Java/Swing JFC/Label

Материал из Java эксперт
Версия от 18:01, 31 мая 2010; (обсуждение)
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Содержание

Active Label Sample

 
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIDefaults;
import javax.swing.UIManager;
public class ActiveSample {
  private static final String LABEL_FACTORY = "LabelFactory";
  public static void main(String args[]) {
    JFrame frame = new JFrame("Active Example");
    UIManager.put(LABEL_FACTORY, new ActiveLabel());
    final JPanel panel = new JPanel();
    JButton button = new JButton("Get");
    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        JLabel label = (JLabel) UIManager.get(LABEL_FACTORY);
        panel.add(label);
        panel.revalidate();
      }
    };
    button.addActionListener(actionListener);
    Container contentPane = frame.getContentPane();
    contentPane.add(panel, BorderLayout.CENTER);
    contentPane.add(button, BorderLayout.SOUTH);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}
class ActiveLabel implements UIDefaults.ActiveValue {
  private int counter = 0;
  public Object createValue(UIDefaults defaults) {
    JLabel label = new JLabel("" + counter++);
    return label;
  }
}





Adding an Icon to a JLabel Component

 
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
public class Main {
  public static void main(String[] argv) throws Exception {
    Icon icon = new ImageIcon("icon.gif");
    JLabel label = new JLabel("Text Label", icon, JLabel.CENTER);
    // a label with only an icon
    label = new JLabel(icon);
  }
}





Adding Drag-and-Drop Support to a JLabel Component

 
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.TransferHandler;
public class Main {
  public static void main(String[] argv) throws Exception {
    JLabel label = new JLabel("Label Text");
    final String propertyName = "text";
    label.setTransferHandler(new TransferHandler(propertyName));
    label.addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent evt) {
        JComponent comp = (JComponent) evt.getSource();
        TransferHandler th = comp.getTransferHandler();
        th.exportAsDrag(comp, evt, TransferHandler.COPY);
      }
    });
  }
}





A JLabel that uses inline HTML to format its text

 
//A JLabel that uses inline HTML to format its text.
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class SwingHtmlLabel extends JPanel {
  public static final String markup = "<html>line 1<p><font color=blue size=+2>"
      + "big blue</font> line 2<p>line 3</html>";
  public static void main(String argv[]) {
    JPanel p = new JPanel(new java.awt.GridLayout(0, 1));
    p.add(new JLabel(markup));
    p.add(new java.awt.Label(markup));
    JFrame f = new JFrame("SwingHtmlLabel");
    f.setContentPane(p);
    f.setSize(600, 200);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
  }
}





A Label that uses inline HTML to format its text

 
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Main extends JPanel {
  public static final String markup = "<html>line 1<p><font color=blue size=+2>"
      + "big blue</font> line 2<p>line 3</html>";
  public static void main(String argv[]) {
    JPanel p = new JPanel(new java.awt.GridLayout(0, 1));
    p.add(new JLabel(markup));
    p.add(new java.awt.Label(markup));
    JFrame f = new JFrame("HtmlLabel");
    f.setContentPane(p);
    f.setSize(600, 200);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
  }
}





A label with no indication it has been clicked

 
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JLabel;
public class MyLabel extends JLabel {
  public MyLabel(String msg) {
    super(msg);
    addMouseListener(new MouseAdapter() {
      public void mouseClicked(MouseEvent me) {
        fireActionPerformed(new ActionEvent(MyLabel.this, ActionEvent.ACTION_PERFORMED,
            "SecretMessage"));
      }
    });
  }
  public void addActionListener(ActionListener l) {
    listenerList.add(ActionListener.class, l);
  }
  public void removeActionListener(ActionListener l) {
    listenerList.remove(ActionListener.class, l);
  }
  protected void fireActionPerformed(ActionEvent ae) {
    Object[] listeners = listenerList.getListeners(ActionListener.class);
    for (int i = 0; i < listeners.length; i++) {
      ((ActionListener) listeners[i]).actionPerformed(ae);
    }
  }
}





Animation label

 
import java.awt.Graphics;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
public class AnimatedLabel extends JLabel implements Runnable {
  protected Icon[] icons;
  protected int index = 0;
  protected boolean isRunning;
  public AnimatedLabel(String gifName, int numGifs) {
    icons = new Icon[numGifs];
    for (int i = 0; i < numGifs; i++)
      icons[i] = new ImageIcon(gifName + i + ".gif");
    setIcon(icons[0]);
    Thread tr = new Thread(this);
    tr.setPriority(Thread.MAX_PRIORITY);
    tr.start();
  }
  public void setRunning(boolean r) {
    isRunning = r;
  }
  public boolean getRunning() {
    return isRunning;
  }
  public void run() {
    while (true) {
      if (isRunning) {
        index++;
        if (index >= icons.length)
          index = 0;
        setIcon(icons[index]);
        Graphics g = getGraphics();
        icons[index].paintIcon(this, g, 0, 0);
      } else {
        if (index > 0) {
          index = 0;
          setIcon(icons[0]);
        }
      }
      try {
        Thread.sleep(500);
      } catch (Exception ex) {
      }
    }
  }
}





A quick application to show a simple JLabel

 
//A quick application to show a simple JLabel.
import javax.swing.JFrame;
import javax.swing.JLabel;
public class SimpleJLabelExample {
  public static void main(String[] args) {
    JLabel label = new JLabel("A Very Simple Text Label");
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(label);
    frame.pack();
    frame.setVisible(true);
  }
}





A simple demonstration of text alignment in JLabels

 
//A simple demonstration of text alignment in JLabels.
import java.awt.Color;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
public class AlignmentExample {
  public static void main(String[] args) {
    JLabel label1 = new JLabel("BottomRight", SwingConstants.RIGHT);
    JLabel label2 = new JLabel("CenterLeft", SwingConstants.LEFT);
    JLabel label3 = new JLabel("TopCenter", SwingConstants.CENTER);
    label1.setVerticalAlignment(SwingConstants.BOTTOM);
    label2.setVerticalAlignment(SwingConstants.CENTER);
    label3.setVerticalAlignment(SwingConstants.TOP);
    label1.setBorder(BorderFactory.createLineBorder(Color.black));
    label2.setBorder(BorderFactory.createLineBorder(Color.black));
    label3.setBorder(BorderFactory.createLineBorder(Color.black));
    JFrame frame = new JFrame("AlignmentExample");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JPanel p = new JPanel(new GridLayout(3, 1, 8, 8));
    p.add(label1);
    p.add(label2);
    p.add(label3);
    p.setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
    frame.setContentPane(p);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}





Create a JLabel component

 
 
import java.awt.FlowLayout;
import java.awt.HeadlessException;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Main extends JFrame {
  public Main() throws HeadlessException {
    setSize(150, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new FlowLayout());
    JLabel label1 = new JLabel("Username :", JLabel.RIGHT);
    JLabel label2 = new JLabel("Password :", JLabel.RIGHT);
    JLabel label3 = new JLabel("Confirm Password :", JLabel.RIGHT);
    JLabel label4 = new JLabel("Remember Me!", JLabel.LEFT);
    JLabel label5 = new JLabel("Hello.", JLabel.CENTER);
    label5.setVerticalAlignment(JLabel.TOP);
    label5.setToolTipText("A tool tip with me!");
    getContentPane().add(label1);
    getContentPane().add(label2);
    getContentPane().add(label3);
    getContentPane().add(label4);
    getContentPane().add(label5);
  }
  public static void main(String[] args) {
    new Main().setVisible(true);
  }
}





Create a JLabel with an image icon

 
 
import java.awt.FlowLayout;
import java.awt.HeadlessException;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Main extends JFrame {
  public Main() throws HeadlessException {
    setSize(300, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new FlowLayout(FlowLayout.LEFT));
    Icon icon = new ImageIcon("a.png");
    JLabel label1 = new JLabel("Full Name :", icon, JLabel.LEFT);
    JLabel label2 = new JLabel("Address :", JLabel.LEFT);
    label2.setIcon(new ImageIcon("b.png"));
    getContentPane().add(label1);
    getContentPane().add(label2);
  }
  public static void main(String[] args) {
    new Main().setVisible(true);
  }
}





Create JLabel component

 
 
import java.awt.FlowLayout;
import java.awt.HeadlessException;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Main extends JFrame {
  public Main() throws HeadlessException {
    setSize(150, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new FlowLayout());
    JLabel label1 = new JLabel("Username :", JLabel.RIGHT);
    JLabel label2 = new JLabel("Password :", JLabel.RIGHT);
    JLabel label3 = new JLabel("Confirm Password :", JLabel.RIGHT);
    JLabel label4 = new JLabel("Remember Me!", JLabel.LEFT);
    JLabel label5 = new JLabel("Hello.", JLabel.CENTER);
    label5.setVerticalAlignment(JLabel.TOP);
    label5.setToolTipText("A tool tip with me!");
    getContentPane().add(label1);
    getContentPane().add(label2);
    getContentPane().add(label3);
    getContentPane().add(label4);
    getContentPane().add(label5);
  }
  public static void main(String[] args) {
    new Main().setVisible(true);
  }
}





Disable a label

 
import java.awt.Color;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("asdf");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    label.setEnabled(false);
    f.add(label);
    f.setVisible(true);
  }
}





Grab and Drag image scroll label

 
import java.awt.Container;
import java.awt.Cursor;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JViewport;
import javax.swing.event.MouseInputAdapter;
public class GrabAndDragDemo extends JFrame {
  public GrabAndDragDemo() {
    super("Grab and drag Demo");
    ImageIcon ii = new ImageIcon("largejexpLogo.jpg");
    JScrollPane jsp = new JScrollPane(new GrabAndScrollLabel(ii));
    getContentPane().add(jsp);
    setSize(300, 250);
    setVisible(true);
    WindowListener l = new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    };
    addWindowListener(l);
  }
  public static void main(String[] args) {
    new GrabAndDragDemo();
  }
}
class GrabAndScrollLabel extends JLabel {
  public GrabAndScrollLabel(ImageIcon i) {
    super(i);
    MouseInputAdapter mia = new MouseInputAdapter() {
      int xDiff, yDiff;
      boolean isDragging;
      Container c;
      public void mouseDragged(MouseEvent e) {
        c = GrabAndScrollLabel.this.getParent();
        if (c instanceof JViewport) {
          JViewport jv = (JViewport) c;
          Point p = jv.getViewPosition();
          int newX = p.x - (e.getX() - xDiff);
          int newY = p.y - (e.getY() - yDiff);
          int maxX = GrabAndScrollLabel.this.getWidth()
              - jv.getWidth();
          int maxY = GrabAndScrollLabel.this.getHeight()
              - jv.getHeight();
          if (newX < 0)
            newX = 0;
          if (newX > maxX)
            newX = maxX;
          if (newY < 0)
            newY = 0;
          if (newY > maxY)
            newY = maxY;
          jv.setViewPosition(new Point(newX, newY));
        }
      }
      public void mousePressed(MouseEvent e) {
        setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));
        xDiff = e.getX();
        yDiff = e.getY();
      }
      public void mouseReleased(MouseEvent e) {
        setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
      }
    };
    addMouseMotionListener(mia);
    addMouseListener(mia);
  }
}





Horizontal Alignment: CENTER

 
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("asdf");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    label.setPreferredSize(new Dimension(150, 100));
    
    label.setText("Centered");
    label.setHorizontalAlignment(JLabel.CENTER);
    label.setVerticalAlignment(JLabel.CENTER);
    
    f.add(label);
    f.setVisible(true);
  }
}





Horizontal Alignment: LEFT

 
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("asdf");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    label.setPreferredSize(new Dimension(150, 100));
    
    label.setText("Top Left");
    label.setHorizontalAlignment(JLabel.LEFT);
    label.setVerticalAlignment(JLabel.TOP);
    
    f.add(label);
    f.setVisible(true);
  }
}





Horizontal Alignment: RIGHT

 
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("asdf");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    label.setPreferredSize(new Dimension(150, 100));
    
    label.setText("Bottom Right");
    label.setHorizontalAlignment(JLabel.RIGHT);
    label.setVerticalAlignment(JLabel.BOTTOM);
    
    f.add(label);
    f.setVisible(true);
  }
}





HTML label

 
import java.awt.FlowLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class HtmlLabel extends JFrame {
  public HtmlLabel() {
    super("HTML Buttons");
    setSize(400, 300);
    getContentPane().setLayout(new FlowLayout());
    String htmlText = "<html><p><font color=\"#800080\" "
        + "size=\"4\" face=\"Verdana\">JButton</font> </p>"
        + "<font size=\"2\"><em>" + "with HTML text</em></font></html>";
    JLabel btn = new JLabel(htmlText);
    getContentPane().add(btn);
    WindowListener wndCloser = new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    };
    addWindowListener(wndCloser);
    setVisible(true);
  }
  public static void main(String args[]) {
    new HtmlLabel();
  }
}





JLabel is for displaying text, images or both. It does not react to input events.

 
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class MyLabel extends JFrame {
  public static void main(String[] args) {
    String lyrics = "<html>Line<br>line<br>line</html>";
    JPanel panel = new JPanel();
    panel.setLayout(new BorderLayout(10, 10));
    JLabel label = new JLabel(lyrics);
    label.setFont(new Font("Georgia", Font.PLAIN, 14));
    label.setForeground(new Color(50, 50, 25));
    panel.add(label, BorderLayout.CENTER);
    panel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
    JFrame f = new JFrame();
    f.add(panel);
    f.pack();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
  }
}





JLabel with lined border

 
import java.awt.Color;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("A default label");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    f.add(label);
    f.setVisible(true);
  }
}





JLabel with more than one row

 
JLabel label = new JLabel();
label.setText("<html>Line 1<br>Line 2</html>");





JSlider lets the user graphically select a value by sliding a knob within a bounded interval.

 
import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Slider {
  public static void main(String[] args) {
    JFrame f = new JFrame();
    final JSlider slider = new JSlider(0, 150, 0);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    slider.setPreferredSize(new Dimension(150, 30));
    slider.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent event) {
        int value = slider.getValue();
        if (value == 0) {
          System.out.println("0");
        } else if (value > 0 && value <= 30) {
          System.out.println("value > 0 && value <= 30");
        } else if (value > 30 && value < 80) {
          System.out.println("value > 30 && value < 80");
        } else {
          System.out.println("max");
        }
      }
    });
    f.add(slider);
    f.pack();
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}





Label alignment

 
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class AlignLabels extends JPanel {
  JLabel[] labels = new JLabel[9];
  public AlignLabels() {
    JLabel label;
    setLayout(new GridLayout(3, 3));
    label = createLabel("NW alignment");
    setNWalignment(label);
    label.setEnabled(false);
    labels[0] = label;
    label = createLabel("N alignment");
    setNalignment(label);
    labels[1] = label;
    label = createLabel("NE alignment");
    setNEalignment(label);
    labels[2] = label;
    label = createLabel("W alignment");
    label.setText("<html><i>html based<br></i><font color=blue>W alignment</font>");
    setWalignment(label);
    labels[3] = label;
    label = createLabel("C alignment");
    setCalignment(label);
    label.setEnabled(false);
    labels[4] = label;
    label = createLabel("E alignment");
    setEalignment(label);
    labels[5] = label;
    label = createLabel("SW alignment");
    setSWalignment(label);
    labels[6] = label;
    label = createLabel("S alignment");
    setSalignment(label);
    labels[7] = label;
    label = createLabel("SE alignment");
    setSEalignment(label);
    label.setEnabled(false);
    labels[8] = label;
  }
  public static void main(String[] a) {
    JFrame mainFrame = new JFrame();
    mainFrame.getContentPane().add(new AlignLabels());
    
    mainFrame.setSize(500,500);
    mainFrame.setVisible(true);
  }
  JLabel[] getLabels() {
    return labels;
  }
  JLabel createLabel(String text) {
    String separator = System.getProperty("line.separator");
    JLabel label = new JLabel(text + separator + "multiline" + separator
        + "label");
    label.setToolTipText(text + "\n\ndoubled space\n\ntooltip");
    label.setBorder(BorderFactory.createEtchedBorder());
    this.add(label);
    label.setPreferredSize(new Dimension(125, 125));
    return label;
  }
  void setNWalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.LEFT);
    b.setVerticalAlignment(JLabel.TOP);
  }
  void setNalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.CENTER);
    b.setVerticalAlignment(JLabel.TOP);
  }
  void setNEalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.RIGHT);
    b.setVerticalAlignment(JLabel.TOP);
  }
  void setWalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.LEFT);
    b.setVerticalAlignment(JLabel.CENTER);
  }
  void setCalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.CENTER);
    b.setVerticalAlignment(JLabel.CENTER);
  }
  void setEalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.RIGHT);
    b.setVerticalAlignment(JLabel.CENTER);
  }
  void setSWalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.LEFT);
    b.setVerticalAlignment(JLabel.BOTTOM);
  }
  void setSalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.CENTER);
    b.setVerticalAlignment(JLabel.BOTTOM);
  }
  void setSEalignment(JLabel b) {
    b.setHorizontalAlignment(JLabel.RIGHT);
    b.setVerticalAlignment(JLabel.BOTTOM);
  }
}
class ColoredSquare implements Icon {
  Color color;
  public ColoredSquare(Color color) {
    this.color = color;
  }
  public void paintIcon(Component c, Graphics g, int x, int y) {
    Color oldColor = g.getColor();
    g.setColor(color);
    g.fill3DRect(x, y, getIconWidth(), getIconHeight(), true);
    g.setColor(oldColor);
  }
  public int getIconWidth() {
    return 12;
  }
  public int getIconHeight() {
    return 12;
  }
}





Label background, icon, align

 
import java.awt.Color;
import java.awt.Font;
import java.awt.GridLayout;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
public class LabelDemo extends JFrame {
  public LabelDemo() {
    super("JLabel Demo");
    setSize(600, 100);
    JPanel content = new JPanel(new GridLayout(1, 4, 4, 4));
    JLabel label = new JLabel("jexp");
    label.setBackground(Color.white);
    content.add(label);
    label = new JLabel("jexp", SwingConstants.CENTER);
    label.setOpaque(true);
    label.setBackground(Color.white);
    content.add(label);
    label = new JLabel("jexp");
    label.setFont(new Font("Helvetica", Font.BOLD, 18));
    label.setOpaque(true);
    label.setBackground(Color.white);
    content.add(label);
    ImageIcon image = new ImageIcon("jexpLogo.gif");
    label = new JLabel("jexp", image, SwingConstants.RIGHT);
    label.setVerticalTextPosition(SwingConstants.TOP);
    label.setOpaque(true);
    label.setBackground(Color.white);
    content.add(label);
    getContentPane().add(content);
    setVisible(true);
  }
  public static void main(String args[]) {
    new LabelDemo();
  }
}





LabelFocusSample: setLabelFor

 
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class LabelFocusSample {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Label Focus Example");
    Container content = frame.getContentPane();
    JPanel panel = new JPanel(new BorderLayout());
    JLabel label = new JLabel("Name: ");
    label.setDisplayedMnemonic(KeyEvent.VK_N);
    JTextField textField = new JTextField();
    label.setLabelFor(textField);
    panel.add(label, BorderLayout.WEST);
    panel.add(textField, BorderLayout.CENTER);
    content.add(panel, BorderLayout.NORTH);
    content.add(new JButton("Somewhere Else"), BorderLayout.SOUTH);
    frame.setSize(250, 150);
    frame.setVisible(true);
  }
}





Label for

 
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.BoundedRangeModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class OffsetSample {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Offset Example");
    Container content = frame.getContentPane();
    JPanel panel = new JPanel(new BorderLayout());
    JLabel label = new JLabel("Name: ");
    label.setDisplayedMnemonic(KeyEvent.VK_N);
    final JTextField textField = new JTextField();
    label.setLabelFor(textField);
    panel.add(label, BorderLayout.WEST);
    panel.add(textField, BorderLayout.CENTER);
    content.add(panel, BorderLayout.NORTH);
    JButton button = new JButton("Get Offset");
    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        System.out.println("Offset: " + textField.getScrollOffset());
        System.out.println("Visibility: "
            + textField.getHorizontalVisibility());
        BoundedRangeModel model = textField.getHorizontalVisibility();
        int extent = model.getExtent();
        textField.setScrollOffset(extent);
      }
    };
    button.addActionListener(actionListener);
    content.add(button, BorderLayout.SOUTH);
    frame.setSize(250, 150);
    frame.setVisible(true);
  }
}





LabelFor Demo

 
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.KeyEvent;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class LabelFor {
  public static void main(String args[]) {
    JFrame f = new JFrame("LabelFor Sample");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = f.getContentPane();
    JLabel label = new JLabel("Username");
    JTextField textField = new JTextField();
    label.setDisplayedMnemonic(KeyEvent.VK_U);
    label.setLabelFor(textField);
    Container box = Box.createHorizontalBox();
    box.add(label);
    box.add(textField);
    content.add(box, BorderLayout.NORTH);
    content.add(new JButton("Submit"), BorderLayout.SOUTH);
    f.setSize(300, 200);
    f.setVisible(true);
  }
}





Label Text Position

 
import java.awt.Container;
import java.awt.GridLayout;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
import javax.swing.border.LineBorder;
public class LabelTextPos {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Label Text Pos");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = frame.getContentPane();
    content.setLayout(new GridLayout(2, 2));
    Border border = LineBorder.createGrayLineBorder();
    Icon warnIcon = new ImageIcon("Warn.gif");
    JLabel label1 = new JLabel(warnIcon);
    label1.setText("Left-Bottom");
    label1.setHorizontalTextPosition(JLabel.LEFT);
    label1.setVerticalTextPosition(JLabel.BOTTOM);
    label1.setBorder(border);
    content.add(label1);
    JLabel label2 = new JLabel(warnIcon);
    label2.setText("Right-TOP");
    label2.setHorizontalTextPosition(JLabel.RIGHT);
    label2.setVerticalTextPosition(JLabel.TOP);
    label2.setBorder(border);
    content.add(label2);
    JLabel label3 = new JLabel(warnIcon);
    label3.setText("Center-Center");
    label3.setHorizontalTextPosition(JLabel.CENTER);
    label3.setVerticalTextPosition(JLabel.CENTER);
    label3.setBorder(border);
    content.add(label3);
    JLabel label4 = new JLabel(warnIcon);
    label4.setText("Center-Bottom");
    label4.setHorizontalTextPosition(JLabel.CENTER);
    label4.setVerticalTextPosition(JLabel.BOTTOM);
    label4.setBorder(border);
    content.add(label4);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}





Label with HTML Sample

 
import java.awt.Container;
import java.awt.GridLayout;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class LabelSample {
  public static void main(String args[]) {
    String title = "JLabel Sample";
    JFrame frame = new JFrame(title);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = frame.getContentPane();
    content.setLayout(new GridLayout(2, 2));
    JLabel label1 = new JLabel("Text Label");
    content.add(label1);
    Icon warnIcon = new ImageIcon("Warn.gif");
    JLabel label2 = new JLabel(warnIcon);
    content.add(label2);
    JLabel label3 = new JLabel("Warning", warnIcon, JLabel.CENTER);
    content.add(label3);
    String htmlLabel = "<html><sup>HTML</sup> <sub><em>Label</em></sub><br>"
        + "<font color=\"#FF0080\"><u>Multi-line</u></font>";
    JLabel label4 = new JLabel(htmlLabel);
    content.add(label4);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}





Label with Icon

 
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Polygon;
import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class LabelIcon {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Label Icon");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = frame.getContentPane();
    Icon icon = new DiamondIcon(Color.red, true, 25, 25);
    JLabel label1 = new JLabel(icon);
    content.add(label1);
    frame.setSize(200, 100);
    frame.setVisible(true);
  }
}
class DiamondIcon implements Icon {
  private Color color;
  private boolean selected;
  private int width;
  private int height;
  private Polygon poly;
  private static final int DEFAULT_WIDTH = 10;
  private static final int DEFAULT_HEIGHT = 10;
  public DiamondIcon(Color color) {
    this(color, true, DEFAULT_WIDTH, DEFAULT_HEIGHT);
  }
  public DiamondIcon(Color color, boolean selected) {
    this(color, selected, DEFAULT_WIDTH, DEFAULT_HEIGHT);
  }
  public DiamondIcon(Color color, boolean selected, int width, int height) {
    this.color = color;
    this.selected = selected;
    this.width = width;
    this.height = height;
    initPolygon();
  }
  private void initPolygon() {
    poly = new Polygon();
    int halfWidth = width / 2;
    int halfHeight = height / 2;
    poly.addPoint(0, halfHeight);
    poly.addPoint(halfWidth, 0);
    poly.addPoint(width, halfHeight);
    poly.addPoint(halfWidth, height);
  }
  public int getIconHeight() {
    return height;
  }
  public int getIconWidth() {
    return width;
  }
  public void paintIcon(Component c, Graphics g, int x, int y) {
    g.setColor(color);
    g.translate(x, y);
    if (selected) {
      g.fillPolygon(poly);
    } else {
      g.drawPolygon(poly);
    }
    g.translate(-x, -y);
  }
}





Label with Image

 
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Toolkit;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class LabelJarSample {
  public static void main(String args[]) {
    String title = "JLabel Sample";
    JFrame frame = new JFrame(title);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = frame.getContentPane();
    content.setLayout(new GridLayout(2, 2));
    JLabel label1 = new JLabel("Text Label");
    content.add(label1);
    Image warnImage = ImageLoader.getImage(LabelJarSample.class, "Warn.gif");
    Icon warnIcon = new ImageIcon(warnImage);
    JLabel label2 = new JLabel(warnIcon);
    content.add(label2);
    JLabel label3 = new JLabel("Warning", warnIcon, JLabel.CENTER);
    content.add(label3);
    String htmlLabel = "<html><sup>HTML</sup> <sub><em>Label</em></sub><br>"
        + "<font color=\"#FF0080\"><u>Multi-line</u></font>";
    JLabel label4 = new JLabel(htmlLabel);
    content.add(label4);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}
final class ImageLoader {
  private ImageLoader() {
  }
  public static Image getImage(Class relativeClass, String filename) {
    Image returnValue = null;
    InputStream is = relativeClass.getResourceAsStream(filename);
    if (is != null) {
      BufferedInputStream bis = new BufferedInputStream(is);
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      try {
        int ch;
        while ((ch = bis.read()) != -1) {
          baos.write(ch);
        }
        returnValue = Toolkit.getDefaultToolkit().createImage(
            baos.toByteArray());
      } catch (IOException exception) {
        System.err.println("Error loading: " + filename);
      }
    }
    return returnValue;
  }
}





Label with ImageIcon (Icon)

 
import java.awt.Color;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    ImageIcon myIcon = new ImageIcon("myIcon.gif");
    
    JLabel label= new JLabel("A default label", myIcon, JLabel.LEFT);
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    f.add(label);
    f.setVisible(true);
  }
}





Label with various effects

 
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.awt.font.FontRenderContext;
import java.awt.font.TextLayout;
import java.awt.geom.AffineTransform;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.LineBorder;
public class JLabel2D extends JLabel {
  public static final int EFFECT_PLAIN = 0;
  public static final int EFFECT_GRADIENT = 1;
  public static final int EFFECT_IMAGE = 2;
  public static final int EFFECT_IMAGE_ANIMATION = 3;
  public static final int EFFECT_COLOR_ANIMATION = 4;
  protected int effectIndex = EFFECT_PLAIN;
  protected double shearFactor = 0.0;
  protected Color outlineColor;
  protected Stroke stroke;
  protected GradientPaint gradient;
  protected Image foregroundImage;
  protected Thread animator;
  protected boolean isRunning = false;
  protected int m_delay;
  protected int m_xShift;
  public JLabel2D() {
    super();
  }
  public JLabel2D(String text) {
    super(text);
  }
  public JLabel2D(String text, int alignment) {
    super(text, alignment);
  }
  public void setEffectIndex(int e) {
    effectIndex = e;
    repaint();
  }
  public int getEffectIndex() {
    return effectIndex;
  }
  public void setShearFactor(double s) {
    shearFactor = s;
    repaint();
  }
  public double getShearFactor() {
    return shearFactor;
  }
  public void setOutlineColor(Color c) {
    outlineColor = c;
    repaint();
  }
  public Color getOutlineColor() {
    return outlineColor;
  }
  public void setStroke(Stroke s) {
    stroke = s;
    repaint();
  }
  public Stroke getStroke() {
    return stroke;
  }
  public void setGradient(GradientPaint g) {
    gradient = g;
    repaint();
  }
  public GradientPaint getGradient() {
    return gradient;
  }
  public void setForegroundImage(Image img) {
    foregroundImage = img;
    repaint();
  }
  public Image getForegroundImage() {
    return foregroundImage;
  }
  public void startAnimation(int delay) {
    if (animator != null)
      return;
    m_delay = delay;
    m_xShift = 0;
    isRunning = true;
    animator = new Thread() {
      double arg = 0;
      public void run() {
        while (isRunning) {
          if (effectIndex == EFFECT_IMAGE_ANIMATION)
            m_xShift += 10;
          else if (effectIndex == EFFECT_COLOR_ANIMATION
              && gradient != null) {
            arg += Math.PI / 10;
            double cos = Math.cos(arg);
            double f1 = (1 + cos) / 2;
            double f2 = (1 - cos) / 2;
            arg = arg % (Math.PI * 2);
            Color c1 = gradient.getColor1();
            Color c2 = gradient.getColor2();
            int r = (int) (c1.getRed() * f1 + c2.getRed() * f2);
            r = Math.min(Math.max(r, 0), 255);
            int g = (int) (c1.getGreen() * f1 + c2.getGreen() * f2);
            g = Math.min(Math.max(g, 0), 255);
            int b = (int) (c1.getBlue() * f1 + c2.getBlue() * f2);
            b = Math.min(Math.max(b, 0), 255);
            setForeground(new Color(r, g, b));
          }
          repaint();
          try {
            sleep(m_delay);
          } catch (InterruptedException ex) {
            break;
          }
        }
      }
    };
    animator.start();
  }
  public void stopAnimation() {
    isRunning = false;
    animator = null;
  }
  public void paintComponent(Graphics g) {
    Dimension d = getSize();
    Insets ins = getInsets();
    int x = ins.left;
    int y = ins.top;
    int w = d.width - ins.left - ins.right;
    int h = d.height - ins.top - ins.bottom;
    if (isOpaque()) {
      g.setColor(getBackground());
      g.fillRect(0, 0, d.width, d.height);
    }
    paintBorder(g);
    Graphics2D g2 = (Graphics2D) g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
        RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setRenderingHint(RenderingHints.KEY_RENDERING,
        RenderingHints.VALUE_RENDER_QUALITY);
    FontRenderContext frc = g2.getFontRenderContext();
    TextLayout tl = new TextLayout(getText(), getFont(), frc);
    AffineTransform shear = AffineTransform.getShearInstance(shearFactor,
        0.0);
    Shape src = tl.getOutline(shear);
    Rectangle rText = src.getBounds();
    float xText = x - rText.x;
    switch (getHorizontalAlignment()) {
    case CENTER:
      xText = x + (w - rText.width) / 2;
      break;
    case RIGHT:
      xText = x + (w - rText.width);
      break;
    }
    float yText = y + h / 2 + tl.getAscent() / 4;
    AffineTransform shift = AffineTransform.getTranslateInstance(xText,
        yText);
    Shape shp = shift.createTransformedShape(src);
    if (outlineColor != null) {
      g2.setColor(outlineColor);
      if (stroke != null)
        g2.setStroke(stroke);
      g2.draw(shp);
    }
    switch (effectIndex) {
    case EFFECT_GRADIENT:
      if (gradient == null)
        break;
      g2.setPaint(gradient);
      g2.fill(shp);
      break;
    case EFFECT_IMAGE:
      fillByImage(g2, shp, 0);
      break;
    case EFFECT_COLOR_ANIMATION:
      g2.setColor(getForeground());
      g2.fill(shp);
      break;
    case EFFECT_IMAGE_ANIMATION:
      if (foregroundImage == null)
        break;
      int wImg = foregroundImage.getWidth(this);
      if (m_xShift > wImg)
        m_xShift = 0;
      fillByImage(g2, shp, m_xShift - wImg);
      break;
    default:
      g2.setColor(getForeground());
      g2.fill(shp);
      break;
    }
  }
  protected void fillByImage(Graphics2D g2, Shape shape, int xOffset) {
    if (foregroundImage == null)
      return;
    int wImg = foregroundImage.getWidth(this);
    int hImg = foregroundImage.getHeight(this);
    if (wImg <= 0 || hImg <= 0)
      return;
    g2.setClip(shape);
    Rectangle bounds = shape.getBounds();
    for (int xx = bounds.x + xOffset; xx < bounds.x + bounds.width; xx += wImg)
      for (int yy = bounds.y; yy < bounds.y + bounds.height; yy += hImg)
        g2.drawImage(foregroundImage, xx, yy, this);
  }
  public static void main(String argv[]) {
    JFrame f = new JFrame("2D Labels");
    f.setSize(600, 300);
    f.getContentPane().setLayout(new GridLayout(6, 1, 5, 5));
    f.getContentPane().setBackground(Color.white);
    Font bigFont = new Font("Helvetica", Font.BOLD, 24);
    JLabel2D lbl = new JLabel2D("Java Source and Support With Outline",
        JLabel.CENTER);
    lbl.setFont(bigFont);
    lbl.setForeground(Color.blue);
    lbl.setBorder(new LineBorder(Color.black));
    lbl.setBackground(Color.cyan);
    lbl.setOutlineColor(Color.yellow);
    lbl.setStroke(new BasicStroke(5f));
    lbl.setOpaque(true);
    lbl.setShearFactor(0.3);
    f.getContentPane().add(lbl);
    lbl = new JLabel2D("Java Source and Support With Color Gradient", JLabel.CENTER);
    lbl.setFont(bigFont);
    lbl.setOutlineColor(Color.black);
    lbl.setEffectIndex(JLabel2D.EFFECT_GRADIENT);
    GradientPaint gp = new GradientPaint(0, 0, Color.red, 100, 50,
        Color.blue, true);
    lbl.setGradient(gp);
    f.getContentPane().add(lbl);
    lbl = new JLabel2D("Java Source and Support Filled With Image", JLabel.CENTER);
    lbl.setFont(bigFont);
    lbl.setEffectIndex(JLabel2D.EFFECT_IMAGE);
    ImageIcon icon = new ImageIcon("mars.gif");
    lbl.setForegroundImage(icon.getImage());
    lbl.setOutlineColor(Color.red);
    f.getContentPane().add(lbl);
    lbl = new JLabel2D("Java Source and Support With Image Animation", JLabel.CENTER);
    lbl.setFont(bigFont);
    lbl.setEffectIndex(JLabel2D.EFFECT_IMAGE_ANIMATION);
    icon = new ImageIcon("ocean.gif");
    lbl.setForegroundImage(icon.getImage());
    lbl.setOutlineColor(Color.black);
    lbl.startAnimation(400);
    f.getContentPane().add(lbl);
    lbl = new JLabel2D("Java Source and Support With Color Animation", JLabel.CENTER);
    lbl.setFont(bigFont);
    lbl.setEffectIndex(JLabel2D.EFFECT_COLOR_ANIMATION);
    lbl.setGradient(gp);
    lbl.setOutlineColor(Color.black);
    lbl.startAnimation(400);
    f.getContentPane().add(lbl);
    JLabel lbl1 = new JLabel("Plain Java Source and Support For Comparison", JLabel.CENTER);
    lbl1.setFont(bigFont);
    lbl1.setForeground(Color.black);
    f.getContentPane().add(lbl1);
    WindowListener wndCloser = new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    };
    f.addWindowListener(wndCloser);
    f.setVisible(true);
  }
}





Multiline label (HTML)

 
import java.awt.Color;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("<html>Use HTML to create<br>" + "a multiline message."
        + "<br>One<br>Two<br>Three");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    f.add(label);
    f.setVisible(true);
  }
}





Putting HTML text on Swing components

 
// : c14:HTMLButton.java
// Putting HTML text on Swing components.
// <applet code=HTMLButton width=250 height=500></applet>
// From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002
// www.BruceEckel.ru. See copyright notice in CopyRight.txt.
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class HTMLButton extends JApplet {
  private JButton b = new JButton("<html><b><font size=+2>"
      + "<center>Hello!<br><i>Press me now!");
  public void init() {
    b.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        getContentPane().add(
            new JLabel("<html>" + "<i><font size=+4>Kapow!"));
        // Force a re-layout to include the new label:
        validate();
      }
    });
    Container cp = getContentPane();
    cp.setLayout(new FlowLayout());
    cp.add(b);
  }
  public static void main(String[] args) {
    run(new HTMLButton(), 200, 500);
  }
  public static void run(JApplet applet, int width, int height) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(applet);
    frame.setSize(width, height);
    applet.init();
    applet.start();
    frame.setVisible(true);
  }
} ///:~





Scrollable Label

 

import java.awt.Dimension;
import java.awt.Rectangle;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.Scrollable;
public class ScrollableLabel extends JLabel implements Scrollable {
  public ScrollableLabel(ImageIcon i) {
    super(i);
  }
  public Dimension getPreferredScrollableViewportSize() {
    return getPreferredSize();
  }
  public int getScrollableBlockIncrement(Rectangle r, int orietation,
      int direction) {
    return 10;
  }
  public boolean getScrollableTracksViewportHeight() {
    return false;
  }
  public boolean getScrollableTracksViewportWidth() {
    return false;
  }
  public int getScrollableUnitIncrement(Rectangle r, int orientation,
      int direction) {
    return 10;
  }
  public static void main(String[] args) {
    JFrame f = new JFrame("JScrollPane Demo");
    ImageIcon ii = new ImageIcon("largejexpLogo.gif");
    JScrollPane jsp = new JScrollPane(new ScrollableLabel(ii));
    f.getContentPane().add(jsp);
    f.setSize(300, 250);
    f.setVisible(true);
  }
}





Set the Preferred Size

 
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("asdf");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    label.setPreferredSize(new Dimension(150, 100));
    f.add(label);
    f.setVisible(true);
  }
}





Setting the Focus of a JTextField Component Using a JLabel Component

 
import java.awt.event.KeyEvent;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class Main {
  public static void main(String[] argv) throws Exception {
    JTextField textfield = new JTextField(25);
    // Create label and associate with text field
    JLabel label = new JLabel("Text Label");
    label.setDisplayedMnemonic(KeyEvent.VK_L);
    label.setLabelFor(textfield);
  }
}





Shows how displayed Mnemonic and labelFor properties work together

 
//Shows how displayedMnemonic and labelFor properties work together
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class MnemonicLabels {
  public static void main(String[] args) {
    JTextField firstField = new JTextField(10);
    JTextField middleField = new JTextField(10);
    JTextField lastField = new JTextField(10);
    JLabel firstLabel = new JLabel("First Name", JLabel.RIGHT);
    firstLabel.setDisplayedMnemonic("F");
    firstLabel.setLabelFor(firstField);
    JLabel middleLabel = new JLabel("Middle Initial", JLabel.RIGHT);
    middleLabel.setDisplayedMnemonic("I");
    middleLabel.setDisplayedMnemonicIndex(7);
    middleLabel.setLabelFor(middleField);
    JLabel lastLabel = new JLabel("Last Name", JLabel.RIGHT);
    lastLabel.setDisplayedMnemonic("L");
    lastLabel.setLabelFor(lastField);
    JPanel p = new JPanel();
    p.setLayout(new GridLayout(3, 2, 5, 5));
    p.add(firstLabel);
    p.add(firstField);
    p.add(middleLabel);
    p.add(middleField);
    p.add(lastLabel);
    p.add(lastField);
    JFrame f = new JFrame("MnemonicLabels");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setContentPane(p);
    f.pack();
    f.setVisible(true);
  }
}





Solve the problem of text alignment in JLabels

 
import java.awt.Color;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
public class Main {
  public static void main(String[] args) {
    JLabel label1 = new JLabel("BottomRight", SwingConstants.RIGHT);
    JLabel label2 = new JLabel("CenterLeft", SwingConstants.LEFT);
    JLabel label3 = new JLabel("TopCenter", SwingConstants.CENTER);
    label1.setVerticalAlignment(SwingConstants.BOTTOM);
    label2.setVerticalAlignment(SwingConstants.CENTER);
    label3.setVerticalAlignment(SwingConstants.TOP);
    label1.setBorder(BorderFactory.createLineBorder(Color.black));
    label2.setBorder(BorderFactory.createLineBorder(Color.black));
    label3.setBorder(BorderFactory.createLineBorder(Color.black));
    JFrame frame = new JFrame("AlignmentExample");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JPanel p = new JPanel(new GridLayout(3, 1, 8, 8));
    p.add(label1);
    p.add(label2);
    p.add(label3);
    p.setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
    frame.setContentPane(p);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}





Swing Label Demo

 
/* From http://java.sun.ru/docs/books/tutorial/index.html */
/*
 * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */
import java.awt.GridLayout;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
/*
 * SwingLabelDemo.java is a 1.4 application that needs one other file:
 *   images/middle.gif
 */
public class SwingLabelDemo extends JPanel {
    public SwingLabelDemo() {
        super(new GridLayout(3,1));  //3 rows, 1 column
        JLabel label1, label2, label3;
        ImageIcon icon = createImageIcon("images/middle.gif",
                                         "a pretty but meaningless splat");
        //Create the first label.
        label1 = new JLabel("Image and Text",
                            icon,
                            JLabel.CENTER);
        //Set the position of its text, relative to its icon:
        label1.setVerticalTextPosition(JLabel.BOTTOM);
        label1.setHorizontalTextPosition(JLabel.CENTER);
        //Create the other labels.
        label2 = new JLabel("Text-Only Label");
        label3 = new JLabel(icon);
        //Create tool tips, for the heck of it.
        label1.setToolTipText("A label containing both image and text");
        label2.setToolTipText("A label containing only text");
        label3.setToolTipText("A label containing only an image");
        //Add the labels.
        add(label1);
        add(label2);
        add(label3);
    }
    /** Returns an ImageIcon, or null if the path was invalid. */
    protected static ImageIcon createImageIcon(String path,
                                               String description) {
        java.net.URL imgURL = SwingLabelDemo.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL, description);
        } else {
            System.err.println("Couldn"t find file: " + path);
            return null;
        }
    }
    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Make sure we have nice window decorations.
        JFrame.setDefaultLookAndFeelDecorated(true);
        //Create and set up the window.
        JFrame frame = new JFrame("SwingLabelDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //Create and set up the content pane.
        SwingLabelDemo newContentPane = new SwingLabelDemo();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);
        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }
    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application"s GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}





The text is horizontally and vertically centered

 
import javax.swing.JLabel;
public class Main {
  public static void main(String[] argv) throws Exception {
    JLabel label = new JLabel("Text Label", JLabel.CENTER);
  }
}





The text is left-justified and bottom-aligned

 
import javax.swing.JLabel;
public class Main {
  public static void main(String[] argv) throws Exception {
    JLabel label = new JLabel("Text Label", JLabel.LEFT);
    label.setVerticalAlignment(JLabel.BOTTOM);
  }
}





The text is left-justified and top-aligned

 
import javax.swing.JLabel;
public class Main {
  public static void main(String[] argv) throws Exception {
    JLabel label = new JLabel("Text Label", JLabel.LEFT);
    label.setVerticalAlignment(JLabel.TOP);
  }
}





The text is right-justified and bottom-aligned

 
import javax.swing.JLabel;
public class Main {
  public static void main(String[] argv) throws Exception {
    JLabel label = new JLabel("Text Label", JLabel.RIGHT);
    label.setVerticalAlignment(JLabel.BOTTOM);
  }
}





The text is right-justified and top-aligned

 
import javax.swing.JLabel;
public class Main {
  public static void main(String[] argv) throws Exception {
    JLabel label = new JLabel("Text Label", JLabel.RIGHT);
    label.setVerticalAlignment(JLabel.TOP);
  }
}





The text is right-justified and vertically centered

 
import javax.swing.JLabel;
public class Main {
  public static void main(String[] argv) throws Exception {
    JLabel label = new JLabel("Text Label", JLabel.RIGHT);
  }
}





Use a ScrollBar in both vertical and horizontal direction

 
import java.awt.BorderLayout;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
public class Main extends JPanel {
  JLabel label = new JLabel();
  public Main() {
    setLayout(new BorderLayout());
    JScrollBar hbar = new JScrollBar(JScrollBar.HORIZONTAL, 30, 20, 0, 300);
    JScrollBar vbar = new JScrollBar(JScrollBar.VERTICAL, 30, 40, 0, 300);
    hbar.setUnitIncrement(2);
    hbar.setBlockIncrement(1);
    hbar.addAdjustmentListener(new MyAdjustmentListener());
    vbar.addAdjustmentListener(new MyAdjustmentListener());
    add(hbar, BorderLayout.SOUTH);
    add(vbar, BorderLayout.EAST);
    add(label, BorderLayout.CENTER);
  }
  public static void main(String s[]) {
    JFrame frame = new JFrame("Scroll Bar Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setContentPane(new Main());
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}
class MyAdjustmentListener implements AdjustmentListener {
  public void adjustmentValueChanged(AdjustmentEvent e) {
    System.out.println("    New Value is " + e.getValue() + "      ");
  }
}





Variations on a text and icon label

 
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
public class ImageLabelExample {
  private static Icon icon = new ImageIcon("1.gif");
  public static void main(String[] args) {
    JLabel[] labels = new JLabel[9];
    labels[0] = makeLabel(JLabel.TOP, JLabel.LEFT);
    labels[1] = makeLabel(JLabel.TOP, JLabel.CENTER);
    labels[2] = makeLabel(JLabel.TOP, JLabel.RIGHT);
    labels[3] = makeLabel(JLabel.CENTER, JLabel.LEFT);
    labels[4] = makeLabel(JLabel.CENTER, JLabel.CENTER);
    labels[5] = makeLabel(JLabel.CENTER, JLabel.RIGHT);
    labels[6] = makeLabel(JLabel.BOTTOM, JLabel.LEFT);
    labels[7] = makeLabel(JLabel.BOTTOM, JLabel.CENTER);
    labels[8] = makeLabel(JLabel.BOTTOM, JLabel.RIGHT);
    labels[0].setEnabled(false);
    labels[1].setDisabledIcon(new ImageIcon("2.gif"));
    labels[1].setEnabled(false);
    labels[2].setIconTextGap(15);
    labels[3].setIconTextGap(0);
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container c = frame.getContentPane();
    c.setLayout(new FlowLayout(FlowLayout.CENTER, 3, 3));
    for (int i = 0; i < 9; i++)
      c.add(labels[i]);
    frame.setSize(350, 150);
    frame.setVisible(true);
  }
  protected static JLabel makeLabel(int vert, int horiz) {
    JLabel l = new JLabel("Smile", icon, SwingConstants.CENTER);
    l.setVerticalTextPosition(vert);
    l.setHorizontalTextPosition(horiz);
    l.setBorder(BorderFactory.createLineBorder(Color.black));
    return l;
  }
}





Vertical Alignment: BOTTOM

 
    
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("asdf");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    label.setPreferredSize(new Dimension(150, 100));
    
    label.setText("Bottom Right");
    label.setHorizontalAlignment(JLabel.RIGHT);
    label.setVerticalAlignment(JLabel.BOTTOM);
    
    f.add(label);
    f.setVisible(true);
  }
}





Vertical Alignment: CENTER

 
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("asdf");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    label.setPreferredSize(new Dimension(150, 100));
    
    label.setText("Centered");
    label.setHorizontalAlignment(JLabel.CENTER);
    label.setVerticalAlignment(JLabel.CENTER);
    
    f.add(label);
    f.setVisible(true);
  }
}





Vertical Alignment: TOP

 

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.Border;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("Label Demo");
    f.setLayout(new FlowLayout());
    f.setSize(200, 360);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JLabel label= new JLabel("asdf");
    Border border = BorderFactory.createLineBorder(Color.BLACK);
    label.setBorder(border);
    label.setPreferredSize(new Dimension(150, 100));
    
    label.setText("Top Left");
    label.setHorizontalAlignment(JLabel.LEFT);
    label.setVerticalAlignment(JLabel.TOP);
    
    f.add(label);
    f.setVisible(true);
  }
}


Источник — «http://jexp.ru/index.php?title=Java/Swing_JFC/Label&oldid=7410»