BoxLayoutPane.java Source code

Introduction

Here is the source code for BoxLayoutPane.java

Source

/*
 * Copyright (c) 2000 David Flanagan. All rights reserved. This code is from the
 * book Java Examples in a Nutshell, 2nd Edition. It is provided AS-IS, WITHOUT
 * ANY WARRANTY either expressed or implied. You may study, use, and modify it
 * for any non-commercial purpose. You may distribute it non-commercially as
 * long as you retain this notice. For a commercial use license, or to purchase
 * the book (recommended), visit http://www.davidflanagan.com/javaexamples2.
 */

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.border.EmptyBorder;
import javax.swing.border.EtchedBorder;
import javax.swing.border.TitledBorder;

public class BoxLayoutPane extends JPanel {
    public BoxLayoutPane() {
        // Use a BorderLayout layout manager to arrange various Box components
        this.setLayout(new BorderLayout());

        // Give the entire panel a margin by adding an empty border
        // We could also do this by overriding getInsets()
        this.setBorder(new EmptyBorder(10, 10, 10, 10));

        // Add a plain row of buttons along the top of the pane
        Box row = Box.createHorizontalBox();
        for (int i = 0; i < 4; i++) {
            JButton b = new JButton("B" + i);
            b.setFont(new Font("serif", Font.BOLD, 12 + i * 2));
            row.add(b);
        }
        this.add(row, BorderLayout.NORTH);

        // Add a plain column of buttons along the right edge
        // Use BoxLayout with a different kind of Swing container
        // Give the column a border: can't do this with the Box class
        JPanel col = new JPanel();
        col.setLayout(new BoxLayout(col, BoxLayout.Y_AXIS));
        col.setBorder(new TitledBorder(new EtchedBorder(), "Column"));
        for (int i = 0; i < 4; i++) {
            JButton b = new JButton("Button " + i);
            b.setFont(new Font("sanserif", Font.BOLD, 10 + i * 2));
            col.add(b);
        }
        this.add(col, BorderLayout.EAST); // Add column to right of panel

        // Add a button box along the bottom of the panel.
        // Use "Glue" to space the buttons evenly
        Box buttonbox = Box.createHorizontalBox();
        buttonbox.add(Box.createHorizontalGlue()); // stretchy space
        buttonbox.add(new JButton("Okay"));
        buttonbox.add(Box.createHorizontalGlue()); // stretchy space
        buttonbox.add(new JButton("Cancel"));
        buttonbox.add(Box.createHorizontalGlue()); // stretchy space
        buttonbox.add(new JButton("Help"));
        buttonbox.add(Box.createHorizontalGlue()); // stretchy space
        this.add(buttonbox, BorderLayout.SOUTH);

        // Create a component to display in the center of the panel
        JTextArea textarea = new JTextArea();
        textarea.setText("This component has 12-pixel margins on left and top"
                + " and has 72-pixel margins on right and bottom.");
        textarea.setLineWrap(true);
        textarea.setWrapStyleWord(true);

        // Use Box objects to give the JTextArea an unusual spacing
        // First, create a column with 3 kids. The first and last kids
        // are rigid spaces. The middle kid is the text area
        Box fixedcol = Box.createVerticalBox();
        fixedcol.add(Box.createVerticalStrut(12)); // 12 rigid pixels
        fixedcol.add(textarea); // Component fills in the rest
        fixedcol.add(Box.createVerticalStrut(72)); // 72 rigid pixels

        // Now create a row. Give it rigid spaces on the left and right,
        // and put the column from above in the middle.
        Box fixedrow = Box.createHorizontalBox();
        fixedrow.add(Box.createHorizontalStrut(12));
        fixedrow.add(fixedcol);
        fixedrow.add(Box.createHorizontalStrut(72));

        // Now add the JTextArea in the column in the row to the panel
        this.add(fixedrow, BorderLayout.CENTER);
    }

    public static void main(String[] a) {
        JFrame f = new JFrame();
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        f.setContentPane(new BoxLayoutPane());
        f.pack();
        f.setVisible(true);
    }

}