AWT Event look for help

[Hui Zhao]

Hi, I want control my graph by select JSlider and Comboxbox such as zoom or so. But the working is obvious wrong.
The problem has two:
(1) when I moved JSlider, the new picture would replace the old picture whatever zoom in or out.
That is my expection. but in my program, many pictures occuried like animation. I guess probably I used repaint(). I don't know how to treat it.
(2) When I choose an item from the Combobox, the whole picture color would be changed because I fired an integer number "id" event to the method in class Drawing.

Thanks

 
import java.io.*;
 
import java.awt.Font;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.BasicStroke;
import java.awt.Dimension;
import java.awt.geom.GeneralPath;
 
import java.awt.geom.*;
import java.applet.Applet;
import java.awt.*;
import javax.swing.*;
 
import java.util.Hashtable;
import java.awt.event.*;
 
import javax.swing.event.*;
 

public class Test extends JApplet 
{
    private LayoutManager Layout;
    private Container Panel;
    private Drawing drawing;
 
    private int id; //PlotEnergyId
    private double x = 5;
    private int min = 1, max = 16, inc = 5;
    double scale = 1.0;
    
    private JSlider dJSlider;
    private JComboBox comb;
    
      public void init() {
         Layout = new BorderLayout ();
         FlowLayout Layout1 = new FlowLayout();
                                
                drawing = new Drawing();
//                drawing.getDrawingData();
         JLabel patternLabel1 = new JLabel("Select one set");
         String e[] = {"1","2"};
         comb = new JComboBox(e);
         comb.setAlignmentX(Component.LEFT_ALIGNMENT);
         comb.setEditable(false);
         comb.setForeground (Color.red);
         comb.setBackground (Color.yellow);
         comb.setAlignmentX(Component.LEFT_ALIGNMENT);
         comb.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
         comb.addActionListener(
                new ActionListener() // anonymous inner class
                {
                    public void actionPerformed(ActionEvent e)
                    {
                       JComboBox cb = (JComboBox)e.getSource();
                       id = cb.getSelectedIndex();
                    }
                }
          );
                dJSlider = new JSlider(min, max, 6);
                dJSlider.setMajorTickSpacing(5);
                dJSlider.setMinorTickSpacing(1);
                dJSlider.setSnapToTicks(true);
                dJSlider.setLabelTable(getLabelTable(min, max, inc));
                dJSlider.setPaintTicks(true);
                dJSlider.setPaintLabels(true);
                dJSlider.addChangeListener(
                        new ChangeListener() // anonymous inner class
                        // handle change in slider value
                       {
                            public void stateChanged(ChangeEvent e)
                            {
                               int value = ((JSlider)e.getSource()).getValue();
                               scale = (value+4)/10.0; 
                               drawing.scaleData(scale);
                            }
                        }
                );     
                JPanel cPanel = new JPanel(); 
                cPanel.setLayout(Layout1);
                cPanel.add(patternLabel1);
                cPanel.add(comb);
                cPanel.add(dJSlider);
 
                Panel = getContentPane();
                Panel.setLayout (Layout);
 
                 Panel.add (drawing, "Center");
                 Panel.add (cPanel, BorderLayout.NORTH); 
 } 
   
    
     private Hashtable getLabelTable(int min, int max, int inc) {
        Hashtable<Integer, JLabel> table = new Hashtable<Integer, JLabel>();
        for(int j = min; j <= max; j+=inc) {
            String s = String.format("%.1f", (j+4)/10.0);
            table.put(Integer.valueOf(j), new JLabel(s));
        }
        return table;
    }
       
  class Drawing extends JPanel
  {
     
       public void paintComponent(Graphics g)
      {
            Graphics2D g2d = (Graphics2D)g; // cast g to Graphics 2D
        
            drawSides(g2d);
        }
       
      public void scaleData(double scale)
         {
            x = x*scale;
            repaint();
         }  
  
        
        public void drawSides(Graphics g2d)
       {
            if (id == 0)
            g2d.setColor(Color.GRAY);
            g2d.setColor(Color.GREEN);
            g2d.fillOval(10,10,(int)x,(int)x);
        }
         
   // end method paintComponent
  }
  public static void main(String[] args) {
   
      /* Set up the frame that holds the applet. */
    JFrame appletFrame = new JFrame("My Applet");
    Applet theApplet = new Test();
 
    appletFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    appletFrame.setSize(800,800);
    appletFrame.add(theApplet, "Center");  // applet fills
 
    /* Now start invoking applet methods. */
    theApplet.init();
 
    appletFrame.setVisible(true); 
    theApplet.start();
    theApplet.stop();
    theApplet.destroy();
 
}
 
            
} // end class 
 

[Craig Wood]

(1) when I moved JSlider, the new picture would replace the old picture whatever zoom in or out. That is my expection. but in my program, many pictures occuried like animation
If the enclosing JPanel is opaque then you must make arrangements to fill its entire background each time its paintComponent method id called. An easy way to do this is with a call to super.paintComponent.
(2)When I choose an item from the Combobox, the whole picture color would be changed
You have to tell the Drawing class that you want to change the color it uses.
because I fired an integer number "id" event to the method in class Drawing.
Not exactly. The JComboBox generated an ActionEvent from user interaction and we can monitor this in the listener to find out what the user selected. We can query the comboBox for the user selection and use this information to select a corresponding Color and then tell the Drawing class to change to this new Color.

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
//import java.awt.geom.*;
//import java.io.*;
import java.util.Hashtable;
import javax.swing.*;
import javax.swing.event.*;
 
public class ATestApplet extends JApplet {
    // You can change some of these member variables
    // to local variables. We generally expose things
    // as member variables (in class scope) so we can
    // access them in methods (outside the constructor)
    // or from other (outside) classes.
//    private LayoutManager Layout;
//    private Container Panel;
    private Drawing drawing;
 
//    private int id;    //PlotEnergyId
//    private double x = 5;
    private int min = 1, max = 16, inc = 5;
//    double scale = 1.0;
 
    private JSlider dJSlider;
    private JComboBox comb;
 
    public void init() {
        // Unless you need to access this later from outside
        // this constructor there is no need to declare it
        // as a member variable (in class scope).
        BorderLayout Layout = new BorderLayout();
        FlowLayout Layout1 = new FlowLayout();
 
        drawing = new Drawing();
//        drawing.getDrawingData();
        JLabel patternLabel1 = new JLabel("Select one set");
        String[] e = { "red", "green", "blue" };
        comb = new JComboBox(e);
        comb.setAlignmentX(Component.LEFT_ALIGNMENT);
        comb.setEditable(false);
        comb.setForeground (Color.red);
        comb.setBackground (Color.yellow);
        comb.setAlignmentX(Component.LEFT_ALIGNMENT);
        comb.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
        comb.addActionListener(
            new ActionListener() { // anonymous inner class
                Color[] colors = { Color.red, Color.green.darker(), Color.blue };
 
                public void actionPerformed(ActionEvent e) {
                    JComboBox cb = (JComboBox)e.getSource();
                    int id = cb.getSelectedIndex();
                    // Get a Color with the selectedIndex.
                    Color color = colors[id];
                    // Tell the Drawing class to change colors.
                    drawing.setColor(color);
                }
            }
        );
        dJSlider = new JSlider(min, max, 6);
        dJSlider.setMajorTickSpacing(5);
        dJSlider.setMinorTickSpacing(1);
        dJSlider.setSnapToTicks(true);
        dJSlider.setLabelTable(getLabelTable(min, max, inc));
        dJSlider.setPaintTicks(true);
        dJSlider.setPaintLabels(true);
        dJSlider.addChangeListener(
            new ChangeListener() {  // anonymous inner class
                // handle change in slider value
                public void stateChanged(ChangeEvent e) {
                    int value = ((JSlider)e.getSource()).getValue();
                    double scale = (value+4)/10.0; 
                    drawing.scaleData(scale);
                }
            }
        ); 
        JPanel cPanel = new JPanel();
        System.out.println("Default layout manager for JPanel is: " +
                            cPanel.getLayout().getClass().getName());
        cPanel.setLayout(Layout1);
        cPanel.add(patternLabel1);
        cPanel.add(comb);
        cPanel.add(dJSlider);
        Container Panel = getContentPane();
        Panel.setLayout (Layout);
 
        Panel.add (drawing, "Center");
        Panel.add (cPanel, BorderLayout.NORTH); 
    }
 
    private Hashtable getLabelTable(int min, int max, int inc) {
        Hashtable<Integer, JLabel> table = new Hashtable<Integer, JLabel>();
        for(int j = min; j <= max; j+=inc) {
            String s = String.format("%.1f", (j+4)/10.0);
            table.put(Integer.valueOf(j), new JLabel(s));
        }
        return table;
    }
 
    class Drawing extends JPanel {
        // Encapsulate these variables in the scope of this (Drawing)
        // class. This simplifies the enclosing class (the JApplet).
        private Color color = Color.GRAY;
        private double x = 5;
        private double scale = 1.0;
 
        public void paintComponent(Graphics g) {
            // This statement asks the superclass (JPanel) to
            // draw/fill in its default background. This will
            // have the affect of erasing any previous drawing.
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D)g; // cast g to Graphics 2D
            drawSides(g2d);
        }
 
        public void scaleData(double scale) {
//            x = x*scale;
            this.scale = scale;
            repaint();
        } 
 
        public void setColor(Color color) {
            this.color = color;
            repaint();
        }
 
        public void drawSides(Graphics g2d) {
//            if (id == 0)
//                g2d.setColor(Color.GRAY);
            g2d.setColor(color);
            g2d.fillOval(10,10,(int)(scale*x),(int)(scale*x));
        }
    }
 
    public static void main(String[] args) {
        /* Set up the frame that holds the applet. */
        JFrame appletFrame = new JFrame("My Applet");
        Applet theApplet = new ATestApplet();
        appletFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        appletFrame.setSize(800,800);
        appletFrame.add(theApplet, "Center"); // applet fills
        /* Now start invoking applet methods. */
        theApplet.init();
        appletFrame.setVisible(true);
        // You generally don't need to call start and stop unless
        // you are overriding them for animations. Overriding them
        // allows the applet to start/stop its timers/threads when
        // restored/minimized so that it remains "friendly" in the
        // environment of its host.
//theApplet.start();
//theApplet.stop();
//theApplet.destroy();
    }
}

[Hui Zhao]

very helpful, thank you very much

[Hui Zhao]

Craig, please help me again.
My more complex code, JSlide is still not working.

import java.io.*;
import java.util.List;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.ListIterator;
 
import java.awt.Graphics;
import java.awt.BasicStroke;
 
import java.awt.AlphaComposite;
import java.awt.Composite;
import java.awt.geom.*;
import java.applet.Applet;
import java.awt.*;
import javax.swing.*;
 
import java.util.Hashtable;
import java.awt.event.*;
 
import javax.swing.event.*;
 
// import AppletAndApplicationExample.AppQuitter;
 
public class Combox extends JApplet 
{
   
//    private double rgb[][]; // Color red, green, blue for each point in each cell
    private LayoutManager Layout;
    private Container Panel;
    private Drawing drawing;
    private double red[][];
    private double green[][];
    private double blue[][];
    private String energyId[];
    
    private int sideId;
    private int sidesTotalNumber; // Total sides number for all cells
    private int rgbLength; // Total rgb color group number for all cells at each point
    private int cellsPointsNumber[]; // point numbers of each cell.(each cell has how many points)
    private int numberofCells;
    private int numberofsets;
    private double lineWidth;
    private int min = 1, max = 16, inc = 5;
    
    private double maximumX;
    private double maximumY;
    
    private JSlider dJSlider;
    private JComboBox comb;
    
      public void init() {
         Layout = new BorderLayout ();
         FlowLayout Layout1 = new FlowLayout();
         getEnergyIdData();                                
                drawing = new Drawing();
                
//                drawing.setBackground (Color.white);
   
    
         JLabel patternLabel1 = new JLabel("Select one set");
         comb = new JComboBox(energyId);
         comb.setAlignmentX(Component.LEFT_ALIGNMENT);
         comb.setEditable(false);
         comb.setForeground (Color.red);
         comb.setBackground (Color.yellow);
         comb.setAlignmentX(Component.LEFT_ALIGNMENT);
         comb.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
         comb.addActionListener(
                new ActionListener() // anonymous inner class
                {
                    public void actionPerformed(ActionEvent e)
                    {
                       JComboBox cb = (JComboBox)e.getSource();
                       int id = cb.getSelectedIndex();
                       drawing.setColor(id);
                    }
                }
          );
                dJSlider = new JSlider(min, max, 6);
                dJSlider.setMajorTickSpacing(5);
                dJSlider.setMinorTickSpacing(1);
                dJSlider.setSnapToTicks(true);
                dJSlider.setLabelTable(getLabelTable(min, max, inc));
                dJSlider.setPaintTicks(true);
                dJSlider.setPaintLabels(true);
                dJSlider.addChangeListener(
                        new ChangeListener() // anonymous inner class
                        // handle change in slider value
                       {
                            public void stateChanged(ChangeEvent e)
                            {
                               int value = ((JSlider)e.getSource()).getValue();
                               double scale = (value+4)/10.0; 
                               drawing.scaleData(scale);
                            }
                        }
                );     
                JPanel cPanel = new JPanel(); 
                cPanel.setLayout(Layout1);
                cPanel.add(patternLabel1);
                cPanel.add(comb);
                cPanel.add(dJSlider);
 
                Panel = getContentPane();
                Panel.setLayout (Layout);
 
                 Panel.add (drawing, "Center");
                 Panel.add (cPanel, BorderLayout.NORTH); 
//        setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
 } 
   
    
     private Hashtable getLabelTable(int min, int max, int inc) {
        Hashtable<Integer, JLabel> table = new Hashtable<Integer, JLabel>();
        for(int j = min; j <= max; j+=inc) {
            String s = String.format("%.1f", (j+4)/10.0);
            table.put(Integer.valueOf(j), new JLabel(s));
        }
        return table;
    }
  
   
    private AlphaComposite makeComposite(float alpha) 
    {
          int type = AlphaComposite.SRC_OVER;
          return(AlphaComposite.getInstance(type, alpha));
    }
   
    
    public void getEnergyIdData()
    {
          TestCell p = new TestCell();
          p.cellNumber();
          numberofCells = p.getnumberofCells();
          numberofsets  = p.getnumberofsets();
 
          energyId = new String[numberofsets];    
          p.energyId();
 
          energyId = p.getenergyId();
        }
  
      
  class Drawing extends JPanel
  {
       private int TRANSITION = 100; // Transition x,y coordinates of cells.
    private double x1, y1, x2, y2; // to plot lines from (x1,y1) to (x2,y2)
 
    private double xCells[][]; // Every cell's points's x coordinates array
    private double yCells[][]; // Every cell's points's y coordinates array
    
    private double xCells0[][]; // Every cell's points's x original coordinates array
    private double yCells0[][]; // Every cell's points's y original coordinates array
     private int id;
       public void paintComponent(Graphics g)
      {
           super.paintComponent(g);
            Graphics2D g2d = (Graphics2D)g; // cast g to Graphics 2D
            g2d.setBackground(Color.LIGHT_GRAY);
                         getDrawingData();
            drawPolygon(g2d);  
//            Composite originalComposite = g2d.getComposite();
            drawSides(g2d);
            g2d.setComposite(makeComposite(1.0f));
//              g2d.setComposite(originalComposite);
        }
       
     public void getDrawingData()
        {
              TestCell p = new TestCell();
              p.cellNumber();
              numberofCells = p.getnumberofCells();
              numberofsets  = p.getnumberofsets();
 
              xCells = new double[numberofCells][];
              yCells = new double[numberofCells][];
              xCells0 = new double[numberofCells][];
              yCells0 = new double[numberofCells][];              
              for(int i = 0; i<numberofCells; i++)
              {
                    xCells[i] = new double[numberofsets]; // maximum points in ith cell
                    yCells[i] = new double[numberofsets]; // maximum points in ith cell
                    xCells0[i] = new double[numberofsets]; // copy for xCells
                    yCells0[i] = new double[numberofsets]; // copy for yCells                  
 
              }
              cellsPointsNumber = new int[numberofCells];
              red = new double[numberofCells][];
              green = new double[numberofCells][];
              blue = new double[numberofCells][]; 
              for(int i=0; i<numberofCells; i++)
              {
                   red[i]   = new double[numberofsets];
                   green[i] = new double[numberofsets];
                   blue[i]  = new double[numberofsets];
              }
 
              p.cellData();
 
              p.rgbs();
              xCells = p.getxCells();
              yCells = p.getyCells();
    
              // clone arrays
                for(int i = 0; i < numberofCells; i++)
                { 
                     for(int j = 0; j<cellsPointsNumber[i]; j++)
                     {
                       xCells0[i][j] = xCells[i][j];
                       yCells0[i][j] = yCells[i][j];
                      }
                 }
              sidesTotalNumber = p.getsidesTotalNumber();
     
              red = p.getred();
              green = p.getgreen();
              blue  = p.getblue();
              cellsPointsNumber = p.getcellsPointsNumber();//array: each cell has how many points          
              rgbLength = p.getrgbLength();
           }
        
         public void scaleData(double scale)
         {
            for(int i = 0; i < numberofCells; i++)
                { 
                  for(int j = 0; j<cellsPointsNumber[i]; j++)
                  {
                      xCells[i][j] = (xCells0[i][j])*scale;
                      yCells[i][j] = (yCells0[i][j])*scale;
                  }
              }
 
        
           repaint();
         }
        public void drawSides(Graphics2D g2d)
       {
            g2d.setColor(Color.GRAY);
            g2d.setStroke(new BasicStroke((float)lineWidth));
 
            for (int i = 0; i<numberofCells; i++)
            {
                for (int j = 0; j<cellsPointsNumber[i]-1; j++)
                {  
                    x1 = xCells[i][j];
                    y1 = yCells[i][j];
                    x2 = xCells[i][j+1];
                    y2 = yCells[i][j+1];
                    Line2D line = new Line2D.Double(x1,y1,x2,y2);
                    g2d.draw(line);// draw Sidess here
                } 
             }
            }
       public void setColor(int id) 
       {            this.id = id;   
                    repaint();   
       }
       public void drawPolygon(Graphics2D g2d)
       {
             for (int i = 0; i<numberofCells; i++)
             {
                Polygon poly = new Polygon();
                float r  = (float)red[i][id]; 
                 // red for ith cell,id is from 0 to numberofsets-1
                 // if id=0, means "Mixture"
                float g  = (float)green[i][id]; // green for ith cell
                float b  = (float)blue[i][id]; // blue for ith cell
                List<Integer> xList = new ArrayList<Integer>(); 
                List<Integer> yList = new ArrayList<Integer>();
                for (int j = 0; j<cellsPointsNumber[i]; j++)
                {  
                    xList.add((int)(xCells[i][j]));
                    yList.add((int)(yCells[i][j]));
                } 
                Integer[] x = xList.toArray(new Integer[xList.size()]);
                Integer[] y = yList.toArray(new Integer[yList.size()]);
                for (int s = 0; s<xList.size(); s++)
                {
                    poly.addPoint(x[s],y[s]);
                }
                g2d.setColor(new Color(r, g, b));// transparent drawing
                  g2d.fillPolygon(poly);
              }  
       }
      
         
   // end method paintComponent
  }
  public static void main(String[] args) {
   
      /* Set up the frame that holds the applet. */
    JFrame appletFrame = new JFrame("My Applet");
    Applet theApplet = new Combox();
 
    appletFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    appletFrame.setSize(800,800);
   // appletFrame.pack();  // create peer frame (hack)
    appletFrame.add(theApplet, "Center");  // applet fills
 

    /* Now start invoking applet methods. */
    theApplet.init();
 //   appletFrame.pack();  // resize frame to fit initialized
                         // applet
    appletFrame.setVisible(true);  // bring frame and initialized
                         // applet on screen
   
}
 
            
} // end class 
    

[Hui Zhao]

I want to pass two 2D array to a defined method in class "Drawing" then to plot a gemeotry. The arrays are initialized by reading a text file.
Do I pass array within init() then pass them with the events?

Thanks

[Craig Wood]

Without the TestCell class and the data it makes available I was unable to try your class.
I did observe something that might be causing some trouble. When you call the setScale
method in Drawing it scales the data in xCells and yCells. On the next repaint this data is
re-computed/reset in the getDrawingData method without any scale factor. You might consider
either calling getDrawingData only one time (you could call it again for componentResized
events) or incorporating a scale factor (member variable) in it to do the scaling.

I want to pass two 2D array to a defined method in class "Drawing" then to plot a
gemeotry. The arrays are initialized by reading a text file.
Do I pass array within init() then pass them with the events?
I would try to read the data from the applet on startup, eg, call a method in your applet
from within init that would read the data and then pass the data to the Drawing
class through its constructor. You could use a setData method, especially if you
plan to change the data during runtime.

public class Pseudo extends JApplet...
    Drawing drawing;
 
    public void init() {
        StringBuilder sb = getDataFromFile();
        int[][] data = prepareData(sb);
        drawing = new Drawing(data);
    }
 
    private StringBuilder getDataFromFile() {
        read file
    }
 
    private int[][] prepareData(StringBuilder sb) {
        ...
    }
 
    class Drawing...
        int[][] data;
 
        Drawing(int[][] data) {
            this.data = data;
        }

[Hui Zhao]

Hi, I am ashamed to bother you again.
Because pass a 2D array is really inconvince. The length of arrays are dynamicly generated by call TestCell class. So I used to clone array to avoid recompute and I just use one class. However the clone is wrong, Could you help me look again?

Thanks so so much.
Best Regardsss!

import java.io.*;
import java.util.List;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.ListIterator;
import java.util.Scanner;
 
import java.awt.Font;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.BasicStroke;
import java.awt.GradientPaint;
import java.awt.geom.GeneralPath;
 
import java.awt.AlphaComposite;
import java.awt.Composite;
import java.awt.geom.*;
import java.applet.Applet;
import java.awt.*;
import javax.swing.*;
 
import java.util.Hashtable;
import java.awt.event.*;
 
import javax.swing.event.*;
 
// import AppletAndApplicationExample.AppQuitter;
 
public class Combox extends JApplet 
{
    private LayoutManager Layout;
    private Container Panel;
    private double xCells[][]; // Every cell's points's x coordinates array
    private double yCells[][]; // Every cell's points's y coordinates array 
    
    private double xCells0[][]; // Every cell's points's x original coordinates array
    private double yCells0[][]; // Every cell's points's y original coordinates array    
    private double red[][];
    private double green[][];
    private double blue[][];
    private String energyId[];
    private int TRANSITION = 100; // Transition x,y coordinates of cells.
    private double x1, y1, x2, y2; // to plot lines from (x1,y1) to (x2,y2)
    private int sideId;
    private int sidesTotalNumber; // Total sides number for all cells
    private int rgbLength; // Total rgb color group number for all cells at each point
    private int cellsPointsNumber[]; // point numbers of each cell.(each cell has how many points)
    private int numberofCells;
    private int numberofsets;
    private double lineWidth;
    private int min = 1, max = 16, inc = 5;
    double scale = 1.0;
     private int id;
    private double maximumX;
    private double maximumY;
    
    private JSlider dJSlider;
    private JComboBox comb;
    
    public void init() {
         Layout = new BorderLayout ();
         FlowLayout Layout1 = new FlowLayout();
         getEnergyIdData();                                
         getDrawingData();
         comb = new JComboBox(energyId);
         comb.setAlignmentX(Component.LEFT_ALIGNMENT);
         comb.setEditable(false);
         comb.setForeground (Color.red);
         comb.setBackground (Color.yellow);
         comb.setAlignmentX(Component.LEFT_ALIGNMENT);
         comb.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
         comb.addActionListener(
                new ActionListener() // anonymous inner class
                {
                    public void actionPerformed(ActionEvent e)
                    {
                       JComboBox cb = (JComboBox)e.getSource();
                       int id = cb.getSelectedIndex();
                       setColor(id);
                    }
                }
          );
                dJSlider = new JSlider(min, max, 6);
                dJSlider.setMajorTickSpacing(5);
                dJSlider.setMinorTickSpacing(1);
                dJSlider.setSnapToTicks(true);
                dJSlider.setLabelTable(getLabelTable(min, max, inc));
                dJSlider.setPaintTicks(true);
                dJSlider.setPaintLabels(true);
                dJSlider.addChangeListener(
                        new ChangeListener() // anonymous inner class
                        // handle change in slider value
                       {
                            public void stateChanged(ChangeEvent e)
                            {
                               int value = ((JSlider)e.getSource()).getValue();
                               scale = (value+4)/10.0; 
                               scaleData(scale);
                            }
                        }
                );     
                JPanel cPanel = new JPanel(); 
                cPanel.setLayout(Layout1);
                cPanel.add(comb);
                cPanel.add(dJSlider);
 
                Panel = getContentPane();
                Panel.setLayout (Layout);
                Panel.add (cPanel, BorderLayout.EAST); 
 } 
   
    
     private Hashtable getLabelTable(int min, int max, int inc) {
        Hashtable<Integer, JLabel> table = new Hashtable<Integer, JLabel>();
        for(int j = min; j <= max; j+=inc) {
            String s = String.format("%.1f", (j+4)/10.0);
            table.put(Integer.valueOf(j), new JLabel(s));
        }
        return table;
    }
    
    private AlphaComposite makeComposite(float alpha) 
    {
          int type = AlphaComposite.SRC_OVER;
          return(AlphaComposite.getInstance(type, alpha));
    }
    
    public void getEnergyIdData()
    {
          TestCell p = new TestCell();
          p.cellNumber();
          numberofCells = p.getnumberofCells();
          numberofsets  = p.getnumberofsets();
 
          energyId = new String[numberofsets];    
          p.energyId();
 
          energyId = p.getenergyId();
        }
  
       public void paint(Graphics g)
      {
           super.paint(g);
            Graphics2D g2d = (Graphics2D)g; // cast g to Graphics 2D
            g2d.setBackground(Color.LIGHT_GRAY);
          
            drawPolygon(g2d);  
//            Composite originalComposite = g2d.getComposite();
            drawSides(g2d);
            g2d.setComposite(makeComposite(1.0f));
//              g2d.setComposite(originalComposite);
        }
       
     public void getDrawingData()
        {
              TestCell p = new TestCell();
              p.cellNumber();
              numberofCells = p.getnumberofCells();
              numberofsets  = p.getnumberofsets();
 
              xCells = new double[numberofCells][];
              yCells = new double[numberofCells][];
              xCells0 = new double[numberofCells][];
              yCells0 = new double[numberofCells][];                       
              for(int i = 0; i<numberofCells; i++)
              {
                    xCells[i] = new double[numberofsets]; // maximum points in ith cell
                    yCells[i] = new double[numberofsets]; // maximum points in ith cell
                    xCells0[i] = new double[numberofsets]; // copy for xCells
                    yCells0[i] = new double[numberofsets]; // copy for yCells                                    
              }
              cellsPointsNumber = new int[numberofCells];
              red = new double[numberofCells][];
              green = new double[numberofCells][];
              blue = new double[numberofCells][]; 
              for(int i=0; i<numberofCells; i++)
              {
                   red[i]   = new double[numberofsets];
                   green[i] = new double[numberofsets];
                   blue[i]  = new double[numberofsets];
              }
 
              p.cellData();
 
              p.rgbs();
              xCells = p.getxCells();
              yCells = p.getyCells();
    
             // clone arrays
                for(int i = 0; i < numberofCells; i++)
                { 
                     for(int j = 0; j<cellsPointsNumber[i]; j++)
                     {
                       xCells0[i][j] = xCells[i][j];
                       yCells0[i][j] = yCells[i][j];
                       System.out.println(xCells[i][j]);[B]no printout at all[/B]
                       System.out.println(xCells0[i][j]);
                     }
                 }
               
              sidesTotalNumber = p.getsidesTotalNumber();
     
              red = p.getred();
              green = p.getgreen();
              blue  = p.getblue();
              cellsPointsNumber = p.getcellsPointsNumber();//array: each cell has how many points          
              rgbLength = p.getrgbLength();
           }
        
         public void scaleData(double scale)
         {
            for(int i = 0; i < numberofCells; i++)
                { 
                  for(int j = 0; j<cellsPointsNumber[i]; j++)
                  {
                      xCells[i][j] = (xCells0[i][j])*scale+TRANSITION;
                      yCells[i][j] = (yCells0[i][j])*scale+TRANSITION;
                  }
              }
           repaint();
         }
         
        public void drawSides(Graphics2D g2d)
       {
            g2d.setColor(Color.GRAY);
            g2d.setStroke(new BasicStroke((float)lineWidth));
 
            for (int i = 0; i<numberofCells; i++)
            {
                for (int j = 0; j<cellsPointsNumber[i]-1; j++)
                {  
                    x1 = xCells[i][j];
                    y1 = yCells[i][j];
                    x2 = xCells[i][j+1];
                    y2 = yCells[i][j+1];
                    Line2D line = new Line2D.Double(x1,y1,x2,y2);
                    g2d.draw(line);// draw Sidess here
                } 
             }
            }
       public void setColor(int id) 
       {            this.id = id;   
                    repaint();   
       }
       public void drawPolygon(Graphics2D g2d)
       {
             for (int i = 0; i<numberofCells; i++)
             {
                Polygon poly = new Polygon();
                float r  = (float)red[i][id]; 
                 // red for ith cell,id is from 0 to numberofsets-1
                 // if id=0, means "Mixture"
                float g  = (float)green[i][id]; // green for ith cell
                float b  = (float)blue[i][id]; // blue for ith cell
                List<Integer> xList = new ArrayList<Integer>(); 
                List<Integer> yList = new ArrayList<Integer>();
                for (int j = 0; j<cellsPointsNumber[i]; j++)
                {  
                    xList.add((int)(xCells[i][j]));
                    yList.add((int)(yCells[i][j]));
                } 
                Integer[] x = xList.toArray(new Integer[xList.size()]);
                Integer[] y = yList.toArray(new Integer[yList.size()]);
                for (int s = 0; s<xList.size(); s++)
                {
                    poly.addPoint(x[s],y[s]);
                }
                g2d.setColor(new Color(r, g, b));// transparent drawing
                  g2d.fillPolygon(poly);
              }  
       
      
         
   // end method paintComponent
  }
  public static void main(String[] args) {
   
      /* Set up the frame that holds the applet. */
    JFrame appletFrame = new JFrame("My Applet");
    Applet theApplet = new Combox();
 
    appletFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    appletFrame.setSize(800,800);
    appletFrame.add(theApplet, "Center");  // applet fills
 

    /* Now start invoking applet methods. */
    theApplet.init();
     appletFrame.setVisible(true);     
}
 
            
} // end class 
    

Also I attached with the TestClass code for reference.

import java.io.*;
import java.util.List;
import java.util.ArrayList;
 
public class TestCell {
        
    final int FACTOR = 400; // TO scale x,y coordinates of cells.
 
    private double xCells[][]; // Every cell's points's x coordinates array
    private double yCells[][]; // Every cell's points's y coordinates array
//    private double rgb[][]; 
    private double red[][];
    private double green[][];
    private double blue[][];
    // Color triplets for in each cell for different Energy group.
    private String energyId[];
    private String fileName = "plotdata4.txt";
    
    private int sideId;
    private int sidesTotalNumber; // Total sides number for all cells
    private int rgbLength; // Total rgb color group number for all cells at each point
    private int cellsPointsNumber[]; // point numbers of each cell.(each cell has how many points)
    private int numberofCells;
    private int numberofsets;
    private double maximumX;
    private double maximumY;
    
    
    public void cellNumber()
    {
        try {     
      FileReader fr = new FileReader(fileName);
      BufferedReader br = new BufferedReader(fr);
       String line;
      String parts[];
     
      line = br.readLine().trim();
      parts = line.split("\\s+");
 

      numberofCells = Integer.parseInt(parts[0]);
      numberofsets = Integer.parseInt(parts[1]);
      setnumberofCells(numberofCells);  
      setnumberofsets(numberofsets);
        }
 catch(Exception e) {
      System.out.println("Exception: " + e);
    }       
        
    }
  public void cellData() {
      
    try {
      FileReader fr = new FileReader(fileName);
      BufferedReader br = new BufferedReader(fr);
 
      String line;
      String parts[];
     
      line = br.readLine().trim();
      parts = line.split("\\s+");
 

      numberofCells = Integer.parseInt(parts[0]);
      numberofsets = Integer.parseInt(parts[1]);
      sidesTotalNumber = 0;
      String Energy = "Energy";
      xCells = new double[numberofCells][];
      yCells = new double[numberofCells][];
      cellsPointsNumber = new int[numberofCells];
      while((line = br.readLine()) != null) 
      {
        parts = line.trim().split("\\s+");
        if (parts[0].equals(Energy)) 
        {
            break;
        }
        for (int i = 0; i<numberofCells; i++)
        {
            List<Double> xy = new ArrayList<Double>();
 
            line = line.trim();
            parts = line.split("\\s+");
            int length = parts.length;
            int numberofSides = Integer.parseInt(parts[0]);
            sidesTotalNumber += numberofSides;
             int j = 0;
             while(j<2*numberofSides+1)
            {
                for ( int k = 0; k<length; k++)
                {
                    j++;
                     xy.add(Double.parseDouble(parts[k]));
                }
                line = br.readLine();
                line = line.trim();
 
                parts = line.split("\\s+");
                length = parts.length;
            }
        
                Double[] xyCell = xy.toArray(new Double[xy.size()]);
 
                xCells[i] = new double[(xy.size()-1)/2]; // maximum points in ith cell
                yCells[i] = new double[(xy.size()-1)/2]; // maximum points in ith cell
                for ( int m = 0; m < (xy.size()-1)/2; m++)
                {
                    xCells[i][m] = xyCell[2*m+1];
                    yCells[i][m] = xyCell[2*m+2];
                }
                cellsPointsNumber[i] = (xy.size() - 1)/2; // ith's cell has the number of points
        }
//      fr.close();
      }
 
                 maximumX = getMax(xCells);
                 maximumY = getMax(yCells);
                for(int i = 0; i < numberofCells; i++)
                { 
                      for(int j = 0; j<cellsPointsNumber[i]; j++)
                      {
                          xCells[i][j] = (xCells[i][j]/maximumX*FACTOR);
                          yCells[i][j] = (yCells[i][j]/maximumX*FACTOR);
                      }
                 }
                setxCells(xCells);
                setyCells(yCells);
                setcellsPointsNumber(cellsPointsNumber);
                setsidesTotalNumber(sidesTotalNumber);
 
 
    }
    catch(Exception e) {
      System.out.println("Exception: " + e);
    }
  }
  
  public void energyId() {
   
    
    try {
      FileReader fr = new FileReader(fileName);
      BufferedReader br = new BufferedReader(fr);
 
      String line;
      String parts[];
     
      line = br.readLine().trim();
      parts = line.split("\\s+");
 
      List<String> pc = new ArrayList<String>();
    
      numberofsets = Integer.parseInt(parts[1]);
      energyId = new String[numberofsets];
      String Energy = "Energy";
      int i = 0;
      while((line = br.readLine()) != null) 
      {
            parts = line.trim().split("\\s+");
            if (parts[0].equals("Mixture")) 
            {
                    energyId[i] = line.trim();
//                    System.out.printf("i=%d energy=%s\n",i,energyId[i]);
                    line = br.readLine();
                    line = line.trim();
                    parts = line.split("\\s+");
                                       
                    while (parts[0].equals("Energy"))
                    {
                        i++;
                        energyId[i] = line;
//                   System.out.printf("i=%d energy=%s\n",i,energyId[i]);
                        line = br.readLine();
                        line = line.trim();
                        parts = line.split("\\s+");
                        
                    }
            }
      }
            setenergyId(energyId);
    }
    catch(Exception e) {
      System.out.println("Exception: " + e);
    }
  }
//  
  public void rgbs() {
      
    try {
      FileReader fr = new FileReader(fileName);
      BufferedReader br = new BufferedReader(fr);
 
      String line;
      String parts[];
     
      line = br.readLine().trim();
      parts = line.split("\\s+");
 
      List<String> cellColor = new ArrayList<String>();
      numberofCells = Integer.parseInt(parts[0]);
      numberofsets = Integer.parseInt(parts[1]);
      red = new double[numberofCells][];
      green = new double[numberofCells][];
      blue = new double[numberofCells][];
      String Energy = "Energy";
  
//      line = br.readLine();
      while((line = br.readLine()) != null) 
      {
            line = line.trim();
            parts = line.split("\\s+");
            if (parts[0].equals("Mixture")) 
            {
                    line = br.readLine();
                    line = line.trim();
                    parts = line.split("\\s+");
                    while (parts[0].equals("Energy"))
                    {
                        line = br.readLine();
                        line = line.trim();
                        parts = line.split("\\s+");
                    }
                 int j = 0;
                 while(line !=null)
                 {
//                       rgb[j] = new double[3];
                       parts = line.trim().split("\\s+");
                       int length = parts.length;
                       for(int k=0; k<length; k++)
                           cellColor.add(parts[k]);
 
                       line = br.readLine();
//                       System.out.printf("r=%20.12f,g=%20.12f,b=%20.12f\n",rgb[j][0],rgb[j][1],rgb[j][2]);
//                       j++; 
                 }
//                   rgbLength = j;
            }
      }
                    String[] colors = cellColor.toArray(new String[cellColor.size()]);
//                    System.out.println(cellColor.size());
                    int c = cellColor.size();
//                    System.out.println(c);
                    for(int i=0; i<numberofCells; i++)
                    {
                        red[i]   = new double[numberofsets];
                        green[i] = new double[numberofsets];
                        blue[i]  = new double[numberofsets];
                        for(int j=0; j<numberofsets; j++)
                        {
                            int d = j+1+i*(numberofsets+1);
                            red[i][j] = Double.parseDouble(colors[d]); 
                            // red color for ith cell at jth set
                            green[i][j] = Double.parseDouble(colors[d+c/3]);
                            // green color for ith cell at jth set
                            blue[i][j] = Double.parseDouble(colors[d+2*c/3]);
                            // blue color for ith cell at jth set
                        }
                    }
                    setred(red);
                    setgreen(green);
                    setblue(blue);
//                    setrgb(rgb);
                    setrgbLength(rgbLength);
     }
    catch(Exception e) {
      System.out.println("Exception: " + e);
    }
  }
  
        public double getMax(double [][]t)
        {
            double maximum = Math.abs(t[0][0]);
            for(int i = 0; i<numberofCells; i++)
                for(int j = 0; j<cellsPointsNumber[i]; j++)
                    if(Math.abs(t[i][j])>maximum) maximum = Math.abs(t[i][j]);
            return maximum;
        }             
        
        public void setxCells(double xCells[][])
        {
            this.xCells = xCells;
        }
        
        public double[][] getxCells()
        {
            return xCells;
        }
        
        
        public void setyCells(double yCells[][])
        {
            this.yCells = yCells;
        }
        
        public double[][] getyCells()
        {
            return yCells;
        }
  
        
        public void setenergyId(String energyId[])
        {
            this.energyId = energyId;
        }
        
        public String[] getenergyId()
        {
            return energyId;
        }
     
        public void setsideId(int sideId)
        {
            this.sideId = sideId;
        }
        
        public int getsideId()
        {
            return sideId;
        }
        
        public void setcellsPointsNumber(int cellsPointsNumber[])
        {
            this.cellsPointsNumber = cellsPointsNumber;
        }
        
        public int[] getcellsPointsNumber()
        {
            return cellsPointsNumber;
        }
        
         public void setrgbLength(int rgbLength)
        {
            this.rgbLength = rgbLength;
        }
        
        public int getrgbLength()
        {
            return rgbLength;
        }
        
        public void setsidesTotalNumber(int sidesTotalNumber)
        {
            this.sidesTotalNumber = sidesTotalNumber;
        }
        
        public int getsidesTotalNumber()
        {
            return sidesTotalNumber;
        }    
        
        public void setnumberofCells(int numberofCells)
        {
            this.numberofCells = numberofCells;
        }
        
        public int getnumberofCells()
        {
            return numberofCells;
        }
        
        public void setnumberofsets(int numberofsets)
        {
            this.numberofsets = numberofsets;
        }
        
        public int getnumberofsets()
        {
            return numberofsets;
        }
        
        public void setred(double red[][])
        {
            this.red = red;
        }
        
        public double[][] getred()
        {
            return red;
        }
        
        public void setgreen(double green[][])
        {
            this.green = green;
        }
        
        public double[][] getgreen()
        {
            return green;
        }
        
        public void setblue(double blue[][])
        {
            this.blue = blue;
        }
        
        public double[][] getblue()
        {
            return blue;
        }
}