606525 - Slow scrolling when zoomed whilst watching a video

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Steve England [:stevee]]

Mozilla/5.0 (Windows NT 5.1; rv:2.0b8pre) Gecko/20101022 Firefox/4.0b8pre ID:20101022043027

Sorry for the crappy report - I have no time to investigate this thoroughly, but I do want it in the system.

1. New profile, start firefox
2. Ensure Smooth Scrolling is enabled in Tools > Options > Advanced
3. Visit www.shacknews.com
4. Press CTRL++ two or three times to zoom into the webpage (NOTE: This bug does not present itself when you are only zooming text; you have to be zooming images too)
5. Find a video on the shacknews front page and click to play it
6. Using the mouse wheel, scroll up and down the page around the location of the playing video

Expected:
- Smooth scrolling

Actual:
- Scrolling gets really poor when the zoomed video comes into view. As soon as it is out of view the page scrolls perfectly smoothly.

If you choose to not zoom, or to Zoom Text Only, the page scrolls fluidly. It's only when the video is being zoomed too that scrolling becomes really rather poor.

Firefox's scrolling is currently in a totally awesome state. It'd be great to see this bug squashed ;-)

Comment 1

[Steve England [:stevee]]

Also note: whilst the zoomed video is playing (without scrolling) it's really hard to click on the menu items in the firefox's chrome. There's often a 5-10 second delay before any clicks are registered, which effects the UX.

Comment 2

[Csaba Kozák [:WonderCsabo]]

Have you tried disabling HW ACC layers?

Comment 3

[Steve England [:stevee]]

Yes. No change in behaviour.

Comment 4

[Steve England [:stevee]]

Mozilla/5.0 (Windows NT 5.1; rv:2.0b8pre) Gecko/20101113 Firefox/4.0b8pre ID:20101113042433

Asynchronous layer-based plugin painting (bug 596451) has not helped.

Comment 5

[Steve England [:stevee]]

This is fixed now.