SWT Java Tutorial

/*******************************************************************************
 * 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
 *******************************************************************************/
/*
 * CoolBar example snippet: drop-down a chevron menu containing hidden tool items
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.CoolBar;
import org.eclipse.swt.widgets.CoolItem;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.ToolItem;
public class ChevronMenuHiddenToolItems {
  static Display display;
  static Shell shell;
  static CoolBar coolBar;
  static Menu chevronMenu = null;
  public static void main(String[] args) {
    display = new Display();
    shell = new Shell(display);
    shell.setLayout(new GridLayout());
    coolBar = new CoolBar(shell, SWT.FLAT | SWT.BORDER);
    coolBar.setLayoutData(new GridData(GridData.FILL_BOTH));
    ToolBar toolBar = new ToolBar(coolBar, SWT.FLAT | SWT.WRAP);
    int minWidth = 0;
    for (int j = 0; j < 5; j++) {
      int width = 0;
      ToolItem item = new ToolItem(toolBar, SWT.PUSH);
      item.setText("B" + j);
      width = item.getWidth();
      /* find the width of the widest tool */
      if (width > minWidth)
        minWidth = width;
    }
    CoolItem coolItem = new CoolItem(coolBar, SWT.DROP_DOWN);
    coolItem.setControl(toolBar);
    Point size = toolBar.computeSize(SWT.DEFAULT, SWT.DEFAULT);
    Point coolSize = coolItem.computeSize(size.x, size.y);
    coolItem.setMinimumSize(minWidth, coolSize.y);
    coolItem.setPreferredSize(coolSize);
    coolItem.setSize(coolSize);
    coolItem.addSelectionListener(new SelectionAdapter() {
      public void widgetSelected(SelectionEvent event) {
        if (event.detail == SWT.ARROW) {
          CoolItem item = (CoolItem) event.widget;
          Rectangle itemBounds = item.getBounds();
          Point pt = coolBar.toDisplay(new Point(itemBounds.x, itemBounds.y));
          itemBounds.x = pt.x;
          itemBounds.y = pt.y;
          ToolBar bar = (ToolBar) item.getControl();
          ToolItem[] tools = bar.getItems();
          int i = 0;
          while (i < tools.length) {
            Rectangle toolBounds = tools[i].getBounds();
            pt = bar.toDisplay(new Point(toolBounds.x, toolBounds.y));
            toolBounds.x = pt.x;
            toolBounds.y = pt.y;
            /*
             * Figure out the visible portion of the tool by looking at the
             * intersection of the tool bounds with the cool item bounds.
             */
            Rectangle intersection = itemBounds.intersection(toolBounds);
            /*
             * If the tool is not completely within the cool item bounds, then
             * it is partially hidden, and all remaining tools are completely
             * hidden.
             */
            if (!intersection.equals(toolBounds))
              break;
            i++;
          }
          /* Create a menu with items for each of the completely hidden buttons. */
          if (chevronMenu != null)
            chevronMenu.dispose();
          chevronMenu = new Menu(coolBar);
          for (int j = i; j < tools.length; j++) {
            MenuItem menuItem = new MenuItem(chevronMenu, SWT.PUSH);
            menuItem.setText(tools[j].getText());
          }
          /* Drop down the menu below the chevron, with the left edges aligned. */
          pt = coolBar.toDisplay(new Point(event.x, event.y));
          chevronMenu.setLocation(pt.x, pt.y);
          chevronMenu.setVisible(true);
        }
      }
    });
    shell.pack();
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}