnetic field on Earth's surface */
286    public static final float MAGNETIC_FIELD_EARTH_MAX = 60.0f;
287    /** Minimum magnetic field on Earth's surface */
288    public static final float MAGNETIC_FIELD_EARTH_MIN = 30.0f;
289
290
291    /** Standard atmosphere, or average sea-level pressure in hPa (millibar) */
292    public static final float PRESSURE_STANDARD_ATMOSPHERE = 1013.25f;
293
294
295    /** Maximum luminance of sunlight in lux */
296    public static final float LIGHT_SUNLIGHT_MAX = 120000.0f;
297    /** luminance of sunlight in lux */
298    public static final float LIGHT_SUNLIGHT     = 110000.0f;
299    /** luminance in shade in lux */
300    public static final float LIGHT_SHADE        = 20000.0f;
301    /** luminance under an overcast sky in lux */
302    public static final float LIGHT_OVERCAST     = 10000.0f;
303    /** luminance at sunrise in lux */
304    public static final float LIGHT_SUNRISE      = 400.0f;
305    /** luminance under a cloudy sky in lux */
306    public static final float LIGHT_CLOUDY       = 100.0f;
307    /** luminance at night with full moon in lux */
308    public static final float LIGHT_FULLMOON     = 0.25f;
309    /** luminance at night with no moon in lux*/
310    public static final float LIGHT_NO_MOON      = 0.001f;
311
312
313    /** get sensor data as fast as possible */
314    public static final int SENSOR_DELAY_FASTEST = 0;
315    /** rate suitable for games */
316    public static final int SENSOR_DELAY_GAME = 1;
317    /** rate suitable for the user interface  */
318    public static final int SENSOR_DELAY_UI = 2;
319    /** rate (default) suitable for screen orientation changes */
320    public static final int SENSOR_DELAY_NORMAL = 3;
321
322
323    /**
324      * The values returned by this sensor cannot be trusted because the sensor
325      * had no contact with what it was measuring (for example, the heart rate
326      * monitor is not in contact with the user).
327      */
328    public static final int SENSOR_STATUS_NO_CONTACT = -1;
329
330    /**
331     * The values returned by this sensor cannot be trusted, calibration is
332     * needed or the environment doesn't allow readings
333     */
334    public static final int SENSOR_STATUS_UNRELIABLE = 0;
335
336    /**
337     * This sensor is reporting data with low accuracy, calibration with the
338     * environment is needed
339     */
340    public static final int SENSOR_STATUS_ACCURACY_LOW = 1;
341
342    /**
343     * This sensor is reporting data with an average level of accuracy,
344     * calibration with the environment may improve the readings
345     */
346    public static final int SENSOR_STATUS_ACCURACY_MEDIUM = 2;
347
348    /** This sensor is reporting data with maximum accuracy */
349    public static final int SENSOR_STATUS_ACCURACY_HIGH = 3;
350
351    /** see {@link #remapCoordinateSystem} */
352    public static final int AXIS_X = 1;
353    /** see {@link #remapCoordinateSystem} */
354    public static final int AXIS_Y = 2;
355    /** see {@link #remapCoordinateSystem} */
356    public static final int AXIS_Z = 3;
357    /** see {@link #remapCoordinateSystem} */
358    public static final int AXIS_MINUS_X = AXIS_X | 0x80;
359    /** see {@link #remapCoordinateSystem} */
360    public static final int AXIS_MINUS_Y = AXIS_Y | 0x80;
361    /** see {@link #remapCoordinateSystem} */
362    public static final int AXIS_MINUS_Z = AXIS_Z | 0x80;
363
364
365    /**
366     * {@hide}
367     */
368    public SensorManager() {
369    }
370
371    /**
372     * Gets the full list of sensors that are available.
373     * @hide
374     */
375    protected abstract List<Sensor> getFullSensorList();
376
377    /**
378     * @return available sensors.
379     * @deprecated This method is deprecated, use
380     *             {@link SensorManager#getSensorList(int)} instead
381     */
382    @Deprecated
383    public int getSensors() {
384        return getLegacySensorManager().getSensors();
385    }
386
387    /**
388     * Use this method to get the list of available sensors of a certain type.
389     * Make multiple calls to get sensors of different types or use
390     * {@link android.hardware.Sensor#TYPE_ALL Sensor.TYPE_ALL} to get all the
391     * sensors.
392     *
393     * <p class="note">
394     * NOTE: Both wake-up and non wake-up sensors matching the given type are
395     * returned. Check {@link Sensor#isWakeUpSensor()} to know the wake-up properties
396     * of the returned {@link Sensor}.
397     * </p>
398     *
399     * @param type
400     *        of sensors requested
401     *
402     * @return a list of sensors matching the asked type.
403     *
404     * @see #getDefaultSensor(int)
405     * @see Sensor
406     */
407    public List<Sensor> getSensorList(int type) {
408        // cache the returned lists the first time
409        List<Sensor> list;
410        final List<Sensor> fullList = getFullSensorList();
411        synchronized (mSensorListByType) {
412            list = mSensorListByType.get(type);
413            if (list == null) {
414                if (type == Sensor.TYPE_ALL) {
415                    list = fullList;
416                } else {
417                    list = new ArrayList<Sensor>();
418                    for (Sensor i : fullList) {
419                        if (i.getType() == type)
420                            list.add(i);
421                    }
422                }
423                list = Collections.unmodifiableList(list);
424                mSensorListByType.append(type, list);
425            }
426        }
427        return list;
428    }
429
430    /**
431     * Use this method to get the default sensor for a given type. Note that the
432     * returned sensor could be a composite sensor, and its data could be
433     * averaged or filtered. If you need to access the raw sensors use
434     * {@link SensorManager#getSensorList(int) getSensorList}.
435     *
436     * @param type
437     *         of sensors requested
438     *
439     * @return the default sensor matching the requested type if one exists and the application
440     *         has the necessary permissions, or null otherwise.
441     *
442     * @see #getSensorList(int)
443     * @see Sensor
444     */
445    public Sensor getDefaultSensor(int type) {
446        // TODO: need to be smarter, for now, just return the 1st sensor
447        List<Sensor> l = getSensorList(type);
448        boolean wakeUpSensor = false;
449        // For the following sensor types, return a wake-up sensor. These types are by default
450        // defined as wake-up sensors. For the rest of the SDK defined sensor types return a
451        // non_wake-up version.
452        if (type == Sensor.TYPE_PROXIMITY || type == Sensor.TYPE_SIGNIFICANT_MOTION ||
453                type == Sensor.TYPE_TILT_DETECTOR || type == Sensor.TYPE_WAKE_GESTURE ||
454                type == Sensor.TYPE_GLANCE_GESTURE || type == Sensor.TYPE_PICK_UP_GESTURE) {
455            wakeUpSensor = true;
456        }
457
458        for (Sensor sensor : l) {
459            if (sensor.isWakeUpSensor() == wakeUpSensor) return sensor;
460        }
461        return null;
462    }
463
464    /**
465     * Return a Sensor with the given type and wakeUp properties. If multiple sensors of this
466     * type exist, any one of them may be returned.
467     * <p>
468     * For example,
469     * <ul>
470     *     <li>getDefaultSensor({@link Sensor#TYPE_ACCELEROMETER}, true) returns a wake-up accelerometer
471     *     sensor if it exists. </li>
472     *     <li>getDefaultSensor({@link Sensor#TYPE_PROXIMITY}, false) returns a non wake-up proximity
473     *     sensor if it exists. </li>
474     *     <li>getDefaultSensor({@link Sensor#TYPE_PROXIMITY}, true) returns a wake-up proximity sensor
475     *     which is the same as the Sensor returned by {@link #getDefaultSensor(int)}. </li>
476     * </ul>
477     * </p>
478     * <p class="note">
479     * Note: Sensors like {@link Sensor#TYPE_PROXIMITY} and {@link Sensor#TYPE_SIGNIFICANT_MOTION}
480     * are declared as wake-up sensors by default.
481     * </p>
482     * @param type
483     *        type of sensor requested
484     * @param wakeUp
485     *        flag to indicate whether the Sensor is a wake-up or non wake-up sensor.
486     * @return the default sensor matching the requested type and wakeUp properties if one exists
487     *         and the application has the necessary permissions, or null otherwise.
488     * @see Sensor#isWakeUpSensor()
489     */
490    public Sensor getDefaultSensor(int type, boolean wakeUp) {
491        List<Sensor> l = getSensorList(type);
492        for (Sensor sensor : l) {
493            if (sensor.isWakeUpSensor() == wakeUp)
494                return sensor;
495        }
496        return null;
497    }
498
499    /**
500     * Registers a listener for given sensors.
501     *
502     * @deprecated This method is deprecated, use
503     *             {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
504     *             instead.
505     *
506     * @param listener
507     *        sensor listener object
508     *
509     * @param sensors
510     *        a bit masks of the sensors to register to
511     *
512     * @return <code>true</code> if the sensor is supported and successfully
513     *         enabled
514     */
515    @Deprecated
516    public boolean registerListener(SensorListener listener, int sensors) {
517        return registerListener(listener, sensors, SENSOR_DELAY_NORMAL);
518    }
519
520    /**
521     * Registers a SensorListener for given sensors.
522     *
523     * @deprecated This method is deprecated, use
524     *             {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
525     *             instead.
526     *
527     * @param listener
528     *        sensor listener object
529     *
530     * @param sensors
531     *        a bit masks of the sensors to register to
532     *
533     * @param rate
534     *        rate of events. This is only a hint to the system. events may be
535     *        received faster or slower than the specified rate. Usually events
536     *        are received faster. The value must be one of
537     *        {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
538     *        {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}.
539     *
540     * @return <code>true</code> if the sensor is supported and successfully
541     *         enabled
542     */
543    @Deprecated
544    public boolean registerListener(SensorListener listener, int sensors, int rate) {
545        return getLegacySensorManager().registerListener(listener, sensors, rate);
546    }
547
548    /**
549     * Unregisters a listener for all sensors.
550     *
551     * @deprecated This method is deprecated, use
552     *             {@link SensorManager#unregisterListener(SensorEventListener)}
553     *             instead.
554     *
555     * @param listener
556     *        a SensorListener object
557     */
558    @Deprecated
559    public void unregisterListener(SensorListener listener) {
560        unregisterListener(listener, SENSOR_ALL | SENSOR_ORIENTATION_RAW);
561    }
562
563    /**
564     * Unregisters a listener for the sensors with which it is registered.
565     *
566     * @deprecated This method is deprecated, use
567     *             {@link SensorManager#unregisterListener(SensorEventListener, Sensor)}
568     *             instead.
569     *
570     * @param listener
571     *        a SensorListener object
572     *
573     * @param sensors
574     *        a bit masks of the sensors to unregister from
575     */
576    @Deprecated
577    public void unregisterListener(SensorListener listener, int sensors) {
578        getLegacySensorManager().unregisterListener(listener, sensors);
579    }
580
581    /**
582     * Unregisters a listener for the sensors with which it is registered.
583     *
584     * <p class="note"></p>
585     * Note: Don't use this method with a one shot trigger sensor such as
586     * {@link Sensor#TYPE_SIGNIFICANT_MOTION}.
587     * Use {@link #cancelTriggerSensor(TriggerEventListener, Sensor)} instead.
588     * </p>
589     *
590     * @param listener
591     *        a SensorEventListener object
592     *
593     * @param sensor
594     *        the sensor to unregister from
595     *
596     * @see #unregisterListener(SensorEventListener)
597     * @see #registerListener(SensorEventListener, Sensor, int)
598     */
599    public void unregisterListener(SensorEventListener listener, Sensor sensor) {
600        if (listener == null || sensor == null) {
601            return;
602        }
603
604        unregisterListenerImpl(listener, sensor);
605    }
606
607    /**
608     * Unregisters a listener for all sensors.
609     *
610     * @param listener
611     *        a SensorListener object
612     *
613     * @see #unregisterListener(SensorEventListener, Sensor)
614     * @see #registerListener(SensorEventListener, Sensor, int)
615     *
616     */
617    public void unregisterListener(SensorEventListener listener) {
618        if (listener == null) {
619            return;
620        }
621
622        unregisterListenerImpl(listener, null);
623    }
624
625    /** @hide */
626    protected abstract void unregisterListenerImpl(SensorEventListener listener, Sensor sensor);
627
628    /**
629     * Registers a {@link android.hardware.SensorEventListener
630     * SensorEventListener} for the given sensor.
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 #requestTriggerSensor(TriggerEventListener, Sensor)} instead.
636     * </p>
637     *
638     * @param listener
639     *        A {@link android.hardware.SensorEventListener SensorEventListener}
640     *        object.
641     *
642     * @param sensor
643     *        The {@link android.hardware.Sensor Sensor} to register to.
644     *
645     * @param rateUs
646     *        The rate {@link android.hardware.SensorEvent sensor events} are
647     *        delivered at. This is only a hint to the system. Events may be
648     *        received faster or slower than the specified rate. Usually events
649     *        are received faster. The value must be one of
650     *        {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
651     *        {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}
652     *        or, the desired delay between events in microseconds.
653     *        Specifying the delay in microseconds only works from Android
654     *        2.3 (API level 9) onwards. For earlier releases, you must use
655     *        one of the {@code SENSOR_DELAY_*} constants.
656     *
657     * @return <code>true</code> if the sensor is supported and successfully
658     *         enabled.
659     *
660     * @see #registerListener(SensorEventListener, Sensor, int, Handler)
661     * @see #unregisterListener(SensorEventListener)
662     * @see #unregisterListener(SensorEventListener, Sensor)
663     *
664     */
665    public boolean registerListener(SensorEventListener listener, Sensor sensor, int rateUs) {
666        return registerListener(listener, sensor, rateUs, null);
667    }
668
669    /**
670     * Enables batch mode for a sensor with the given rate and maxBatchReportLatency. If the
671     * underlying hardware does not support batch mode, this defaults to
672     * {@link #registerListener(SensorEventListener, Sensor, int)} and other parameters are
673     * ignored. In non-batch mode, all sensor events must be reported as soon as they are detected.
674     * While in batch mode, sensor events do not need to be reported as soon as they are detected.
675     * They can be temporarily stored in batches and reported in batches, as long as no event is
676     * delayed by more than "maxBatchReportLatency" microseconds. That is, all events since the
677     * previous batch are recorded and returned all at once. This allows to reduce the amount of
678     * interrupts sent to the SoC, and allows the SoC to switch to a lower power state (Idle) while
679     * the sensor is capturing and batching data.
680     * <p>
681     * Registering to a sensor in batch mode will not prevent the SoC from going to suspend mode. In
682     * this case, the sensor will continue to gather events and store it in a hardware FIFO. If the
683     * FIFO gets full before the AP wakes up again, some events will be lost, as the older events
684     * get overwritten by new events in the hardware FIFO. This can be avoided by holding a wake
685     * lock. If the application holds a wake lock, the SoC will not go to suspend mode, so no events
686     * will be lost, as the events will be reported before the FIFO gets full.
687     * </p>
688     * <p>
689     * Batching is always best effort. If a different application requests updates in continuous
690     * mode, this application will also get events in continuous mode. Batch mode updates can be
691     * unregistered by calling {@link #unregisterListener(SensorEventListener)}.
692     * </p>
693     * <p class="note">
694     * </p>
695     * Note: Don't use this method with a one shot trigger sensor such as
696     * {@link Sensor#TYPE_SIGNIFICANT_MOTION}. Use
697     * {@link #requestTriggerSensor(TriggerEventListener, Sensor)} instead. </p>
698     *
699     * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
700     *            that will receive the sensor events. If the application is interested in receiving
701     *            flush complete notifications, it should register with
702     *            {@link android.hardware.SensorEventListener SensorEventListener2} instead.
703     * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
704     * @param rateUs The desired delay between two consecutive events in microseconds. This is only
705     *            a hint to the system. Events may be received faster or slower than the specified
706     *            rate. Usually events are received faster. Can be one of
707     *            {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
708     *            {@link #SENSOR_DELAY_GAME}, {@link #SENSOR_DELAY_FASTEST} or the delay in
709     *            microseconds.
710     * @param maxBatchReportLatencyUs An event in the batch can be delayed by at most
711     *            maxBatchReportLatency microseconds. More events can be batched if this value is
712     *            large. If this is set to zero, batch mode is disabled and events are delivered in
713     *            continuous mode as soon as they are available which is equivalent to calling
714     *            {@link #registerListener(SensorEventListener, Sensor, int)}.
715     * @return <code>true</code> if batch mode is successfully enabled for this sensor,
716     *         <code>false</code> otherwise.
717     * @see #registerListener(SensorEventListener, Sensor, int)
718     * @see #unregisterListener(SensorEventListener)
719     * @see #flush(SensorEventListener)
720     */
721    public boolean registerListener(SensorEventListener listener, Sensor sensor, int rateUs,
722            int maxBatchReportLatencyUs) {
723        int delay = getDelay(rateUs);
724        return registerListenerImpl(listener, sensor, delay, null, maxBatchReportLatencyUs, 0);
725    }
726
727    /**
728     * Registers a {@link android.hardware.SensorEventListener SensorEventListener} for the given
729     * sensor. Events are delivered in continuous mode as soon as they are available. To reduce the
730     * battery usage, use {@link #registerListener(SensorEventListener, Sensor, int, int)} which
731     * enables batch mode for the sensor.
732     *
733     * <p class="note"></p>
734     * Note: Don't use this method with a one shot trigger sensor such as
735     * {@link Sensor#TYPE_SIGNIFICANT_MOTION}.
736     * Use {@link #requestTriggerSensor(TriggerEventListener, Sensor)} instead.
737     * </p>
738     *
739     * @param listener
740     *        A {@link android.hardware.SensorEventListener SensorEventListener}
741     *        object.
742     *
743     * @param sensor
744     *        The {@link android.hardware.Sensor Sensor} to register to.
745     *
746     * @param rateUs
747     *        The rate {@link android.hardware.SensorEvent sensor events} are
748     *        delivered at. This is only a hint to the system. Events may be
749     *        received faster or slower than the specified rate. Usually events
750     *        are received faster. The value must be one of
751     *        {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
752     *        {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}.
753     *        or, the desired delay between events in microseconds.
754     *        Specifying the delay in microseconds only works from Android
755     *        2.3 (API level 9) onwards. For earlier releases, you must use
756     *        one of the {@code SENSOR_DELAY_*} constants.
757     *
758     * @param handler
759     *        The {@link android.os.Handler Handler} the
760     *        {@link android.hardware.SensorEvent sensor events} will be
761     *        delivered to.
762     *
763     * @return <code>true</code> if the sensor is supported and successfully enabled.
764     *
765     * @see #registerListener(SensorEventListener, Sensor, int)
766     * @see #unregisterListener(SensorEventListener)
767     * @see #unregisterListener(SensorEventListener, Sensor)
768     */
769    public boolean registerListener(SensorEventListener listener, Sensor sensor, int rateUs,
770            Handler handler) {
771        int delay = getDelay(rateUs);
772        return registerListenerImpl(listener, sensor, delay, handler, 0, 0);
773    }
774
775    /**
776     * Enables batch mode for a sensor with the given rate and maxBatchReportLatency.
777     * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
778     *            that will receive the sensor events. If the application is interested in receiving
779     *            flush complete notifications, it should register with
780     *            {@link android.hardware.SensorEventListener SensorEventListener2} instead.
781     * @param sensor The {@link android.hardware.Sensor Sensor} to register to.
782     * @param rateUs The desired delay between two consecutive events in microseconds. This is only
783     *            a hint to the system. Events may be received faster or slower than the specified
784     *            rate. Usually events are received faster. Can be one of
785     *            {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
786     *            {@link #SENSOR_DELAY_GAME}, {@link #SENSOR_DELAY_FASTEST} or the delay in
787     *            microseconds.
788     * @param maxBatchReportLatencyUs An event in the batch can be delayed by at most
789     *            maxBatchReportLatency microseconds. More events can be batched if this value is
790     *            large. If this is set to zero, batch mode is disabled and events are delivered in
791     *            continuous mode as soon as they are available which is equivalent to calling
792     *            {@link #registerListener(SensorEventListener, Sensor, int)}.
793     * @param handler The {@link android.os.Handler Handler} the
794     *        {@link android.hardware.SensorEvent sensor events} will be delivered to.
795     *
796     * @return <code>true</code> if batch mode is successfully enabled for this sensor,
797     *         <code>false</code> otherwise.
798     * @see #registerListener(SensorEventListener, Sensor, int, int)
799     */
800    public boolean registerListener(SensorEventListener listener, Sensor sensor, int rateUs,
801            int maxBatchReportLatencyUs, Handler handler) {
802        int delayUs = getDelay(rateUs);
803        return registerListenerImpl(listener, sensor, delayUs, handler, maxBatchReportLatencyUs, 0);
804    }
805
806    /** @hide */
807    protected abstract boolean registerListenerImpl(SensorEventListener listener, Sensor sensor,
808            int delayUs, Handler handler, int maxBatchReportLatencyUs, int reservedFlags);
809
810
811    /**
812     * Flushes the batch FIFO of all the sensors registered for this listener. If there are events
813     * in the FIFO of the sensor, they are returned as if the batch timeout in the FIFO of the
814     * sensors had expired. Events are returned in the usual way through the SensorEventListener.
815     * This call doesn't affect the batch timeout for this sensor. This call is asynchronous and
816     * returns immediately.
817     * {@link android.hardware.SensorEventListener2#onFlushCompleted onFlushCompleted} is called
818     * after all the events in the batch at the time of calling this method have been delivered
819     * successfully. If the hardware doesn't support flush, it still returns true and a trivial
820     * flush complete event is sent after the current event for all the clients registered for this
821     * sensor.
822     *
823     * @param listener A {@link android.hardware.SensorEventListener SensorEventListener} object
824     *        which was previously used in a registerListener call.
825     * @return <code>true</code> if the flush is initiated successfully on all the sensors
826     *         registered for this listener, false if no sensor is previously registered for this
827     *         listener or flush on one of the sensors fails.
828     * @see #registerListener(SensorEventListener, Sensor, int, int)
829     * @throws IllegalArgumentException when listener is null.
830     */
831    public boolean flush(SensorEventListener listener) {
832        return flushImpl(listener);
833    }
834
835    /** @hide */
836    protected abstract boolean flushImpl(SensorEventListener listener);
837
838    /**
839     * <p>
840     * Computes the inclination matrix <b>I</b> as well as the rotation matrix
841     * <b>R</b> transforming a vector from the device coordinate system to the
842     * world's coordinate system which is defined as a direct orthonormal basis,
843     * where:
844     * </p>
845     *
846     * <ul>
847     * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to
848     * the ground at the device's current location and roughly points East).</li>
849     * <li>Y is tangential to the ground at the device's current location and
850     * points towards the magnetic North Pole.</li>
851     * <li>Z points towards the sky and is perpendicular to the ground.</li>
852     * </ul>
853     *
854     * <p>
855     * <center><img src="../../../images/axis_globe.png"
856     * alt="World coordinate-system diagram." border="0" /></center>
857     * </p>
858     *
859     * <p>
860     * <hr>
861     * <p>
862     * By definition:
863     * <p>
864     * [0 0 g] = <b>R</b> * <b>gravity</b> (g = magnitude of gravity)
865     * <p>
866     * [0 m 0] = <b>I</b> * <b>R</b> * <b>geomagnetic</b> (m = magnitude of
867     * geomagnetic field)
868     * <p>
869     * <b>R</b> is the identity matrix when the device is aligned with the
870     * world's coordinate system, that is, when the device's X axis points
871     * toward East, the Y axis points to the North Pole and the device is facing
872     * the sky.
873     *
874     * <p>
875     * <b>I</b> is a rotation matrix transforming the geomagnetic vector into
876     * the same coordinate space as gravity (the world's coordinate space).
877     * <b>I</b> is a simple rotation around the X axis. The inclination angle in
878     * radians can be computed with {@link #getInclination}.
879     * <hr>
880     *
881     * <p>
882     * Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending
883     * on the length of the passed array:
884     * <p>
885     * <u>If the array length is 16:</u>
886     *
887     * <pre>
888     *   /  M[ 0]   M[ 1]   M[ 2]   M[ 3]  \
889     *   |  M[ 4]   M[ 5]   M[ 6]   M[ 7]  |
890     *   |  M[ 8]   M[ 9]   M[10]   M[11]  |
891     *   \  M[12]   M[13]   M[14]   M[15]  /
892     *</pre>
893     *
894     * This matrix is ready to be used by OpenGL ES's
895     * {@link javax.microedition.khronos.opengles.GL10#glLoadMatrixf(float[], int)
896     * glLoadMatrixf(float[], int)}.
897     * <p>
898     * Note that because OpenGL matrices are column-major matrices you must
899     * transpose the matrix before using it. However, since the matrix is a
900     * rotation matrix, its transpose is also its inverse, conveniently, it is
901     * often the inverse of the rotation that is needed for rendering; it can
902     * therefore be used with OpenGL ES directly.
903     * <p>
904     * Also note that the returned matrices always have this form:
905     *
906     * <pre>
907     *   /  M[ 0]   M[ 1]   M[ 2]   0  \
908     *   |  M[ 4]   M[ 5]   M[ 6]   0  |
909     *   |  M[ 8]   M[ 9]   M[10]   0  |
910     *   \      0       0       0   1  /
911     *</pre>
912     *
913     * <p>
914     * <u>If the array length is 9:</u>
915     *
916     * <pre>
917     *   /  M[ 0]   M[ 1]   M[ 2]  \
918     *   |  M[ 3]   M[ 4]   M[ 5]  |
919     *   \  M[ 6]   M[ 7]   M[ 8]  /
920     *</pre>
921     *
922     * <hr>
923     * <p>
924     * The inverse of each matrix can be computed easily by taking its
925     * transpose.
926     *
927     * <p>
928     * The matrices returned by this function are meaningful only when the
929     * device is not free-falling and it is not close to the magnetic north. If
930     * the device is accelerating, or placed into a strong magnetic field, the
931     * returned matrices may be inaccurate.
932     *
933     * @param R
934     *        is an array of 9 floats holding the rotation matrix <b>R</b> when
935     *        this function returns. R can be null.
936     *        <p>
937     *
938     * @param I
939     *        is an array of 9 floats holding the rotation matrix <b>I</b> when
940     *        this function returns. I can be null.
941     *        <p>
942     *
943     * @param gravity
944     *        is an array of 3 floats containing the gravity vector expressed in
945     *        the device's coordinate. You can simply use the
946     *        {@link android.hardware.SensorEvent#values values} returned by a
947     *        {@link android.hardware.SensorEvent SensorEvent} of a
948     *        {@link android.hardware.Sensor Sensor} of type
949     *        {@link android.hardware.Sensor#TYPE_ACCELEROMETER
950     *        TYPE_ACCELEROMETER}.
951     *        <p>
952     *
953     * @param geomagnetic
954     *        is an array of 3 floats containing the geomagnetic vector
955     *        expressed in the device's coordinate. You can simply use the
956     *        {@link android.hardware.SensorEvent#values values} returned by a
957     *        {@link android.hardware.SensorEvent SensorEvent} of a
958     *        {@link android.hardware.Sensor Sensor} of type
959     *        {@link android.hardware.Sensor#TYPE_MAGNETIC_FIELD
960     *        TYPE_MAGNETIC_FIELD}.
961     *
962     * @return <code>true</code> on success, <code>false</code> on failure (for
963     *         instance, if the device is in free fall). On failure the output
964     *         matrices are not modified.
965     *
966     * @see #getInclination(float[])
967     * @see #getOrientation(float[], float[])
968     * @see #remapCoordinateSystem(float[], int, int, float[])
969     */
970
971    public static boolean getRotationMatrix(float[] R, float[] I,
972            float[] gravity, float[] geomagnetic) {
973        // TODO: move this to native code for efficiency
974        float Ax = gravity[0];
975        float Ay = gravity[1];
976        float Az = gravity[2];
977        final float Ex = geomagnetic[0];
978        final float Ey = geomagnetic[1];
979        final float Ez = geomagnetic[2];
980        float Hx = Ey*Az - Ez*Ay;
981        float Hy = Ez*Ax - Ex*Az;
982        float Hz = Ex*Ay - Ey*Ax;
983        final float normH = (float)Math.sqrt(Hx*Hx + Hy*Hy + Hz*Hz);
984        if (normH < 0.1f) {
985            // device is close to free fall (or in space?), or close to
986            // magnetic north pole. Typical values are  > 100.
987            return false;
988        }
989        final float invH = 1.0f / normH;
990        Hx *= invH;
991        Hy *= invH;
992        Hz *= invH;
993        final float invA = 1.0f / (float)Math.sqrt(Ax*Ax + Ay*Ay + Az*Az);
994        Ax *= invA;
995        Ay *= invA;
996        Az *= invA;
997        final float Mx = Ay*Hz - Az*Hy;
998        final float My = Az*Hx - Ax*Hz;
999        final float Mz = Ax*Hy - Ay*Hx;
1000        if (R != null) {
1001            if (R.length == 9) {
1002                R[0] = Hx;     R[1] = Hy;     R[2] = Hz;
1003                R[3] = Mx;     R[4] = My;     R[5] = Mz;
1004                R[6] = Ax;     R[7] = Ay;     R[8] = Az;
1005            } else if (R.length == 16) {
1006                R[0]  = Hx;    R[1]  = Hy;    R[2]  = Hz;   R[3]  = 0;
1007                R[4]  = Mx;    R[5]  = My;    R[6]  = Mz;   R[7]  = 0;
1008                R[8]  = Ax;    R[9]  = Ay;    R[10] = Az;   R[11] = 0;
1009                R[12] = 0;     R[13] = 0;     R[14] = 0;    R[15] = 1;
1010            }
1011        }
1012        if (I != null) {
1013            // compute the inclination matrix by projecting the geomagnetic
1014            // vector onto the Z (gravity) and X (horizontal component
1015            // of geomagnetic vector) axes.
1016            final float invE = 1.0f / (float)Math.sqrt(Ex*Ex + Ey*Ey + Ez*Ez);
1017            final float c = (Ex*Mx + Ey*My + Ez*Mz) * invE;
1018            final float s = (Ex*Ax + Ey*Ay + Ez*Az) * invE;
1019            if (I.length == 9) {
1020                I[0] = 1;     I[1] = 0;     I[2] = 0;
1021                I[3] = 0;     I[4] = c;     I[5] = s;
1022                I[6] = 0;     I[7] =-s;     I[8] = c;
1023            } else if (I.length == 16) {
1024                I[0] = 1;     I[1] = 0;     I[2] = 0;
1025                I[4] = 0;     I[5] = c;     I[6] = s;
1026                I[8] = 0;     I[9] =-s;     I[10]= c;
1027                I[3] = I[7] = I[11] = I[12] = I[13] = I[14] = 0;
1028                I[15] = 1;
1029            }
1030        }
1031        return true;
1032    }
1033
1034    /**
1035     * Computes the geomagnetic inclination angle in radians from the
1036     * inclination matrix <b>I</b> returned by {@link #getRotationMatrix}.
1037     *
1038     * @param I
1039     *        inclination matrix see {@link #getRotationMatrix}.
1040     *
1041     * @return The geomagnetic inclination angle in radians.
1042     *
1043     * @see #getRotationMatrix(float[], float[], float[], float[])
1044     * @see #getOrientation(float[], float[])
1045     * @see GeomagneticField
1046     *
1047     */
1048    public static float getInclination(float[] I) {
1049        if (I.length == 9) {
1050            return (float)Math.atan2(I[5], I[4]);
1051        } else {
1052            return (float)Math.atan2(I[6], I[5]);
1053        }
1054    }
1055
1056    /**
1057     * <p>
1058     * Rotates the supplied rotation matrix so it is expressed in a different
1059     * coordinate system. This is typically used when an application needs to
1060     * compute the three orientation angles of the device (see
1061     * {@link #getOrientation}) in a different coordinate system.
1062     * </p>
1063     *
1064     * <p>
1065     * When the rotation matrix is used for drawing (for instance with OpenGL
1066     * ES), it usually <b>doesn't need</b> to be transformed by this function,
1067     * unless the screen is physically rotated, in which case you can use
1068     * {@link android.view.Display#getRotation() Display.getRotation()} to
1069     * retrieve the current rotation of the screen. Note that because the user
1070     * is generally free to rotate their screen, you often should consider the
1071     * rotation in deciding the parameters to use here.
1072     * </p>
1073     *
1074     * <p>
1075     * <u>Examples:</u>
1076     * <p>
1077     *
1078     * <ul>
1079     * <li>Using the camera (Y axis along the camera's axis) for an augmented
1080     * reality application where the rotation angles are needed:</li>
1081     *
1082     * <p>
1083     * <ul>
1084     * <code>remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);</code>
1085     * </ul>
1086     * </p>
1087     *
1088     * <li>Using the device as a mechanical compass when rotation is
1089     * {@link android.view.Surface#ROTATION_90 Surface.ROTATION_90}:</li>
1090     *
1091     * <p>
1092     * <ul>
1093     * <code>remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);</code>
1094     * </ul>
1095     * </p>
1096     *
1097     * Beware of the above example. This call is needed only to account for a
1098     * rotation from its natural orientation when calculating the rotation
1099     * angles (see {@link #getOrientation}). If the rotation matrix is also used
1100     * for rendering, it may not need to be transformed, for instance if your
1101     * {@link android.app.Activity Activity} is running in landscape mode.
1102     * </ul>
1103     *
1104     * <p>
1105     * Since the resulting coordinate system is orthonormal, only two axes need
1106     * to be specified.
1107     *
1108     * @param inR
1109     *        the rotation matrix to be transformed. Usually it is the matrix
1110     *        returned by {@link #getRotationMatrix}.
1111     *
1112     * @param X
1113     *        defines on which world axis and direction the X axis of the device
1114     *        is mapped.
1115     *
1116     * @param Y
1117     *        defines on which world axis and direction the Y axis of the device
1118     *        is mapped.
1119     *
1120     * @param outR
1121     *        the transformed rotation matrix. inR and outR should not be the same
1122     *        array.
1123     *
1124     * @return <code>true</code> on success. <code>false</code> if the input
1125     *         parameters are incorrect, for instance if X and Y define the same
1126     *         axis. Or if inR and outR don't have the same length.
1127     *
1128     * @see #getRotationMatrix(float[], float[], float[], float[])
1129     */
1130
1131    public static boolean remapCoordinateSystem(float[] inR, int X, int Y,
1132            float[] outR)
1133    {
1134        if (inR == outR) {
1135            final float[] temp = mTempMatrix;
1136            synchronized(temp) {
1137                // we don't expect to have a lot of contention
1138                if (remapCoordinateSystemImpl(inR, X, Y, temp)) {
1139                    final int size = outR.length;
1140                    for (int i=0 ; i<size ; i++)
1141                        outR[i] = temp[i];
1142                    return true;
1143                }
1144            }
1145        }
1146        return remapCoordinateSystemImpl(inR, X, Y, outR);
1147    }
1148
1149    private static boolean remapCoordinateSystemImpl(float[] inR, int X, int Y,
1150            float[] outR)
1151    {
1152        /*
1153         * X and Y define a rotation matrix 'r':
1154         *
1155         *  (X==1)?((X&0x80)?-1:1):0    (X==2)?((X&0x80)?-1:1):0    (X==3)?((X&0x80)?-1:1):0
1156         *  (Y==1)?((Y&0x80)?-1:1):0    (Y==2)?((Y&0x80)?-1:1):0    (Y==3)?((X&0x80)?-1:1):0
1157         *                              r[0] ^ r[1]
1158         *
1159         * where the 3rd line is the vector product of the first 2 lines
1160         *
1161         */
1162
1163        final int length = outR.length;
1164        if (inR.length != length)
1165            return false;   // invalid parameter
1166        if ((X & 0x7C)!=0 || (Y & 0x7C)!=0)
1167            return false;   // invalid parameter
1168        if (((X & 0x3)==0) || ((Y & 0x3)==0))
1169            return false;   // no axis specified
1170        if ((X & 0x3) == (Y & 0x3))
1171            return false;   // same axis specified
1172
1173        // Z is "the other" axis, its sign is either +/- sign(X)*sign(Y)
1174        // this can be calculated by exclusive-or'ing X and Y; except for
1175        // the sign inversion (+/-) which is calculated below.
1176        int Z = X ^ Y;
1177
1178        // extract the axis (remove the sign), offset in the range 0 to 2.
1179        final int x = (X & 0x3)-1;
1180        final int y = (Y & 0x3)-1;
1181        final int z = (Z & 0x3)-1;
1182
1183        // compute the sign of Z (whether it needs to be inverted)
1184        final int axis_y = (z+1)%3;
1185        final int axis_z = (z+2)%3;
1186        if (((x^axis_y)|(y^axis_z)) != 0)
1187            Z ^= 0x80;
1188
1189        final boolean sx = (X>=0x80);
1190        final boolean sy = (Y>=0x80);
1191        final boolean sz = (Z>=0x80);
1192
1193        // Perform R * r, in avoiding actual muls and adds.
1194        final int rowLength = ((length==16)?4:3);
1195        for (int j=0 ; j<3 ; j++) {
1196            final int offset = j*rowLength;
1197            for (int i=0 ; i<3 ; i++) {
1198                if (x==i)   outR[offset+i] = sx ? -inR[offset+0] : inR[offset+0];
1199                if (y==i)   outR[offset+i] = sy ? -inR[offset+1] : inR[offset+1];
1200                if (z==i)   outR[offset+i] = sz ? -inR[offset+2] : inR[offset+2];
1201            }
1202        }
1203        if (length == 16) {
1204            outR[3] = outR[7] = outR[11] = outR[12] = outR[13] = outR[14] = 0;
1205            outR[15] = 1;
1206        }
1207        return true;
1208    }
1209
1210    /**
1211     * Computes the device's orientation based on the rotation matrix.
1212     * <p>
1213     * When it returns, the array values is filled with the result:
1214     * <ul>
1215     * <li>values[0]: <i>azimuth</i>, rotation around the Z axis.</li>
1216     * <li>values[1]: <i>pitch</i>, rotation around the X axis.</li>
1217     * <li>values[2]: <i>roll</i>, rotation around the Y axis.</li>
1218     * </ul>
1219     * <p>The reference coordinate-system used is different from the world
1220     * coordinate-system defined for the rotation matrix:</p>
1221     * <ul>
1222     * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to
1223     * the ground at the device's current location and roughly points West).</li>
1224     * <li>Y is tangential to the ground at the device's current location and
1225     * points towards the magnetic North Pole.</li>
1226     * <li>Z points towards the center of the Earth and is perpendicular to the ground.</li>
1227     * </ul>
1228     *
1229     * <p>
1230     * <center><img src="../../../images/axis_globe_inverted.png"
1231     * alt="Inverted world coordinate-system diagram." border="0" /></center>
1232     * </p>
1233     * <p>
1234     * All three angles above are in <b>radians</b> and <b>positive</b> in the
1235     * <b>counter-clockwise</b> direction.
1236     *
1237     * @param R
1238     *        rotation matrix see {@link #getRotationMatrix}.
1239     *
1240     * @param values
1241     *        an array of 3 floats to hold the result.
1242     *
1243     * @return The array values passed as argument.
1244     *
1245     * @see #getRotationMatrix(float[], float[], float[], float[])
1246     * @see GeomagneticField
1247     */
1248    public static float[] getOrientation(float[] R, float values[]) {
1249        /*
1250         * 4x4 (length=16) case:
1251         *   /  R[ 0]   R[ 1]   R[ 2]   0  \
1252         *   |  R[ 4]   R[ 5]   R[ 6]   0  |
1253         *   |  R[ 8]   R[ 9]   R[10]   0  |
1254         *   \      0       0       0   1  /
1255         *
1256         * 3x3 (length=9) case:
1257         *   /  R[ 0]   R[ 1]   R[ 2]  \
1258         *   |  R[ 3]   R[ 4]   R[ 5]  |
1259         *   \  R[ 6]   R[ 7]   R[ 8]  /
1260         *
1261         */
1262        if (R.length == 9) {
1263            values[0] = (float)Math.atan2(R[1], R[4]);
1264            values[1] = (float)Math.asin(-R[7]);
1265            values[2] = (float)Math.atan2(-R[6], R[8]);
1266        } else {
1267            values[0] = (float)Math.atan2(R[1], R[5]);
1268            values[1] = (float)Math.asin(-R[9]);
1269            values[2] = (float)Math.atan2(-R[8], R[10]);
1270        }
1271        return values;
1272    }
1273
1274    /**
1275     * Computes the Altitude in meters from the atmospheric pressure and the
1276     * pressure at sea level.
1277     * <p>
1278     * Typically the atmospheric pressure is read from a
1279     * {@link Sensor#TYPE_PRESSURE} sensor. The pressure at sea level must be
1280     * known, usually it can be retrieved from airport databases in the
1281     * vicinity. If unknown, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE}
1282     * as an approximation, but absolute altitudes won't be accurate.
1283     * </p>
1284     * <p>
1285     * To calculate altitude differences, you must calculate the difference
1286     * between the altitudes at both points. If you don't know the altitude
1287     * as sea level, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} instead,
1288     * which will give good results considering the range of pressure typically
1289     * involved.
1290     * </p>
1291     * <p>
1292     * <code><ul>
1293     *  float altitude_difference =
1294     *      getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2)
1295     *      - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1);
1296     * </ul></code>
1297     * </p>
1298     *
1299     * @param p0 pressure at sea level
1300     * @param p atmospheric pressure
1301     * @return Altitude in meters
1302     */
1303    public static float getAltitude(float p0, float p) {
1304        final float coef = 1.0f / 5.255f;
1305        return 44330.0f * (1.0f - (float)Math.pow(p/p0, coef));
1306    }
1307
1308    /** Helper function to compute the angle change between two rotation matrices.
1309     *  Given a current rotation matrix (R) and a previous rotation matrix
1310     *  (prevR) computes the rotation around the z,x, and y axes which
1311     *  transforms prevR to R.
1312     *  outputs a 3 element vector containing the z,x, and y angle
1313     *  change at indexes 0, 1, and 2 respectively.
1314     * <p> Each input matrix is either as a 3x3 or 4x4 row-major matrix
1315     * depending on the length of the passed array:
1316     * <p>If the array length is 9, then the array elements represent this matrix
1317     * <pre>
1318     *   /  R[ 0]   R[ 1]   R[ 2]   \
1319     *   |  R[ 3]   R[ 4]   R[ 5]   |
1320     *   \  R[ 6]   R[ 7]   R[ 8]   /
1321     *</pre>
1322     * <p>If the array length is 16, then the array elements represent this matrix
1323     * <pre>
1324     *   /  R[ 0]   R[ 1]   R[ 2]   R[ 3]  \
1325     *   |  R[ 4]   R[ 5]   R[ 6]   R[ 7]  |
1326     *   |  R[ 8]   R[ 9]   R[10]   R[11]  |
1327     *   \  R[12]   R[13]   R[14]   R[15]  /
1328     *</pre>
1329     * @param R current rotation matrix
1330     * @param prevR previous rotation matrix
1331     * @param angleChange an an array of floats (z, x, and y) in which the angle change is stored
1332     */
1333
1334    public static void getAngleChange( float[] angleChange, float[] R, float[] prevR) {
1335        float rd1=0,rd4=0, rd6=0,rd7=0, rd8=0;
1336        float ri0=0,ri1=0,ri2=0,ri3=0,ri4=0,ri5=0,ri6=0,ri7=0,ri8=0;
1337        float pri0=0, pri1=0, pri2=0, pri3=0, pri4=0, pri5=0, pri6=0, pri7=0, pri8=0;
1338
1339        if(R.length == 9) {
1340            ri0 = R[0];
1341            ri1 = R[1];
1342            ri2 = R[2];
1343            ri3 = R[3];
1344            ri4 = R[4];
1345            ri5 = R[5];
1346            ri6 = R[6];
1347            ri7 = R[7];
1348            ri8 = R[8];
1349        } else if(R.length == 16) {
1350            ri0 = R[0];
1351            ri1 = R[1];
1352            ri2 = R[2];
1353            ri3 = R[4];
1354            ri4 = R[5];
1355            ri5 = R[6];
1356            ri6 = R[8];
1357            ri7 = R[9];
1358            ri8 = R[10];
1359        }
1360
1361        if(prevR.length == 9) {
1362            pri0 = prevR[0];
1363            pri1 = prevR[1];
1364            pri2 = prevR[2];
1365            pri3 = prevR[3];
1366            pri4 = prevR[4];
1367            pri5 = prevR[5];
1368            pri6 = prevR[6];
1369            pri7 = prevR[7];
1370            pri8 = prevR[8];
1371        } else if(prevR.length == 16) {
1372            pri0 = prevR[0];
1373            pri1 = prevR[1];
1374            pri2 = prevR[2];
1375            pri3 = prevR[4];
1376            pri4 = prevR[5];
1377            pri5 = prevR[6];
1378            pri6 = prevR[8];
1379            pri7 = prevR[9];
1380            pri8 = prevR[10];
1381        }
1382
1383        // calculate the parts of the rotation difference matrix we need
1384        // rd[i][j] = pri[0][i] * ri[0][j] + pri[1][i] * ri[1][j] + pri[2][i] * ri[2][j];
1385
1386        rd1 = pri0 * ri1 + pri3 * ri4 + pri6 * ri7; //rd[0][1]
1387        rd4 = pri1 * ri1 + pri4 * ri4 + pri7 * ri7; //rd[1][1]
1388        rd6 = pri2 * ri0 + pri5 * ri3 + pri8 * ri6; //rd[2][0]
1389        rd7 = pri2 * ri1 + pri5 * ri4 + pri8 * ri7; //rd[2][1]
1390        rd8 = pri2 * ri2 + pri5 * ri5 + pri8 * ri8; //rd[2][2]
1391
1392        angleChange[0] = (float)Math.atan2(rd1, rd4);
1393        angleChange[1] = (float)Math.asin(-rd7);
1394        angleChange[2] = (float)Math.atan2(-rd6, rd8);
1395
1396    }
1397
1398    /** Helper function to convert a rotation vector to a rotation matrix.
1399     *  Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a
1400     *  9  or 16 element rotation matrix in the array R.  R must have length 9 or 16.
1401     *  If R.length == 9, the following matrix is returned:
1402     * <pre>
1403     *   /  R[ 0]   R[ 1]   R[ 2]   \
1404     *   |  R[ 3]   R[ 4]   R[ 5]   |
1405     *   \  R[ 6]   R[ 7]   R[ 8]   /
1406     *</pre>
1407     * If R.length == 16, the following matrix is returned:
1408     * <pre>
1409     *   /  R[ 0]   R[ 1]   R[ 2]   0  \
1410     *   |  R[ 4]   R[ 5]   R[ 6]   0  |
1411     *   |  R[ 8]   R[ 9]   R[10]   0  |
1412     *   \  0       0       0       1  /
1413     *</pre>
1414     *  @param rotationVector the rotation vector to convert
1415     *  @param R an array of floats in which to store the rotation matrix
1416     */
1417    public static void getRotationMatrixFromVector(float[] R, float[] rotationVector) {
1418
1419        float q0;
1420        float q1 = rotationVector[0];
1421        float q2 = rotationVector[1];
1422        float q3 = rotationVector[2];
1423
1424        if (rotationVector.length >= 4) {
1425            q0 = rotationVector[3];
1426        } else {
1427            q0 = 1 - q1*q1 - q2*q2 - q3*q3;
1428            q0 = (q0 > 0) ? (float)Math.sqrt(q0) : 0;
1429        }
1430
1431        float sq_q1 = 2 * q1 * q1;
1432        float sq_q2 = 2 * q2 * q2;
1433        float sq_q3 = 2 * q3 * q3;
1434        float q1_q2 = 2 * q1 * q2;
1435        float q3_q0 = 2 * q3 * q0;
1436        float q1_q3 = 2 * q1 * q3;
1437        float q2_q0 = 2 * q2 * q0;
1438        float q2_q3 = 2 * q2 * q3;
1439        float q1_q0 = 2 * q1 * q0;
1440
1441        if(R.length == 9) {
1442            R[0] = 1 - sq_q2 - sq_q3;
1443            R[1] = q1_q2 - q3_q0;
1444            R[2] = q1_q3 + q2_q0;
1445
1446            R[3] = q1_q2 + q3_q0;
1447            R[4] = 1 - sq_q1 - sq_q3;
1448            R[5] = q2_q3 - q1_q0;
1449
1450            R[6] = q1_q3 - q2_q0;
1451            R[7] = q2_q3 + q1_q0;
1452            R[8] = 1 - sq_q1 - sq_q2;
1453        } else if (R.length == 16) {
1454            R[0] = 1 - sq_q2 - sq_q3;
1455            R[1] = q1_q2 - q3_q0;
1456            R[2] = q1_q3 + q2_q0;
1457            R[3] = 0.0f;
1458
1459            R[4] = q1_q2 + q3_q0;
1460            R[5] = 1 - sq_q1 - sq_q3;
1461            R[6] = q2_q3 - q1_q0;
1462            R[7] = 0.0f;
1463
1464            R[8] = q1_q3 - q2_q0;
1465            R[9] = q2_q3 + q1_q0;
1466            R[10] = 1 - sq_q1 - sq_q2;
1467            R[11] = 0.0f;
1468
1469            R[12] = R[13] = R[14] = 0.0f;
1470            R[15] = 1.0f;
1471        }
1472    }
1473
1474    /** Helper function to convert a rotation vector to a normalized quaternion.
1475     *  Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized
1476     *  quaternion in the array Q.  The quaternion is stored as [w, x, y, z]
1477     *  @param rv the rotation vector to convert
1478     *  @param Q an array of floats in which to store the computed quaternion
1479     */
1480    public static void getQuaternionFromVector(float[] Q, float[] rv) {
1481        if (rv.length >= 4) {
1482            Q[0] = rv[3];
1483        } else {
1484            Q[0] = 1 - rv[0]*rv[0] - rv[1]*rv[1] - rv[2]*rv[2];
1485            Q[0] = (Q[0] > 0) ? (float)Math.sqrt(Q[0]) : 0;
1486        }
1487        Q[1] = rv[0];
1488        Q[2] = rv[1];
1489        Q[3] = rv[2];
1490    }
1491
1492    /**
1493     * Requests receiving trigger events for a trigger sensor.
1494     *
1495     * <p>
1496     * When the sensor detects a trigger event condition, such as significant motion in
1497     * the case of the {@link Sensor#TYPE_SIGNIFICANT_MOTION}, the provided trigger listener
1498     * will be invoked once and then its request to receive trigger events will be canceled.
1499     * To continue receiving trigger events, the application must request to receive trigger
1500     * events again.
1501     * </p>
1502     *
1503     * @param listener The listener on which the
1504     *        {@link TriggerEventListener#onTrigger(TriggerEvent)} will be delivered.
1505     * @param sensor The sensor to be enabled.
1506     *
1507     * @return true if the sensor was successfully enabled.
1508     *
1509     * @throws IllegalArgumentException when sensor is null or not a trigger sensor.
1510     */
1511    public boolean requestTriggerSensor(TriggerEventListener listener, Sensor sensor) {
1512        return requestTriggerSensorImpl(listener, sensor);
1513    }
1514
1515    /**
1516     * @hide
1517     */
1518    protected abstract boolean requestTriggerSensorImpl(TriggerEventListener listener,
1519            Sensor sensor);
1520
1521    /**
1522     * Cancels receiving trigger events for a trigger sensor.
1523     *
1524     * <p>
1525     * Note that a Trigger sensor will be auto disabled if
1526     * {@link TriggerEventListener#onTrigger(TriggerEvent)} has triggered.
1527     * This method is provided in case the user wants to explicitly cancel the request
1528     * to receive trigger events.
1529     * </p>
1530     *
1531     * @param listener The listener on which the
1532     *        {@link TriggerEventListener#onTrigger(TriggerEvent)}
1533     *        is delivered.It should be the same as the one used
1534     *        in {@link #requestTriggerSensor(TriggerEventListener, Sensor)}
1535     * @param sensor The sensor for which the trigger request should be canceled.
1536     *        If null, it cancels receiving trigger for all sensors associated
1537     *        with the listener.
1538     *
1539     * @return true if successfully canceled.
1540     *
1541     * @throws IllegalArgumentException when sensor is a trigger sensor.
1542     */
1543    public boolean cancelTriggerSensor(TriggerEventListener listener, Sensor sensor) {
1544        return cancelTriggerSensorImpl(listener, sensor, true);
1545    }
1546
1547    /**
1548     * @hide
1549     */
1550    protected abstract boolean cancelTriggerSensorImpl(TriggerEventListener listener,
1551            Sensor sensor, boolean disable);
1552
1553
1554    private LegacySensorManager getLegacySensorManager() {
1555        synchronized (mSensorListByType) {
1556            if (mLegacySensorManager == null) {
1557                Log.i(TAG, "This application is using deprecated SensorManager API which will "
1558                        + "be removed someday.  Please consider switching to the new API.");
1559                mLegacySensorManager = new LegacySensorManager(this);
1560            }
1561            return mLegacySensorManager;
1562        }
1563    }
1564
1565    private static int getDelay(int rate) {
1566        int delay = -1;
1567        switch (rate) {
1568            case SENSOR_DELAY_FASTEST:
1569                delay = 0;
1570                break;
1571            case SENSOR_DELAY_GAME:
1572                delay = 20000;
1573                break;
1574            case SENSOR_DELAY_UI:
1575                delay = 66667;
1576                break;
1577            case SENSOR_DELAY_NORMAL:
1578                delay = 200000;
1579                break;
1580            default:
1581                delay = rate;
1582                break;
1583        }
1584        return delay;
1585    }
1586}
1587