173453 - DHTML scroller scrolls slowly

Status: RESOLVED DUPLICATE of bug 188331

(SeaMonkey :: General, defect)

Description

[Noam Halevy]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.1) Gecko/20020826
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.1) Gecko/20020826

In this page there are a couple of images with a special scrollbar (javascript?).
When the mouse is over the scrollbar - the images scroll.

The problem is that the images scroll very very slowly.
In IE it scrolls fine

Reproducible: Always

Steps to Reproduce:
1. go to:
http://www.ea.com/eagames/official/battlefield1942/editorial/weeklyscreen.jsp
2. put the mouse over the image scrollbar
3. watch the images scroll very very slowly

Actual Results:  
the images scroll very very slowly

Expected Results:  
scroll in normal speed

Comment 1

[WD]

WFM
2002100911 scrolls at approximately the same speed as IE 5, Win2k

Comment 2

[Noam Halevy]

I now think it is relayted to the way mozilla uses (or probably don't use) the
graphics accelerator.

I am using a IBM laptop (T21) with screen resolution of 1280x1024
When I switch to 1024x800, the performance is OK.

But in high resolution I get all the above performance problems.
Since IE works just fine at this resolution, my guess is that IE uses the
graphics acceleratort through the windows API, and mozilla - since it is cross
platform - does not.
Can you comment on that ?

Thanks,
           Noam.

Comment 3

[M. A. Sridhar]

I am seeing similar problems with pages containing large images. I have observed
this with Mozilla 1.2.1 on Windows NT. Here is another page that exhibits this
problem:

http://java.sun.com/j2ee/tutorial/1_3-fcs/doc/Ebank.html

Comment 4

[Stephan Grossklass]

This problem seems to appear when scrolling (particularly via the keyboard) over
images that have been resized (at least if they're being displayed smaller than
they actually are). This page of mine is also affected:
http://jgrossklass.bei.t-online.de/dolby&co.htm (images at the bottom)
The problem has been observed in
Mozilla 1.2.1, WinNT 4.0
Mozilla 1.3, WinNT 4.0
Mozilla 1.3, WinNT 5.0
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4a) Gecko/20030315
Mozilla/5.0 (X11; U; Linux i586; en-US; rv:1.4a) Gecko/2003031522-sea

Also, when I have some other window floating over Mozilla displaying a big image
to fit the window size (that new 1.3 feature) and switch back to Mozilla, it
takes a while until the image gets redrawn - probably the same problem.

Comment 5

[Stephan Grossklass]

Seems that comments #3 and #4 represent the same problem, but one that is
different from the one that led to this bug here. Creating new bug now.

Comment 6

[Jon Henry]

Hi Noam. Are you still experiencing this problem in recent Mozilla builds? I
just tried the Battlefield 1942 page in Firebird's 20030918 build, and while
still a bit slower than IE, it wasn't bad. It might be worse on lower-end
systems though, I don't have a way of testing at the moment. If this is still
giving you trouble, I'll confirm the bug. Thanks.

Comment 7

[Jon Henry]

Noam responded to me via email:

Hi,

the scroll rate is reasonable on Firebird and on
800MHz
laptop, win2K.

However, it does take up 90% cpu doing it.
In IE it is barely noticable and it scrolls faster.

There is definitely something strange in the
JavaScript
implementation of Mozilla.

Thanks,
    Noam.

So I guess there is still something going on. I'll keep looking for
dupes/related bugs since this isn't an isolated problem.

Comment 8

[Jon Henry]

This is a duplicate, the site referenced by bug 188331 has nearly an identical
setup. That bug itself is probably a dupe of something else (bug 70156 ?), but
this is a start at cleaning things up.

*** This bug has been marked as a duplicate of 188331 ***