Help for my background color changer Java program

[Nipuna]

Hi friends.

With my simple Java knowledge I made a program yesterday and it didn't work as expected. So I wrote it again today and posting here to get helps from you guys

In this program I tried to make a program to change background of a window according to seconds, Like this. After 1 second background is blue then red and etc... I wrote this to gain my knowledge so even changing to 5 colors is enough.

So I searched the net and and found there is a class for this in the API called Timer. And I found out there are 2 classes in Java that has same name, Here are they,

java.util.Timer
and
javax.swing.Timer

So for my task I found out that second one is the one I need. So I used it. Because I know the other stuff what I can't figure out is the timer. Finally I found that too So I made a program by using that. And using API I learned how to use it's functions and of course how to use the class itself too

But my problem is, I could only write the program only to change to one color after 1 second then I couldn't figure out how to change the color according to seconds.
Program only works 1 time then stay as is, Of course you can see that I haven't written the other stuff to do the rest, I did so because I couldn't figure out it

So here goes the code,

Code: Select all

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.Timer;

public class BGChanger extends JFrame{

	private int delay = 1000;

	public BGChanger(){
		super("Background Changer");
		setSize(300,300);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
		
		
		
		ActionListener ac = new ActionListener(){
						public void actionPerformed(ActionEvent e){
										
							getContentPane().setBackground(Color.BLUE);
							} 
						};
										
		Timer timer = new Timer(delay,ac);
		
		timer.start();

		}
		
		
		
		public static void main(String args[]){
		
			BGChanger gui = new BGChanger();
		
		}	
		
}

Can anyone help me with this? This is just written for fun to gain my knowledge





Thanks

[SevenZero]

I'll give you a tip on how to do it.

Define a variable say int curColour and set it to 0 at the constructor. Delete the line getContentPane().setBackground(Color.BLUE); and add something like below with function actionPerformed.

Code: Select all

switch (curColour){
	case 0: //Blue 
		getContentPane().setBackground(Color.BLUE);
		break;
	case 1: //Red
		getContentPane().setBackground(Color.RED);
		break;
	.......
	.......
	.......
	case n: //XXXX  Last colour you need
		getContentPane().setBackground(Color.XXXX);
		break;
}

if (curColour == n){ // We reached last colour -> start from beginning  (replace n with the number for your last colour)
	curColour  = 0;
}

[Nipuna]

Hi

Thanks for the reply

But it is working same as before not changing according to seconds. after 1st second it become blue and then it doesn't change

Here is the new code

Code: Select all

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.Timer;
 
public class BGChanger extends JFrame{
 
        private int delay = 1000;
		  int curColour;
 
        public BGChanger(){
                super("Background Changer");
                setSize(300,300);
                setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                setVisible(true);
               
                curColour = 0;
               
                ActionListener ac = new ActionListener(){
                                                public void actionPerformed(ActionEvent e){
                                                         
								switch (curColour){
       									case 0: 
          									getContentPane().setBackground(Color.BLUE);
          								break;
       									case 1: 
          									getContentPane().setBackground(Color.RED);
          								break;
			 
       									case 3: 
          									getContentPane().setBackground(Color.WHITE);
          								break;
    								}

    								if (curColour == 3){
       									curColour  = 0;
    								}                      
                                                        
                                                }
					};
                                                                               
                Timer timer = new Timer(delay,ac);
               
                timer.start();
					 
 
                }
               
               
               
                public static void main(String args[]){
               
                        BGChanger gui = new BGChanger();
               
                }      
               
}

Since we get those ugly marks in the syntax highlighting so I am attaching my code too. Since Expertcore doesn't let to attach .java files. I added a .zip file and inside that there is the .java file.

BGChanger.zip

(628 Bytes) Downloaded 281 times

[Saman]

Put timer.start(); again as the last line of function actionPerformed.

[Nipuna]

Yeah I did few adjustments and got it to work.

I added timer.start() again but it didn't work so I did few changes and then it worked.

Thanks friends.

Here goes the new code

Code: Select all

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.Timer;
 
public class BGChanger extends JFrame{
 
        private int delay = 1000;
	private int curColour;
        private Timer timer;
 
        public BGChanger(){
                super("Background Changer");
                setSize(300,300);

                curColour = 0;
                                 
                
                Handler ac = new Handler();
                
                timer = new Timer(delay,ac);
               
                timer.start();
                }
               
               
               
                public static void main(String args[]){
               
                        BGChanger gui = new BGChanger();
                        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                        gui.setVisible(true);
               
                }      
               
                
                
       private class Handler implements ActionListener {
                    
                
          public void actionPerformed(ActionEvent e){
                                                         
              switch (curColour){
                  case 0: 
                      getContentPane().setBackground(Color.BLUE);
                      curColour++;
                  break;
                                
                  case 1: 
                      getContentPane().setBackground(Color.RED);
                      curColour++;
                  break;
			 
                  case 2: 
                       getContentPane().setBackground(Color.WHITE);
                       curColour++;
                  break;
                        }

               if (curColour == 3)
                   curColour  = 0;
                       
                
          }
     }
}