Snippet : TestJLabel.java

/*
 * [TestJLabel.java]
 *
 * Summary: demonstrate the use of javax.swing.JLabel.
 *
 * Copyright: (c) 2009-2012 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.7+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 2009-01-01 initial version
 */
package com.mindprod.example;

import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.border.Border;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

/**
 * demonstrate the use of javax.swing.JLabel.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2009-01-01 initial version
 * @since 2009-01-01
 */
public final class TestJLabel
    {
    // ------------------------------ CONSTANTS ------------------------------

    private static final Color FOREGROUND_FOR_LABEL = new Color( 0x0000b0 );

    private static final Color PALE_CYAN = new Color( 200, 255, 200 );

    private static final Font FONT_FOR_LABELS = new Font( "Dialog", Font.PLAIN, 15 );

    /**
     * track whether showing false=short or true=long string.
     */
    private static boolean toggle = false;

    // --------------------------- main() method ---------------------------

    /**
     * Debugging harness for a Frame
     *
     * @param args command line arguments are ignored.
     */
    public static void main( String args[] )
        {
        SwingUtilities.invokeLater( new Runnable()
        {
        /**
         * fire up a JFrame on the Swing thread
         */
        public void run()
            {
            final JFrame jFrame = new JFrame();
            final Container contentPane = jFrame.getContentPane();
            contentPane.setLayout( new FlowLayout( FlowLayout.LEADING ) );
            // typical JLabel
            final JLabel plainLabel = new JLabel( "this is a TEST" );
            plainLabel.setBackground( Color.BLACK );
            plainLabel.setForeground( Color.YELLOW );
            plainLabel.setOpaque( true );
            plainLabel.setFont( new Font( "Dialog", Font.BOLD, 15 ) );
            plainLabel.setHorizontalAlignment( JTextField.RIGHT );
            plainLabel.setEnabled( true );
            // embedded HTML to underline
            final JLabel htmlLabel =
                    new JLabel( "<html lang=\"en-CA\"><u>look! underlined!</u></html>" );
            htmlLabel.setFont( new Font( "Dialog", Font.BOLD, 15 ) );
            htmlLabel.setHorizontalAlignment( JTextField.LEFT );
            htmlLabel.setEnabled( true );
            // all the bells and whistles
            final JLabel fancyLabel = new JLabel( "Hello" );
            fancyLabel.setHorizontalAlignment( JLabel.RIGHT );
            fancyLabel.setHorizontalTextPosition( JLabel.LEFT );
            fancyLabel.setBackground( Color.YELLOW );
            fancyLabel.setForeground( FOREGROUND_FOR_LABEL );
            fancyLabel.setOpaque( true );
            fancyLabel.setFont( FONT_FOR_LABELS );
            // add an image
            // The jar contains the resource com/mindprod/example/raspberry.png
            final ImageIcon raspberry = new ImageIcon( TestJLabel.class.getResource(
                    "raspberry.png" ) );
            fancyLabel.setIcon( raspberry );
            Border border = BorderFactory.createEmptyBorder( 2/*top*/, 2/* left*/, 2/*bottom */, 2/*right*/ );
            fancyLabel.setBorder( border );
            fancyLabel.setText( "adios" );
            // dynamically changing JLabel
            final JLabel varyingLabel = new JLabel( "a short string" );
            varyingLabel.setHorizontalAlignment( JLabel.CENTER );
            varyingLabel.setHorizontalTextPosition( JLabel.CENTER );
            varyingLabel.setBackground( PALE_CYAN );
            varyingLabel.setForeground( FOREGROUND_FOR_LABEL );
            varyingLabel.setOpaque( true );
            varyingLabel.setFont( FONT_FOR_LABELS );
            // toggle button, to change length of varying label
            final JButton toggleButton = new JButton( "toggle" );
            toggleButton.setHorizontalAlignment( JLabel.CENTER );
            toggleButton.setHorizontalTextPosition( JLabel.CENTER );
            toggleButton.setBackground( PALE_CYAN );
            toggleButton.setForeground( FOREGROUND_FOR_LABEL );
            toggleButton.setOpaque( true );
            toggleButton.setFont( FONT_FOR_LABELS );
            toggleButton.setBorder( BorderFactory.createRaisedBevelBorder() );
            toggleButton.setFocusPainted( false );
            toggleButton.setToolTipText( "Toggle long and short label text." );
            toggleButton.addActionListener( new ActionListener()
            {
            /**
             * Invoked when  button pressed
             */
            public void actionPerformed( ActionEvent e )
                {
                // toggle back and forth between displaying long and short string.
                toggle = !toggle;
                varyingLabel.setText( toggle ? "a long string of text to display" : "a short string" );
                }
            } );
            // lay components out is a line, left to right.
            contentPane.add( plainLabel );
            contentPane.add( htmlLabel );
            contentPane.add( fancyLabel );
            contentPane.add( varyingLabel );
            contentPane.add( toggleButton );
            jFrame.setSize( 560, 70 );
            jFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
            jFrame.validate();
            jFrame.setVisible( true );
            }
        } );
        }// end main
    }