Having trouble getting jlabel icons to change size with window resize?

[Louis Lewis]

Hello, I'm trying to create a chess program in java swing, and for the board I'm using an 8 by 8 array of jlabels stuck inside a jpanel with a grid layout. I would like the board to change size when the window changes size, and the grid layout accomplishes this succesfully, until I add the actual icons to the jlabels. Then the board just stays a fixed size. Someone suggested I use their "Stretch Icon" class, found here: http://www.camick.com/java/source/StretchIcon.java, so I tried initializing the icons using one of the constructors in the class (the one that takes an image name and a boolean value for whether or not you want the resisizing to be proportionate (to maintain the aspect ratio)). However, the same thing happened. The board appears, but it does not resisize. To attempt to fix this problem, I tried simplifying my code, reducing the program to two jlabels within the jpanel, for which I then tried to set the image in the same way. Here is my simplified code:

 
import java.awt.*; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JLabel; 
import javax.swing.JOptionPane; 
import javax.swing.ImageIcon; 

public class GUI extends JFrame 
{ 
private JPanel panel; 
private JLabel label1; 
private JLabel label2; 

public GUI() 
{ 
super("Test"); 

panel = new JPanel(); 
panel.setSize(350,250); 
add(panel); 
panel.setLayout(new FlowLayout()); 

label1 = new JLabel(); 
label1.setSize(100,100); 
label1.setText("label1"); 
panel.add(label1); 
label2 = new JLabel(); 
label2.setSize(100,100); 
label2.setText("label2"); 
panel.add(label2); 

//test regular icons 
ImageIcon blackSquare = new ImageIcon("src/testproject/Black Square.jpg"); 
ImageIcon whiteSquare = new ImageIcon("src/testproject/White Square.jpg"); 

//test stretchable squares using streth icon class 
StretchIcon blackSquareStretchable = new StretchIcon("src/testproject/Black Square.jpg", true); 
StretchIcon whiteSquareStretchable = new StretchIcon("src/testproject/White Square.jpg", true); 

//these two lines result in two 100 by 100 squares that are black and white, respectively, but that do not change size upon window resize 
//label1.setIcon(blackSquare); 
//label2.setIcon(whiteSquare); 

//these two lines result in two much smaller squares (maybe 10 by 10) that don't even appear if I don't set the label text, and that also do not resize upon window resize 
label1.setIcon(blackSquareStretchable); 
label2.setIcon(whiteSquareStretchable); 

} 
} 

Anyone know if I'm misusing the stretch icon class, or just generally what's going wrong/how to fix it?

[Rob Camick]

A FlowLayout always displays a component at its preferred size.

If you want the grid to change size, then use a GridLayout. Read the section from the Swing tutorial on How to Use Grid Layout for more information.

Also fix your code tags. The end tag should be "code" not "java".

[Louis Lewis]

Alright, I changed it and it worked! What I have now is:

package testproject;

import java.awt.*;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.ImageIcon;

public class GUI extends JFrame
{
    private JPanel panel;
    private JLabel label1;
    private JLabel label2;
    private JLabel[][] chessBoard = new JLabel[8][8];
    
    public GUI()
    {
        super("Test");
        
        panel = new JPanel();
        panel.setSize(1000,1000);
        add(panel);
        panel.setLayout(new GridLayout(8,8));
        
        //test stretchable squares using streth icon class
        StretchIcon blackSquareStretchable = new StretchIcon("src/testproject/Black Square.jpg", true);
        StretchIcon whiteSquareStretchable = new StretchIcon("src/testproject/White Square.jpg", true);
        
        for (int rows=0;rows<8;rows++)
        {
            for (int columns=0;columns<8;columns++)
            {
                if ((rows+columns)%2==0) //rows+columns=even
                {
                    chessBoard[rows][columns]=new JLabel();
                    chessBoard[rows][columns].setIcon(blackSquareStretchable);
                    panel.add(chessBoard[rows][columns]);
                } else //rows+columns=odd
                {
                    chessBoard[rows][columns]=new JLabel();
                    chessBoard[rows][columns].setIcon(whiteSquareStretchable);
                    panel.add(chessBoard[rows][columns]);
                }
            }
        }      
    }
}

Thanks a lot!

[Louis Lewis]

A new question now though, is there any way I can lock the aspect ratio of the gridlayout? Right now the individual chessboard panels keep their aspect ratios, but since the panel containing them does not, they space out differently depending on what shape the panel is. And since this is a chessboard, I would like there to be no space between any of the panels. Do you know if there is a way to do this?