iOS 10 beta: UIWebView: can't change text size on iPad

Originator:skyriser
Number:rdar://27201529 Date Originated:2015.07.06
Status:Closed Resolved:2016.11.02
Product:iOS 10 Product Version:
Classification: Reproducible:
 
Using Xcode 8 beta 2, on iPad simulator with iOS 10 beta (14A5297c)

See sample project and screenshots for references.


In our production app, we can't seem to be able to change the text size of a UIWebView on iOS 10 on iPad.

We're using this method to change the text size:
[self.webview stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.getElementsByTagName('body')[0].style.webkitTextSizeAdjust = '%d%%'", size]];


Running sample project, always running on iPad simulator with iOS 10, by clicking the "Bigger" and "Smaller" buttons to change the text size:
(always running in iPad simulator, but switching Deployment device setting)
-On iOS9, built for iPhone device: works
-On iOS9, built for iPad device: works
-On iOS10, built for iPhone device: works
-On iOS10, built for iPad device: DOESN'T WORK, no resizing, no errors or warnings


For the sample project, to switch between building for iPad or iPhone in the sample project, change the Deployment Info "Device" project settings.

We are aware of WKWebView, and there are similar issues, using similar methods, except that it doesn't work for both iPad and iPhone on iOS10, but works on iOS9.


Tried with iOS beta 1 and iOS beta 2 with same results.

Comments

Still fixed in iOS10.2b2 :)

By skyriser at Nov. 7, 2016, 6:58 p.m. (reply...)

Looks fixed in iOS10.2b1! I'll keep testing to confirm.

By skyriser at Nov. 1, 2016, 2:07 p.m. (reply...)

Still broken in iOS 10.1GM.

By skyriser at Oct. 24, 2016, 5:43 p.m. (reply...)

Fixed here on WebKit trunk:

Bug 162227: REGRESSION (r201090): Setting style.webkitTextSizeAdjust does not change text change on iPad

https://bugs.webkit.org/show_bug.cgi?id=162227

http://trac.webkit.org/changeset/206217

We is aware that this is a regression in iOS 10 and that developers would like a fix soon.

By ddkilzer at Oct. 20, 2016, 2:36 a.m. (reply...)

Thanks for the update ddkilzer, looking forward to the fix :)

By skyriser at Oct. 20, 2016, 6:25 p.m. (reply...)

Still broken in iOS 10.1b4.

By skyriser at Oct. 19, 2016, 2:05 p.m. (reply...)

Still broken in iOS 10.1b3.

By skyriser at Oct. 11, 2016, 1:56 p.m. (reply...)

Still broken in iOS 10.1b2.

By skyriser at Oct. 4, 2016, 5:59 p.m. (reply...)

Thanks @ddkilzer! Please let us know if have any idea which iOS version this will be included in.

By skyriser at Sept. 27, 2016, 1:12 p.m. (reply...)

This bug tracks the fix in open source WebKit:

REGRESSION (r201090): Setting style.webkitTextSizeAdjust does not change text change on iPad

https://bugs.webkit.org/show_bug.cgi?id=162227

By ddkilzer at Sept. 22, 2016, 6:30 p.m. (reply...)

Workarounds (private APIs)

I've found workarounds involving private APIs.

UIWebView:

[[[webView.scrollView.subviews.firstObject webView] preferences] _setTextAutosizingEnabled:YES];

WKWebView:

[webView.configuration.preferences _setTextAutosizingEnabled:YES];

If you'd like to submit to AppStore, take some precautions like using performSelector:, NSSelectorFromString() and so on.

By cahn at Sept. 22, 2016, 5:26 a.m. (reply...)

Still broken in iOS 10.1 b1.

By skyriser at Sept. 21, 2016, 6:54 p.m. (reply...)

Still broken in iOS10 GM.

By skyriser at Sept. 9, 2016, 5:22 p.m. (reply...)

Apple Please Fix this ASAP

This is a big issue that was reported early in the beta. Why isn't it fixed?

By ronnie at Sept. 8, 2016, 2:44 p.m. (reply...)

Still broken in iOS10b8.

By skyriser at Aug. 26, 2016, 6:40 p.m. (reply...)

Note: In the Safari inspector, with the same code/project running in the simulator, the iPhone is modified correctly ("-webkit-text-size-adjust: 220%;"), but not on iPad ("-webkit-text-size-adjust: auto;").

By skyriser at July 20, 2016, 3:12 p.m. (reply...)

Still broken in iOS10b3.

By skyriser at July 18, 2016, 7:53 p.m. (reply...)

Maybe related?

http://stackoverflow.com/questions/37808180/disable-viewport-zooming-ios-10-safari

"From the iOS 10 beta 1 release notes: To improve accessibility on websites in Safari, users can now pinch-to-zoom even when a website sets user-scalable=no in the viewport."

By skyriser at July 7, 2016, 3:26 p.m. (reply...)

Also created forums discussion: https://forums.developer.apple.com/message/151610#151610

By skyriser at July 6, 2016, 7:15 p.m. (reply...)

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