true if the sensor is supported and successfully
* enabled
*/
@Deprecated
public boolean registerListener(SensorListener listener, int sensors) {
return registerListener(listener, sensors, SENSOR_DELAY_NORMAL);
}
/**
* Registers a SensorListener for given sensors.
*
* @deprecated This method is deprecated, use
* {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
* instead.
*
* @param listener
* sensor listener object
*
* @param sensors
* a bit masks of the sensors to register to
*
* @param rate
* rate of events. This is only a hint to the system. events may be
* received faster or slower than the specified rate. Usually events
* are received faster. The value must be one of
* {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
* {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}.
*
* @return true if the sensor is supported and successfully
* enabled
*/
@Deprecated
public boolean registerListener(SensorListener listener, int sensors, int rate) {
return getLegacySensorManager().registerListener(listener, sensors, rate);
}
/**
* Unregisters a listener for all sensors.
*
* @deprecated This method is deprecated, use
* {@link SensorManager#unregisterListener(SensorEventListener)}
* instead.
*
* @param listener
* a SensorListener object
*/
@Deprecated
public void unregisterListener(SensorListener listener) {
unregisterListener(listener, SENSOR_ALL | SENSOR_ORIENTATION_RAW);
}
/**
* Unregisters a listener for the sensors with which it is registered.
*
* @deprecated This method is deprecated, use
* {@link SensorManager#unregisterListener(SensorEventListener, Sensor)}
* instead.
*
* @param listener
* a SensorListener object
*
* @param sensors
* a bit masks of the sensors to unregister from
*/
@Deprecated
public void unregisterListener(SensorListener listener, int sensors) {
getLegacySensorManager().unregisterListener(listener, sensors);
}
/**
* Unregisters a listener for the sensors with which it is registered.
*
* @param listener
* a SensorEventListener object
*
* @param sensor
* the sensor to unregister from
*
* @see #unregisterListener(SensorEventListener)
* @see #registerListener(SensorEventListener, Sensor, int)
*
*/
public void unregisterListener(SensorEventListener listener, Sensor sensor) {
if (listener == null || sensor == null) {
return;
}
unregisterListenerImpl(listener, sensor);
}
/**
* Unregisters a listener for all sensors.
*
* @param listener
* a SensorListener object
*
* @see #unregisterListener(SensorEventListener, Sensor)
* @see #registerListener(SensorEventListener, Sensor, int)
*
*/
public void unregisterListener(SensorEventListener listener) {
if (listener == null) {
return;
}
unregisterListenerImpl(listener, null);
}
/** @hide */
protected abstract void unregisterListenerImpl(SensorEventListener listener, Sensor sensor);
/**
* Registers a {@link android.hardware.SensorEventListener
* SensorEventListener} for the given sensor.
*
* @param listener
* A {@link android.hardware.SensorEventListener SensorEventListener}
* object.
*
* @param sensor
* The {@link android.hardware.Sensor Sensor} to register to.
*
* @param rate
* The rate {@link android.hardware.SensorEvent sensor events} are
* delivered at. This is only a hint to the system. Events may be
* received faster or slower than the specified rate. Usually events
* are received faster. The value must be one of
* {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
* {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}
* or, the desired delay between events in microsecond.
*
* @return true if the sensor is supported and successfully
* enabled.
*
* @see #registerListener(SensorEventListener, Sensor, int, Handler)
* @see #unregisterListener(SensorEventListener)
* @see #unregisterListener(SensorEventListener, Sensor)
*
*/
public boolean registerListener(SensorEventListener listener, Sensor sensor, int rate) {
return registerListener(listener, sensor, rate, null);
}
/**
* Registers a {@link android.hardware.SensorEventListener
* SensorEventListener} for the given sensor.
*
* @param listener
* A {@link android.hardware.SensorEventListener SensorEventListener}
* object.
*
* @param sensor
* The {@link android.hardware.Sensor Sensor} to register to.
*
* @param rate
* The rate {@link android.hardware.SensorEvent sensor events} are
* delivered at. This is only a hint to the system. Events may be
* received faster or slower than the specified rate. Usually events
* are received faster. The value must be one of
* {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
* {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}.
* or, the desired delay between events in microsecond.
*
* @param handler
* The {@link android.os.Handler Handler} the
* {@link android.hardware.SensorEvent sensor events} will be
* delivered to.
*
* @return true if the sensor is supported and successfully enabled.
*
* @see #registerListener(SensorEventListener, Sensor, int)
* @see #unregisterListener(SensorEventListener)
* @see #unregisterListener(SensorEventListener, Sensor)
*
*/
public boolean registerListener(SensorEventListener listener, Sensor sensor, int rate,
Handler handler) {
if (listener == null || sensor == null) {
return false;
}
int delay = -1;
switch (rate) {
case SENSOR_DELAY_FASTEST:
delay = 0;
break;
case SENSOR_DELAY_GAME:
delay = 20000;
break;
case SENSOR_DELAY_UI:
delay = 66667;
break;
case SENSOR_DELAY_NORMAL:
delay = 200000;
break;
default:
delay = rate;
break;
}
return registerListenerImpl(listener, sensor, delay, handler);
}
/** @hide */
protected abstract boolean registerListenerImpl(SensorEventListener listener, Sensor sensor,
int delay, Handler handler);
/**
* * Computes the inclination matrix I as well as the rotation matrix * R transforming a vector from the device coordinate system to the * world's coordinate system which is defined as a direct orthonormal basis, * where: *
* *-
*
- X is defined as the vector product Y.Z (It is tangential to * the ground at the device's current location and roughly points East). *
- Y is tangential to the ground at the device's current location and * points towards the magnetic North Pole. *
- Z points towards the sky and is perpendicular to the ground. *
*
*
*
* By definition: *
* [0 0 g] = R * gravity (g = magnitude of gravity) *
* [0 m 0] = I * R * geomagnetic (m = magnitude of * geomagnetic field) *
* R is the identity matrix when the device is aligned with the * world's coordinate system, that is, when the device's X axis points * toward East, the Y axis points to the North Pole and the device is facing * the sky. * *
* I is a rotation matrix transforming the geomagnetic vector into * the same coordinate space as gravity (the world's coordinate space). * I is a simple rotation around the X axis. The inclination angle in * radians can be computed with {@link #getInclination}. *
* *
* Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending * on the length of the passed array: *
* If the array length is 16: * *
* / M[ 0] M[ 1] M[ 2] M[ 3] \
* | M[ 4] M[ 5] M[ 6] M[ 7] |
* | M[ 8] M[ 9] M[10] M[11] |
* \ M[12] M[13] M[14] M[15] /
*
*
* This matrix is ready to be used by OpenGL ES's
* {@link javax.microedition.khronos.opengles.GL10#glLoadMatrixf(float[], int)
* glLoadMatrixf(float[], int)}.
* * Note that because OpenGL matrices are column-major matrices you must * transpose the matrix before using it. However, since the matrix is a * rotation matrix, its transpose is also its inverse, conveniently, it is * often the inverse of the rotation that is needed for rendering; it can * therefore be used with OpenGL ES directly. *
* Also note that the returned matrices always have this form: * *
* / M[ 0] M[ 1] M[ 2] 0 \
* | M[ 4] M[ 5] M[ 6] 0 |
* | M[ 8] M[ 9] M[10] 0 |
* \ 0 0 0 1 /
*
*
* * If the array length is 9: * *
* / M[ 0] M[ 1] M[ 2] \
* | M[ 3] M[ 4] M[ 5] |
* \ M[ 6] M[ 7] M[ 8] /
*
*
* *
* The inverse of each matrix can be computed easily by taking its * transpose. * *
* The matrices returned by this function are meaningful only when the * device is not free-falling and it is not close to the magnetic north. If * the device is accelerating, or placed into a strong magnetic field, the * returned matrices may be inaccurate. * * @param R * is an array of 9 floats holding the rotation matrix R when * this function returns. R can be null. *
* * @param I * is an array of 9 floats holding the rotation matrix I when * this function returns. I can be null. *
* * @param gravity * is an array of 3 floats containing the gravity vector expressed in * the device's coordinate. You can simply use the * {@link android.hardware.SensorEvent#values values} returned by a * {@link android.hardware.SensorEvent SensorEvent} of a * {@link android.hardware.Sensor Sensor} of type * {@link android.hardware.Sensor#TYPE_ACCELEROMETER * TYPE_ACCELEROMETER}. *
*
* @param geomagnetic
* is an array of 3 floats containing the geomagnetic vector
* expressed in the device's coordinate. You can simply use the
* {@link android.hardware.SensorEvent#values values} returned by a
* {@link android.hardware.SensorEvent SensorEvent} of a
* {@link android.hardware.Sensor Sensor} of type
* {@link android.hardware.Sensor#TYPE_MAGNETIC_FIELD
* TYPE_MAGNETIC_FIELD}.
*
* @return true on success, false on failure (for
* instance, if the device is in free fall). On failure the output
* matrices are not modified.
*
* @see #getInclination(float[])
* @see #getOrientation(float[], float[])
* @see #remapCoordinateSystem(float[], int, int, float[])
*/
public static boolean getRotationMatrix(float[] R, float[] I,
float[] gravity, float[] geomagnetic) {
// TODO: move this to native code for efficiency
float Ax = gravity[0];
float Ay = gravity[1];
float Az = gravity[2];
final float Ex = geomagnetic[0];
final float Ey = geomagnetic[1];
final float Ez = geomagnetic[2];
float Hx = Ey*Az - Ez*Ay;
float Hy = Ez*Ax - Ex*Az;
float Hz = Ex*Ay - Ey*Ax;
final float normH = (float)Math.sqrt(Hx*Hx + Hy*Hy + Hz*Hz);
if (normH < 0.1f) {
// device is close to free fall (or in space?), or close to
// magnetic north pole. Typical values are > 100.
return false;
}
final float invH = 1.0f / normH;
Hx *= invH;
Hy *= invH;
Hz *= invH;
final float invA = 1.0f / (float)Math.sqrt(Ax*Ax + Ay*Ay + Az*Az);
Ax *= invA;
Ay *= invA;
Az *= invA;
final float Mx = Ay*Hz - Az*Hy;
final float My = Az*Hx - Ax*Hz;
final float Mz = Ax*Hy - Ay*Hx;
if (R != null) {
if (R.length == 9) {
R[0] = Hx; R[1] = Hy; R[2] = Hz;
R[3] = Mx; R[4] = My; R[5] = Mz;
R[6] = Ax; R[7] = Ay; R[8] = Az;
} else if (R.length == 16) {
R[0] = Hx; R[1] = Hy; R[2] = Hz; R[3] = 0;
R[4] = Mx; R[5] = My; R[6] = Mz; R[7] = 0;
R[8] = Ax; R[9] = Ay; R[10] = Az; R[11] = 0;
R[12] = 0; R[13] = 0; R[14] = 0; R[15] = 1;
}
}
if (I != null) {
// compute the inclination matrix by projecting the geomagnetic
// vector onto the Z (gravity) and X (horizontal component
// of geomagnetic vector) axes.
final float invE = 1.0f / (float)Math.sqrt(Ex*Ex + Ey*Ey + Ez*Ez);
final float c = (Ex*Mx + Ey*My + Ez*Mz) * invE;
final float s = (Ex*Ax + Ey*Ay + Ez*Az) * invE;
if (I.length == 9) {
I[0] = 1; I[1] = 0; I[2] = 0;
I[3] = 0; I[4] = c; I[5] = s;
I[6] = 0; I[7] =-s; I[8] = c;
} else if (I.length == 16) {
I[0] = 1; I[1] = 0; I[2] = 0;
I[4] = 0; I[5] = c; I[6] = s;
I[8] = 0; I[9] =-s; I[10]= c;
I[3] = I[7] = I[11] = I[12] = I[13] = I[14] = 0;
I[15] = 1;
}
}
return true;
}
/**
* Computes the geomagnetic inclination angle in radians from the
* inclination matrix I returned by {@link #getRotationMatrix}.
*
* @param I
* inclination matrix see {@link #getRotationMatrix}.
*
* @return The geomagnetic inclination angle in radians.
*
* @see #getRotationMatrix(float[], float[], float[], float[])
* @see #getOrientation(float[], float[])
* @see GeomagneticField
*
*/
public static float getInclination(float[] I) {
if (I.length == 9) {
return (float)Math.atan2(I[5], I[4]);
} else {
return (float)Math.atan2(I[6], I[5]);
}
}
/**
*
* Rotates the supplied rotation matrix so it is expressed in a different * coordinate system. This is typically used when an application needs to * compute the three orientation angles of the device (see * {@link #getOrientation}) in a different coordinate system. *
* ** When the rotation matrix is used for drawing (for instance with OpenGL * ES), it usually doesn't need to be transformed by this function, * unless the screen is physically rotated, in which case you can use * {@link android.view.Display#getRotation() Display.getRotation()} to * retrieve the current rotation of the screen. Note that because the user * is generally free to rotate their screen, you often should consider the * rotation in deciding the parameters to use here. *
* ** Examples: *
* *
-
*
- Using the camera (Y axis along the camera's axis) for an augmented * reality application where the rotation angles are needed: * *
- Using the device as a mechanical compass when rotation is * {@link android.view.Surface#ROTATION_90 Surface.ROTATION_90}: * *
*
-
*
remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);
* *
-
*
remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);
*
* Since the resulting coordinate system is orthonormal, only two axes need
* to be specified.
*
* @param inR
* the rotation matrix to be transformed. Usually it is the matrix
* returned by {@link #getRotationMatrix}.
*
* @param X
* defines on which world axis and direction the X axis of the device
* is mapped.
*
* @param Y
* defines on which world axis and direction the Y axis of the device
* is mapped.
*
* @param outR
* the transformed rotation matrix. inR and outR can be the same
* array, but it is not recommended for performance reason.
*
* @return
* When it returns, the array values is filled with the result:
* The reference coordinate-system used is different from the world
* coordinate-system defined for the rotation matrix:
* true on success. false if the input
* parameters are incorrect, for instance if X and Y define the same
* axis. Or if inR and outR don't have the same length.
*
* @see #getRotationMatrix(float[], float[], float[], float[])
*/
public static boolean remapCoordinateSystem(float[] inR, int X, int Y,
float[] outR)
{
if (inR == outR) {
final float[] temp = mTempMatrix;
synchronized(temp) {
// we don't expect to have a lot of contention
if (remapCoordinateSystemImpl(inR, X, Y, temp)) {
final int size = outR.length;
for (int i=0 ; i
*
*
*
*
* 
* All three angles above are in radians and positive in the * counter-clockwise direction. * * @param R * rotation matrix see {@link #getRotationMatrix}. * * @param values * an array of 3 floats to hold the result. * * @return The array values passed as argument. * * @see #getRotationMatrix(float[], float[], float[], float[]) * @see GeomagneticField */ public static float[] getOrientation(float[] R, float values[]) { /* * 4x4 (length=16) case: * / R[ 0] R[ 1] R[ 2] 0 \ * | R[ 4] R[ 5] R[ 6] 0 | * | R[ 8] R[ 9] R[10] 0 | * \ 0 0 0 1 / * * 3x3 (length=9) case: * / R[ 0] R[ 1] R[ 2] \ * | R[ 3] R[ 4] R[ 5] | * \ R[ 6] R[ 7] R[ 8] / * */ if (R.length == 9) { values[0] = (float)Math.atan2(R[1], R[4]); values[1] = (float)Math.asin(-R[7]); values[2] = (float)Math.atan2(-R[6], R[8]); } else { values[0] = (float)Math.atan2(R[1], R[5]); values[1] = (float)Math.asin(-R[9]); values[2] = (float)Math.atan2(-R[8], R[10]); } return values; } /** * Computes the Altitude in meters from the atmospheric pressure and the * pressure at sea level. *
* Typically the atmospheric pressure is read from a * {@link Sensor#TYPE_PRESSURE} sensor. The pressure at sea level must be * known, usually it can be retrieved from airport databases in the * vicinity. If unknown, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} * as an approximation, but absolute altitudes won't be accurate. *
** To calculate altitude differences, you must calculate the difference * between the altitudes at both points. If you don't know the altitude * as sea level, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} instead, * which will give good results considering the range of pressure typically * involved. *
*
*
* float altitude_difference =
* getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2)
* - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1);
*
Each input matrix is either as a 3x3 or 4x4 row-major matrix * depending on the length of the passed array: *
If the array length is 9, then the array elements represent this matrix *
* / R[ 0] R[ 1] R[ 2] \
* | R[ 3] R[ 4] R[ 5] |
* \ R[ 6] R[ 7] R[ 8] /
*
* If the array length is 16, then the array elements represent this matrix *
* / R[ 0] R[ 1] R[ 2] R[ 3] \
* | R[ 4] R[ 5] R[ 6] R[ 7] |
* | R[ 8] R[ 9] R[10] R[11] |
* \ R[12] R[13] R[14] R[15] /
*
* @param R current rotation matrix
* @param prevR previous rotation matrix
* @param angleChange an an array of floats (z, x, and y) in which the angle change is stored
*/
public static void getAngleChange( float[] angleChange, float[] R, float[] prevR) {
float rd1=0,rd4=0, rd6=0,rd7=0, rd8=0;
float ri0=0,ri1=0,ri2=0,ri3=0,ri4=0,ri5=0,ri6=0,ri7=0,ri8=0;
float pri0=0, pri1=0, pri2=0, pri3=0, pri4=0, pri5=0, pri6=0, pri7=0, pri8=0;
if(R.length == 9) {
ri0 = R[0];
ri1 = R[1];
ri2 = R[2];
ri3 = R[3];
ri4 = R[4];
ri5 = R[5];
ri6 = R[6];
ri7 = R[7];
ri8 = R[8];
} else if(R.length == 16) {
ri0 = R[0];
ri1 = R[1];
ri2 = R[2];
ri3 = R[4];
ri4 = R[5];
ri5 = R[6];
ri6 = R[8];
ri7 = R[9];
ri8 = R[10];
}
if(prevR.length == 9) {
pri0 = prevR[0];
pri1 = prevR[1];
pri2 = prevR[2];
pri3 = prevR[3];
pri4 = prevR[4];
pri5 = prevR[5];
pri6 = prevR[6];
pri7 = prevR[7];
pri8 = prevR[8];
} else if(prevR.length == 16) {
pri0 = prevR[0];
pri1 = prevR[1];
pri2 = prevR[2];
pri3 = prevR[4];
pri4 = prevR[5];
pri5 = prevR[6];
pri6 = prevR[8];
pri7 = prevR[9];
pri8 = prevR[10];
}
// calculate the parts of the rotation difference matrix we need
// rd[i][j] = pri[0][i] * ri[0][j] + pri[1][i] * ri[1][j] + pri[2][i] * ri[2][j];
rd1 = pri0 * ri1 + pri3 * ri4 + pri6 * ri7; //rd[0][1]
rd4 = pri1 * ri1 + pri4 * ri4 + pri7 * ri7; //rd[1][1]
rd6 = pri2 * ri0 + pri5 * ri3 + pri8 * ri6; //rd[2][0]
rd7 = pri2 * ri1 + pri5 * ri4 + pri8 * ri7; //rd[2][1]
rd8 = pri2 * ri2 + pri5 * ri5 + pri8 * ri8; //rd[2][2]
angleChange[0] = (float)Math.atan2(rd1, rd4);
angleChange[1] = (float)Math.asin(-rd7);
angleChange[2] = (float)Math.atan2(-rd6, rd8);
}
/** Helper function to convert a rotation vector to a rotation matrix.
* Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a
* 9 or 16 element rotation matrix in the array R. R must have length 9 or 16.
* If R.length == 9, the following matrix is returned:
*
* / R[ 0] R[ 1] R[ 2] \
* | R[ 3] R[ 4] R[ 5] |
* \ R[ 6] R[ 7] R[ 8] /
*
* If R.length == 16, the following matrix is returned:
*
* / R[ 0] R[ 1] R[ 2] 0 \
* | R[ 4] R[ 5] R[ 6] 0 |
* | R[ 8] R[ 9] R[10] 0 |
* \ 0 0 0 1 /
*
* @param rotationVector the rotation vector to convert
* @param R an array of floats in which to store the rotation matrix
*/
public static void getRotationMatrixFromVector(float[] R, float[] rotationVector) {
float q0;
float q1 = rotationVector[0];
float q2 = rotationVector[1];
float q3 = rotationVector[2];
if (rotationVector.length == 4) {
q0 = rotationVector[3];
} else {
q0 = 1 - q1*q1 - q2*q2 - q3*q3;
q0 = (q0 > 0) ? (float)Math.sqrt(q0) : 0;
}
float sq_q1 = 2 * q1 * q1;
float sq_q2 = 2 * q2 * q2;
float sq_q3 = 2 * q3 * q3;
float q1_q2 = 2 * q1 * q2;
float q3_q0 = 2 * q3 * q0;
float q1_q3 = 2 * q1 * q3;
float q2_q0 = 2 * q2 * q0;
float q2_q3 = 2 * q2 * q3;
float q1_q0 = 2 * q1 * q0;
if(R.length == 9) {
R[0] = 1 - sq_q2 - sq_q3;
R[1] = q1_q2 - q3_q0;
R[2] = q1_q3 + q2_q0;
R[3] = q1_q2 + q3_q0;
R[4] = 1 - sq_q1 - sq_q3;
R[5] = q2_q3 - q1_q0;
R[6] = q1_q3 - q2_q0;
R[7] = q2_q3 + q1_q0;
R[8] = 1 - sq_q1 - sq_q2;
} else if (R.length == 16) {
R[0] = 1 - sq_q2 - sq_q3;
R[1] = q1_q2 - q3_q0;
R[2] = q1_q3 + q2_q0;
R[3] = 0.0f;
R[4] = q1_q2 + q3_q0;
R[5] = 1 - sq_q1 - sq_q3;
R[6] = q2_q3 - q1_q0;
R[7] = 0.0f;
R[8] = q1_q3 - q2_q0;
R[9] = q2_q3 + q1_q0;
R[10] = 1 - sq_q1 - sq_q2;
R[11] = 0.0f;
R[12] = R[13] = R[14] = 0.0f;
R[15] = 1.0f;
}
}
/** Helper function to convert a rotation vector to a normalized quaternion.
* Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized
* quaternion in the array Q. The quaternion is stored as [w, x, y, z]
* @param rv the rotation vector to convert
* @param Q an array of floats in which to store the computed quaternion
*/
public static void getQuaternionFromVector(float[] Q, float[] rv) {
if (rv.length == 4) {
Q[0] = rv[3];
} else {
Q[0] = 1 - rv[0]*rv[0] - rv[1]*rv[1] - rv[2]*rv[2];
Q[0] = (Q[0] > 0) ? (float)Math.sqrt(Q[0]) : 0;
}
Q[1] = rv[0];
Q[2] = rv[1];
Q[3] = rv[2];
}
private LegacySensorManager getLegacySensorManager() {
synchronized (mSensorListByType) {
if (mLegacySensorManager == null) {
Log.i(TAG, "This application is using deprecated SensorManager API which will "
+ "be removed someday. Please consider switching to the new API.");
mLegacySensorManager = new LegacySensorManager(this);
}
return mLegacySensorManager;
}
}
/**
* Sensor event pool implementation.
* @hide
*/
protected static final class SensorEventPool {
private final int mPoolSize;
private final SensorEvent mPool[];
private int mNumItemsInPool;
private SensorEvent createSensorEvent() {
// maximal size for all legacy events is 3
return new SensorEvent(3);
}
SensorEventPool(int poolSize) {
mPoolSize = poolSize;
mNumItemsInPool = poolSize;
mPool = new SensorEvent[poolSize];
}
SensorEvent getFromPool() {
SensorEvent t = null;
synchronized (this) {
if (mNumItemsInPool > 0) {
// remove the "top" item from the pool
final int index = mPoolSize - mNumItemsInPool;
t = mPool[index];
mPool[index] = null;
mNumItemsInPool--;
}
}
if (t == null) {
// the pool was empty or this item was removed from the pool for
// the first time. In any case, we need to create a new item.
t = createSensorEvent();
}
return t;
}
void returnToPool(SensorEvent t) {
synchronized (this) {
// is there space left in the pool?
if (mNumItemsInPool < mPoolSize) {
// if so, return the item to the pool
mNumItemsInPool++;
final int index = mPoolSize - mNumItemsInPool;
mPool[index] = t;
}
}
}
}
}