Scroll Chart : Chart « Advanced Graphics « Java





Scroll Chart

Scroll Chart
 
import java.awt.*;
import java.applet.*;
import java.net.URL;
import java.util.*;
import graph.*;
/*************************************************************************
**
**    Applet example2a
**                                              Version 1.0   August 1996
**
**************************************************************************
**    Copyright (C) 1996 Leigh Brookshaw
**
**    This program is free software; you can redistribute it and/or modify
**    it under the terms of the GNU General Public License as published by
**    the Free Software Foundation; either version 2 of the License, or
**    (at your option) any later version.
**
**    This program is distributed in the hope that it will be useful,
**    but WITHOUT ANY WARRANTY; without even the implied warranty of
**    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**    GNU General Public License for more details.
**
**    You should have received a copy of the GNU General Public License
**    along with this program; if not, write to the Free Software
**    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**************************************************************************
**
**    This is a simple applet that creates a Scroll Chart using the 
**    Graph2D class library and double buffering
**
*************************************************************************/

public class example2a extends Applet implements Runnable {

      Graph2D graph;
      Label title;
      DataSet data1 = new DataSet();

      Axis    yaxis_right;

      Image    osi = null;
      Graphics osg = null;
      int iwidth  = 0;
      int iheight = 0;

      Thread runner = null;
      Random random = new Random();
      int count = 0;



/*
**    In milliseconds how often do we want to add a new data point.
*/
      int period      = 500;
/*
**    Maximum number of points to display before scrolling the data
*/
      int maximum        = 25;
      URL markersURL;
/*
**    Initialize the applet. The Parameters passed are the title of the plot
**    the marker file to use and the update period in milliseconds
*/
      public void init() {
        int i;
        int j;

/*
**      Get the passed parameters
*/
        String st       = "TITLE";
        String mfile    = "marker.txt";
        period   = 10;
/*
**      Create the Graph instance and modify the default behaviour
*/
        graph = new Graph2D();
        graph.zerocolor = new Color(0,255,0);
        graph.borderTop    = 50;
        graph.borderBottom = 50;
        graph.setDataBackground(Color.black);
/*
**      Create the Title
*/
        title = new Label(st, Label.CENTER);
        title.setFont(new Font("TimesRoman",Font.PLAIN,25));

        setLayout( new BorderLayout() );
        add("North",  title);
        add("Center", graph);
/*
**      Load a file containing Marker definitions
*/
        try {
           markersURL = this.getClass().getResource(mfile);
           graph.setMarkers(new Markers(markersURL));
        } catch(Exception e) {
           System.out.println("Failed to create Marker URL!");
        }
 

/*
**      Modify the default Data behaviour
*/
        data1.linecolor   = new Color(255,0,0);
        data1.marker      = 1;
        data1.markercolor = new Color(100,100,255);
/*
**      Setup the Axis. Attach it to the Graph2D instance, and attach the data
**      to it.
*/
        yaxis_right = graph.createAxis(Axis.RIGHT);
        yaxis_right.attachDataSet(data1);
        yaxis_right.setLabelFont(new Font("Helvetica",Font.PLAIN,20));

        graph.attachDataSet(data1);


      }

      public void start() {
  if(runner == null) {
          runner = new Thread(this);
          runner.start();
        }
      }


      public void stop() {
  if(runner != null) {
          runner.stop();
          runner = null;
        }
      }




        public void run() {
              int i =0;
              double data[] = new double[2];
              Graphics g;

              while(true) {


                   count++;

                   if(count >= maximum) data1.delete(0,0);

                   data[1] = (2.0*random.nextDouble()-1.0)*50.0;
                   data[0] = count;

                   try {
                        data1.append(data,1);
          }
                   catch (Exception e) {
                        System.out.println("Error appending Data!");
                   }

                   data1.yaxis.maximum =  50.0;
                   data1.yaxis.minimum = -50.0;

                   
                   g = graph.getGraphics();
       if( osi == null || iwidth != graph.size().width
                                   || iheight != graph.size().height  ) {
                       iwidth = graph.size().width;
                       iheight = graph.size().height;
                       osi = graph.createImage(iwidth,iheight);
                       osg = osi.getGraphics();
                   }

                   osg.setColor(this.getBackground());
                   osg.fillRect(0,0,iwidth,iheight);
                   osg.setColor(g.getColor());

                   osg.clipRect(0,0,iwidth,iheight);


                   graph.update(osg);

                   g.drawImage(osi,0,0,graph);



                   try {  Thread.sleep(period); }
                   catch(Exception e) { }

       }

  }
      public static void main(String[] a){
         javax.swing.JFrame f = new javax.swing.JFrame();
         Applet app = new example2();
         app.init();
         
         f.getContentPane().add (app);

         f.pack();
         f.setSize (new Dimension (500, 500));
         f.setVisible(true);
      }


}



           
         
  










Graph-Scroll-Chart.zip( 198 k)

Related examples in the same category

1.Chart based on Graph libraryChart based on Graph library
2.Animation Line ChartAnimation Line Chart
3.Pie ChartPie Chart
4.A rudimentary chart libraryA rudimentary chart library
5.A rudimentary bar chart classA rudimentary bar chart class
6.bar-graph drawable