GL_BOOK_11

CHAPTER 12
传感器
光照传感器 加速度传感器 地磁传感器 压力传感器 温度传感器

光照传感器 自动调整屏幕亮度
SensorManager sensorManager 是所有传感器的管理器
getSystemService(Context.SENSOR_SERVICE)
通过调用 getDefaultSensor(Sensor.TYPE_LIGHT);
来得到相应的传感器类型
Sensor sensor = sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);

package com.asen.demo;

import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

public class SensorActivity extends Activity implements OnClickListener{

    private TextView tv;
    private Button btLight,btAccelerometer,btMagneticAndAccelerometer;
    private ImageView iv;
    private SensorManager sensorManager;
    private Sensor sensor;
    private SensorEventListener listener;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.sensor);

        tv = (TextView) findViewById(R.id.tv);
        iv = (ImageView) findViewById(R.id.img);
        btLight = (Button) findViewById(R.id.light);
        btAccelerometer = (Button) findViewById(R.id.accelerometer);
        btMagneticAndAccelerometer = (Button) findViewById(R.id.accelerometerandmagnetic);

        btLight.setOnClickListener(this);
        btAccelerometer.setOnClickListener(this);
        btMagneticAndAccelerometer.setOnClickListener(this);

        sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    }
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.light:
            startLightSensor();
            break;
        case R.id.accelerometer:
            startAccelerometer();
            break;
        case R.id.accelerometerandmagnetic:
            startAccelerometerAndMagnetic();
            break;

        default:
            break;
        }
    }
    private void startAccelerometerAndMagnetic() {
        Sensor aSensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        Sensor mSensor = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
        listener = new MagneticAndAccelerometerListener();
        sensorManager.registerListener(listener, aSensor, SensorManager.SENSOR_DELAY_GAME);
        sensorManager.registerListener(listener, mSensor, SensorManager.SENSOR_DELAY_GAME);
    }
    private void startAccelerometer() {
        sensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        listener = new AccelerateListener();
        sensorManager.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_GAME);

    }
    private void startLightSensor() {
        sensor = sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
        listener = new LightSensorListener();
        //SENSOR_DELAY_UI\SENSOR_DELAY_NORMAL\SENSOR_DELAY_GAME\SENSOR_DELAY_FASTEST
        sensorManager.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_NORMAL);
    }

    class LightSensorListener implements SensorEventListener{

        @Override
        public void onSensorChanged(SensorEvent event) {
            //光照传感器监听 value 数组中第一个下标的值就是当前的光照强度
            float value = event.values[0];
            tv.setText("当前光照强度  : "+value);
        }

        @Override
        public void onAccuracyChanged(Sensor sensor, int accuracy) {

        }

    }
    class AccelerateListener implements SensorEventListener{

        @Override
        public void onSensorChanged(SensorEvent event) {
            float xValue = Math.abs(event.values[0]);
            float yValue = Math.abs(event.values[1]);
            float zValue = Math.abs(event.values[2]);
            if (xValue>15||yValue>15||zValue>15) {
                tv.setText("检测到摇一摇  : x 轴 加速度 _"+xValue+"  y 轴 加速度_"+yValue+"  z 轴 加速度_"+zValue);
            }
        }

        @Override
        public void onAccuracyChanged(Sensor sensor, int accuracy) {

        }

    }
    class MagneticAndAccelerometerListener implements SensorEventListener{

        float[] accelerometerValues = new float[3];
        float[] magneticValues = new float[3];
        private float lastRotateDegree;
        @Override
        public void onSensorChanged(SensorEvent event) {
            //判断当前传感器是地磁传感器还是加速度传感器
            if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
                //赋值时要调用 clone 方法 不然两个valuse将会指向同一个引用
                accelerometerValues = event.values.clone();
            }else if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) {
                magneticValues = event.values.clone();
            }

            float[] R = new float[9];
            float[] values = new float[3];
            //调用 getRotationMatrix 为 R 赋值
            SensorManager.getRotationMatrix(R, null, accelerometerValues, magneticValues);
            //再调用 getOrientation 为 values 赋值
            SensorManager.getOrientation(R, values);
            //此时 values 已包含所有方向上旋转的弧度了 ， 其中 values[0] 表示手机围绕z轴旋转的弧度 
            //调用Math.getDegrees()将它转化成角度
            float rotateDegree = -(float) Math.toDegrees(values[0]);
            if (Math.abs(rotateDegree - lastRotateDegree)>1) {
                tv.setText("围绕 z 轴旋转的弧度  : "+values[0]);
                RotateAnimation animation = new RotateAnimation(lastRotateDegree, rotateDegree, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
                animation.setFillAfter(true);
                iv.startAnimation(animation);
                lastRotateDegree = rotateDegree;
            }
        }

        @Override
        public void onAccuracyChanged(Sensor sensor, int accuracy) {

        }

    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (listener!=null) {
            sensorManager.unregisterListener(listener);
        }
    }
}