Slider not working

Hello,

I am writing an applet that will display me four different polygons using four buttons.Also, i have a slider that is used to change the sizes of the displayed shape.Using this slider, when for example a rectangle is displayed, moving it ahead will increase it's size and vice versa.

I wrote the code, but i cannot increase/decrease the size using slider.I am sure the slider can listen to the event.But, i am not sure where it's going wrong.Please help.

Note: I have four classes for the four polygons to initialize the co-ordinate points.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

import javax.swing.border.*;
import java.util.*;
import javax.swing.event.*;
import static java.lang.Math.*;

public class CS342Lab04 extends JApplet implements ActionListener, ChangeListener
{

//variable declarations
	int[] x;
	int[] y;
	int w;
	int h;
	int sides=4;
	String title ="Change Shapes";
	int length,height;
	int scale= 4;
	int change;
	
	JButton button1,button2,button3,button4;
	JLabel label =new JLabel("Draw");
	JSlider slider =new JSlider(JSlider.HORIZONTAL,0,100,50);
	Container c =getContentPane();
	Border border = new LineBorder(Color.GREEN,5);
	Font font = new Font("Arial", Font.ITALIC,15);
	TitledBorder titledborder = new TitledBorder(border, title,TitledBorder.CENTER, TitledBorder.BOTTOM, font, Color.RED);

//object declaration 
	Rectangle1 r;
	Point rpt1,rpt2,rpt3,rpt4;
	Trapezoid1 tr;
	Point tpt1,tpt2,tpt3,tpt4;
	Square1 sr;
	Point spt1,spt2,spt3,spt4;
	Parallelogram1 pr;
	Point ppt1,ppt2,ppt3,ppt4;

public void init()
	{
		setLayout(new FlowLayout());
		addButtons();
		add(label);
		slider.setMajorTickSpacing(50);
		slider.setPaintLabels(true);
		add(slider);	
		slider.addChangeListener(this);
		slider.setBorder(titledborder);	
		x = new int[4];
		y = new int[4];
	
		//Initializing the first appearance of rectangle
		/*rpt1 = new Point(60,90);
		rpt2 = new Point(300,90);
		rpt3 = new Point(300,40);
		rpt4 = new Point(60,40);
	    r = new Rectangle1(rpt1,rpt2,rpt3,rpt4); */
	    
	  //Initializing the first appearance of square
		/*spt1 = new Point(100,80);
		spt2 = new Point(200,80);
		spt3 = new Point(200,180);
		spt4 = new Point(100,180);
	    sr = new Square1(spt1,spt2,spt3,spt4); */
	    
	/*  //Initializing the first appearance of parallelogram
		ppt1 = new Point(60,90);
		ppt2 = new Point(300,90);
		ppt3 = new Point(300,40);
		ppt4 = new Point(60,40);
	    pr = new Parallelogram1(rpt1,rpt2,rpt3,rpt4);
	    
	  //Initializing the first appearance of trapezoid
	    
		tpt1 = new Point(60,90);
		tpt2 = new Point(300,90);
		tpt3 = new Point(300,40);
		tpt4 = new Point(60,40);
	    tr = new Trapezoid1(tpt1,tpt2,tpt3,tpt4);   */
	} 
	
	/** This method adds all the  button to the container */
	
	public void addButtons()
	{
		    button1 = new JButton("Draw Rectangle");
			button1.setForeground(Color.BLACK);
		    c.add(button1);
		    button1.addActionListener(this);
		    
			button2 = new JButton("Draw Square");
			button2.setForeground(Color.BLACK);
		    c.add(button2);
		    button2.addActionListener(this);
		    
			button3 = new JButton("Draw Parallelogram");
			button3.setForeground(Color.BLACK);
		    c.add(button3);
		    button3.addActionListener(this);
		    
			button4 = new JButton("Draw Trapezoid");
			button4.setForeground(Color.BLACK);
		    c.add(button4);
		    button4.addActionListener(this);
		    
	}

public void actionPerformed(ActionEvent e)
	{
		//draw a trapezoid in the middle of the screen and display area
		if(e.getSource() == button1)
		{
			initializeRectangle1();
			repaint();
		}
		else if(e.getSource() == button2)
		{
			initializeSquare1();
			repaint();
		}
		
		else if(e.getSource() == button3)
		{
			initializeParallelogram1();
			repaint();
		}
		if(e.getSource() == button4)
		{
			initializeTrapezoid1();
			repaint();
		}

}

//paint method to output areas of each shape to the screen
	public void paint (Graphics g)
    {
		super.paint(g);
		w = getWidth();
		h = getHeight();
		g.drawPolygon(x, y, sides);

}
	
	public void initializeRectangle1()
	{
		//int height = (int)((new Point(60,40).getY() - new Point(60,90).getY()));   //4- 1
		//int length = (int)((new Point(300,400).getX() -  new Point(60,40).getX())); //3-4
		
	/*	x[0] = ((w/2)*scale - (length/2)); y[0] = ((h/2) - (height/2));
		x[1] = ((w/2)*scale + (length/2)); y[1] = ((h/2) - (height/2));
		x[2] = ((w/2)*scale + (length/2)); y[2] = ((h/2) + (height/2));
		x[3] = ((w/2)*scale - (length/2)); y[3] = ((h/2) + (height/2));
		*/
		
		x[0] = ((w/2)- scale*2); y[0] = ((h/2) - scale*1);
		x[1] = ((w/2)+ scale*2); y[1] = ((h/2) - scale*1);
		x[2] = ((w/2)+ scale*2); y[2] = ((h/2) + scale*1);
		x[3] = ((w/2) -scale*2); y[3] = ((h/2) + scale*1);
		
	}
	
		
	
	public void initializeSquare1() 
	{
		int height = (int)(new Point(100,180).getY() - new Point(100,80).getY());
		int length = (int)(new Point(200,180).getX() - new Point(100,80).getX());
		x[0] = ((w/2) - (length/2)); y[0] = ((h/2) - (height/2));
		x[1] = ((w/2) + (length/2)); y[1] = ((h/2) - (height/2));
		x[2] = ((w/2) + (length/2)); y[2] = ((h/2) + (height/2));
		x[3] = ((w/2) - (length/2)); y[3] = ((h/2) + (height/2));

}
	
	public void initializeParallelogram1() 
	{
		int height = (int)(new Point(150,90).getY() - new Point(60,40).getY());// 1,4
		int hshift = (int)(new Point(350,90).getX() - new Point(45,90).getX());
		int lshift = (int)(new Point(60,40).getX()- new Point(150,400).getX());
		int length = (int)(new Point(350,90).getX() - new Point(45,90).getX()); //2,1
		x[0] = ((w/2) - (length/2)-(lshift/2)); y[0] = ((h/2) - (height/2)-(hshift/2));
		x[1] = ((w/2) + (length/2)-(lshift/2)); y[1] = ((h/2) - (height/2)-(hshift/2));
		x[2] = ((w/2) + (length/2)+(lshift/2)); y[2] = ((h/2) + (height/2)+(hshift/2));
		x[3] = ((w/2) - (length/2)+(lshift/2)); y[3] = ((h/2) + (height/2)+(hshift/2));
	}
	
	
	public void initializeTrapezoid1() 
	{
		int height = (int)(new Point(60,90).getY() - new Point(60,40).getY());
		int length = (int)(new Point(300,90).getX() - new Point(60,90).getX());
		x[0] = ((w/2) - (length/2)); y[0] = ((h/2) - (height/2));
		x[1] = ((w/2) + (length/2)); y[1] = ((h/2) - (height/2));
		x[2] = ((w/2) + (length/2)); y[2] = ((h/2) + (height/2));
		x[3] = ((w/2) - (length/2)); y[3] = ((h/2) + (height/2));

} 
	
	public void stateChanged(ChangeEvent e)
	{
		change = slider.getValue()/100;
     	scale = (int)(pow((double)2 , (double)change)* 8);	
		repaint();
	}

}

So what is the maximum value on your Slider? Why are you dividing it by 100?

Campbell Ritchie wrote:So what is the maximum value on your Slider? Why are you dividing it by 100?

The maximum value is 100 , minimum is 0 and middle is 50.I got this formula from a book, (2^50 -1), for calculating the value when slider changes its position.

. . . and what is the result when you divide the slide position by 100?

72 posts and you still don't know better than to post oodles of commented-out code and excess vertical whitespace? Honestly, making your code and posts more readable is in your best interests.