Java Tutorial/SWT/BusyIndicator

BusyIndicator: display busy cursor during long running task

/*******************************************************************************
 * 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
 *******************************************************************************/
/*
 * 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 org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class BusyCursorDisplay {
  public static void main(String[] args) {
    final Display display = new Display();
    final Shell shell = new Shell(display);
    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(new SelectionAdapter() {
      public void widgetSelected(SelectionEvent e) {
        Runnable longJob = new Runnable() {
          boolean done = false;
          int id;
          public void run() {
            Thread thread = new Thread(new Runnable() {
              public void run() {
                id = nextId[0]++;
                display.syncExec(new Runnable() {
                  public void run() {
                    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(new Runnable() {
                  public void run() {
                    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();
  }
}

Using BusyIndicator

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class BusyIndicatorDemo {
  // The amount of time to sleep (in ms)
  private static final int SLEEP_TIME = 3000;
  // Labels for the button
  private static final String RUN = "Press to Run";
  private static final String IS_RUNNING = "Running...";
  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("BusyIndicator Test");
    shell.setLayout(new FillLayout());
    final Button button = new Button(shell, SWT.PUSH);
    button.setText(RUN);
    button.addSelectionListener(new SelectionAdapter() {
      public void widgetSelected(SelectionEvent event) {
        // Change the button"s text
        button.setText(IS_RUNNING);
        // Show the busy indicator
        BusyIndicator.showWhile(button.getDisplay(), new SleepThread(SLEEP_TIME));
        // Thread has completed; reset the button"s text
        button.setText(RUN);
      }
    });
    shell.pack();
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }
    display.dispose();
  }
}
class SleepThread extends Thread {
  private long ms;
  public SleepThread(long ms) {
    this.ms = ms;
  }
  public void run() {
    try {
      sleep(ms);
    } catch (InterruptedException e) {
    }
  }
}