Android 三轴绘制实时加速度曲线

public class GsensorActivity extends Activity implements SensorEventListener {

    private static final String TAG = "GsensorActivity";
    private SensorManager mSensorManager;
    private Sensor mSensor;
    private TextView textviewX;
    private TextView textviewY;
    private TextView textviewZ;
    private TextView textviewF;

    private float mX, mY, mZ;
    private long lasttimestamp = 0;
    Calendar mCalendar;
    private GraphicalView chart;
    /** 曲线数量 */
    private static final int SERIES_NR = 1;
    private TimeSeries series1;
    private XYMultipleSeriesDataset dataset1;
    private float addY = -1;
    private long addX;
    /** 时间数据 */
    Date[] xcache = new Date[20];
    /** 数据 */
    float[] ycache = new float[20];
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gsensor);
        textviewX = (TextView) findViewById(R.id.textView1);
        textviewY = (TextView) findViewById(R.id.textView3);
        textviewZ = (TextView) findViewById(R.id.textView4);
        textviewF = (TextView) findViewById(R.id.textView2);
        
        lasttimestamp = System.currentTimeMillis();
        
        LinearLayout layout = (LinearLayout) findViewById(R.id.linearlayout);
        // 生成图表
        chart = ChartFactory.getTimeChartView(this, getDateDemoDataset(),
                getDemoRenderer(), "hh:mm:ss");
        layout.addView(chart, new LayoutParams(LayoutParams.WRAP_CONTENT, 380));
        
        

        mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
        mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);// TYPE_GRAVITY
        if (null == mSensorManager) {
            Log.d(TAG, "deveice not support SensorManager");
        }
        // 参数三，检测的精准度
        mSensorManager.registerListener(this, mSensor,
                SensorManager.SENSOR_DELAY_NORMAL);// SENSOR_DELAY_GAME

    }
    
    private void updateChart(float a) {
        // 设定长度为20
        int length = series1.getItemCount();
        if (length >= 20)
            length = 20;
        addY = a;
        addX = new Date().getTime();
        
        // 将前面的点放入缓存
        for (int i = 0; i < length; i++) {
            xcache[i] = new Date((long) series1.getX(i));
            ycache[i] = (float) series1.getY(i);
        }
        series1.clear();
        series1.add(new Date(addX), addY);
        for (int k = 0; k < length; k++) {
            series1.add(xcache[k], ycache[k]);
        }
        // 在数据集中添加新的点集
        dataset1.removeSeries(series1);
        dataset1.addSeries(series1);
        // 曲线更新
        chart.invalidate();
    }

    
    /**
     * 设定如表样式
     * 
     * @return
     */
    private XYMultipleSeriesRenderer getDemoRenderer() {
        XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
        renderer.setChartTitle("实时曲线");// 标题
        renderer.setChartTitleTextSize(20);
        renderer.setXTitle("时间"); // x轴说明
        renderer.setAxisTitleTextSize(16);
        renderer.setAxesColor(Color.BLACK);
        renderer.setLabelsTextSize(15); // 数轴刻度字体大小
        renderer.setLabelsColor(Color.BLACK);
        renderer.setLegendTextSize(15); // 曲线说明
        renderer.setXLabelsColor(Color.BLACK);
        renderer.setYLabelsColor(0, Color.BLACK);
        renderer.setShowLegend(false);
        renderer.setMargins(new int[] { 20, 30, 100, 0 });
        XYSeriesRenderer r = new XYSeriesRenderer();
        r.setColor(Color.BLUE);
        r.setChartValuesTextSize(15);
        r.setChartValuesSpacing(3);
        r.setPointStyle(PointStyle.CIRCLE);
        r.setFillBelowLine(true);
        r.setFillBelowLineColor(Color.WHITE);
        r.setFillPoints(true);
        renderer.addSeriesRenderer(r);
        renderer.setMarginsColor(Color.WHITE);
        renderer.setPanEnabled(false, false);
        renderer.setShowGrid(true);
        renderer.setYAxisMax(50);
        renderer.setYAxisMin(-30);
        renderer.setInScroll(true); // 调整大小
        return renderer;
    }
    /**
     * 数据对象
     * 
     * @return
     */
    private XYMultipleSeriesDataset getDateDemoDataset() {
        dataset1 = new XYMultipleSeriesDataset();
        final int nr = 10;
        long value = new Date().getTime();
        Random r = new Random();
        for (int i = 0; i < SERIES_NR; i++) {
            series1 = new TimeSeries("Demo series " + (i + 1));
            for (int k = 0; k < nr; k++) {
                series1.add(new Date(value + k * 1000), 0);
            }
            dataset1.addSeries(series1);
        }
        Log.i(TAG, dataset1.toString());
        return dataset1;
    }
    
    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        if (event.sensor == null) {
            return;
        }

        if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
            float x =  event.values[0];
            float y =  event.values[1];
            float z =  event.values[2];
            mCalendar = Calendar.getInstance();
            long stamp = mCalendar.getTimeInMillis();// 1393844912

            textviewX.setText(String.valueOf(x));
            textviewY.setText(String.valueOf(y));
            textviewZ.setText(String.valueOf(z));

            int second = mCalendar.get(Calendar.SECOND);// 53

            float px = Math.abs(mX - x);
            float py = Math.abs(mY - y);
            float pz = Math.abs(mZ - z);
            Log.d(TAG, "pX:" + px + "  pY:" + py + "  pZ:" + pz + "    stamp:"
                    + stamp + "  second:" + second);
            float maxvalue = getMaxValue(px, py, pz);
            if (maxvalue > 2 && (stamp - lasttimestamp) > 200) {
                lasttimestamp = stamp;
                
                updateChart(x+y+z);
                
                textviewF.setText("检测手机在移动..");
            }

            mX = x;
            mY = y;
            mZ = z;

        }
    }

    /**
     * 获取一个最大值
     * 
     * @param px
     * @param py
     * @param pz
     * @return
     */
    public float getMaxValue(float px, float py, float pz) {
        float max = 0;
        if (px > py && px > pz) {
            max = px;
        } else if (py > px && py > pz) {
            max = py;
        } else if (pz > px && pz > py) {
            max = pz;
        }

        return max;
    }
}