[Bug swing/24651] JMenu layout problem with nested menus

[hendrich at informatik dot uni-hamburg dot de]

------- Comment #26 from hendrich at informatik dot uni-hamburg dot de  
2005-11-10 07:54 -------
Hello Roman,

> Do you have any more hints what could cause the performance loss? Is the
> CPU actually working when you open a menu, or is it at 0% (maybe a
> locking issue).

when I activate the popup and move the mouse around within it, CPU usage
goes up to 100%. The menu item highlighting is very slow - it lags behind
noticeably. To me it seems as if the whole application (including image #
canvas) is repainted instead of just the popup menu... 


> Really strange. I tried with JamVM1.3.3 and current Classpath. I even
> installed and tried ctwm, but it still is reasonably fast (at least with
> opening menus).

I am certain that ctwm is not responsible for the performance problems.
I mentioned it only because ctwm seems to expose some window focus and
window placement 'features'...  One harmless but optically annoying example
are the window decorations on some of the Swing menus and popup-menus 
(usually the heavyweight ones).

BTW, I did multiple test runs. In most of these, I got the massive flickering
I reported earlier, but two times there was no flickering and image scrolling
was rather smooth (if slow). I have no idea how this can happen.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24651