Bug 148086 – Cannot change WKWebView scrollView deceleration rate

• Component: WebKit2
• Status: RESOLVED FIXED

[Wenson Hsieh]

Currently, developers are not able to change a WKScrollView's decelerationRate by explicitly setting it, e.g. webView.scrollView.decelerationRate = UIScrollViewDecelerationRateNormal; This fixes the deceleration rate to UIScrollViewDecelerationRateFast. This is because _preferredScrollDecelerationFactor in WKScrollView is not updated when [WKScrollView setDecelerationRate] is invoked, so when the snap points code determines whether the decelerationRate should be fast or whatever the preferred value is, the decelerationRate is always set to UIScrollViewDecelerationRateFast.

[Wenson Hsieh]

<rdar://problem/21893685>

[Wenson Hsieh]

Created attachment 259173 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 259173 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=259173&action=review

> Source/WebKit2/ChangeLog:5
> +        https://bugs.webkit.org/show_bug.cgi?id=148086
> +

There should be a radar url here too.

> Source/WebKit2/ChangeLog:8
> +        Updates the preferred scroll deceleration factor when the scrollView's decelerationRate is explicitly set.

Can you put more words here to say why this fixes the bug?

[Wenson Hsieh]

Committed r188541: <http://trac.webkit.org/changeset/188541>

[rob]

(In reply to comment #4)
> Committed r188541: <http://trac.webkit.org/changeset/188541>

@Wenson: Can you specify what version of iOS this bug fix was released with? Still seems to be an issue in iOS 9.3 13E230.

[Wenson Hsieh]

Hi Rob,

As far as I know, this fix did not make it into iOS 9. Could you try it out on the iOS 10 beta?

Thanks!
Wenson