java Swing - orbit

/*

Write a java program to plot the path of small circle moving around the circumference of a larger circle.

*/

         

// Java Graphics

// Orbit

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

import java.awt.Graphics;

import java.awt.geom.*;

import java.lang.Math.*;

public class Orbit extends Frame

{

     double degree=0;

     int x1, y1;

    

     public void paint(Graphics g)

     {  

          g.fillOval(200,200,100,100);

     g.drawOval(50,50,400,400);

    

          degree=(degree+10)%360;

          x1 = (int)(200*java.lang.Math.cos((degree*2.0*3.142)/360.0))+250;

          y1 = (int)(200*java.lang.Math.sin((degree*2.0*3.142)/360.0))+250;

          g.drawOval(x1-15,y1-15,30,30);

             

          try

          {

              Thread.sleep(100);

          }

          catch(Exception e)

          {}

             

          repaint();

     }

     public static void main(String as[])

     {

          Orbit obj = new Orbit();

         

          obj.setSize(new Dimension(500,500));

          obj.setTitle("Orbit");

                       

          obj.setVisible(true);       

     }

}

Output:

Java Swing - distance converter

/*

Create a new Java GUI application to convert miles to kilometers when pressing the "Convert!" button. Note that you need to implement the ActionListener interface and override the actionPerformed() method.  Note that 1 mile is equal to 1.609 kilometers.

*/

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

class Converter implements ActionListener

{

     JFrame jf;

     JLabel L1, L2;

     JTextField tf1, tf2;

     JButton b1;

    

     Converter()

     {

          jf = new JFrame();

         

          jf.setSize(350,200);

          jf.setTitle("Converter");

         

          FlowLayout FL = new FlowLayout(FlowLayout.CENTER,20,20);

          jf.setLayout(FL);

         

          Font f1 = new Font("Freestyle Script", Font.BOLD, 20);

          Font f2 = new Font("Freestyle Script", Font.BOLD, 15);

          Dimension d1 = new Dimension(100,30);

          Dimension d2 = new Dimension(75,30);

          L1 = new JLabel("Miles : ", SwingConstants.RIGHT);

          L2 = new JLabel("Kilometers : ",SwingConstants.RIGHT);

          L1.setFont(f1);

          L1.setPreferredSize(d1);

          L2.setFont(f1);

          L2.setPreferredSize(d1);

         

          tf1=new JTextField("",15);

          tf2=new JTextField("",15);

         

          tf1.setFont(f1);

          tf2.setFont(f1);

         

                  

          b1 = new JButton("Convert!");

          b1.setFont(f2);

          b1.setPreferredSize(d2);

             

          jf.add(L1);

         

          jf.add(tf1);

          jf.add(L2);

          jf.add(tf2);

          jf.add(b1);

         

          b1.addActionListener(this);

                       

          jf.setVisible(true);

          jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

     }

    

    

     public void actionPerformed(ActionEvent ae)

     {

          double m = Double.parseDouble(tf1.getText());

          double km = m*1.609;

         

          tf2.setText(Double.toString(km));

     }

    

     public static void main(String as[])

     {

          new Converter();

     }

}

Output:

Java Swing - Traffic lights

/*

Write a java program that simulates a traffic light . The program lets the  user select one of three lights: red, yellow, or green with radio buttons. On selecting a button, an appropriate message with stop or ready or go should appear above the buttons in a selected color . Initially there is no  message shown .

*/

// Swing components

// Traffic light

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

class TrafficLights implements ActionListener

{

     JFrame jf;

     JRadioButtonMenuItem r1, r2, r3;

     JLabel L1;

    

     TrafficLights()

     {

          jf = new JFrame();

         

          jf.setSize(350,200);

          jf.setTitle("Traffic Lights");

         

          FlowLayout FL = new FlowLayout(FlowLayout.CENTER,20,20);

          jf.setLayout(FL);

         

          Font f1 = new Font("Freestyle Script", Font.BOLD, 30);

          Font f2 = new Font("Freestyle Script", Font.BOLD, 20);

          Dimension d1 = new Dimension(250,50);

          Dimension d2 = new Dimension(75,30);

         

          L1 = new JLabel("",SwingConstants.CENTER);

          L1.setFont(f1);

          L1.setPreferredSize(d1);

                  

          r1 = new JRadioButtonMenuItem("Red");

          r2 = new JRadioButtonMenuItem("Yellow");

          r3 = new JRadioButtonMenuItem("Green");

         

          r1.setFont(f2);

          r2.setFont(f2);

          r3.setFont(f2);

          r1.setPreferredSize(d2);

          r2.setPreferredSize(d2);

          r3.setPreferredSize(d2);

          ButtonGroup bg = new ButtonGroup();

          bg.add(r1);

          bg.add(r2);

          bg.add(r3);

                  

          jf.add(L1);

         

          jf.add(r1);

          jf.add(r2);

          jf.add(r3);

         

          r1.addActionListener(this);

          r2.addActionListener(this);

          r3.addActionListener(this);

             

          jf.setVisible(true);

          jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

     }

    

    

     public void actionPerformed(ActionEvent ae)

     {

          Color c1 = Color.black;

          String str = "";

                  

          if(r1.isSelected())

          {  

              str = "Stop";

              c1 = Color.red;

          }

          if(r2.isSelected())

          {

              str = "Ready";

              c1 = Color.yellow;

          }

          if(r3.isSelected())

          {

              str = "Go";

              c1 = Color.green;

          }

         

             

          L1.setText(str);

          L1.setForeground(c1);   

         

     }

    

     public static void main(String as[])

     {

          new TrafficLights();

     }

}

Output:

Initial window

 

Red Selected

Yellow Selected

Green Selected