SWT: Add listeners to Menu

By using ‘MenuListener’, you can get notifications, whenever menu is shown (or) hidden. ‘MenuListener’ interface provides following methods.

Method	Description
public void menuHidden(MenuEvent e)	Notify when menu is hidden.
public void menuShown(MenuEvent e)	Notify when menu is shown.

fileMenu.addMenuListener(new MenuListener() {

         @Override

         public void menuShown(MenuEvent e) {

                 System.out.println("SubMenu shown");

         }

         @Override

         public void menuHidden(MenuEvent e) {

                 System.out.println("SubMenu hidden");

         }

});

Following is the complete working application.

package swt_app;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MenuEvent;
import org.eclipse.swt.events.MenuListener;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Shell;

public class Test {

 private static int shellWidth = 1000;
 private static int shellHeight = 700;

 private static void addWidgetsToShell(Display display, Shell shell) {

  Menu menu = new Menu(shell, SWT.BAR);
  shell.setMenuBar(menu);

  MenuItem fileMenuItem = new MenuItem(menu, SWT.CASCADE);
  fileMenuItem.setText("File");
  // SWT.ALT is not working, but MOD1 is working
  fileMenuItem.setAccelerator(SWT.MOD1 + 'F');

  MenuItem edit = new MenuItem(menu, SWT.CASCADE);
  edit.setText("Edit");

  MenuItem source = new MenuItem(menu, SWT.CASCADE);
  source.setText("Source");

  addSubMenuToFile(shell, fileMenuItem);

  /* Add Action Listeners */
  fileMenuItem.addListener(SWT.Selection, new Listener() {
   @Override
   public void handleEvent(Event event) {
    System.out.println("fileMenuItem item is clicked");
   }
  });

 }

 private static void addSubMenuToFile(Shell shell, MenuItem fileMenuItem) {

  Menu fileMenu = new Menu(shell, SWT.DROP_DOWN);
  fileMenuItem.setMenu(fileMenu);

  MenuItem newFileItem = new MenuItem(fileMenu, SWT.PUSH);
  newFileItem.setText("New (CTRL + n)");
  newFileItem.setAccelerator(SWT.CTRL + 'n');

  MenuItem openFileItem = new MenuItem(fileMenu, SWT.PUSH);
  openFileItem.setText("Open File (CTRL + f)");
  openFileItem.setAccelerator(SWT.CTRL + 'o');

  /* Add Separator */
  MenuItem separator1 = new MenuItem(fileMenu, SWT.SEPARATOR);

  /* Define switch workspace menu */
  MenuItem switchWorkSpaceItem = new MenuItem(fileMenu, SWT.CASCADE);
  switchWorkSpaceItem.setText("Switch Workspace");
  switchWorkSpaceItem.setAccelerator(SWT.MOD1 + 'w');

  Menu switchWorkSpacemenu = new Menu(shell, SWT.DROP_DOWN);
  switchWorkSpaceItem.setMenu(switchWorkSpacemenu);

  MenuItem prevWorkSpaceItem = new MenuItem(switchWorkSpacemenu, SWT.PUSH);
  prevWorkSpaceItem.setText("Previous Workspace");

  /* Add Separator */
  MenuItem separator2 = new MenuItem(fileMenu, SWT.SEPARATOR);

  /* Adding check boxes and radio buttons */
  MenuItem radioItem = new MenuItem(fileMenu, SWT.RADIO);
  radioItem.setText("Radio");

  MenuItem checkItem = new MenuItem(fileMenu, SWT.CHECK);
  checkItem.setText("Check");

  /* Add Action Listeners */
  newFileItem.addListener(SWT.Selection, new Listener() {
   @Override
   public void handleEvent(Event event) {
    System.out.println("new file item is clicked");
   }
  });

  openFileItem.addListener(SWT.Selection, new Listener() {
   @Override
   public void handleEvent(Event event) {
    System.out.println("Open file item is clicked");
   }
  });

  radioItem.addListener(SWT.Selection, new Listener() {
   public void handleEvent(Event e) {
    System.out.println("Radio item toggled to:" + radioItem.getSelection());
   }
  });
  checkItem.addListener(SWT.Selection, new Listener() {
   public void handleEvent(Event e) {
    System.out.println("Check item toggled to:" + checkItem.getSelection());
   }
  });

  fileMenu.addMenuListener(new MenuListener() {
   @Override
   public void menuShown(MenuEvent e) {
    System.out.println("SubMenu shown");
   }

   @Override
   public void menuHidden(MenuEvent e) {
    System.out.println("SubMenu hidden");
   }
  });

 }

 public static void main(String[] args) {

  /* Instantiate Display object, it represents SWT session */
  Display display = new Display();

  /*
   * Define Shell, it represent a window, You can add more than one shell
   * to Display
   */
  Shell shell = new Shell(display);
  shell.setSize(shellWidth, shellHeight);
  shell.setText("SWT Tutorial");

  addWidgetsToShell(display, shell);

  /* Open shell window */
  shell.open();

  /*
   * Run the event dispatching loop until an exit condition occurs, which
   * is typically when the main shell window is closed by the user.
   */

  while (!shell.isDisposed()) {
   if (!display.readAndDispatch())
    display.sleep();
  }

  /* Dispose the display */
  display.dispose();

 }
}

Previous                                                 Next                                                 Home