swing:menus_checkboxes_radio

CheckBox Menu Items & RadioButton Menu Items

Σε αναλογία με τα check box buttons και radio buttons μπορείτε να ορίσετε σε ένα μενού CheckBox Menu Items και RadioButton Menu Items. Δείτε το παρακάτω παράδειγμα χρήσης ενός τέτοιου μενού από το site της Oracle.

MenuLookDemo.java
package components;
 
import java.awt.*;
import java.awt.event.*;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.ButtonGroup;
import javax.swing.JMenuBar;
import javax.swing.KeyStroke;
import javax.swing.ImageIcon;
 
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JScrollPane;
import javax.swing.JFrame;
 
/* MenuLookDemo.java requires images/middle.gif. */
 
/*
 * This class exists solely to show you what menus look like.
 * It has no menu-related event handling.
 */
public class MenuLookDemo {
  JTextArea output;
  JScrollPane scrollPane;
 
  public JMenuBar createMenuBar() {
    JMenuBar menuBar;
    JMenu menu, submenu;
    JMenuItem menuItem;
    JRadioButtonMenuItem rbMenuItem;
    JCheckBoxMenuItem cbMenuItem;
 
    //Create the menu bar.
    menuBar = new JMenuBar();
 
    //Build the first menu.
    menu = new JMenu("A Menu");
    menu.setMnemonic(KeyEvent.VK_A);
    menu.getAccessibleContext().setAccessibleDescription(
        "The only menu in this program that has menu items");
    menuBar.add(menu);
 
    //a group of JMenuItems
    menuItem = new JMenuItem("A text-only menu item",
                 KeyEvent.VK_T);
    //menuItem.setMnemonic(KeyEvent.VK_T); //used constructor instead
    menuItem.setAccelerator(KeyStroke.getKeyStroke(
        KeyEvent.VK_1, ActionEvent.ALT_MASK));
    menuItem.getAccessibleContext().setAccessibleDescription(
        "This doesn't really do anything");
    menu.add(menuItem);
 
    ImageIcon icon = createImageIcon("images/middle.gif");
    menuItem = new JMenuItem("Both text and icon", icon);
    menuItem.setMnemonic(KeyEvent.VK_B);
    menu.add(menuItem);
 
    menuItem = new JMenuItem(icon);
    menuItem.setMnemonic(KeyEvent.VK_D);
    menu.add(menuItem);
 
    //a group of radio button menu items
    menu.addSeparator();
    ButtonGroup group = new ButtonGroup();
 
    rbMenuItem = new JRadioButtonMenuItem("A radio button menu item");
    rbMenuItem.setSelected(true);
    rbMenuItem.setMnemonic(KeyEvent.VK_R);
    group.add(rbMenuItem);
    menu.add(rbMenuItem);
 
    rbMenuItem = new JRadioButtonMenuItem("Another one");
    rbMenuItem.setMnemonic(KeyEvent.VK_O);
    group.add(rbMenuItem);
    menu.add(rbMenuItem);
 
    //a group of check box menu items
    menu.addSeparator();
    cbMenuItem = new JCheckBoxMenuItem("A check box menu item");
    cbMenuItem.setMnemonic(KeyEvent.VK_C);
    menu.add(cbMenuItem);
 
    cbMenuItem = new JCheckBoxMenuItem("Another one");
    cbMenuItem.setMnemonic(KeyEvent.VK_H);
    menu.add(cbMenuItem);
 
    //a submenu
    menu.addSeparator();
    submenu = new JMenu("A submenu");
    submenu.setMnemonic(KeyEvent.VK_S);
 
    menuItem = new JMenuItem("An item in the submenu");
    menuItem.setAccelerator(KeyStroke.getKeyStroke(
        KeyEvent.VK_2, ActionEvent.ALT_MASK));
    submenu.add(menuItem);
 
    menuItem = new JMenuItem("Another item");
    submenu.add(menuItem);
    menu.add(submenu);
 
    //Build second menu in the menu bar.
    menu = new JMenu("Another Menu");
    menu.setMnemonic(KeyEvent.VK_N);
    menu.getAccessibleContext().setAccessibleDescription(
        "This menu does nothing");
    menuBar.add(menu);
 
    return menuBar;
  }
 
  public Container createContentPane() {
    //Create the content-pane-to-be.
    JPanel contentPane = new JPanel(new BorderLayout());
    contentPane.setOpaque(true);
 
    //Create a scrolled text area.
    output = new JTextArea(5, 30);
    output.setEditable(true);
    scrollPane = new JScrollPane(output);
 
    //Add the text area to the content pane.
    contentPane.add(scrollPane, BorderLayout.CENTER);
 
    return contentPane;
  }
 
  /** Returns an ImageIcon, or null if the path was invalid. */
  protected static ImageIcon createImageIcon(String path) {
    java.net.URL imgURL = MenuLookDemo.class.getResource(path);
    if (imgURL != null) {
      return new ImageIcon(imgURL);
    } 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() {
    //Create and set up the window.
    JFrame frame = new JFrame("MenuLookDemo");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
    //Create and set up the content pane.
    MenuLookDemo demo = new MenuLookDemo();
    frame.setJMenuBar(demo.createMenuBar());
    frame.setContentPane(demo.createContentPane());
 
    //Display the window.
    frame.setSize(450, 260);
    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();
      }
    });
  }
}
swing/menus_checkboxes_radio.txt · Last modified: 2016/02/26 11:15 (external edit)