Multi Line Label : JLabel « Swing « Java Tutorial

 This file is part of the BlueJ program. 
 Copyright (C) 1999-2009  Michael Klling and John Rosenberg 
 This program is free software; you can redistribute it and/or 
 modify it under the terms of the GNU General Public License 
 as published by the Free Software Foundation; either version 2 
 of the License, or (at your option) any later version. 
 This program is distributed in the hope that it will be useful, 
 but WITHOUT ANY WARRANTY; without even the implied warranty of 
 GNU General Public License for more details. 
 You should have received a copy of the GNU General Public License 
 along with this program; if not, write to the Free Software 
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA. 
 This file is subject to the Classpath exception as provided in the  
 LICENSE.txt file that accompanied this code.

import java.awt.Color;
import java.awt.Component;
import java.awt.Font;
import java.util.ArrayList;
import java.util.List;

import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JLabel;
import javax.swing.JPanel;

 ** @version $Id: 6164 2009-02-19 18:11:32Z polle $
 ** @author Justin Tan
 ** A multi-line Label-like AWT component.
public class MultiLineLabel extends JPanel
    protected int fontAttributes = Font.PLAIN;
    protected float alignment;
    protected Color col = null;
  protected int spacing = 0;
     ** Constructor - make a multiline label
    public MultiLineLabel(String text, float alignment)
        this.alignment = alignment;
        setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
        if(text != null)

     ** Constructor, defaults to centered text
    public MultiLineLabel(String text)
        this(text, LEFT_ALIGNMENT);

     * Constructor, empty with the given alignment
    public MultiLineLabel(float alignment)
        this(null, alignment);

     * Constructor, empty with the given alignment and line spacing
    public MultiLineLabel(float alignment, int spacing)
        this(null, alignment);
        this.spacing = spacing;

     ** Constructor - make an empty multiline label
    public MultiLineLabel()
        this(null, LEFT_ALIGNMENT);
    public void setText(String text)
        // clear the existing lines from the panel
    public void addText(String text)
        addText(text, 12);
    public void addText(String text, int size)
        if(spacing > 0)

        String strs[] = splitLines(text);
        JLabel l;
        Font font = new Font("SansSerif", fontAttributes, size);

        for (int i = 0; strs != null && i < strs.length; i++) {
            l = new JLabel(strs[i]);

            if (col != null)


     * Splits "string" by "Delimiter"
     * @param str - the string to be split
     * @param delimiter - the field delimiter within str
     * @returns an array of Strings
    public static String[] split(String str, String delimiter)
        List<String> strings = new ArrayList<String>();
        int start = 0;
        int len = str.length();
        int dlen = delimiter.length();
        int offset = str.lastIndexOf(delimiter); // First of all, find the
        // Last occurance of the Delimiter
        // Stop empty delimiters
        if (dlen < 1)
            return null;
        else if (offset < 0) // one element
            String[] result = {str};
            return result;

        // Append the delimiter onto the end if it doesn't already exit
        if (len > offset + dlen) {
            str += delimiter;
            len += dlen;

        do {
            // Get the new Offset
            offset = str.indexOf(delimiter, start);
            strings.add(str.substring(start, offset));

            // Get the new Start position
            start = offset + dlen;
        } while ((start < len) && (offset != -1));

        // Convert the list into an Array of Strings
        String result[] = new String[strings.size()];
        return result;

     * Splits "string" into lines (stripping end-of-line characters)
     * @param str - the string to be split
     * @returns an array of Strings
    public static String[] splitLines(String str)
        return (str == null ? null : split(str, "\n"));

    public void addText(String text, boolean bold, boolean italic)
        int oldAttributes = fontAttributes;
        fontAttributes = oldAttributes;

    public void setForeground(Color col)
        this.col = col;    
        Component[] components = this.getComponents();
        for (int i = 0; i < components.length; i++) {
      Component component = components[i];
    public void setItalic(boolean italic)
           fontAttributes |= Font.ITALIC;
            fontAttributes &= ~Font.ITALIC;
    public void setBold(boolean bold)
            fontAttributes |= Font.BOLD;
            fontAttributes &= ~Font.BOLD;

14.3.2.Create JLabel component
14.3.3.Create a JLabel with an image icon
14.3.4.JLabel is for displaying text, images or both. It does not react to input events.
14.3.5.Horizontal Alignment: CENTER
14.3.6.Vertical Alignment: CENTER
14.3.7.Horizontal Alignment: LEFT
14.3.8.Vertical Alignment: TOP
14.3.9.Horizontal Alignment: RIGHT
14.3.10.Vertical Alignment: BOTTOM
14.3.11.The text is horizontally and vertically centered
14.3.12.The text is right-justified and vertically centered
14.3.13.The text is left-justified and top-aligned
14.3.14.The text is right-justified and top-aligned
14.3.15.The text is left-justified and bottom-aligned
14.3.16.The text is right-justified and bottom-aligned
14.3.17.Add Icon to JLabelAdd Icon to JLabel
14.3.18.Mix Icon and text in JLabelMix Icon and text in JLabel
14.3.19.Set Font and foreground color for a JLabelSet Font and foreground color for a JLabel
14.3.20.Load image from disk file and add it to a JLabelLoad image from disk file and add it to a JLabel
14.3.21.Using JLabel Mnemonics: Interconnect a specific JLabel and JTextField.Using JLabel Mnemonics: Interconnect a specific JLabel and JTextField.
14.3.22.Using a JLabel and pass in HTML for the textUsing a JLabel and pass in HTML for the text
14.3.23.Multiline label (HTML)
14.3.24.JLabel with more than one row
14.3.25.A simple Bean which extends JLabel
14.3.26.Add JLabel to JScrollPane
14.3.27.Disable a label
14.3.28.Unicode with Label
14.3.29.Customizing a JLabel Look and Feel
14.3.30.Associate JLabel component with a JTextField
14.3.31.Setting the Focus of a JTextField Component Using a JLabel Component
14.3.32.JLabel with lined border
14.3.33.A Label that uses inline HTML to format its text
14.3.34.A label with no indication it has been clicked
14.3.35.Adding Drag-and-Drop Support to a JLabel Component
14.3.36.Have a Label with underlined text
14.3.37.Multi Line Label
14.3.38.Vertical Label UI
14.3.39.Time panel shows the current time.
14.3.40.URL Label
14.3.41.Hyperlink Label
14.3.42.Gradient Label