ProgressBar e Tasks con Netbeans

Quando si crea una Java Desktop Application con Netbeans, vengono automaticamente generati il codice ed i componenti per l'utilizzo di una JProgressBar, di uno StatusPanel e di una AnimationLabel:

// status bar initialization - message timeout, idle icon and busy animation, etc

ResourceMap resourceMap = getResourceMap();

int messageTimeout = resourceMap.getInteger("StatusBar.messageTimeout");

messageTimer = new Timer(messageTimeout, new ActionListener() {

public void actionPerformed(ActionEvent e) {

statusMessageLabel.setText("");

}

});

messageTimer.setRepeats(false);

int busyAnimationRate = resourceMap.getInteger("StatusBar.busyAnimationRate");

for (int i = 0; i <>

busyIcons[i] = resourceMap.getIcon("StatusBar.busyIcons[" + i + "]");

}

busyIconTimer = new Timer(busyAnimationRate, new ActionListener() {

public void actionPerformed(ActionEvent e) {

busyIconIndex = (busyIconIndex + 1) % busyIcons.length;

statusAnimationLabel.setIcon(busyIcons[busyIconIndex]);

}

});

idleIcon = resourceMap.getIcon("StatusBar.idleIcon");

statusAnimationLabel.setIcon(idleIcon);

progressBar.setVisible(false);

// connecting action tasks to status bar via TaskMonitor

taskMonitor = new TaskMonitor(getApplication().getContext());

taskMonitor.addPropertyChangeListener(new java.beans.PropertyChangeListener() {

public void propertyChange(java.beans.PropertyChangeEvent evt) {

String propertyName = evt.getPropertyName();

if ("started".equals(propertyName)) {

if (!busyIconTimer.isRunning()) {

statusAnimationLabel.setIcon(busyIcons[0]);

busyIconIndex = 0;

busyIconTimer.start();

}

progressBar.setVisible(true);

progressBar.setIndeterminate(true);

} else if ("done".equals(propertyName)) {

busyIconTimer.stop();

statusAnimationLabel.setIcon(idleIcon);

progressBar.setVisible(false);

progressBar.setValue(0);

} else if ("message".equals(propertyName)) {

String text = (String) (evt.getNewValue());

statusMessageLabel.setText((text == null) ? "" : text);

messageTimer.restart();

} else if ("progress".equals(propertyName)) {

int value = (Integer) (evt.getNewValue());

progressBar.setVisible(true);

progressBar.setIndeterminate(false);

progressBar.setValue(value);

}

}

});

Se si desidera agganciare l'esecuzione di un proprio codice ai suddetti componenti, basta creare una classe che estenda la classe Task ed esegua in background il codice desiderato, nel seguente modo:

@Action

public Task avviaTask() {

return new MyTask(getApplication());

}

private class MyTask extends Task {

estrazioneTask(org.jdesktop.application.Application app) {

super(app);

}

@SuppressWarnings("unchecked")

@Override

protected Void doInBackground() {

setMessage("Working...");

//il codice va inserito qui

return null;

}

@Override

protected void finished() {

setMessage("Done.");

}

}