How to delegate SwingWorker's publish to other methods
- by Savvas Dalkitsis
My "problem" can be described by the following. Assume we have an intensive process that we want to have running in the background and have it update a Swing JProgress bar. The solution is easy:
import java.util.List;
import javax.swing.JOptionPane;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
/**
* @author Savvas Dalkitsis
*/
public class Test {
public static void main(String[] args) {
final JProgressBar progressBar = new JProgressBar(0,99);
SwingWorker<Void, Integer> w = new SwingWorker<Void, Integer>(){
@Override
protected void process(List<Integer> chunks) {
progressBar.setValue(chunks.get(chunks.size()-1));
}
@Override
protected Void doInBackground() throws Exception {
for (int i=0;i<100;i++) {
publish(i);
Thread.sleep(300);
}
return null;
}
};
w.execute();
JOptionPane.showOptionDialog(null,
new Object[] { "Process", progressBar }, "Process",
JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE,
null, null, null);
}
}
Now assume that i have various methods that take a long time. For instance we have a method that downloads a file from a server. Or another that uploads to a server. Or anything really. What is the proper way of delegating the publish method to those methods so that they can update the GUI appropriately?
What i have found so far is this (assume that the method "aMethod" resides in some other package for instance):
import java.awt.event.ActionEvent;
import java.util.List;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JOptionPane;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
/**
* @author Savvas Dalkitsis
*/
public class Test {
public static void main(String[] args) {
final JProgressBar progressBar = new JProgressBar(0,99);
SwingWorker<Void, Integer> w = new SwingWorker<Void, Integer>(){
@Override
protected void process(List<Integer> chunks) {
progressBar.setValue(chunks.get(chunks.size()-1));
}
@SuppressWarnings("serial")
@Override
protected Void doInBackground() throws Exception {
aMethod(new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
publish((Integer)getValue("progress"));
}
});
return null;
}
};
w.execute();
JOptionPane.showOptionDialog(null,
new Object[] { "Process", progressBar }, "Process",
JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE,
null, null, null);
}
public static void aMethod (Action action) {
for (int i=0;i<100;i++) {
action.putValue("progress", i);
action.actionPerformed(null);
try {
Thread.sleep(300);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
It works but i know it lacks something. Any thoughts?
