读 Beginning Android Games 2nd Edition (四) 创建罗盘事件监听类

package com.badlogic.androidgames.framework.impl;

import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;

public class CompassHandler implements SensorEventListener {
    float yaw;
    float pitch;
    float roll;

    public CompassHandler(Context context) {
        SensorManager manager = (SensorManager) context
                .getSystemService(Context.SENSOR_SERVICE);
        if (manager.getSensorList(Sensor.TYPE_ORIENTATION).size() != 0) {
            Sensor compass = manager.getDefaultSensor(Sensor.TYPE_ORIENTATION);
            manager.registerListener(this, compass,
                    SensorManager.SENSOR_DELAY_GAME);
        }
    }

    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // nothing to do here
    }

    public void onSensorChanged(SensorEvent event) {
        yaw = event.values[0];
        pitch = event.values[1];
        roll = event.values[2];
    }

    public float getYaw() {
        return yaw;
    }

    public float getPitch() {
        return pitch;
    }

    public float getRoll() {
        return roll;
    }
}