BoxLayout Behaviour

PetalumaBoy · #1 (**permalink**) 06-08-2009, 12:13 PM

Dear Folks,

I do have an issue with the Java BoxLayout Manager.

if I use BoxLayout with Y-Axis all buttons within a JPanel
are as wide as their container, in other words have the same width.

if I use BoxLaout with X-Axis orientation all buttons within a JPanel
are not as wide as thier container, in other words have different hights.

Here a small example, switch the commented line:

import java.awt.Component;
import java.awt.Container;

import javax.swing.JFrame;
import javax.swing.JComponent;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.BoxLayout;

public class SameHight {

public static void main( String args[] ) {

JFrame frame = new JFrame("Box Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOS E);

Container contentPane = frame.getContentPane();

JPanel panel = new JPanel();
// panel.setLayout( new BoxLayout( panel, BoxLayout.Y_AXIS ));
panel.setLayout( new BoxLayout( panel, BoxLayout.X_AXIS ));
contentPane.add(panel);

JButton b1 = new JButton("<html><body>Button 1</html></body>");
panel.add(b1);
JButton b2 = new JButton("<html><body>Button 2<br>Spring Water</html></body>");
panel.add(b2);
JButton b3 = new JButton("<html><body>Button 3</html></body>");
panel.add(b3);
JButton b4 = new JButton("<html><body>Button 4<br>Fountain Water</html></body>");
panel.add(b4);
JButton b5 = new JButton("<html><body>Button 5</html></body>");
panel.add(b5);
JButton b6 = new JButton("<html><body>Button 6<br>Moutain Spring Water</html></body>");
panel.add(b6);

frame.pack();
frame.setVisible(true);
}
}

Fubarable · #2 (**permalink**) 06-08-2009, 01:06 PM

One solution is to place each button into its own JPanel that uses BorderLayout, and place the jpanels into your boxlayout using container. For example:

Code:

import java.awt.BorderLayout;
import java.awt.Container;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class SameHeight {
  public static final String[] BUTTON_STRINGS = {
    "<html>Button 1</html>",
    "<html>Button 2<br>Spring Water</html>",
    "<html>Button 3</html>",
    "<html>Button 4<br>Fountain Water</html>",
    "<html>Button 5</html>",
    "<html>Button 6<br>Moutain Spring Water</html>"
  };
  
  public static void main(String args[]) {

    JFrame frame = new JFrame("Box Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Container contentPane = frame.getContentPane();

    JPanel panel = new JPanel();
    //panel.setLayout( new BoxLayout( panel, BoxLayout.Y_AXIS ));
    panel.setLayout(new BoxLayout(panel, BoxLayout.X_AXIS));
    contentPane.add(panel);

    for (String text : BUTTON_STRINGS) {
      JButton button = new JButton(text);
      
      JPanel btnPane = new JPanel(new BorderLayout());
      btnPane.add(button);
      panel.add(btnPane);
    }

    frame.pack();
    frame.setVisible(true);
  }
}

hardwired · #3 (**permalink**) 06-08-2009, 09:08 PM

Code:

import java.awt.*;
import javax.swing.*;

public class SameHeight {
    private JPanel getContent() {
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.fill = GridBagConstraints.VERTICAL;
        panel.add(getButton(1, ""), gbc);
        panel.add(getButton(2, "<br>Spring Water"), gbc);
        panel.add(getButton(3, ""), gbc);
        panel.add(getButton(4, "<br>Fountain Water"), gbc);
        panel.add(getButton(5, ""), gbc);
        panel.add(getButton(6, "<br>Moutain Spring Water"), gbc);
        return panel;
    }

    private JButton getButton(int n, String text) {
        String s = "<html><body>Button " + n +
                    text + "</html></body>";
        return new JButton(s);
    }

    public static void main( String args[] ) {
        SameHeight test = new SameHeight();
        JFrame frame = new JFrame("Box Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Container contentPane = frame.getContentPane();
        contentPane.add(test.getContent());
        frame.pack();
        frame.setVisible(true);
    }
}

PetalumaBoy · #4 (**permalink**) 06-10-2009, 11:45 AM

Thank you very much folks, both solutions work fine.
Fubarable your solution also works with GUI Builder
(Swing Designer) which I am using.

Fubarable · #5 (**permalink**) 06-10-2009, 02:27 PM

A different solution is to set the maximum size of the buttons to an appropriately large size.