863170 - Entering fullscreen animation displays twitchy element positioning

Status: NEW

(Core :: Layout, defect)

Description

[Bram Speeckaert]

Filing a separate bug as requested in bug 767710 comment 13.

STR:
1. Open https://bugzilla.mozilla.org/describecomponents.cgi
2. Enter full screen mode
3. Watch it dance!

To make it more visible, try scrolling down all the way before entering full screen mode. This makes the page itself remain stationary, allowing you to observe the changing element positioning.

Comment 1

[Karl Tomlinson (:karlt)]

(In reply to Bram Speeckaert from comment #0)
> To make it more visible, try scrolling down all the way before entering full
> screen mode. This makes the page itself remain stationary, allowing you to
> observe the changing element positioning.

That looks like it might be something in addition to the subpixel animation frames.
At the end of the animation, the scrollable content may not be at the end of the scrollable range (visible because the scroll-down button because active, if the native theme supports that).