20754 - Javascript animation does not finish

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P2)

Description

[Sitsofe Wheeler]

At the bottom of the page there are some pictures and when you hover over them
they animate with Javascript. However, in Mozilla the last frame (the explosion)
is not shown. This page works fine in both NS 4.5 and IE 4.01 on WinNT 4 and NS
4.6 on Linux.

Expected:
Flicker then explosion.

Result:
Flicker but no explosion.

System:
Build ID: 1999120216 Linux

Comment 1

[Mike McCabe]

Looks like you need to click on the 'napalm' area to get to the problem page.
It looks like the problem is with either setTimeout or assigning to image.src.

Reassigning to the DOM component in the hopes that somebody can look more
closely at this.

sitsofe - I've seen stuff like this, and this might be a duplicate bug; it'd be
a big help if you could do some bugzilla searches (on setTimeout or image.src,
possibly) to see if it is.  Thanks!

Mike

Comment 2

[Sitsofe Wheeler]

Closest I could find after exhaustive searching was bug 15215. Sorry.

Comment 3

[vidur (gone)]

In an attempt to get my bug list in order again, marking all the bugs I have
currently as ASSIGNED.

Comment 4

[vidur (gone)]

Here's what's happening: the explosion image is pre-loaded, but only stored in
the image cache in its default size. When the scaled version of it is used for
each of the animated buttons, we don't get a hit in the image cache since the
cache stores images in their final displayed size. As a result, we start loading
the image again from a stream. Since we currently don't have a networking cache,
the stream load happens across the network. The load is aborted since the
animation timeout fires before it completes and we never actually load and
decode the scaled image.

Turning on the memory cache helps the problem but, even with it on, loading and
decoding of images seem slower than they were in 4.x. Of course, if the timeout
for the last frame were made short enough, we'd see the same problem in 4.x as
well. I'm not sure what to do with this bug - there's little else we can do on
the DOM side.

Here are the alternatives:
1) We can and should profile image loading and work on performance.
2) We can investigate storing cached images in their original size and using
StretchBlt type methods to do the scaling on the fly (at least for platforms
that support it). This way, preloading the image will actually do something
worthwhile.
3) We leave things as they are and just rely on caching to improve performance
in some cases.

Passing the bug on to pnunn to investigate the first couple of options.

Comment 5

[pnunn]

I've got to ponder this one awhile.

-pn

Comment 6

[pnunn]

It would be really great if I could get
a copy of this page so it doesn't load the
next page immediately.
-pn

Comment 7

[pnunn]

hint hint
It would be really great if I could get
a copy of this page so it doesn't immediately load the
next page.
-pn

Comment 8

[pnunn]

moving out milestone.

Comment 9

[Sitsofe Wheeler]

I'm sorry I haven't replied to this sooner but the page with the script on it 
chanaged so I had to mail the author of the page to get a copy (thanks 
[e-mail]!). I haven't had time to work on it to turn it into a 
working page so I'll post it up as-is for now.

Comment 10

[Sitsofe Wheeler]

Attachment: Original napalm page

Comment 11

[pnunn]

much thanks.
I'll dig back into it after the time crunch.
-p

Comment 12

[neeti]

Moving to m17

Comment 13

[neeti]

Moving to m18

Comment 14

[pnunn]

In looking at this bug I'm having trouble generating the
original problem. The html page was attached, but no images.

In trying to create a similar effect, it appears to be working
ok..

I'm marking as fixed. But if you can give me another example of the
bug, reopen this bug or create a new one for the problem.

-P

Comment 15

[Pulsebot]

Pushed by ffxbld-merge:
https://hg.mozilla.org/releases/mozilla-beta/rev/db68770b4d93
[fenix] For https://github.com/mozilla-mobile/fenix/issues/20754: fix intermittent click failure in verifyAboutFirefoxPreview test
https://hg.mozilla.org/releases/mozilla-beta/rev/a22c1d1a46dd
[fenix] Disable intermittent tests https://github.com/mozilla-mobile/fenix/issues/20754.
https://hg.mozilla.org/releases/mozilla-beta/rev/d455689e0140
[fenix] For https://github.com/mozilla-mobile/fenix/issues/20754: Fix scrolling issues and re-enable verifyAboutFirefoxPreview