Name: jk109818 Date: 04/04/2003


FULL PRODUCT VERSION :
java version "1.4.1"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-b21)
Java Hotspot(TM) Client VM (build 1.4.1-b21, mixed mode)

FULL OPERATING SYSTEM VERSION :
Microsoft Windows 2000 [Version 5.00.2195]
(also occurs on OSX VM 1.3.1 and prior windows VMs)

A DESCRIPTION OF THE PROBLEM :
When java.awt.Robot is used to generate click events immediately
after a frame opens, sometimes the very first mouse event on that
frame registers a click count > 1.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
0. Add an AWTEventListener to the system queue to examine
mouse events
1. Create a frame with a JList
2. Create a second frame with a JList
4. Show the first frame
5. Use java.awt.Robot to click in the first list, auto delay = 0
6. Close the first frame, show the second
7. Use java.awt.Robot to click in the second list
8. Close the second frame
9. Dispose both frames
10. Go to #1 above, repeat all steps

The first list will often get mouse events with a click count > 1

Code to test for this bug exists at
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/abbot/abbot/test/
abbot/PlatformTest.java?rev=1.9&content-type=text/vnd.viewcvs-
markup



EXPECTED VERSUS ACTUAL BEHAVIOR :
I'm not sure what the definition of a multi-click is, but I would
assume the following are required:

1) no intervening mouse motion
2) subsequent clicks are on the same component

Given that the clicks are on different components, a click on one
component should not count towards a multi-click on another.

The problem is not likely as straightforward as it might seem, since
only the first list seems to be encountering the multi-clicks.

REPRODUCIBILITY :
This bug can be reproduced often.

---------- BEGIN SOURCE ----------

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

/** Demonstrate click count > 1 on the first click in a component. */
public class MultiClickBug {

    private static ArrayList events = new ArrayList();
    private static Robot robot;

    private static void waitForVisibility(final Window win, boolean visible) {
        long start = System.currentTimeMillis();
        if (visible) {
            while (!win.isVisible() || !win.isShowing()) {
                if (System.currentTimeMillis() - start > 5000)
                    throw new RuntimeException("Window failed to show");
                robot.delay(100);
            }
        }
        else {
            while (win.isVisible() || win.isShowing()) {
                if (System.currentTimeMillis() - start > 5000)
                    throw new RuntimeException("Window failed to show");
                robot.delay(100);
            }
        }
    }

    private static void showWindow(final Window w) throws Throwable {
        EventQueue.invokeAndWait(new Runnable() {
            public void run() {
                w.pack();
                w.show();
            }
        });
        waitForVisibility(w, true);
    }

    private static void click(Component c) throws Throwable {
        Point p = c.getLocationOnScreen();
        p.translate(c.getWidth()/2, c.getHeight()/2);
        robot.mouseMove(p.x, p.y);
        robot.mousePress(MouseEvent.BUTTON1_MASK);
        robot.mouseRelease(MouseEvent.BUTTON1_MASK);
        // Wait for the events to be processed
        EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue();
        while (eq.peekEvent() != null) {
            robot.waitForIdle();
        }
    }

    /** This will fail if the multi-click frame bug shows up somewhere we
        don't expect it.
    */
    private static void multiClickFrameBug() throws Throwable {
        robot = new Robot();

        String[] data = { "one", "two", "three", "four", "five" };
        JFrame frame1 = new JFrame("Multi-click Bug");
        JList list1 = new JList(data);
        list1.setName("List 1");
        frame1.getContentPane().add(list1);
        frame1.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent we) {
                System.exit(0);
            }
        });
        
        MouseListener ml = new MouseAdapter() {
            public void mouseClicked(MouseEvent me) {
                events.add(me);
            }
        };
        list1.addMouseListener(ml);

        showWindow(frame1);
        click(list1);
        frame1.hide();
        waitForVisibility(frame1, false);
        showWindow(frame1);
        click(list1);

        long start = System.currentTimeMillis();
        while (events.size() < 2) {
            if (System.currentTimeMillis() - start > 5000) {
                System.err.println("Timed out waiting for click events");
                System.exit(1);
            }
        }

        // Both events should have a click count of one
        int errs = 0;
        MouseEvent me = (MouseEvent)events.get(0);
        if (me.getClickCount() != 1) {
            ++errs;
            System.err.println("Incorrect click count on " + me.getSource());
        }
        me = (MouseEvent)events.get(1);
        if (me.getClickCount() != 1) {
            ++errs;
            System.err.println("Incorrect click count on " + me.getSource());
        }
        if (errs == 0) {
            System.out.println("No bugs encountered");
        }
        System.exit(errs);
    }

    public static void main(String[] args) {
        try {
            multiClickFrameBug();
        }
        catch(Throwable thr) {
            thr.printStackTrace();
            System.exit(0);
        }
    }
}



---------- END SOURCE ----------

CUSTOMER WORKAROUND :
Delay 200 ms prior to showing a frame.
(Review ID: 179990)
======================================================================