mouseEnter-Leave conundrum

[Devin Asay]

I've run into an interesting problem in a small demo stack I'm  
working on. I am creating an interactive labeled picture in which a  
label field appears when the user mouses over an object in a  
photograph. I use a filled, partially transparent irregular polygon  
graphic to define the outline of the object in the photo I want to  
label. The label field overlaps the graphic object (this detail is  
important.) I use a script like this on the card to control the  
hiding and showing of the label field:

on mouseEnter
   if the name of the target contains "graphic" then show fld "myLabel"
end mouseEnter

on mouseLeave
   if the name of the target contains "graphic" then hide fld "myLabel"
end mouseLeave

Pretty straightforward. Now consider this sequence of events:

mouse enters graphic --> field is shown
mouse leaves graphic --> field is hidden

No problems. But this is what happens when the mouse enters the  
graphic, then, without leaving the graphic, enters the now visible  
field:

mouse enters graphic --> field is shown
mouse enters field --> since mouse is over field, it has left the  
graphic, so
   mouse has left graphic --> field is hidden
   mouse has entered graphic again --> field is shown
   mouse has left graphic --> field is hidden
   mouse has entered graphic again --> field is shown
   ... [ad infinitum]

This resultant "fluttering" of the field only stops after the mouse  
has been moved out of the graphic and enough time has elapsed so that  
all of the queued mouseLeave/mouseEnter events have run through.

go stack url "http://asay.byu.edu/enter-leave.rev" --to see a  
demonstration

I understand why this happens, and it seems consistent with the  
engine logic, so I'm not inclined to call it a bug. On the other  
hand, when uncontrolled "thrashing" of messages like this happens, it  
feels like a bug.

What do you all think? Should I report it as a bug? Is there an  
obvious workaround that I'm missing? (FlushEvents has no effect on  
these messages.) Insights appreciated.

Devin

Devin Asay
Humanities Technology and Research Support Center
Brigham Young University