Re: Question about updati

From:
"Knute Johnson" <knute.johnson@THRWHITE.remove-dii-this>
Newsgroups:
comp.lang.java.gui
Date:
Wed, 27 Apr 2011 15:29:12 GMT
Message-ID:
<1vRrh.153489$Pv5.34240@newsfe17.lga>
  To: comp.lang.java.gui
steen@jost.dk wrote:

Hey all,

I've been so "lucky" that I've inherited a big applet that I would like
to improve.

It has a set of buttons that perform some very lengthy processes and I
would like to add a progressbar to it, so the user can see that
something is actually happening..;)

But I cant quite get it to work. The following code shows how the code
is right now, can anyone tell me how I get the loop inside the
MouseAdapter to actually update the progressbar ? (The code needs to be
1.3 compliant)

The solution is probably very straightforward, but this is my first
adventure into the world of Swing...:)

[code]
public class SwingTest extends JFrame {

    static JProgressBar bar;

    public static void main(String[] args) {
        SwingTest t = new SwingTest();
        t.setVisible(true);
        t.setLayout(new FlowLayout());
        bar = new JProgressBar();
        JButton button = new JButton("CLICK");
        button.setSize(100,20);
        t.add(button);
        t.add(bar);
        bar.setMinimum(0);
        bar.setMaximum(100);
        t.pack();
        button.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent ev) {
                for (int i=0; i<101;i++) {
                    bar.setValue(i);
                    try {
                        Thread.sleep(500);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
           }
        });
        while (true) {
            try {
                Thread.sleep(10000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}
[/code]


You are blocking the event dispatch thread by not returning immediately
from the mouse listener. Start a thread running in the mouse listener
and have that update your progress bar.

--

Knute Johnson
email s/nospam/knute/

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