org.eclipse.swt.snippets.Snippet130.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet130.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
 *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 502845
 *******************************************************************************/
package org.eclipse.swt.snippets;

/*
 * BusyIndicator example snippet: display busy cursor during long running task
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */

import static org.eclipse.swt.events.SelectionListener.*;

import org.eclipse.swt.*;
import org.eclipse.swt.custom.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

public class Snippet130 {

    public static void main(String[] args) {
        final Display display = new Display();
        final Shell shell = new Shell(display);
        shell.setText("Snippet 130");
        shell.setLayout(new GridLayout());
        final Text text = new Text(shell, SWT.MULTI | SWT.BORDER | SWT.V_SCROLL);
        text.setLayoutData(new GridData(GridData.FILL_BOTH));
        final int[] nextId = new int[1];
        Button b = new Button(shell, SWT.PUSH);
        b.setText("invoke long running job");
        b.addSelectionListener(widgetSelectedAdapter(e -> {
            Runnable longJob = new Runnable() {
                boolean done = false;
                int id;

                @Override
                public void run() {
                    Thread thread = new Thread(() -> {
                        id = nextId[0]++;
                        display.syncExec(() -> {
                            if (text.isDisposed())
                                return;
                            text.append("\nStart long running task " + id);
                        });
                        for (int i = 0; i < 100000; i++) {
                            if (display.isDisposed())
                                return;
                            System.out.println("do task that takes a long time in a separate thread " + id);
                        }
                        if (display.isDisposed())
                            return;
                        display.syncExec(() -> {
                            if (text.isDisposed())
                                return;
                            text.append("\nCompleted long running task " + id);
                        });
                        done = true;
                        display.wake();
                    });
                    thread.start();
                    while (!done && !shell.isDisposed()) {
                        if (!display.readAndDispatch())
                            display.sleep();
                    }
                }
            };
            BusyIndicator.showWhile(display, longJob);
        }));
        shell.setSize(250, 150);
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }
}