JProgressBar Array

[ronald deux]

int[] JProgresseBar = new int [15];
			
	for(int i = 0; i<JProgressBar.length; i++)
	{
		JProgressBar jpb = new JProgressBar(0,200);
		jpb.setBounds(400,495-i*25,200,15);         
		jpb.setValue(0);    
		jpb.setStringPainted(true);
		
	}

I try to make a table of 15 bars of progression.
I wonder if it is possible
Thank you for your help

[Carey Brown]

ronald deux wrote:

int[] JProgresseBar = new int [15];
			
	for(int i = 0; i<JProgressBar.length; i++)
	{
		JProgressBar jpb = new JProgressBar(0,200);
		jpb.setBounds(400,495-i*25,200,15);         
		jpb.setValue(0);    
		jpb.setStringPainted(true);
		
	}

Sure, it's possible.

On line 1 you have a VARIABLE named JProgressBar. You don't want that, it's name is already the name of a common swing class, not a variable, and variable names should always begin with a lower case letter.

On line 5 you create a LOCAL variable for each progress bar which disappears each time around the loop. You need to keep a reference to it in an array so that you can access it to set its value. And somewhere, perhaps inside the loop, you need to add the object to a swing component, such as a JPanel.

[ronald deux]

I don't see how to do it
I'm wondering if we don't need fifteen references
can you clarify me a little more?

[Piet Souris]

use

JProgressBar[] bars = new JProgressBar[15];
for (int i = 0, i < 15; i++) {
    // k=make a new JProgressBar and add it to the array at location i
}

can you explain why you need all those ProgressBars?

[ronald deux]

I'm trying to create a music album or a jukebox
each song will have its progression bar following the song's time
the songs are written in JLabel
I'm wrong because as each album does not necessarily have 15 songs
that's why I try to create lots of progress bars

[Campbell Ritchie]

How are you reading an album? How does it tell you how many tracks it has?

[ronald deux]

I opened a sounds folder and put 15 songs in it
a bit like an images folder where we put the images

[Paul Clapham]

Well, it looks like you got your answer about how to create and fill an array of JProgressBars. Or am I wrong?

[Piet Souris]

But you need a progressbar only for the song that is playing. Why would each song have its own progressbar?

[ronald deux]

I prefer a progress bar for each song than a bar for 15 songs
even though I was given the answer, I haven't found the answer yet.
here is my answer

JProgressBar[] bars = new JProgressBar [i];
		
	for(int i = 0; i<bars.length; i++)
	{		
		JProgressBar jpb = new JProgressBar(0,200);
		jpb.add(bars[i]);
		jpb.setBounds(400,495-i*25,200,15);         
		jpb.setValue(0);    
		jpb.setStringPainted(true);
		
	}

it does not work

[Paul Clapham]

Of course it doesn't work. You need some other code which does something with the progress bars.

[Piet Souris]

ronald deux wrote:

JProgressBar[] bars = new JProgressBar [i];
		
	for(int i = 0; i<bars.length; i++)
	{		
		JProgressBar jpb = new JProgressBar(0,200);
		jpb.add(bars[i]);
		jpb.setBounds(400,495-i*25,200,15);         
		jpb.setValue(0);    
		jpb.setStringPainted(true);
		
	}

it does not work

Have a look at line 1. Notice anything wrong here? And what about line 6? A JProgressBar extends Container, so it does have an 'add' method. But after that line, what is bars[i]?

[Carey Brown]

You seem to have some misconceptions about how to utilize the JProgressBar class. I suggest getting a single bar to work first and then consider what it would take to make and control an array of them.

[ronald deux]

import javax.swing.JFrame;
import javax.swing.JProgressBar;

public class Test{
		
	public Test()
	{
		
	}
	
	public static void main(String[] args) {
		
			JFrame frame = new JFrame();
			
			JProgressBar[][] bars = new JProgressBar[15][3];
			for(int i = 0; i<bars.length; i++)
			{
				for(int j = 0; j<bars[i].length; j++)
				{
					JProgressBar jpb = new JProgressBar(0,100);			
					jpb.setBounds(100+j*250,495-i*25,200,15);         
					jpb.setValue(0);    
					jpb.setStringPainted(true);			
					frame.add(jpb);	
				}
			}
			
			frame.setSize(900,600);
			frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
			frame.setLocationRelativeTo(null);
			frame.setLayout(null);
			frame.setVisible(true);
	}
}

the code works, tell me what you think?
I'm going to complicate it a bit, I'll try with setvalue for each progress bar

[Piet Souris]

Was a 1D array insufficient?    

Two remarks:

1) make a print of your 2D array, after all the PBs have been created.

2) what is it that makes you say: "it works"?

[ronald deux]

you want me to do System.print.out?
it works because it gives what I want by pressing run

[Paul Clapham]

ronald deux wrote:it works because it gives what I want by pressing run

You get a frame with 45 progress bars, right? So yeah, that's progress.

We see a fair number of posts here where people post 300 lines of code and say "It doesn't work", and it doesn't work because the 300 lines are all wrong. Small steps, like what you did, are much better. So good work so far, onwards to the next step.

[ronald deux]

Thank you
better start small and end big
also ask if I can do better by improving the code

[Paul Clapham]

I'd say the code was fine for a first step. There's still a long way to go.

[ronald deux]

public void actionPerformed(ActionEvent ae)
	{
	    int k = 0;
	    
	    if (ae.getSource() == jb) 
	    {
	      jpb.setVisible(true);
	      try 
	      {
	        while (k <= 100)
	        {
	          Thread.sleep(50);
	          jpb.paintImmediately(0, 0, 200, 15);
	          jpb.setValue(k);
	          k++;
	        }
	      } 
	      catch (Exception e)
	      {
	        
	      }
	    }
	 }

I created a button and found a piece of code
since it is an array of progress bars
I don't know how to explain it to you
Do you have any advice to give me ?.
thank you

[Carey Brown]

I'm guessing that 'jb' is a JButton, so you'd need one of those if you are going to exercise this code. And last seen you didn't have a 'jpb', you had a JProgressBar[][] bars instead.

Have you tried printing out bars as suggested?

[ronald deux]

no I did not print but it works with run

[Carey Brown]

ronald deux wrote:no I did not print but it works with run

NOT THE SAME

[ronald deux]

it means that I have to redo the code but using system out print
what will it bring me?

[Carey Brown]

Here. Took all of two seconds. Now see if you still think "it works".

import javax.swing.JFrame;
import javax.swing.JProgressBar;
 
public class Test{
         
    public Test()
    {
         
    }
     
    public static void main(String[] args) {
         
            JFrame frame = new JFrame();
             
            JProgressBar[][] bars = new JProgressBar[15][3];
            for(int i = 0; i<bars.length; i++)
            {
                for(int j = 0; j<bars[i].length; j++)
                {
                    JProgressBar jpb = new JProgressBar(0,100);         
                    jpb.setBounds(100+j*250,495-i*25,200,15);         
                    jpb.setValue(0);    
                    jpb.setStringPainted(true);         
                    frame.add(jpb); 
                }
            }
             
            System.out.println( bars[0][0] );

            frame.setSize(900,600);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setLocationRelativeTo(null);
            frame.setLayout(null);
            frame.setVisible(true);
    }
}

[ronald deux]

this code works by pressing run but after all
I tell myself that with tables of progress bars it could not work with actionperformed with a button
I don't know where you are coming from
tell me the bottom of your mind

[Carey Brown]

So, what was the output of the print?

[Carey Brown]

What if you replaced the print with;

bars[0][0].setValue( 50 );

[ronald deux]

I no longer have progress bars but a window

[ronald deux]

I no longer have progress bars but a window

[Carey Brown]

Are you running this from an IDE or Windows or some other environment. I'm assuming that you get both a console (either on the IDE or on a command line window) that will display the output of any print statements, and also get a graphic window displaying your progress bars. I some cases one lays on top of the other so you can't see the console window unless you minimize your progress bar window.

[Carey Brown]

Figuring out how to get to the console window is extremely useful for debugging.

Note: Don't launch your program with "javaw" (note the 'w') when doing this, it will typically suppress the console window, use the plain vanilla "java".

[Carey Brown]

ronald deux wrote:I no longer have progress bars but a window

Does the window display anything? Text perhaps?

[Carey Brown]

The console window should be completely blank except for a single word

null

[ronald deux]

excuse me, I redid the code to add a button
the console displays
Exception in thread "main" java.lang.NullPointerException
at Test.main (Test.java:43)

by using the old code
it's the same exception

[Carey Brown]

Carey Brown wrote:What if you replaced the print with;

bars[0][0].setValue( 50 );

If you did this you would have gotten a null pointer exception.

[ronald deux]

that's good null point exception
it's not the same as null

[ronald deux]

you want me to understand debugging or use window and console at the same time

[Carey Brown]

A null in the wrong place will cause a null pointer exception.

System.out.println( bars[0][0] ); // tells you it is null
bars[0][0].setValue(50); // throws exception because it is null