poundtokg.java

this program is to convert your weight from pound to kg.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.TitledBorder;
import java.io.*;
import java.util.*;
import java.math.*;


public class PoundToKg
{
	public static void main(String[] args)
	{
		PoundToKgFrame frame = new PoundToKgFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setVisible(true);
	}
}


//Create Frame
class PoundToKgFrame extends JFrame
{	
	public PoundToKgPanel panel;
	public DisplayPanel displaypanel;

	public PoundToKgFrame()
	{	
		setTitle("Weight from Pound to Kg");
		setSize(DefualtX,DefualtY);
		
		
		//the panel on the frame
	
		////the top panel of the frame
		panel =new PoundToKgPanel();
		panel.setPreferredSize(new java.awt.Dimension(100,50));
		
		////the bottom panel of the frame
		displaypanel =new DisplayPanel();
		displaypanel.setPreferredSize(new java.awt.Dimension(600,500));
		
		//separate the panels 
		setLayout(new BorderLayout());	
		add(panel, BorderLayout.NORTH);	
		add(displaypanel, BorderLayout.CENTER);

		//set background color to show the previous action
		panel.PoundToKgButton.addActionListener(new ColorAction(Color.YELLOW));
		panel.clearButton.addActionListener(new ColorAction(Color.MAGENTA));


		//add action of all the buttons
		panel.PoundToKgButton.addActionListener(new PoundToKgAction());
		panel.clearButton.addActionListener(new clearAction());

	}
	public static final int DefualtX = 300;
	public static final int DefualtY = 400;


//Action of PoundToKg Button
private class PoundToKgAction implements ActionListener
{ 
	 public void actionPerformed(ActionEvent event)
	{  reading();	//call the function reading
	}
}


//Action of Clear Button
private class clearAction implements ActionListener
{ 
	 public void actionPerformed(ActionEvent event)
	{  clearDisplayText();	//call the function clearDisplayText
	}
}



//Action of background color change
private class ColorAction implements ActionListener
{ public ColorAction(Color c)
	{ backgroundColor = c;
	}
	public void actionPerformed(ActionEvent event)
		{ panel.setBackground(backgroundColor);
		}
	private Color backgroundColor;
}

	

//Get data from user
public void reading()
{			
	String input="";	//initial the input string
								
	input = JOptionPane.showInputDialog("Please input your weight in pound : ");
	double weight= Double.parseDouble(input);
			;
	display("\nInput weight in pound: "+ weight);
	//call the function comparison	
	exchange(weight);
}	


//to change thw weight in kg
public void exchange(double Weight)
{	double POUND_IN_ONE_KG=2.20463;
	double WeightInKg;
	WeightInKg= Weight/POUND_IN_ONE_KG;

	display("\nYour weight is "+WeightInKg+" Kg\n");

}



//display the output data to the textArea
public void display(String outputDisplay)
{ 	
	//append the display text
	displaypanel.screen.append(outputDisplay);
}



//clear the text on the display
public void clearDisplayText()
{
	//reset the display text
	displaypanel.screen.setText("");
}


} //end of frame




//Create PoundToKgPanel
class PoundToKgPanel extends JPanel
{
	public JTextArea screen;
	public DisplayPanel displaypanel;
	public PoundToKgPanel panel;
	public JButton PoundToKgButton;
	public JButton clearButton;
	

	public PoundToKgPanel()
	{			
	
		//Button for input the data
		PoundToKgButton = new JButton("Pound To Kg");
		add(PoundToKgButton,BorderLayout.NORTH);


		//Button for clear display text
		clearButton = new JButton("Clear");
		add(clearButton,BorderLayout.NORTH);

		//Button for exit 
		JButton ExitButton = new JButton("Exit");
		add(ExitButton,BorderLayout.NORTH);
		ExitButton.addActionListener(new ExitAction());

	}
	
//Action of Exit Button	
private class ExitAction implements ActionListener
{
		public void actionPerformed(ActionEvent event)
		{  System.exit(0);	//exit the system
		}
}

}//end for PoundToKgPanel


//DisplayPanel
class DisplayPanel extends JPanel
{	
	public JTextArea screen;
	public DisplayPanel()	
	{	
		//Screen for display
		setLayout(new BorderLayout());
           	screen = new JTextArea("Screen for display\n",25,25);		
 		JScrollPane scroller=new JScrollPane();
		add(scroller, BorderLayout.CENTER);
		scroller.setViewportView(screen);
           	screen.setEditable(false);
           	screen.setLineWrap(true);		
	}
}