CODEWITHSUNDEEP
javaswing
user1002973
user1002973

Reputation: 2100

JPanel Layout managers - how to prevent components filling space?

I am trying to build a set of two labels and a button (label-button-label) that looks something like the top row of this:

enter image description here.

I am struggling to do this with Java Swing. I've tried BorderLayout, with BorderLayout.WEST, BorderLayout.CENTER, BorderLayout.EAST but that makes the button fill the space: enter image description here

here's the code I used for that:

panel = new JPanel(new BorderLayout());
l1 = new JLabel("l1");
button = new JButton("B");
l2 = new JLabel("l2");
panel.add(l1, BorderLayout.WEST);
panel.add(button, BorderLayout.CENTER);
panel.add(l2, BorderLayout.EAST);

I've also tried GridBagLayout, and the closest I've come there is to have them spaced out, but not hugging the sides:

enter image description here

Code for that:

panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.VERTICAL;
l1 = new JLabel("L1");
l2 = new JLabel("L2");
button = new JButton("B");
c.weightx = Integer.MAX_VALUE;
c.gridx = 0;
panel.add(l1, c);
c.weightx = 1;
c.gridx = 1;
panel.add(button, c);
c.weightx = Integer.MAX_VALUE;
c.gridx = 2;
panel.add(l2, c);

Any ideas?

Upvotes: 2

Views: 4050

Answers (3)

TheWaterWave222
TheWaterWave222

Reputation: 129

You can add a "cheater," like this:

JButton buttonNeeded = new JButton();
   window.add(buttonNeeded);
JButton cheaterButton = new JButton();
   cheaterButton.setEnabled(false);
   window.add(cheaterButton);

The cheaterButton fills the screen, but then the user can't click it or see it. Not great for everything, but it works for adding JButtons, at least.

Upvotes: 0

trashgod
trashgod

Reputation: 205775

Try GridLayout with LEFT, CENTER & RIGHT labels.

    JPanel p = new JPanel(new GridLayout(1,0));
    p.add(new JLabel("Test", JLabel.LEFT));
    p.add(new JLabel("Test", JLabel.CENTER));
    p.add(new JLabel("Test", JLabel.RIGHT));

image

SSCCE:

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/** @see http://stackoverflow.com/a/14501446/230513 */
public class Test {

    private void display() {
        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel p = new JPanel(new GridLayout(1, 0));
        p.add(new JLabel("Test", JLabel.LEFT));
        JPanel buttonPanel = new JPanel();
        buttonPanel.add(new JButton("Test"));
        p.add(buttonPanel);
        p.add(new JLabel("Test", JLabel.RIGHT));
        f.add(p, BorderLayout.NORTH);
        f.add(new JPanel() {

            @Override
            public Dimension getPreferredSize() {
                return new Dimension(320, 120);
            }
        }, BorderLayout.CENTER);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Test().display();
            }
        });
    }
}

Upvotes: 4

Guillaume Polet
Guillaume Polet

Reputation: 47608

Here are two ways to doit. Once with a BorderLayout and once with a GridBagLayout:

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class TestGridBagLayout {

    protected void initUI1() {
        final JFrame frame = new JFrame("Grid bag layout");
        frame.setTitle(TestGridBagLayout.class.getSimpleName());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JLabel l1 = new JLabel("L1");
        JLabel l2 = new JLabel("L2");
        JButton b = new JButton("B");
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        panel.add(l1, gbc);
        gbc.weightx = 1.0;
        gbc.anchor = GridBagConstraints.CENTER;
        panel.add(b, gbc);
        gbc.weightx = 0;
        panel.add(l2, gbc);
        frame.add(panel);
        frame.setSize(800, 100);
        frame.setVisible(true);
    }

    protected void initUI2() {
        final JFrame frame = new JFrame("Border layout");
        frame.setTitle(TestGridBagLayout.class.getSimpleName());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new JPanel(new BorderLayout());
        JLabel l1 = new JLabel("L1");
        JLabel l2 = new JLabel("L2");
        JButton b = new JButton("B");
        JPanel wrappingPanel = new JPanel(new FlowLayout());
        wrappingPanel.add(b);
        panel.add(l1, BorderLayout.WEST);
        panel.add(l2, BorderLayout.EAST);
        panel.add(wrappingPanel);
        frame.add(panel);
        frame.setLocation(0, 125);
        frame.setSize(800, 100);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                TestGridBagLayout test = new TestGridBagLayout();
                test.initUI1();
                test.initUI2();
            }
        });
    }

}

Upvotes: 4

Related Questions