1327839 - Findbar causes twitching of page content when it hides

Status: NEW

(Toolkit :: Find Toolbar, defect)

Description

[arni2033]

>>>   My Info:   Win7_64, Nightly 49, 32bit, ID 20160526082509
STR_1:
1. Open   data:text/html,<style>body{background:gray}   in a new tab
2. Press F3
3. Press Escape
AR:
 After Step 2 white area (~16px in height) promptly appears at the bottom of content area, then it
 smoothly grows in height and becomes a normal findbar. I.e. all elements located at the bottom with
 absolute/fixed position promptly teleport by ~16px to the top, then smoothly move by ~11px to the top

 After Step 3 findbar smoothly shrinks in height, until it becomes an empty white area (~16px in
 height). Then white area promptly disappears. I.e. all elements located at the bottom with absolute/
 fixed position smoothly move by ~11px to the bottom, then promptly teleport by ~16px to the bottom.
ER:  Either X or Y
 X) No twitching, evetything should work smoothly
 Y) No animation:  don't even try to make it look smooth, since it causes abrupt movement.

If you don't trust me, apply this CSS via userChrome.css/browser toolbox and check findbar's behavior:
>   /* it is the same, but 10 times slower! */
>   findbar{ transition-duration: 1500ms, 1500ms, 0s; }
>   findbar[hidden]{ transition-delay: 0s, 0s, 1500ms; }

This twitching was implemented in bug 836867. Regression range:
> http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=36525224b14e&tochange=b3e65fe37681