Web scripts can cause the interface to freeze

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Conditions:
- Device: Samsung Galaxy S III (I747)
- OS: 4.1.1
- TalkBack: 3.3.1 (issue observed at least since 3.2.x)

When using an application with rapidly updating webview areas, interacting with
these areas causes the interface to become unresponsive for anywhere from a few
seconds to over a minute. During that period TalkBack reacts neither to touches
nor gestures and only pressing the physical home button aborts the freeze. This
does not occur when a11y webscripts are disabled.

Typical scenario: Applications sporting advertisement banners are the most
common cause for this problem, but webviews with rapidly changing content seem
to have the potential for triggering the issue.

If the problem cannot be resolved altogether, the ability to blacklist
webscripts for certain applications would go a long way towards mitigating the
side-effects it causes.

Original issue reported on code.google.com by sma...@gmail.com on 15 Apr 2013 at 11:46

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In which app are you most frequently seeing this behavior?

Have you observed this behavior in Browser/Chrome itself?

Original comment by caseybur...@google.com on 21 Apr 2013 at 9:35

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By far the quickest way to reproduce this issue is by using an app which 
employs advertisement banners; here are two random examples:
https://play.google.com/store/apps/details?id=com.andrconstruction.andrecord
https://play.google.com/store/apps/details?id=com.mictale.gpsessentials

Placing the a11y focus on the banner triggers the issue.

The issue does come up in the browser; TalkBack becomes unresponsive while a 
page is loading and tries to "catch up" on touch events afterwards. However, it 
is far less noticeable because it only lasts a second or two. On the other 
hand, a constantly refreshing webpage could possibly cause similar problems.

Original comment by sma...@gmail.com on 22 Apr 2013 at 3:50

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Stumbled upon an instance of this problem within a Google app today. In the 
Gmail app, in on the forward screen (More options -> Forward), swiping passed 
"Respond inline" or touching the area at the bottom of the screen will trigger 
the issue.

I'd also like to ammend that the UI itself does not freeze, but rather the a11y 
stack hangs. HTH

Original comment by sma...@gmail.com on 21 May 2013 at 5:47

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Issue 183 has been merged into this issue.

Original comment by caseybur...@google.com on 29 May 2013 at 8:13

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Original comment by caseybur...@google.com on 29 May 2013 at 8:14

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Hello, I see the exact same thing on the app I am developping.

Context : a ViewPager of WebView
Android 4.1.2
TalkBack 3.4
Samsung Galaxy S2

It seems to be related to this call : 

setJavaScriptEnabled (true) on the WebSettings of the WebView.

If I don't make that call, it doesn't hangs anymore but then TalkBack fails to 
encode the caracters (accents and others...) and the gestures I've setup in 
TalkBack preferences to read the full page won't work.

Regards.

Original comment by eric.lap...@gmail.com on 16 Oct 2013 at 2:29

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I too see this issue in Kitcat 4.4.2 with either ads or apps that refresh 
quickly.  Here is an example of some apps, color detector by mobailian, snap 
tagon AccuWeather and that is just the tip of the ice burg.  I wish I could 
point out the code causing this issue but I am just a talkback user not a 
developer.
Enter your comments

Original comment by danny.ma...@gmail.com on 9 May 2014 at 8:08

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I see this quite a bit in the play newsstand app.  I'm running 4.4.2 on a Nexus 
seven.

Original comment by mikereis...@gmail.com on 9 May 2014 at 10:44

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Observed behaviour similar, if not identical, to that described while using 
Chrome (40.0.2214.109) on  multiple devices: 4.4.4 (Sony Xperia Z1) and 4.4.2 
(Samsung Galaxy S4). URL accessed is 
https://m.coles.com.au/customer-service/contact-us (as at 2015-02-11).

Shoftly after page load, the UI completely hangs for between 10-20 seconds, but 
input is buffered. On completion of [whatever is causing the issue] it will 
execute all buffered input.

Original comment by cae...@cyberseraphic.com on 10 Feb 2015 at 11:43