TreePopulateLazy.java Source code

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Here is the source code for TreePopulateLazy.java

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/*******************************************************************************
 * Copyright (c) 2000, 2005 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
 *******************************************************************************/
//package org.eclipse.swt.snippets;
/*
 * Virtual Tree example snippet: populate tree lazily
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 * 
 * @since 3.2
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;

public class TreePopulateLazy {

    public static void main(String[] args) {
        Display display = new Display();
        final Shell shell = new Shell(display);
        shell.setLayout(new FillLayout());
        final Tree tree = new Tree(shell, SWT.VIRTUAL | SWT.BORDER);
        tree.addListener(SWT.SetData, new Listener() {
            public void handleEvent(Event event) {
                TreeItem item = (TreeItem) event.item;
                TreeItem parentItem = item.getParentItem();
                String text = null;
                if (parentItem == null) {
                    text = "node " + tree.indexOf(item);
                } else {
                    text = parentItem.getText() + " - " + parentItem.indexOf(item);
                }
                item.setText(text);
                item.setItemCount(10);
            }
        });
        tree.setItemCount(20);
        shell.setSize(400, 300);
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }
}