<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:ap="http://schemas.android.com/apk/res-auto"
 style="@style/sample_activity">
 <com.androidplot.xy.XYPlot
 style="@style/simple_xy"
 android:id="@+id/dynamicXYPlot"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 androidplot.renderMode="use_background_thread"
 ap:label="A Dynamic XY Plot"
 ap:domainLabel="Domain"
 ap:rangeLabel="Range"
 ap:legendTextSize="15sp"
 ap:legendIconHeight="15dp"
 ap:legendIconWidth="15dp"
 ap:legendHeight="25dp"
 ap:legendAnchorPosition="right_bottom"/>
</LinearLayout>

package com.androidplot.demos;
import android.app.Activity;
import android.graphics.Color;
import android.graphics.DashPathEffect;
import android.graphics.Paint;
import android.os.Bundle;
import com.androidplot.Plot;
import com.androidplot.util.PixelUtils;
import com.androidplot.xy.XYSeries;
import com.androidplot.xy.*;
import java.text.DecimalFormat;
import java.util.Observable;
import java.util.Observer;
public class DynamicXYPlotActivity extends Activity {
 // redraws a plot whenever an update is received:
 private class MyPlotUpdater implements Observer {
 Plot plot;
 public MyPlotUpdater(Plot plot) {
 this.plot = plot;
 }
 @Override
 public void update(Observable o, Object arg) {
 plot.redraw();
 }
 }
 private XYPlot dynamicPlot;
 private MyPlotUpdater plotUpdater;
 SampleDynamicXYDatasource data;
 private Thread myThread;
 @Override
 public void onCreate(Bundle savedInstanceState) {
 // android boilerplate stuff
 super.onCreate(savedInstanceState);
 setContentView(R.layout.dynamicxyplot_example);
 // get handles to our View defined in layout.xml:
 dynamicPlot = (XYPlot) findViewById(R.id.dynamicXYPlot);
 plotUpdater = new MyPlotUpdater(dynamicPlot);
 // only display whole numbers in domain labels
 dynamicPlot.getGraphWidget().setDomainValueFormat(new DecimalFormat("0"));
 // getInstance and position datasets:
 data = new SampleDynamicXYDatasource();
 SampleDynamicSeries sine1Series = new SampleDynamicSeries(data, 0, "Sine 1");
 SampleDynamicSeries sine2Series = new SampleDynamicSeries(data, 1, "Sine 2");
 LineAndPointFormatter formatter1 = new LineAndPointFormatter(
 Color.rgb(0, 0, 0), null, null, null);
 formatter1.getLinePaint().setStrokeJoin(Paint.Join.ROUND);
 formatter1.getLinePaint().setStrokeWidth(10);
 dynamicPlot.addSeries(sine1Series,
 formatter1);
 LineAndPointFormatter formatter2 =
 new LineAndPointFormatter(Color.rgb(0, 0, 200), null, null, null);
 formatter2.getLinePaint().setStrokeWidth(10);
 formatter2.getLinePaint().setStrokeJoin(Paint.Join.ROUND);
 //formatter2.getFillPaint().setAlpha(220);
 dynamicPlot.addSeries(sine2Series, formatter2);
 // hook up the plotUpdater to the data model:
 data.addObserver(plotUpdater);
 // thin out domain tick labels so they dont overlap each other:
 dynamicPlot.setDomainStepMode(XYStepMode.INCREMENT_BY_VAL);
 dynamicPlot.setDomainStepValue(5);
 dynamicPlot.setRangeStepMode(XYStepMode.INCREMENT_BY_VAL);
 dynamicPlot.setRangeStepValue(10);
 dynamicPlot.setRangeValueFormat(new DecimalFormat("###.#"));
 // uncomment this line to freeze the range boundaries:
 dynamicPlot.setRangeBoundaries(-100, 100, BoundaryMode.FIXED);
 // create a dash effect for domain and range grid lines:
 DashPathEffect dashFx = new DashPathEffect(
 new float[] {PixelUtils.dpToPix(3), PixelUtils.dpToPix(3)}, 0);
 dynamicPlot.getGraphWidget().getDomainGridLinePaint().setPathEffect(dashFx);
 dynamicPlot.getGraphWidget().getRangeGridLinePaint().setPathEffect(dashFx);
 }
 @Override
 public void onResume() {
 // kick off the data generating thread:
 myThread = new Thread(data);
 myThread.start();
 super.onResume();
 }
 @Override
 public void onPause() {
 data.stopThread();
 super.onPause();
 }
 class SampleDynamicXYDatasource implements Runnable {
 // encapsulates management of the observers watching this datasource for update events:
 class MyObservable extends Observable {
 @Override
 public void notifyObservers() {
 setChanged();
 super.notifyObservers();
 }
 }
 private static final double FREQUENCY = 5; // larger is lower frequency
 private static final int MAX_AMP_SEED = 100;
 private static final int MIN_AMP_SEED = 10;
 private static final int AMP_STEP = 1;
 public static final int SINE1 = 0;
 public static final int SINE2 = 1;
 private static final int SAMPLE_SIZE = 30;
 private int phase = 0;
 private int sinAmp = 1;
 private MyObservable notifier;
 private boolean keepRunning = false;
 {
 notifier = new MyObservable();
 }
 public void stopThread() {
 keepRunning = false;
 }
 //@Override
 public void run() {
 try {
 keepRunning = true;
 boolean isRising = true;
 while (keepRunning) {
 Thread.sleep(10); // decrease or remove to speed up the refresh rate.
 phase++;
 if (sinAmp >= MAX_AMP_SEED) {
 isRising = false;
 } else if (sinAmp <= MIN_AMP_SEED) {
 isRising = true;
 }
 if (isRising) {
 sinAmp += AMP_STEP;
 } else {
 sinAmp -= AMP_STEP;
 }
 notifier.notifyObservers();
 }
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 }
 public int getItemCount(int series) {
 return SAMPLE_SIZE;
 }
 public Number getX(int series, int index) {
 if (index >= SAMPLE_SIZE) {
 throw new IllegalArgumentException();
 }
 return index;
 }
 public Number getY(int series, int index) {
 if (index >= SAMPLE_SIZE) {
 throw new IllegalArgumentException();
 }
 double angle = (index + (phase))/FREQUENCY;
 double amp = sinAmp * Math.sin(angle);
 switch (series) {
 case SINE1:
 return amp;
 case SINE2:
 return -amp;
 default:
 throw new IllegalArgumentException();
 }
 }
 public void addObserver(Observer observer) {
 notifier.addObserver(observer);
 }
 public void removeObserver(Observer observer) {
 notifier.deleteObserver(observer);
 }
 }
 class SampleDynamicSeries implements XYSeries {
 private SampleDynamicXYDatasource datasource;
 private int seriesIndex;
 private String title;
 public SampleDynamicSeries(SampleDynamicXYDatasource datasource, int seriesIndex, String title) {
 this.datasource = datasource;
 this.seriesIndex = seriesIndex;
 this.title = title;
 }
 @Override
 public String getTitle() {
 return title;
 }
 @Override
 public int size() {
 return datasource.getItemCount(seriesIndex);
 }
 @Override
 public Number getX(int index) {
 return datasource.getX(seriesIndex, index);
 }
 @Override
 public Number getY(int index) {
 return datasource.getY(seriesIndex, index);
 }
 }
}