tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug92176_TreeScrolling.java

/*******************************************************************************
 * Copyright (c) 2018 Red Hat and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Red Hat - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.tests.gtk.snippets;


import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Button;
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 Bug92176_TreeScrolling {

	public static void main(String[] args) {
		Display display = new Display();
		Shell shell = new Shell(display);
		shell.setText("PR");

		final Tree tree = new Tree (shell, SWT.BORDER);
		tree.setSize (100, 100);
		shell.setSize (200, 200);

	final TreeItem[] items = new TreeItem[100];
		items[0] = new TreeItem(tree, 0);
		items[0].setText("elt"+0);
		int n = 50;
		for (int i = 1; i < n; i++) {
			items[i] = new TreeItem(items[i-1], 0);
			items[i].setText("child"+i);
		}
		for (int i = n; i < items.length; i++) {
			items[i] = new TreeItem(tree, 0);
			items[i].setText("elt "+i);
		}

		Button button = new Button(shell, SWT.PUSH);
		button.setBounds(120,0,50,20);
		button.setText("show");
		button.addListener(SWT.Selection, new Listener() {
			@Override
			public void handleEvent(Event e) {
				tree.showItem(items[45]);
			}
		});

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