Name: krT82822 Date: 10/13/99


10/13/99 eval1127@eng -- our mouse-movement sensitivity is high, and the (distance) tolerance low. Given this source code example, it's pretty easy to avoid
the intervening mouseMoved events. However, "normal" human hands are likely to move the mouse a bit "before" the beginning of the drag is detected.
Thus, the "mouse moved" events.

I'm not sure what we can do about this, but this has been the subject of a few recent reports (citing older bugs), so am filing a new reference bug for consideration.

This report was filed against 1.1.8, but the behavior is identical in 1.3.0 build "I" (a/k/a kestrel RA release).

------------

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

/**
 * The following bug was observed on Solaris and hp-ux with jdk1.1.8 and swing swing-1.1.1fcs, but not on Windows NT.
 * To reproduce: Start program,
 * press left or right mouse button in window and move the mouse immediately.
 * most likely one gets output like that
 * mouse pressed
 * mouse moved !!!!!! false
 * mouse moved !!!!!! false
 * mouse dragged
 * mouse dragged
 * mouse dragged and so on.
 *
 * This bug increases the possibility of an occurence of a popup freeze. Another bug which I submit separately.
 */
public class EventTest
{
    
    public static final void main ( String[] args ) {
       
       JFrame f = new JFrame();
       f.setSize(200,200);
       java.awt.Container c = f.getContentPane();
       c.addMouseListener(new MouseListener() {
public void mouseEntered ( java.awt.event.MouseEvent e ) {
               System.out.println("mouse entered");
           }
        
public void mouseExited ( java.awt.event.MouseEvent e ) {
               System.out.println("mouse exited");
}
 
public void mouseClicked ( java.awt.event.MouseEvent e ) {
               System.out.println("mouse clicked");
}

public void mousePressed ( java.awt.event.MouseEvent e ) {
               System.out.println("mouse pressed");
}
public void mouseReleased ( java.awt.event.MouseEvent e ) {
               System.out.println("mouse released");
}

        });

        c.addMouseMotionListener(new MouseMotionListener() {
public void mouseDragged ( java.awt.event.MouseEvent e ) {
               System.out.println("mouse dragged");
           }
        
public void mouseMoved ( java.awt.event.MouseEvent e ) {
               System.out.println("mouse moved");
}
       });
      
       f.show();
    }
}
(Review ID: 96482)
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Name: rlT66838 Date: 11/11/99


jdk1.1.8, swing-1.1.1.fcs
This problem is related to bug 4280900, which I submitted a few weeks before.

I do not have a source code for that, because the problem does not occur very
often. Instead I describe the problem.

Invoke the popup with right mouse button pressed (hold down), and drag ....

When the first MOUSE_DRAGGED Event occurs, the mouseEventTarget will be set.
It should be the invoker, but if you assume bug 4280900 there
can be some MOUSE_MOVED events between the MOUSE_PRESSED and the first
MOUSE_DRAGGED event. Therefore the mouseEventTarget can be something else
than the invoker. In the worst case it is the JPopupMenu.
Let's say one uses
   popup.show(invoker,event.getX(), event.getY());
to show a popup, then it is pretty likely that the mouse pointer
is at the edge of the popup, when the first MOUSE_DRAGGED event occur.
In this case JPopupMenu will be the mouseEventTarget and then
gets all the MOUSE_EVENTS. But the UI of the Popup does not grab the JPopupMenu.
Therefore the UI is not updated, so that the popup looks like it is freezed.

How to fix it?
May be fix bug 4280900 or set the mouseEventTarget if the MOUSE_PRESSED
arrives ....

(Dragging makes it very complicated for popups. Why not shut of the
dragging-mode during a popup is there. OK, the one is in AWT, the other in
swing. Then add a little functionality to AWT :-) )
(Review ID: 97404)
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