Locked "close window" icon : Sun, Java, JDK 6, Java JDK 6

Run it in a separate thread.

05.08.2008 at 04:11AM PDT, ID: 21523722

Rank: Genius

Remove the commented code from the paint() method and instad invoke it using a Swing Timer

http://java.sun.com/docs/books/tutorial/uiswing/misc/timer.html

05.08.2008 at 04:13AM PDT, ID: 21523730

Rank: Genius

and remove the loop, and instead have youe timer invoked repeatedly executing:

if (i > 300)
i = 0;
else
i++;

circle1.move(50+i, 60+i);
repaint();

You'll need to make i a member variable

> Circle circle1 = new Circle(50, 60, 100, g);

also make your circle a member var

Let me know if you need a hand.

05.08.2008 at 07:23AM PDT, ID: 21524971

I'm really astonished that there is a no way out of this other thatn using threads or timers. I programmed in a lot of different languages and interacting with the "close window" icon has never been so difficult. Is this due to the fact that I used the paint method of the frame object? Is there a cleaner way that will replace the paint/main methods of my code without having to use timers or threads? Thanks for your help.

If threads or timers are the only solution I need a clear explanation as the web page suggested wasn't very explanatory to me.

05.08.2008 at 07:44AM PDT, ID: 21525171

Rank: Genius

problem is caused by swing being single threaded. You block that thread so all gui processing is blocked.
Swing timer will allow you to periodicly have code executed by that thread, just make sure the code executes and returns quickly.

05.08.2008 at 01:35PM PDT, ID: 21528228

Rank: Guru

Because of what has been said above (effectively the event dispatch thread beng used up by the hogging process), you'll get nowhere unless you implement a timer, or spawn a separate thread. You're right - it's very -very - annoying if you don't know about it. (Think of it as the equivalent of needing doEvents() in VB (if you are familiar with that at all)). It's one of the fewish things that can irk you about Java, but you've got to bite the ole bullet, and take the road that has been suggested.

05.09.2008 at 04:00AM PDT, ID: 21531621

Rank: Guru

You may like to read this and its associated pages :

http://www.javaworld.com/javaworld/jw-06-2003/jw-0606-swingworker.html?page=2

from which comes:

"This artificial delay demonstrates the negative effect of executing a time-consuming task, which can be a complex SQL statement execution in a more realistic situation. Remember the thread that becomes dormant is the event-dispatch thread, which is also responsible for dispatching painting events. Therefore, when the user makes a new table selection, the user interface ceases to properly repaint itself during the delay. The application will display bizarre effects when the user resizes the window during the delay, as seen in Figure 3 below. During this problematic delay, the user can also queue up additional events by clicking on the unresponsive screen, potentially causing further unintended consequences. Feel free to verify these problems by running the demo application in delay mode. "

Swingworker is probably what you need.

05.09.2008 at 07:25AM PDT, ID: 21533129

Ok, whatever you think is the simplest solution (thread or timer) I need to ask you for the modified version of my code that will react to the "close window" event. Thanks for your help.

05.13.2008 at 10:38AM PDT, ID: 21557373

Is there no one able to modify my code so that it will have the desired behaviour(with threads or timers)?

05.13.2008 at 11:03AM PDT, ID: 21557595

Rank: Guru

You could have a shot yourself. Just remember 1) loops need relief; like a Thread.sleep(); (open Task Manager to see the CPU burn without such relief at up to 100%; 2) you may be able to use a Daemon thread for the drawing, that must end by definition once the main class is dropped; 3) you may as well use a timer as iobject said, because you are effectively using one already when moving the circle. It's not that much more hassle enveloping that in a thread.

05.13.2008 at 11:04AM PDT, ID: 21557607

Rank: Guru

iobject = objects. ;)

05.13.2008 at 11:18AM PDT, ID: 21557738

If I had either known how to do it or had time to study this subject I wouldn't have asked :-)

05.13.2008 at 12:12PM PDT, ID: 21558290

Rank: Guru

I can see that. But y'know, you'd have a 'right' to be even *more* surprised if you were to find that the screen *did* die when you asked it to, when, in fact, all the time you'd just asked it to loop until it drooped, - wouldn't you? ;) (The logic *is* in there, but its not explicit, and that's the problem.

You've got the options, and personally, I'd take up objects' offer to lend a hand on this one. :)

05.13.2008 at 12:14PM PDT, ID: 21558323

Rank: Guru

>> (The logic *is* in there ....

... by which of course I meant to say the logic of only having asked your code to do what you'd instructed. ;) Loop.

05.13.2008 at 12:21PM PDT, ID: 21558397

Rank: Guru

>>If I had either known how to do it or had time to study this subject I wouldn't have asked :-) <<

You came perilously close to succeeding, and your code, otherwise, was very nice. ;) CU later.

05.13.2008 at 01:00PM PDT, ID: 21558742

Rank: Genius

CEHJ:

You need to do a bit of rearranging. But the following works:

                       
                          
                             
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                                import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
 
public class AniMain extends Frame implements Runnable {
	private Circle circle1;
 
	public AniMain() {
		circle1 = new Circle(50, 60, 100);
		addWindowListener(new WindowCloser());
		new Thread(this).start();
	}
 
	public void paint(Graphics g) {
		circle1.draw(g);
	}
 
	public static void main(String args[]) {
		Frame frame = new AniMain();
		frame.setBounds(100, 100, 400, 400);
		frame.setBackground(Color.white);
		frame.setResizable(false);
		// register event
		frame.setVisible(true);
 
	}
 
	// end the program when the user hits the Frame's close button
	private class WindowCloser extends WindowAdapter {
		public void windowClosing(WindowEvent e) {
			System.exit(1);
		}
	}
 
	public void run() {
		int i;		
		i = 0;
		while (true) {
			if (i > 300)
				i = 0;
			else
				i++;
 
			circle1.move(50 + i, 60 + i);
			try {
				Thread.sleep(50);
				repaint();
			} catch (Exception e) {
			}
		}
	}
 
}
 
//=============================================================
 
/** AniMain.java - Java versione 1.6 - 05 05 2008 */
import java.awt.Color;
import java.awt.Graphics;
 
class Circle {
	int x;
 
	int y;
 
	int radius;
 
	public Circle(int x, int y, int radius) {
		this.x = x;
		this.y = y;
		this.radius = radius;
	}
 
	void draw(Graphics graphics) {
		graphics.setColor(Color.RED);
		graphics.drawOval(x - radius, y - radius, 2 * radius, 2 * radius);
	}
 
	void delete(Graphics graphics) {
		graphics.setColor(Color.white);
		graphics.drawOval(x - radius, y - radius, 2 * radius, 2 * radius);
	}
 
	void move(int newx, int newy) {
		x = newx;
		y = newy;
	}
 
}
                             
                          

                    

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Accepted Solution

05.13.2008 at 05:29PM PDT, ID: 21560375

Rank: Genius

I already explained above what you needed to change, which part did you not understand?

05.15.2008 at 02:53PM PDT, ID: 21578284