772140 - On some pages, text selection is so unresponsive that it's basically unusable

Status: RESOLVED DUPLICATE of bug 774938

(Firefox for Android Graveyard :: Text Selection, defect)

Description

[Jeff Muizelaar [:jrmuizel]]

I tested on a Galaxy S III and it was really really slow.

Comment 1

[Aaron Train [:aaronmt]]

Recent change on inbound is making it impossible to use.

Comment 2

[Aaron Train [:aaronmt]]

Is this the same as bug 767070?

Comment 3

[Jeff Muizelaar [:jrmuizel]]

(In reply to Aaron Train [:aaronmt] from comment #2)
> Is this the same as bug 767070?

No. That bug is just about text selection being slow but still quite usable.

Comment 4

[:Margaret Leibovic]

It seems like we just run into a really extreme version of bug 767070 on some pages, but hopefully the same fix could improve both of these issues.

Testing on cnn.com, I'm also experiencing bug 766588, which is what's making it unusable for me.

Comment 5

[:Margaret Leibovic]

Attachment: (debugging) don't change the selection until the touch is over

I've been trying to figure out the source of this slowness. This patch stops us from trying to reposition the handles and update the selection until the touch is over, and selection is still super slow, so that indicates that the "tons of fake mouse events" hack isn't the source of the problem.

Jeff's profile from bug 767070 indicates that painting is a problem, and I wonder if it's so bad on some pages that even that one moveSelection() call can take a long time.

I've been trying all sorts of hacks like this patch to work around this problem, but I haven't come across anything that works. I think we need a layout person to help us here.

Comment 6

[:Margaret Leibovic]

I don't think this is a regression.

Comment 7

[:Margaret Leibovic]

I just uplifted text selection to aurora (bug 695173 and a ton of follow-ups). However, if this issue isn't sorted out and a fix uplifted as well, we'll want to consider disabling this feature before shipping.

Comment 8

[Lukas Blakk [:lsblakk] use ?needinfo]

Margaret, I'm assigning this to you so we have a point person to do the disabling if that is needed before we ship 15.

Comment 9

[:Margaret Leibovic]

Okay, I'm working on a patch to use native handles over in bug 774938. That would fix this problem, but there are likely going to be follow-up issues to deal with, since it's a lot of different code.

Comment 10

[:Margaret Leibovic]

I'm duping this to bug 774938, because that solved the perf problem.

Comment 11

[Lukas Blakk [:lsblakk] use ?needinfo]

removing tracking since we're following this in bug 774938 now.