Android传感器API之:加速度Accelerometer功能源码
加速度传感器,主要是感应手机的运动。捕获三个参数,分别表示空间坐标系中X、Y、Z轴方向上的加速度减去重力加速度在相应轴上的分量,其单位均为m/s2。和之前几篇传感器功能介绍中的一样,这几个方向就不再多说了~~
Rexsee的源码如下,有兴趣的朋友可以再去找找,社区公开的源码里有包括加速度在内的,重力、磁场、温度、距离和方向等传感器功能。http://www.
/*
* Copyright (C) 2011 The Rexsee Open Source Project
*
* Licensed under the Rexsee License, Version 1.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package rexsee.sensor;
import rexsee.core.browser.JavascriptInterface;
import rexsee.core.browser.RexseeBrowser;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
public class RexseeSensorAccelerometer implements JavascriptInterface {
private static final String INTERFACE_NAME = "Accelerometer";
@Override
public String getInterfaceName() {
return mBrowser.application.resources.prefix + INTERFACE_NAME;
}
@Override
public JavascriptInterface getInheritInterface(RexseeBrowser childBrowser) {
return this;
}
@Override
public JavascriptInterface getNewInterface(RexseeBrowser childBrowser) {
return new RexseeSensorAccelerometer(childBrowser);
}
public static final String EVENT_ONACCELERATE = "onAccelerometerChanged";
private final Context mContext;
private final RexseeBrowser mBrowser;
private final SensorManager mSensorManager;
private final SensorEventListener mSensorListener;
private final Sensor mSensor;
private int mRate = SensorManager.SENSOR_DELAY_NORMAL;
private int mCycle = 100;
private int mEventCycle = 100;
private float mAccuracyX = 0;
private float mAccuracyY = 0;
private float mAccuracyZ = 0;
private long lastUpdate = -1;
private long lastEvent = -1;
private float x = -999, y = -999, z = -999;
public RexseeSensorAccelerometer(RexseeBrowser browser) {
mContext = browser.getContext();
mBrowser = browser;
browser.eventList.add(EVENT_ONACCELERATE);
mSensorManager = (SensorManager) mContext.getSystemService(Context.SENSOR_SERVICE);
mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mSensorListener = new SensorEventListener() {
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
@Override
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER) return;
long curTime = System.currentTimeMillis();
if (lastUpdate == -1 || (curTime - lastUpdate) > mCycle) {
lastUpdate = curTime;
float lastX = x;
float lastY = y;
float lastZ = z;
x = event.values[SensorManager.DATA_X];
y = event.values[SensorManager.DATA_Y];
z = event.values[SensorManager.DATA_Z];
if (lastEvent == -1 || (curTime - lastEvent) > mEventCycle) {
if (
(mAccuracyX >= 0 && Math.abs(x - lastX) > mAccuracyX)
|| (mAccuracyY >= 0 && Math.abs(y - lastY) > mAccuracyY)
|| (mAccuracyZ >= 0 && Math.abs(z - lastZ) > mAccuracyZ)
) {
lastEvent = curTime;
mBrowser.eventList.run(EVENT_ONACCELERATE);
}
}
}
}
};
}
public String getLastKnownX() {
return (x == -999) ? "null" : String.valueOf(x);
}
public String getLastKnownY() {
return (y == -999) ? "null" : String.valueOf(y);
}
public String getLastKnownZ() {
return (z == -999) ? "null" : String.valueOf(z);
}
public void setRate(String rate) {
mRate = SensorRate.getInt(rate);
}
public String getRate() {
return SensorRate.getString(mRate);
}
public void setCycle(int milliseconds) {
mCycle = milliseconds;
}
public int getCycle() {
return mCycle;
}
public void setEventCycle(int milliseconds) {
mEventCycle = milliseconds;
}
public int getEventCycle() {
return mEventCycle;
}
public void setAccuracy(float x, float y, float z) {
mAccuracyX = x;
mAccuracyY = y;
mAccuracyZ = z;
}
public float getAccuracyX() {
return mAccuracyX;
}
public float getAccuracyY() {
return mAccuracyY;
}
public float getAccuracyZ() {
return mAccuracyZ;
}
public boolean isReady() {
return (mSensor == null) ? false : true;
}
public void start() {
if (isReady()) {
mSensorManager.registerListener(mSensorListener, mSensor, mRate);
} else {
mBrowser.exception(getInterfaceName(), "Accelerometer is not found.");
}
}
public void stop() {
if (isReady()) {
mSensorManager.unregisterListener(mSensorListener);
}
}
}