org.eclipse.swt.snippets.Snippet201.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet201.java

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/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.snippets;

/*
 * Virtual Table example snippet: create a table with 1,000,000 items (lazy, page size 64)
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 *
 * @since 3.0
 */
import org.eclipse.swt.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

public class Snippet201 {

    static final int PAGE_SIZE = 64;
    static final int COUNT = 100000;

    public static void main(String[] args) {
        Display display = new Display();
        final Shell shell = new Shell(display);
        shell.setText("Snippet 201");
        shell.setLayout(new RowLayout(SWT.VERTICAL));
        final Table table = new Table(shell, SWT.VIRTUAL | SWT.BORDER);
        table.addListener(SWT.SetData, event -> {
            TableItem item = (TableItem) event.item;
            int index = table.indexOf(item);
            int start = index / PAGE_SIZE * PAGE_SIZE;
            int end = Math.min(start + PAGE_SIZE, table.getItemCount());
            for (int i = start; i < end; i++) {
                item = table.getItem(i);
                item.setText("Item " + i);
            }
        });
        table.setLayoutData(new RowData(200, 200));
        Button button = new Button(shell, SWT.PUSH);
        button.setText("Add Items");
        final Label label = new Label(shell, SWT.NONE);
        button.addListener(SWT.Selection, event -> {
            long t1 = System.currentTimeMillis();
            table.setItemCount(COUNT);
            long t2 = System.currentTimeMillis();
            label.setText("Items: " + COUNT + ", Time: " + (t2 - t1) + " (ms) [page=" + PAGE_SIZE + "]");
            shell.layout();
        });
        shell.pack();
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }
}