Android重力传感器--随重力旋转的图标

相机拍摄都有横屏拍摄和竖屏拍摄，横竖屏切换，图标也会跟着重力方向旋转，于是也做了一个相机旋转效果。
代码在这里面

啥也不说了，先上效果图，gif大小限制，只截取了一小段：

演示

在Android平台中，传感器框架通常是使用一个标准的三维坐标系去表示一个值的。以方向传感器为例，确定一个方向当然也需要一个三维坐标，三个方向值就是一个长度为3的float数组。

旋转工具类：

根据重力传感器的监听，获取X、Y方向上分量计算数值角度。为了不实时旋转，定义4个方向范围，对应角度分别为0，90，180，270度，遍历view作属性动画。

import android.animation.ObjectAnimator;
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.view.View;
import java.util.ArrayList;

public class RotateSensorUtil implements SensorEventListener{
    private Context context;
    private SensorManager sensorManager;
    //默认旋转角度code，分别为 0,1/2,3,4/-1
    private int curRotateCode = 0;
    //记录当前的角度，每次旋转从此处开始
    private int curAngle = 0;
    //需要操作旋转的集合
    private ArrayList views = new ArrayList<>();

    public RotateSensorUtil(Context context, ArrayList views){

        this.context = context;
        this.views = views;
        sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
        //通过传感器管理器获取重力加速度传感器
        sensorManager.registerListener(this,sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),SensorManager.SENSOR_DELAY_NORMAL);
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        if(event.sensor.getType() != Sensor.TYPE_ACCELEROMETER){
            return;
        }

        float[] values = event.values;
        float ax = values[0];
        float ay = values[1];


        double g = Math.sqrt(ax * ax + ay * ay);
        double cos = ay / g;
        if (cos > 1) {
            cos = 1;
        } else if (cos < -1) {
            cos = -1;
        }
        double rad = Math.acos(cos);
        if (ax < 0) {
            rad = 2 * Math.PI - rad;
        }

        int uiRot = ((Activity)context).getWindowManager().getDefaultDisplay().getRotation();
        double uiRad = Math.PI / 2 * uiRot;
        rad -= uiRad;

        checkBundray((int) rad);
    }

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

    }

    /**
     * 旋转检测
     * @param rotateCode
     */
    private void checkBundray(int rotateCode){
        if(rotateCode == 2) rotateCode = 1;
        if(rotateCode == -1) rotateCode = 4;
        int angle = 0;

        switch (rotateCode){
            case 0:
                angle = 0;
                break;
            case 1:
                angle = 90;
                break;
            case 3:
                angle = 180;
                break;
            case 4:
                angle = 270;
                break;
        }

        if(rotateCode == curRotateCode){

        }else{
            valueRotateAnim(angle);
            curAngle = angle;
            curRotateCode = rotateCode;
        }
    }

    private void valueRotateAnim(int angle){
        //特别处理从270-0度的反向旋转
        if(curAngle == 270){
            angle = 360;
        }
        for(int i=0;i

MainActivity调用，传递所有要旋转图标，并调用相机。

import android.graphics.SurfaceTexture;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.TextureView;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageView;
import java.util.ArrayList;
import butterknife.Bind;
import butterknife.ButterKnife;

public class MainActivity extends AppCompatActivity implements TextureView.SurfaceTextureListener {
    @Bind(R.id.textureview)
    TextureView textureview;
    @Bind(R.id.iv_close)
    ImageView ivClose;
    @Bind(R.id.more)
    ImageView more;
    @Bind(R.id.iv_switch)
    ImageView ivSwitch;
    @Bind(R.id.iv_pic)
    ImageView ivPic;
    @Bind(R.id.iv_beauty)
    ImageView ivBeauty;
    @Bind(R.id.iv_face)
    ImageView ivFace;
    @Bind(R.id.iv_filter)
    ImageView ivFilter;
    private TextureView textureView;
    private OpenCamera openCamera;
    private RotateSensorUtil sensorUtil;
    private ArrayList rotateViews = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);

        openCamera();
        addViews();
        startAnim();
    }

    private void startAnim() {
        sensorUtil = new RotateSensorUtil(this,rotateViews);
    }

    private void addViews(){
        rotateViews.add(ivClose);
        rotateViews.add(more);
        rotateViews.add(ivSwitch);
        rotateViews.add(ivPic);
        rotateViews.add(ivBeauty);
        rotateViews.add(ivFace);
        rotateViews.add(ivFilter);
    }

    private void openCamera(){
        textureView = (TextureView) findViewById(R.id.textureview);
        openCamera = new OpenCamera(getApplicationContext(), textureView);

        openCamera.startCameraThread();

        if (!textureView.isAvailable()) {
            textureView.setSurfaceTextureListener(this);
        } else {
            openCamera.startPreview();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        sensorUtil.unregisterSensor();
    }

    @Override
    public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
        openCamera.setupCamera(width, height);  //设置相机参数,回调的是textureview的宽高
        openCamera.openCamera();
    }

    @Override
    public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {

    }

    @Override
    public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
        return false;
    }

    @Override
    public void onSurfaceTextureUpdated(SurfaceTexture surface) {

    }
}