Java by API/javax.swing/JComponent

JComponent: addPropertyChangeListener(PropertyChangeListener listener)

  
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.Action;
import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JFrame;
class ActionChangedListener implements PropertyChangeListener {
  private JButton button;
  public ActionChangedListener(JButton button) {
    this.button = button;
  }
  public void propertyChange(PropertyChangeEvent e) {
    String propertyName = e.getPropertyName();
    System.out.println(propertyName);
    if (e.getPropertyName().equals(Action.NAME)) {
      String text = (String) e.getNewValue();
      button.setText(text);
      button.repaint();
    } else if (propertyName.equals("enabled")) {
      Boolean enabledState = (Boolean) e.getNewValue();
      button.setEnabled(enabledState.booleanValue());
      button.repaint();
    } else if (e.getPropertyName().equals(Action.SMALL_ICON)) {
      Icon icon = (Icon) e.getNewValue();
      button.setIcon(icon);
      button.invalidate();
      button.repaint();
    }
  }
}
public class Main {
  public static void main(String[] a) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JButton bn = new JButton();
    bn.addPropertyChangeListener(new ActionChangedListener(bn));
    frame.add(bn);
    bn.setEnabled(false);
    frame.setSize(300, 300);
    frame.setVisible(true);
    frame.add(bn);
  }
}

JComponent: addVetoableChangeListener(VetoableChangeListener listener)

  
import java.awt.BorderLayout;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyVetoException;
import java.beans.VetoableChangeListener;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
public class MainClass {
  public static void main(final String args[]) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JDesktopPane desktop = new JDesktopPane();
    JInternalFrame palette = new JInternalFrame("Palette", true, true, true,
        true);
    
    palette.addVetoableChangeListener(new IconPolice());
    
    palette.setBounds(350, 150, 100, 100);
     desktop.add(palette, JDesktopPane.PALETTE_LAYER);
    palette.setVisible(true);
    
    frame.add(desktop, BorderLayout.CENTER);
    frame.setSize(500, 300);
    frame.setVisible(true);
  }
}
class IconPolice implements VetoableChangeListener {
  public void vetoableChange(PropertyChangeEvent ev) throws PropertyVetoException {
    String name = ev.getPropertyName();
    if (name.equals(JInternalFrame.IS_ICON_PROPERTY) && (ev.getNewValue() == Boolean.TRUE)) {
   System.out.println("JInternalFrame.IS_ICON_PROPERTY"); 
    }
  }
}

JComponent: getAccessibleContext()

  
import java.awt.Dimension;
import javax.accessibility.AccessibleContext;
import javax.accessibility.AccessibleRelation;
import javax.accessibility.AccessibleRelationSet;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class MainClass extends JFrame {
  
  MainClass() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JPanel p = new JPanel();
    p.setPreferredSize(new Dimension(300, 50));
    JLabel jl = new JLabel("Name:");
    p.add(jl);
    JTextField jtf = new JTextField(20);
    jtf.getAccessibleContext().setAccessibleName("Name-entry");
    p.add(jtf);
    AccessibleRelation ar = new AccessibleRelation("connector", jtf);
    AccessibleContext ac = jl.getAccessibleContext();
    ac.getAccessibleRelationSet().add(ar);
    getContentPane().add(p);
    pack();
    setVisible(true);
  }
  public static void main(String[] args) {
    MainClass ad11 = new MainClass();
    try {
      Thread.sleep(5000);
    } catch (InterruptedException e) {
    }
    ad11.dumpConnectedInfo(ad11.getAccessibleContext());
  }
  void dumpConnectedInfo(AccessibleContext ac) {
    AccessibleRelationSet ars = ac.getAccessibleRelationSet();
    AccessibleRelation ar = null;
    if (ars != null)
      ar = ars.get("connector");
    if (ar != null) {
      Object[] o = ar.getTarget();
      JComponent jc = (JComponent) o[0];
      System.out.println("Label connected to: " + jc.getAccessibleContext().getAccessibleName());
      return;
    }
    int nChildren = ac.getAccessibleChildrenCount();
    for (int i = 0; i < nChildren; i++)
      dumpConnectedInfo(ac.getAccessibleChild(i).getAccessibleContext());
  }
}

JComponent: getActionMap()

  

 
import java.awt.ruponent;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.KeyStroke;
public class Main {
  public static void main(String[] argv) {
    JButton component = new JButton();
    NextFocusAction nextFocusAction = new NextFocusAction();
    component.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke("SPACE"),
        nextFocusAction.getValue(Action.NAME));
    component.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke("F2"),
        nextFocusAction.getValue(Action.NAME));
    component.getActionMap().put(nextFocusAction.getValue(Action.NAME), nextFocusAction);
    
  }
}
class NextFocusAction extends AbstractAction {
  public NextFocusAction() {
    super("Move Focus Forwards");
  }
  public void actionPerformed(ActionEvent evt) {
    ((Component) evt.getSource()).transferFocus();
  }
}

JComponent: getHeight()

  
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.TitledBorder;
public class Main extends JFrame {
  JComponent comp = new JLabel("Test label");
  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    comp.setToolTipText("Some tooltip text for component");
    comp.setBorder(new TitledBorder("Button"));
    System.out.println("X:" + comp.getX() + " Y:" + comp.getY() + " width:"
        + comp.getWidth() + " height:" + comp.getHeight());
    getContentPane().add(comp);
    pack();
    System.out.println("X:" + comp.getX() + " Y:" + comp.getY() + " width:"
        + comp.getWidth() + " height:" + comp.getHeight());
    setVisible(true);
  }
  public static void main(String arg[]) {
    new Main();
  }
}

JComponent: getInputMap()

  
import java.awt.Event;
import java.awt.event.KeyEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.text.DefaultEditorKit;
public class MainClass extends JFrame {
  MainClass(String title) {
    super(title);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JPanel jp = new JPanel();
    JLabel jl = new JLabel("Name:");
    jp.add(jl);
    JTextField jt = new JTextField(20);
    jp.add(jt);
    KeyStroke ks = KeyStroke.getKeyStroke(KeyEvent.VK_B, Event.CTRL_MASK);
    jt.getInputMap().put(ks, DefaultEditorKit.beepAction);
    getContentPane().add(jp);
    pack();
    setVisible(true);
  }
  public static void main(String[] args) {
    new MainClass("Binding Demo2");
  }
}

JComponent: getTransferHandler()

  
/**
 * Demonstrate various aspects of Swing "data transfer".
 * @author Ian Darwin, http://www.darwinsys.ru
 * @author Jonathan Fuerth, http://www.SQLPower.ca
 */       
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.TransferHandler;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class MainClass extends JFrame {
  public static void main(String[] args) {
    new MainClass().setVisible(true);
  }
  private JTextField tf;
  private JLabel l;
  private JComboBox propertyComboBox;
  public MainClass() {
    Container cp = new Box(BoxLayout.X_AXIS);
    setContentPane(cp);
    JPanel firstPanel = new JPanel();
    propertyComboBox = new JComboBox();
    propertyComboBox.addItem("text");
    propertyComboBox.addItem("font");
    propertyComboBox.addItem("background");
    propertyComboBox.addItem("foreground");
    firstPanel.add(propertyComboBox);
    cp.add(firstPanel);
    cp.add(Box.createGlue());
    tf = new JTextField("Hello");
    tf.setForeground(Color.RED);
    tf.setDragEnabled(true);
    cp.add(tf);
    cp.add(Box.createGlue());
    l = new JLabel("Hello");
    l.setBackground(Color.YELLOW);
    cp.add(l);
    cp.add(Box.createGlue());
    JSlider stryder = new JSlider(SwingConstants.VERTICAL);
    stryder.setMinimum(10);
    stryder.setValue(14);
    stryder.setMaximum(72);
    stryder.setMajorTickSpacing(10);
    stryder.setPaintTicks(true);
    cp.add(stryder);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500, 300);
    setMyTransferHandlers((String) propertyComboBox.getSelectedItem());
    MouseListener myDragListener = new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        JComponent c = (JComponent) e.getSource();
        TransferHandler handler = c.getTransferHandler();
        handler.exportAsDrag(c, e, TransferHandler.COPY);
      }
    };
    l.addMouseListener(myDragListener);
    propertyComboBox.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ce) {
        JComboBox bx = (JComboBox) ce.getSource();
        String prop = (String) bx.getSelectedItem();
        setMyTransferHandlers(prop);
      }
    });
    tf.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        JTextField jtf = (JTextField) evt.getSource();
        String fontName = jtf.getText();
        Font font = new Font(fontName, Font.BOLD, 18);
        tf.setFont(font);
      }
    });
    stryder.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent evt) {
        JSlider sl = (JSlider) evt.getSource();
        Font oldf = tf.getFont();
        Font newf = oldf.deriveFont((float) sl.getValue());
        tf.setFont(newf);
      }
    });
  }
  private void setMyTransferHandlers(String s) {
    TransferHandler th = new TransferHandler(s);
    tf.setTransferHandler(th);
    l.setTransferHandler(th);
  }
}

JComponent: getWidth()

  
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.TitledBorder;
public class Main extends JFrame {
  JComponent comp = new JLabel("Test label");
  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    comp.setToolTipText("Some tooltip text for component");
    comp.setBorder(new TitledBorder("Button"));
    System.out.println("X:" + comp.getX() + " Y:" + comp.getY() + " width:"
        + comp.getWidth() + " height:" + comp.getHeight());
    getContentPane().add(comp);
    pack();
    System.out.println("X:" + comp.getX() + " Y:" + comp.getY() + " width:"
        + comp.getWidth() + " height:" + comp.getHeight());
    setVisible(true);
  }
  public static void main(String arg[]) {
    new Main();
  }
}

JComponent: getX()

  
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.TitledBorder;
public class Main extends JFrame {
  JComponent comp = new JLabel("Test label");
  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    comp.setToolTipText("Some tooltip text for component");
    comp.setBorder(new TitledBorder("Button"));
    System.out.println("X:" + comp.getX() + " Y:" + comp.getY() + " width:"
        + comp.getWidth() + " height:" + comp.getHeight());
    getContentPane().add(comp);
    pack();
    System.out.println("X:" + comp.getX() + " Y:" + comp.getY() + " width:"
        + comp.getWidth() + " height:" + comp.getHeight());
    setVisible(true);
  }
  public static void main(String arg[]) {
    new Main();
  }
}

JComponent: getY()

  
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.border.TitledBorder;
public class Main extends JFrame {
  JComponent comp = new JLabel("Test label");
  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    comp.setToolTipText("Some tooltip text for component");
    comp.setBorder(new TitledBorder("Button"));
    System.out.println("X:" + comp.getX() + " Y:" + comp.getY() + " width:"
        + comp.getWidth() + " height:" + comp.getHeight());
    getContentPane().add(comp);
    pack();
    System.out.println("X:" + comp.getX() + " Y:" + comp.getY() + " width:"
        + comp.getWidth() + " height:" + comp.getHeight());
    setVisible(true);
  }
  public static void main(String arg[]) {
    new Main();
  }
}

JComponent: putClientProperty(Object key, Object value)

  
import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JSlider;
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Tick Slider");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JSlider oneJSlider = new JSlider();
    oneJSlider.putClientProperty("JSlider.isFilled", Boolean.TRUE);
    JSlider anotherJSlider = new JSlider();
    // Set to default setting
    anotherJSlider.putClientProperty("JSlider.isFilled", Boolean.FALSE);
    frame.add(oneJSlider, BorderLayout.NORTH);
    frame.add(anotherJSlider, BorderLayout.SOUTH);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}

JComponent: registerKeyboardAction(ActionListener anAction, KeyStroke aKeyStroke, int aCondition)

  

import java.awt.BorderLayout;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.text.BadLocationException;
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Popup Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final JPopupMenu popup = new JPopupMenu();
    JMenuItem menuItem1 = new JMenuItem("Option 1");
    popup.add(menuItem1);
    JMenuItem menuItem2 = new JMenuItem("Option 2");
    popup.add(menuItem2);
    final JTextField textField = new JTextField();
    frame.add(textField, BorderLayout.NORTH);
    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        try {
          int dotPosition = textField.getCaretPosition();
          Rectangle popupLocation = textField.modelToView(dotPosition);
          popup.show(textField, popupLocation.x, popupLocation.y);
        } catch (BadLocationException badLocationException) {
          System.err.println("Oops");
        }
      }
    };
    KeyStroke keystroke = KeyStroke.getKeyStroke(KeyEvent.VK_PERIOD, 0, false);
    textField.registerKeyboardAction(actionListener, keystroke, JComponent.WHEN_FOCUSED);
    frame.add(new JLabel("Press "." to activate Popup menu"), BorderLayout.SOUTH);
    frame.setSize(250, 150);
    frame.setVisible(true);
  }
}

JComponent: requestFocusInWindow()

  
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.EventListener;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.event.EventListenerList;
public class MainClass {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Key Text Sample");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    KeyTextComponent keyTextComponent = new KeyTextComponent();
    final JTextField textField = new JTextField();
    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        String keyText = actionEvent.getActionCommand();
        textField.setText(keyText);
      }
    };
    keyTextComponent.addActionListener(actionListener);
    frame.add(keyTextComponent, BorderLayout.CENTER);
    frame.add(textField, BorderLayout.SOUTH);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}
class KeyTextComponent extends JComponent {
  private EventListenerList actionListenerList = new EventListenerList();
  public KeyTextComponent() {
    setBackground(Color.CYAN);
    KeyListener internalKeyListener = new KeyAdapter() {
      public void keyPressed(KeyEvent keyEvent) {
        if (actionListenerList != null) {
          int keyCode = keyEvent.getKeyCode();
          String keyText = KeyEvent.getKeyText(keyCode);
          ActionEvent actionEvent = new ActionEvent(this,
              ActionEvent.ACTION_PERFORMED, keyText);
          fireActionPerformed(actionEvent);
        }
      }
    };
    MouseListener internalMouseListener = new MouseAdapter() {
      public void mousePressed(MouseEvent mouseEvent) {
        requestFocusInWindow();
      }
    };
    addKeyListener(internalKeyListener);
    addMouseListener(internalMouseListener);
  }
  public void addActionListener(ActionListener actionListener) {
    actionListenerList.add(ActionListener.class, actionListener);
  }
  public void removeActionListener(ActionListener actionListener) {
    actionListenerList.remove(ActionListener.class, actionListener);
  }
  protected void fireActionPerformed(ActionEvent actionEvent) {
    EventListener listenerList[] = actionListenerList
        .getListeners(ActionListener.class);
    for (int i = 0, n = listenerList.length; i < n; i++) {
      ((ActionListener) listenerList[i]).actionPerformed(actionEvent);
    }
  }
  public boolean isFocusable() {
    return true;
  }
}

JComponent: revalidate()

  
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
public class MainClass extends JFrame {
  public MainClass() {
    super("Revalidation Demo");
    setSize(300, 150);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    Font font = new Font("Dialog", Font.PLAIN, 10);
    final JButton b = new JButton("Add");
    b.setFont(font);
    Container c = getContentPane();
    c.setLayout(new FlowLayout());
    c.add(b);
    b.addActionListener(new ActionListener() {
      int size = 10;
      public void actionPerformed(ActionEvent ev) {
        b.setFont(new Font("Dialog", Font.PLAIN, ++size));
        b.revalidate();
      }
    });
  }
  public static void main(String[] args) {
    MainClass re = new MainClass();
    re.setVisible(true);
  }
}

JComponent: setComponentPopupMenu(JPopupMenu popup)

  
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.event.PopupMenuEvent;
import javax.swing.event.PopupMenuListener;
class MyPopupMenuListener implements PopupMenuListener {
  public void popupMenuCanceled(PopupMenuEvent popupMenuEvent) {
    System.out.println("Canceled");
  }
  public void popupMenuWillBecomeInvisible(PopupMenuEvent popupMenuEvent) {
    System.out.println("Becoming Invisible");
  }
  public void popupMenuWillBecomeVisible(PopupMenuEvent popupMenuEvent) {
    System.out.println("Becoming Visible");
  }
}
public class Main {
  public static void main(final String args[]) {
    JFrame frame = new JFrame("Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JPopupMenu popupMenu = new JPopupMenu("Title");
    PopupMenuListener popupMenuListener = new MyPopupMenuListener();
    popupMenu.addPopupMenuListener(popupMenuListener);
    JMenuItem cutMenuItem = new JMenuItem("Cut");
    popupMenu.add(cutMenuItem);
    JMenuItem copyMenuItem = new JMenuItem("Copy");
    popupMenu.add(copyMenuItem);
 
    JMenuItem pasteMenuItem = new JMenuItem("Paste");
    pasteMenuItem.setEnabled(false);
    popupMenu.add(pasteMenuItem);
    popupMenu.addSeparator();
    JMenuItem findMenuItem = new JMenuItem("Find");
    popupMenu.add(findMenuItem);
    JButton label = new JButton();
    frame.add(label);
    label.setComponentPopupMenu(popupMenu);
    frame.setSize(350, 250);
    frame.setVisible(true);
  }
}

JComponent: setFocusTraversalKeys(int arg0, Set<? extends AWTKeyStroke> arg1)

  
import java.awt.AWTKeyStroke;
import java.awt.KeyboardFocusManager;
import java.util.HashSet;
import java.util.Set;
import javax.swing.JButton;
import javax.swing.KeyStroke;
public class Main {
  public static void main(String[] argv) throws Exception {
    JButton component = new JButton("a");
    Set<AWTKeyStroke> set = new HashSet<AWTKeyStroke>(component
        .getFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS));
    set.add(KeyStroke.getKeyStroke("F2"));
    component.setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, set);
  }
}

JComponent: setFont(Font font)

  
import java.awt.BorderLayout;
import java.awt.Font;
import javax.swing.JButton;
import javax.swing.JFrame;
public class Main {
  public static void main(String args[]) {
    JFrame f = new JFrame("JColorChooser Sample");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final JButton button = new JButton("Pick to Change Background");
    Font myFont = new Font("Serif", Font.ITALIC | Font.BOLD, 12);
    button.setFont(myFont);
    f.add(button, BorderLayout.CENTER);
    f.setSize(300, 200);
    f.setVisible(true);
  }
}

JComponent: setInputMap(int condition, InputMap map)

  
import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.KeyStroke;
public class Main {
  public static void main(String[] argv) throws Exception {
    InputMap inputMap = new InputMap();
    inputMap.put(KeyStroke.getKeyStroke("F2"), "actionName");
    JButton component = new JButton("button");
    
    inputMap.setParent(component.getInputMap(JComponent.WHEN_FOCUSED));
    component.setInputMap(JComponent.WHEN_FOCUSED, inputMap);
  }
}

JComponent: setInputVerifier(InputVerifier inputVerifier)

  
       
import java.awt.BorderLayout;
import java.awt.Container;
import javax.swing.InputVerifier;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Verifier Sample");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextField textField1 = new JTextField();
    JTextField textField2 = new JTextField();
    JTextField textField3 = new JTextField();
    InputVerifier verifier = new InputVerifier() {
      public boolean verify(JComponent comp) {
        boolean returnValue;
        JTextField textField = (JTextField) comp;
        try {
          Integer.parseInt(textField.getText());
          returnValue = true;
        } catch (NumberFormatException e) {
          returnValue = false;
        }
        return returnValue;
      }
    };
    textField1.setInputVerifier(verifier);
    textField3.setInputVerifier(verifier);
    Container contentPane = frame.getContentPane();
    contentPane.add(textField1, BorderLayout.NORTH);
    contentPane.add(textField2, BorderLayout.CENTER);
    contentPane.add(textField3, BorderLayout.SOUTH);
    frame.setSize(300, 100);
    frame.setVisible(true);
  }
}

JComponent: setOpaque(boolean isOpaque)

  
import java.awt.Color;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainClass extends JFrame {
  public MainClass() {
    super("Opaque JPanel Demo");
    setSize(400, 200);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    JPanel opaque = createNested(true);
    JPanel notOpaque = createNested(false);
    getContentPane().setLayout(new FlowLayout());
    getContentPane().add(opaque);
    getContentPane().add(notOpaque);
  }
  public static void main(String[] args) {
    MainClass oe = new MainClass();
    oe.setVisible(true);
  }
  public JPanel createNested(boolean opaque) {
    JPanel outer = new JPanel(new FlowLayout());
    JPanel inner = new JPanel(new FlowLayout());
    outer.setBackground(Color.white);
    inner.setBackground(Color.black);
    inner.setOpaque(opaque);
    inner.setBorder(BorderFactory.createLineBorder(Color.gray));
    inner.add(new JButton("Button"));
    outer.add(inner);
    return outer;
  }
}

JComponent: setTransferHandler(TransferHandler newHandler)

  
       
/**
 * Demonstrate various aspects of Swing "data transfer".
 * @author Ian Darwin, http://www.darwinsys.ru
 * @author Jonathan Fuerth, http://www.SQLPower.ca
 */       
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.TransferHandler;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class MainClass extends JFrame {
  public static void main(String[] args) {
    new MainClass().setVisible(true);
  }
  private JTextField tf;
  private JLabel l;
  private JComboBox propertyComboBox;
  public MainClass() {
    Container cp = new Box(BoxLayout.X_AXIS);
    setContentPane(cp);
    JPanel firstPanel = new JPanel();
    propertyComboBox = new JComboBox();
    propertyComboBox.addItem("text");
    propertyComboBox.addItem("font");
    propertyComboBox.addItem("background");
    propertyComboBox.addItem("foreground");
    firstPanel.add(propertyComboBox);
    cp.add(firstPanel);
    cp.add(Box.createGlue());
    tf = new JTextField("Hello");
    tf.setForeground(Color.RED);
    tf.setDragEnabled(true);
    cp.add(tf);
    cp.add(Box.createGlue());
    l = new JLabel("Hello");
    l.setBackground(Color.YELLOW);
    cp.add(l);
    cp.add(Box.createGlue());
    JSlider stryder = new JSlider(SwingConstants.VERTICAL);
    stryder.setMinimum(10);
    stryder.setValue(14);
    stryder.setMaximum(72);
    stryder.setMajorTickSpacing(10);
    stryder.setPaintTicks(true);
    cp.add(stryder);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500, 300);
    setMyTransferHandlers((String) propertyComboBox.getSelectedItem());
    MouseListener myDragListener = new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        JComponent c = (JComponent) e.getSource();
        TransferHandler handler = c.getTransferHandler();
        handler.exportAsDrag(c, e, TransferHandler.COPY);
      }
    };
    l.addMouseListener(myDragListener);
    propertyComboBox.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ce) {
        JComboBox bx = (JComboBox) ce.getSource();
        String prop = (String) bx.getSelectedItem();
        setMyTransferHandlers(prop);
      }
    });
    tf.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        JTextField jtf = (JTextField) evt.getSource();
        String fontName = jtf.getText();
        Font font = new Font(fontName, Font.BOLD, 18);
        tf.setFont(font);
      }
    });
    stryder.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent evt) {
        JSlider sl = (JSlider) evt.getSource();
        Font oldf = tf.getFont();
        Font newf = oldf.deriveFont((float) sl.getValue());
        tf.setFont(newf);
      }
    });
  }
  private void setMyTransferHandlers(String s) {
    TransferHandler th = new TransferHandler(s);
    tf.setTransferHandler(th);
    l.setTransferHandler(th);
  }
}

JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT

  
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.KeyStroke;
public class MainClass {
  public static void main(String args[]) {
    String ACTION_KEY = "The Action";
    
    JFrame frame = new JFrame("KeyStroke Sample");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JButton buttonA = new JButton("FOCUSED (control alt 7)");
    JButton buttonB = new JButton("FOCUS/RELEASE (VK_ENTER)");
    JButton buttonC = new JButton("ANCESTOR  (VK_F4+SHIFT_MASK)");
    JButton buttonD = new JButton("WINDOW (" ")");
    Action actionListener = new AbstractAction() {
      public void actionPerformed(ActionEvent actionEvent) {
        JButton source = (JButton) actionEvent.getSource();
        System.out.println("Activated: " + source.getText());
      }
    };
    KeyStroke controlAlt7 = KeyStroke.getKeyStroke("control alt 7");
    InputMap inputMap = buttonA.getInputMap();
    inputMap.put(controlAlt7, ACTION_KEY);
    ActionMap actionMap = buttonA.getActionMap();
    actionMap.put(ACTION_KEY, actionListener);
    KeyStroke enter = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, true);
    inputMap = buttonB.getInputMap();
    inputMap.put(enter, ACTION_KEY);
    buttonB.setActionMap(actionMap);
    KeyStroke shiftF4 = KeyStroke.getKeyStroke(KeyEvent.VK_F4,
        InputEvent.SHIFT_MASK);
    inputMap = buttonC
        .getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
    inputMap.put(shiftF4, ACTION_KEY);
    buttonC.setActionMap(actionMap);
    KeyStroke space = KeyStroke.getKeyStroke(" ");
    inputMap = buttonD.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
    inputMap.put(space, ACTION_KEY);
    buttonD.setActionMap(actionMap);
    frame.setLayout(new GridLayout(2, 2));
    frame.add(buttonA);
    frame.add(buttonB);
    frame.add(buttonC);
    frame.add(buttonD);
    frame.setSize(400, 200);
    frame.setVisible(true);
  }
}

JComponent.WHEN_IN_FOCUSED_WINDOW

  
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.KeyStroke;
public class MainClass {
  public static void main(String args[]) {
    String ACTION_KEY = "The Action";
    
    JFrame frame = new JFrame("KeyStroke Sample");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JButton buttonA = new JButton("FOCUSED (control alt 7)");
    JButton buttonB = new JButton("FOCUS/RELEASE (VK_ENTER)");
    JButton buttonC = new JButton("ANCESTOR  (VK_F4+SHIFT_MASK)");
    JButton buttonD = new JButton("WINDOW (" ")");
    Action actionListener = new AbstractAction() {
      public void actionPerformed(ActionEvent actionEvent) {
        JButton source = (JButton) actionEvent.getSource();
        System.out.println("Activated: " + source.getText());
      }
    };
    KeyStroke controlAlt7 = KeyStroke.getKeyStroke("control alt 7");
    InputMap inputMap = buttonA.getInputMap();
    inputMap.put(controlAlt7, ACTION_KEY);
    ActionMap actionMap = buttonA.getActionMap();
    actionMap.put(ACTION_KEY, actionListener);
    KeyStroke enter = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, true);
    inputMap = buttonB.getInputMap();
    inputMap.put(enter, ACTION_KEY);
    buttonB.setActionMap(actionMap);
    KeyStroke shiftF4 = KeyStroke.getKeyStroke(KeyEvent.VK_F4,
        InputEvent.SHIFT_MASK);
    inputMap = buttonC
        .getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
    inputMap.put(shiftF4, ACTION_KEY);
    buttonC.setActionMap(actionMap);
    KeyStroke space = KeyStroke.getKeyStroke(" ");
    inputMap = buttonD.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
    inputMap.put(space, ACTION_KEY);
    buttonD.setActionMap(actionMap);
    frame.setLayout(new GridLayout(2, 2));
    frame.add(buttonA);
    frame.add(buttonB);
    frame.add(buttonC);
    frame.add(buttonD);
    frame.setSize(400, 200);
    frame.setVisible(true);
  }
}