Enable menu items dynamically (when menu shown) : Menu « SWT « Java Tutorial






Enable menu items dynamically (when menu shown)
/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
import org.eclipse.swt.SWT;
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;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;

public class MenuItemEnableDynamically {

  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI);
    final Menu menu = new Menu(shell, SWT.POP_UP);
    tree.setMenu(menu);
    for (int i = 0; i < 12; i++) {
      TreeItem treeItem = new TreeItem(tree, SWT.NONE);
      treeItem.setText("Item " + i);
      MenuItem menuItem = new MenuItem(menu, SWT.PUSH);
      menuItem.setText(treeItem.getText());
    }
    menu.addListener(SWT.Show, new Listener() {
      public void handleEvent(Event event) {
        MenuItem[] menuItems = menu.getItems();
        TreeItem[] treeItems = tree.getSelection();
        for (int i = 0; i < menuItems.length; i++) {
          String text = menuItems[i].getText();
          int index = 0;
          while (index < treeItems.length) {
            if (treeItems[index].getText().equals(text))
              break;
            index++;
          }
          menuItems[i].setEnabled(index != treeItems.length);
        }
      }
    });
    tree.setSize(200, 200);
    shell.setSize(300, 300);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}








17.30.Menu
17.30.1.Add MenuItem to MenuAdd MenuItem to Menu
17.30.2.Add Menu SeparatorAdd Menu Separator
17.30.3.Cascade MenuCascade Menu
17.30.4.Fill a menu dynamically (when menu shown)Fill a menu dynamically (when menu shown)
17.30.5.Enable menu items dynamically (when menu shown)Enable menu items dynamically (when menu shown)