627103 - Double tap zoom/unzoom (with reflow) takes too long to respond

Status: VERIFIED FIXED

(Firefox for Android Graveyard :: Panning/Zooming, defect)

Description

[Benjamin Stover (:stechz)]

STR (on Nexus One):
1. Go to news.google.com (desktop version)
2. Double tap

It takes over a second to do anything. Part of the problem is we are reflowing before we begin the zoom.

Comment 1

[Benjamin Stover (:stechz)]

It's about 5 seconds on p.m.o.

Comment 2

[Matt Brubeck (:mbrubeck)]

We intentionally wait for reflow to finish before starting the animation; see bug 623313.  If we don't want to revert that, maybe we should show some other user feedback in the meantime (like a highlight or outline of the double-tapped element).

Comment 3

[Matt Brubeck (:mbrubeck)]

Attachment: patch

With this patch, we will immediately zoom toward the element's current location, then do the reflow.  When the reflow completes, we zoom toward the element's new location.

On pages like http://news.ycombinator.com/ where reflow is fast, this looks like a single zoom that changes direction mid-zoom.

On pages like http://planet.mozilla.org/ where reflow is very slow, this causes a zoom, then a pause for a second or more (the old content remains "fuzzy" during the pause because the content process is busy doing reflow), then another zoom after the reflow finishes.

On pages where the layout doesn't change significantly, the second zoom is not as noticeable.  When it changes a lot, it is more disruptive.

Comment 4

[Mark Finkle (:mfinkle) (use needinfo?)]

Comment on attachment 514849 [details] [diff] [review]
patch

Let's see how this feels in nightlies

Comment 5

[Matt Brubeck (:mbrubeck)]

http://hg.mozilla.org/mobile-browser/rev/5a066561497d

Comment 6

[Tony Chung [:tchung]]

Verified fix on Mozilla/5.0 (Android; Linux armv71; rv:2.0b13pre)
Gecko/20110315 Firefox/4.0b13pre Fennec/4.0b6pre