199630 - Example of sluggish scrolling on page with DHTML menus

Status: RESOLVED WORKSFORME

(Core :: DOM: Core & HTML, defect)

Description

[Nick Guarracino]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3) Gecko/20030312
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3) Gecko/20030312

I have a test case to add to bug 21762, for poor DHTML preformance.  I wasn't
sure if this should be added as a comment to that bug or separately.  My
apologies if I've done it incorrectly.

Crate and Barrel uses DHTML to control some navigation menus on their site. 
This causes vertical scrolling to be very slow.  The scrolling returns to normal
once you disable Javascript.  Scrolling up or down by a single line with the
keyboard works properly, but once you use the mouse wheel to scroll multiple
lines at a time, it gets slow.  It should be noted that IE on my Win2000 box,
and konqueror on my Linux box both scroll slowly as well, but still faster than
Mozilla.

I tried stepping through some of the code to get a more specific test case, but
I'm no Javascript expert, and I didn't get very far.

Reproducible: Always

Steps to Reproduce:
1. Go to URL with Javascript enabled
2. Scoll up and down with the mouse wheel
3. Disable Javascript, try scrolling again

Actual Results:  
Slow scrolling when Javascript is enabled

Expected Results:  
There should be no delay when scrolling up/down the page

Comment 1

[Chris Casciano]

I'm seeing some of this with mozilla trunk on OS X (but not Camino - different
widgets). Using the scroller via the mouse there is some delay for the scrolling
to "take"/start like the scrollbar has been fixed in place, but once it starts
moving its ok.

Comment 2

[Zibi Braniecki [:zbraniecki][:gandalf]]

Confirming - Moz 20030328 WinXP.

Comment 3

[Kevin Gadd]

Verified Moz 2003032808/WXP SP1
Note that scrolling with the mousewheel is always fast, but dragging the
scrollbar thumb manually is extremely slow.

Comment 4

[Nick Guarracino]

Hmmm... I visited the Crate & Barrel site again today, and scrolling is just as
fast as can be.  I'm using the same Mozilla build, so I wonder if they've
changed their code?

Can someone else verify that scrolling has sped up considerably?

Comment 5

[Markus Hübner]

trunk build 2003041508 on winxp pro, scrolling is fine.
marking wfme ?

Comment 6

[Zibi Braniecki [:zbraniecki][:gandalf]]

Agree.
Moz 20030414