Java Tutorial/SWT/BusyIndicator

BusyIndicator: display busy cursor during long running task

   <source lang="java">

/*******************************************************************************

* 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();
 }

}</source>

Using BusyIndicator

   <source lang="java">

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) {
   }
 }

}</source>