Re: [ANN] java.awt.SecondaryLoop

On 06/03/12 01:54, Jeff Higgins wrote:


How will that work? I suppose that the enter() call sets off a new EDT,
and then blocks until exit() is called. Then it tries to claim back
responsibility for event dispatch as soon as the current EDT completes
an event. Each time the current EDT completes an event, it checks for
completed SecondaryLoops, i.e. one which has been exit()ed. At that
point, it wakes the thread blocked on that SL, and terminates, allowing
the other thread to take over as EDT.

Hmm, no it doesn't work like that. Try the progam below. It creates two
buttons; we'll call them A and B. When you click A, it greys out for 5
seconds; B for 10 seconds. If you click A then B before A is restored, A
has to wait for B to complete. It seems that A's SL simply re-enters the
event loop, so the second click is handled by that invocation, and must
re-enter the loop again. They can only unwind in reverse order.

Am I doing it wrong?

import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.SwingUtilities;
import java.awt.SecondaryLoop;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.Toolkit;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Container;

public class TestSL {
private static JFrame frame;

private static JButton makeButton(String text, final int delay) {
final JButton button = new JButton(text);
ActionListener al = new ActionListener() {
public void actionPerformed(ActionEvent e) {
Toolkit tk = Toolkit.getDefaultToolkit();
EventQueue eq = tk.getSystemEventQueue();
SecondaryLoop loop = eq.createSecondaryLoop();

button.setEnabled(false);
new Sleeper(delay, loop).start();
loop.enter();
button.setEnabled(true);
}
};
button.addActionListener(al);
return button;
}

private static void init() {
frame = new JFrame("Boo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Container content = frame.getContentPane();
content.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
content.add(makeButton("5 seconds", 5), c);
content.add(makeButton("10 seconds", 10), c);
frame.pack();
frame.setVisible(true);
}

public static void main(String[] args) throws Exception {
Runnable action = new Runnable() {
public void run() {
init();
}
};

SwingUtilities.invokeLater(action);
}

private static class Sleeper extends Thread {
private final int seconds;
private final SecondaryLoop loop;

public Sleeper(int seconds, SecondaryLoop loop) {
this.seconds = seconds;
this.loop = loop;
}

public void run() {
try {
Thread.sleep(1000 * seconds);
} catch (InterruptedException ex) {
// Ignore.
}
loop.exit();
}
}
}