Question

Develop a simple GUI-based Java program that may be used to control a lighting system

Answer 1

/* THIS IS A ELECTRIC BALL CONTROL PROGRAM. USING GUI BUTTON WE CAN SWITCH ON OR OFF THE BALL. ONE SLIDER IS AVAILABLE TO CONTROL CONTRAST LABEL */
/* STRUCTURE OF PROGRAM

PARENT FRAME CONSISTING OF TWO PANEL (panelTop AND panelButtom) WITH FlowLayout.
IN TOP PANEL ONE LABLE HAS ADDED TO SHOW THE IMAGE OF BALL IN ICON FORMAT
HERE WE HAVE TAKEN TWO IMAGE FOR BALL (b1.png and b2.png), ONE FOR OFF STATE AND ANOTHER FOR OFF STATE

IN BUTTOM PANEL , TWO OTHER PANELS(P1,P2) ARE ADDED.
TO PANEL ONE, BUTTON SWITCH (ON/OFF) ADDED.
TO PANEL TWO, SLIDER WITH LABEL ADDED.

INITALIZE THE LABEL WITH OFF STATE BALL

ONE CUSTOM EVENT HANDELER CLASS EventHandler HAS BEEN DEFINED WITH ACTIONLISTER,CHANGELISTER

EVENT HANDELER REGISTERED TO BUTTON (ON/OFF)
EVENT HANDELER REGISTERED TO JSLIDER

PLEASE VIEW SCREENSHOT OF CODE FOR BETTER UNDERSTANDING OF STRCUTURE

*/

import java.awt.*;   // for gridlayout
import java.awt.image.*;
import java.io.*;
import javax.swing.*;
import javax.imageio.ImageIO;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.event.*;
import java.util.Hashtable;

public class Ball {

   JButton bl,b2;
   JPanel panelTop,panelButtom;
   JFrame frame ;
   JLabel label,label2;
float scaleFactor=1.0f;//change scaleFactor to change contrast
/*keep the value scaleFactor = 1.0f; as for a normal image*/
RescaleOp rescale;
JSlider slider;
int Switch=0;

   Ball()
   {
       // main window
       JFrame.setDefaultLookAndFeelDecorated(true);
       frame = new JFrame("Control a Lighting System");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

      panelTop = new JPanel();
      panelButtom = new JPanel();

      frame.setLayout(new FlowLayout());
       frame.add(panelTop);
   frame.add(panelButtom);

       /*       PANEL 1 LAYOUT            */
       label=new JLabel();
       label.setBounds(50,50,300,300);
   showImg("b1.png",1.0f); // initialize with off state ball
   panelTop.add(label);

       /*       PANEL 2 LAYOUT            */

       panelButtom.setLayout(new GridLayout(2,1));
       JPanel p1=new JPanel();
       JPanel p2=new JPanel();

       panelButtom.add(p1);
       panelButtom.add(p2);

       bl=new JButton(" Swith On ");
   p1.add(bl);

       label2=new JLabel("Control Contrast");
      p2.add(label2);

   slider = new JSlider(JSlider.HORIZONTAL, 0, 100, 0);

       //Turn on labels at major tick marks.
       slider.setMajorTickSpacing(10);
       slider.setMinorTickSpacing(1);
       slider.setPaintTicks(true); // ALLOW RO SHOW TICK BARS ON SLIDERS
       slider.setPaintLabels(true); // ALLOW RO SHOW LABELS ON SLIDERS
       p2.add(slider);

       /*SLIDDER WITH LABEL ON 0 POSITION AND 100 POSITION */
       Hashtable<Integer, JLabel> labels = new Hashtable<>();
       labels.put(0, new JLabel("Max"));
       labels.put(100, new JLabel("Low"));
       slider.setLabelTable(labels);

      /*       REGISTERING EVENT HANDELER (CUSTOME EVENT HANDELER)           */

   ActionListener myHandlerButton = new EventHandler();
        bl.addActionListener(myHandlerButton); /// Binding the custom event handler

       ChangeListener myHandleSlide = new EventHandler();
       slider.addChangeListener(myHandleSlide);

       /*SETTING OF PARENT FRAME TO DISPPLAY */
       frame.pack();
       frame.setVisible(true);
       frame.setSize(400,500);
}
   /* CUSTOM EVENT HANDELER CLASS */
    class EventHandler implements ActionListener,ChangeListener
    {
   public void actionPerformed(ActionEvent e) // WHEN BUTTON CLICK OCCURED
   {
           if(e.getSource() == bl)
           {
               if(Switch==0)
               {
                   Switch=1;
                   showImg("b2.png",1.0f); // call showImg function to show off image
                   bl.setText(" Switch Off "); // change label of button

               }else
               {
                   Switch=0;
                   showImg("b1.png",1.0f); // call showImg function to show off image
                   bl.setText(" Switch On "); // change label of button

               }
           }
   }
   public void stateChanged(ChangeEvent event) // WHEN JSLIDER VALUE CHANGED
   {
           if(Switch==0)
               /*WHEN BALB IF OFF , AND TRY TO CONTROL CONTRAST*/
              JOptionPane.showMessageDialog(panelButtom, "Please switch on ball","ERROR", JOptionPane.ERROR_MESSAGE);
          else
          {
               int value = slider.getValue(); // getting value form slider
               double f=value/100.0 + 1 ; // WE NORMAL SCALE FACTOR IN FORM OF 1.0f
               showImg("b2.png",(float)f); // call showImg function to show on image with desired contrast
           }
   }

   } // END OF EventHandler CLASS

   void showImg(String img,float sFactor )
   {
       try
       {
           BufferedImage image = ImageIO.read(new File(img)); //READING THE FILE IMAGE FROM STORAGE

           // Setting up the scaling and
   // the offset parameters for processing
   // WE ARE CONTROLING scaleFactor FROM SLIDER VALUE TO CONTROL CONTRAST
           rescale = new RescaleOp(sFactor,0.0f, null); // RescaleOp(float scaleFactor, float offset, RenderingHints hints)

           // applying the parameters on the image
   // by using filter() method,
           image=rescale.filter(image,null);
           ImageIcon icon = new ImageIcon(image);
           label.setIcon(icon);   //SET IMAGE TO LABEL IN BUTTON PANEL
       }
       catch(IOException ex)
       {
           System.out.println(ex);
       }

   }

   public static void main(String[] arguments)
   {
       new Ball();

   }
}

IMAGES OF BALL

b1.png

b2.png

SCREEN SHOT OF CODE

SCREEN SHOT OF OUTPUT