Java by API/java.awt.event/ActionEvent

ActionEvent.ALT_MASK

 
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.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame();
    Container contentPane = frame.getContentPane();
    ActionListener listener = new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        System.out.println("Command: " + e.getActionCommand());
        int modifiers = e.getModifiers();
        System.out.println("\tALT : "
            + checkMod(modifiers, ActionEvent.ALT_MASK));
        System.out.println("\tCTRL : "
            + checkMod(modifiers, ActionEvent.CTRL_MASK));
        System.out.println("\tMETA : "
            + checkMod(modifiers, ActionEvent.META_MASK));
        System.out.println("\tSHIFT: "
            + checkMod(modifiers, ActionEvent.SHIFT_MASK));
        Object source = e.getSource();
        if (source instanceof JComboBox) {
          JComboBox jb = (JComboBox) source;
          System.out.println("Combo: " + jb.getSelectedItem());
        }
      }
      private boolean checkMod(int modifiers, int mask) {
        return ((modifiers & mask) == mask);
      }
    };
    String flavors[] = { "Item 1", "Item 2", "Item 3"};
    JComboBox jc = new JComboBox(flavors);
    jc.setMaximumRowCount(4);
    jc.setEditable(true);
    jc.addActionListener(listener);
    contentPane.add(jc, BorderLayout.NORTH);
    JButton b = new JButton("Button!");
    b.addActionListener(listener);
    contentPane.add(b, BorderLayout.CENTER);
    JPanel panel = new JPanel();
    JLabel label = new JLabel("Label 1: ");
    JTextField text = new JTextField("Type your text", 15);
    text.addActionListener(listener);
    label.setDisplayedMnemonic(KeyEvent.VK_1);
    label.setLabelFor(text);
    panel.add(label);
    panel.add(text);
    contentPane.add(panel, BorderLayout.SOUTH);
    frame.pack();
    frame.setVisible(true);
  }
}

ActionEvent.CTRL_MASK

 
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.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame();
    Container contentPane = frame.getContentPane();
    ActionListener listener = new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        System.out.println("Command: " + e.getActionCommand());
        int modifiers = e.getModifiers();
        System.out.println("\tALT : "
            + checkMod(modifiers, ActionEvent.ALT_MASK));
        System.out.println("\tCTRL : "
            + checkMod(modifiers, ActionEvent.CTRL_MASK));
        System.out.println("\tMETA : "
            + checkMod(modifiers, ActionEvent.META_MASK));
        System.out.println("\tSHIFT: "
            + checkMod(modifiers, ActionEvent.SHIFT_MASK));
        Object source = e.getSource();
        if (source instanceof JComboBox) {
          JComboBox jb = (JComboBox) source;
          System.out.println("Combo: " + jb.getSelectedItem());
        }
      }
      private boolean checkMod(int modifiers, int mask) {
        return ((modifiers & mask) == mask);
      }
    };
    String flavors[] = { "Item 1", "Item 2", "Item 3"};
    JComboBox jc = new JComboBox(flavors);
    jc.setMaximumRowCount(4);
    jc.setEditable(true);
    jc.addActionListener(listener);
    contentPane.add(jc, BorderLayout.NORTH);
    JButton b = new JButton("Button!");
    b.addActionListener(listener);
    contentPane.add(b, BorderLayout.CENTER);
    JPanel panel = new JPanel();
    JLabel label = new JLabel("Label 1: ");
    JTextField text = new JTextField("Type your text", 15);
    text.addActionListener(listener);
    label.setDisplayedMnemonic(KeyEvent.VK_1);
    label.setLabelFor(text);
    panel.add(label);
    panel.add(text);
    contentPane.add(panel, BorderLayout.SOUTH);
    frame.pack();
    frame.setVisible(true);
  }
}

ActionEvent: getActionCommand()

 
import java.awt.BorderLayout;
import java.awt.ItemSelectable;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JComboBox;
import javax.swing.JFrame;
public class MainClass {
  public static void main(final String args[]) {
    final String labels[] = { "A", "B", "C", "D", "E" };
    JFrame frame = new JFrame("Selecting JComboBox");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JComboBox comboBox = new JComboBox(labels);
    frame.add(comboBox, BorderLayout.SOUTH);
    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        System.out.println("Command: " + actionEvent.getActionCommand());
        ItemSelectable is = (ItemSelectable)actionEvent.getSource();
        System.out.println(", Selected: " + selectedString(is));
      }
    };
    comboBox.addActionListener(actionListener);
    frame.setSize(400, 200);
    frame.setVisible(true);
  }
  static private String selectedString(ItemSelectable is) {
    Object selected[] = is.getSelectedObjects();
    return ((selected.length == 0) ? "null" : (String)selected[0]);
  }  
}

ActionEvent: getModifiers()

 
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.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame();
    Container contentPane = frame.getContentPane();
    ActionListener listener = new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        System.out.println("Command: " + e.getActionCommand());
        int modifiers = e.getModifiers();
        System.out.println("\tALT : "
            + checkMod(modifiers, ActionEvent.ALT_MASK));
        System.out.println("\tCTRL : "
            + checkMod(modifiers, ActionEvent.CTRL_MASK));
        System.out.println("\tMETA : "
            + checkMod(modifiers, ActionEvent.META_MASK));
        System.out.println("\tSHIFT: "
            + checkMod(modifiers, ActionEvent.SHIFT_MASK));
        Object source = e.getSource();
        if (source instanceof JComboBox) {
          JComboBox jb = (JComboBox) source;
          System.out.println("Combo: " + jb.getSelectedItem());
        }
      }
      private boolean checkMod(int modifiers, int mask) {
        return ((modifiers & mask) == mask);
      }
    };
    String flavors[] = { "Item 1", "Item 2", "Item 3"};
    JComboBox jc = new JComboBox(flavors);
    jc.setMaximumRowCount(4);
    jc.setEditable(true);
    jc.addActionListener(listener);
    contentPane.add(jc, BorderLayout.NORTH);
    JButton b = new JButton("Button!");
    b.addActionListener(listener);
    contentPane.add(b, BorderLayout.CENTER);
    JPanel panel = new JPanel();
    JLabel label = new JLabel("Label 1: ");
    JTextField text = new JTextField("Type your text", 15);
    text.addActionListener(listener);
    label.setDisplayedMnemonic(KeyEvent.VK_1);
    label.setLabelFor(text);
    panel.add(label);
    panel.add(text);
    contentPane.add(panel, BorderLayout.SOUTH);
    frame.pack();
    frame.setVisible(true);
  }
}

ActionEvent: getSource()

 
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
public class MainClass {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Button Sample");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final JButton button1 = new JButton("Select Me");
    final JButton button2 = new JButton("No Select Me");
    final Random random = new Random();
    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        JButton button = (JButton) actionEvent.getSource();
        int red = random.nextInt(255);
        int green = random.nextInt(255);
        int blue = random.nextInt(255);
        button.setBackground(new Color(red, green, blue));
      }
    };
    PropertyChangeListener propertyChangeListener = new PropertyChangeListener() {
      public void propertyChange(PropertyChangeEvent propertyChangeEvent) {
        String property = propertyChangeEvent.getPropertyName();
        if ("background".equals(property)) {
          button2.setBackground((Color) propertyChangeEvent.getNewValue());
        }
      }
    };
    button1.addActionListener(actionListener);
    button1.addPropertyChangeListener(propertyChangeListener);
    button2.addActionListener(actionListener);
    frame.add(button1, BorderLayout.NORTH);
    frame.add(button2, BorderLayout.SOUTH);
    frame.setSize(300, 100);
    frame.setVisible(true);
  }
}

ActionEvent.META_MASK

 
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.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame();
    Container contentPane = frame.getContentPane();
    ActionListener listener = new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        System.out.println("Command: " + e.getActionCommand());
        int modifiers = e.getModifiers();
        System.out.println("\tALT : "
            + checkMod(modifiers, ActionEvent.ALT_MASK));
        System.out.println("\tCTRL : "
            + checkMod(modifiers, ActionEvent.CTRL_MASK));
        System.out.println("\tMETA : "
            + checkMod(modifiers, ActionEvent.META_MASK));
        System.out.println("\tSHIFT: "
            + checkMod(modifiers, ActionEvent.SHIFT_MASK));
        Object source = e.getSource();
        if (source instanceof JComboBox) {
          JComboBox jb = (JComboBox) source;
          System.out.println("Combo: " + jb.getSelectedItem());
        }
      }
      private boolean checkMod(int modifiers, int mask) {
        return ((modifiers & mask) == mask);
      }
    };
    String flavors[] = { "Item 1", "Item 2", "Item 3"};
    JComboBox jc = new JComboBox(flavors);
    jc.setMaximumRowCount(4);
    jc.setEditable(true);
    jc.addActionListener(listener);
    contentPane.add(jc, BorderLayout.NORTH);
    JButton b = new JButton("Button!");
    b.addActionListener(listener);
    contentPane.add(b, BorderLayout.CENTER);
    JPanel panel = new JPanel();
    JLabel label = new JLabel("Label 1: ");
    JTextField text = new JTextField("Type your text", 15);
    text.addActionListener(listener);
    label.setDisplayedMnemonic(KeyEvent.VK_1);
    label.setLabelFor(text);
    panel.add(label);
    panel.add(text);
    contentPane.add(panel, BorderLayout.SOUTH);
    frame.pack();
    frame.setVisible(true);
  }
}

ActionEvent.SHIFT_MASK

 
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.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame();
    Container contentPane = frame.getContentPane();
    ActionListener listener = new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        System.out.println("Command: " + e.getActionCommand());
        int modifiers = e.getModifiers();
        System.out.println("\tALT : "
            + checkMod(modifiers, ActionEvent.ALT_MASK));
        System.out.println("\tCTRL : "
            + checkMod(modifiers, ActionEvent.CTRL_MASK));
        System.out.println("\tMETA : "
            + checkMod(modifiers, ActionEvent.META_MASK));
        System.out.println("\tSHIFT: "
            + checkMod(modifiers, ActionEvent.SHIFT_MASK));
        Object source = e.getSource();
        if (source instanceof JComboBox) {
          JComboBox jb = (JComboBox) source;
          System.out.println("Combo: " + jb.getSelectedItem());
        }
      }
      private boolean checkMod(int modifiers, int mask) {
        return ((modifiers & mask) == mask);
      }
    };
    String flavors[] = { "Item 1", "Item 2", "Item 3"};
    JComboBox jc = new JComboBox(flavors);
    jc.setMaximumRowCount(4);
    jc.setEditable(true);
    jc.addActionListener(listener);
    contentPane.add(jc, BorderLayout.NORTH);
    JButton b = new JButton("Button!");
    b.addActionListener(listener);
    contentPane.add(b, BorderLayout.CENTER);
    JPanel panel = new JPanel();
    JLabel label = new JLabel("Label 1: ");
    JTextField text = new JTextField("Type your text", 15);
    text.addActionListener(listener);
    label.setDisplayedMnemonic(KeyEvent.VK_1);
    label.setLabelFor(text);
    panel.add(label);
    panel.add(text);
    contentPane.add(panel, BorderLayout.SOUTH);
    frame.pack();
    frame.setVisible(true);
  }
}

new ActionEvent(Object source, int id, String command)

 
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;
  }
}