/* $Id: SwingWorker.java 17841 2010-01-12 19:17:52Z linus $
*****************************************************************************
* Copyright (c) 2009 Contributors - see below
* 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:
* tfmorris
*****************************************************************************
*
* Some portions of this file was previously release using the BSD License:
*/
// Copyright (c) 1996-2007 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies. This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason. IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
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package org.argouml.ui;
import java.awt.Cursor;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import org.apache.log4j.Logger;
import org.argouml.swingext.GlassPane;
import org.argouml.taskmgmt.ProgressMonitor;
import org.argouml.util.ArgoFrame;
/**
* This is the 3rd version of SwingWorker (also known as
* SwingWorker 3), an abstract class that you subclass to
* perform GUI-related work in a dedicated thread. For
* instructions on and examples of using this class, see:
*
* http://java.sun.com/docs/books/tutorial/uiswing/misc/threads.html
*
* Note that the API changed slightly in the 3rd version:
* You must now invoke start() on the SwingWorker after
* creating it.
*/
public abstract class SwingWorker {
private static final Logger LOG =
Logger.getLogger(SwingWorker.class);
private Object value; // see getValue(), setValue()
private GlassPane glassPane;
private Timer timer;
private ProgressMonitor pmw;
/**
* Class to maintain reference to current worker thread
* under separate synchronization control.
*/
private static class ThreadVar {
private Thread thread;
ThreadVar(Thread t) {
thread = t;
}
synchronized Thread get() {
return thread;
}
synchronized void clear() {
thread = null;
}
}
private ThreadVar threadVar;
/**
* Get the value produced by the worker thread, or null if it
* hasn't been constructed yet.
*
* @return the value produced by the worker thread
*/
protected synchronized Object getValue() {
return value;
}
/**
* Set the value produced by worker thread
*/
private synchronized void setValue(Object x) {
value = x;
}
/**
* Compute the value to be returned by the <code>get</code> method.
*
* @param progressMonitor the ProgressMonitorWindow class - this
* class shall be registered as a progress listener.
* @return the value to be returned
*/
public abstract Object construct(ProgressMonitor progressMonitor);
/**
* Instantiate and initialize an instance of ProgressMonitorWindow
*
* @return an instance of ProgressMonitorWindow
*/
public abstract ProgressMonitor initProgressMonitorWindow();
/**
* This method calls the construct(),
*
* @return the value to be returned by the <code>get</code> method.
*/
public Object doConstruct() {
activateGlassPane();
pmw = initProgressMonitorWindow();
ArgoFrame.getFrame().setCursor(
Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
Object retVal = null;
//Create a timer.
timer = new Timer(25, new TimerListener());
timer.start();
try {
retVal = construct(pmw);
} catch (Exception exc) {
// TODO: This error needs to be reported!
LOG.error("Error while loading project: ", exc);
} finally {
pmw.close();
}
return retVal;
}
/**
* The actionPerformed method in this class
* is called each time the Timer "goes off".
*/
class TimerListener implements ActionListener {
public void actionPerformed(ActionEvent evt) {
if (pmw.isCanceled()) {
threadVar.thread.interrupt();
interrupt();
timer.stop();
}
}
}
/**
* Activate the capabilities of glasspane
*/
protected void activateGlassPane() {
// Mount the glasspane on the component window
GlassPane aPane = GlassPane.mount(ArgoFrame.getFrame(), true);
// keep track of the glasspane as an instance variable
setGlassPane(aPane);
if (getGlassPane() != null) {
// Start interception UI interactions
getGlassPane().setVisible(true);
}
}
/**
* Deactivate the glasspane
*/
private void deactivateGlassPane() {
if (getGlassPane() != null) {
// Stop UI interception
getGlassPane().setVisible(false);
}
}
/**
* Called on the event dispatching thread (not on the worker thread)
* after the <code>construct</code> method has returned.
*/
public void finished() {
deactivateGlassPane();
ArgoFrame.getFrame().setCursor(Cursor.getPredefinedCursor(
Cursor.DEFAULT_CURSOR));
}
/**
* Getter method for the glassPange
*
* @return GlassPane the blocking glassPane
*/
protected GlassPane getGlassPane() {
return glassPane;
}
/**
* Setter method
*
* @param newGlassPane GlassPane
*/
protected void setGlassPane(GlassPane newGlassPane) {
glassPane = newGlassPane;
}
/**
* A new method that interrupts the worker thread. Call this method
* to force the worker to stop what it's doing.
*/
public void interrupt() {
Thread t = threadVar.get();
if (t != null) {
t.interrupt();
}
threadVar.clear();
}
/**
* Return the value created by the <code>construct</code> method.
* Returns null if either the constructing thread or the current
* thread was interrupted before a value was produced.
*
* @return the value created by the <code>construct</code> method
*/
public Object get() {
while (true) {
Thread t = threadVar.get();
if (t == null) {
return getValue();
}
try {
t.join();
}
catch (InterruptedException e) {
Thread.currentThread().interrupt(); // propagate
return null;
}
}
}
/**
* Construct a worker thread that will call the <code>construct</code> method
* and then exit.
*/
public SwingWorker() {
final Runnable doFinished = new Runnable() {
public void run() {
finished();
}
};
Runnable doConstruct = new Runnable() {
public void run() {
try {
setValue(doConstruct());
}
finally {
threadVar.clear();
}
SwingUtilities.invokeLater(doFinished);
}
};
Thread t = new Thread(doConstruct);
threadVar = new ThreadVar(t);
}
public SwingWorker(String threadName) {
this();
threadVar.get().setName(threadName);
}
/**
* Start the worker thread.
*/
public void start() {
Thread t = threadVar.get();
if (t != null) {
t.start();
}
}
}