Some MathJax character-related problems in Android webview

[pkra]

This is mostly to investigate and to check if other people have experienced similar problems.

I often have small issues with some characters not showing in Android's webview (at least on 4.1, 4.2).

For example, viewing this post in a webview (via an RSS-reading app) the $\latex$ in the OP was missing only the A.

This might be a webfont detection problem since I think (but have yet to confirm) that it's always some "special" characters (e.g., fraktur or small sizes).

[fred-wang]

In the $\latex$ command, the A is reduced by the increase of scriptlevel and positioned by mpadded. I don't think font is involved here?

[pkra]

Oh, that would be worse. Maybe Davide can clarify. I guess this brings up the problem of better testing on mobile devices. We need to improve situation. I think Selenium has an Android solution which looks like just installing an APK (we could use an Android VM like androvm?)

[fred-wang]

Installing the Selenium APK is the trivial part, I already did some experiments. But I only tried the Android emulator on a Linux virtual machine and that was very very slow... It's probably worth trying a more efficient set up.

[dpvc]

The example page loads fine for me in the Android Browser app, which (I assume) uses a webview, in Android 4.1.2. There should not be a font issue, as the same font is used for all the letters in the symbol, even though some are sized. Not sure what else to suggest.

[pkra]

I think I'm able to reproduce this. I'll send you an APK to try.

[pkra]

BTW: no webview is something different from the browser. But IIUC it's the only thing apps have access to.

[dpvc]

I didn't mean that webview was the browser, but I assumed the browser used a webview. I'll take a look at your code and see if I can get it to run to test with.

[pkra]

Ah, not sure, cf. https://developers.google.com/chrome/mobile/docs/faq. Then again from http://www.zdnet.com/blog/burnette/google-io-2012-android-fireside-chat/2637:

WebView will be converted to Chromium based code. Android and Chrome engineers are working together.

Since I only experienced this on JellyBean, maybe the actual reason is that change to WebView...

[pkra]

Hm. Who added the "cannot reproduce" label? I can reproduce this with the app I linked to.

[taninamdar]

Even I suffer from the same problem for the letter 'A' and \right) in math mode in Nexus 7. Is there any solution to this?

[bosbeles]

I have a nexus 4 with android 4.3.
Google chrome displays inconsistent font sizes in some sites like http://geomania.org/forum/1988-82/3-3158/msg11934/?topicseen#new
When i look at http://geomania.org/forum/2001-41/1-3044/ with dolphine it does not show capital A s but there is no inconsistency problems on font sizes.
The above site does not have any problem on ios safari, on android 2.x platforms. This is not the complete list.

[pkra]

Thanks. Yes, Dolphin exhibits the same webview bug because it's using webview -- that should make it easier to track this issue down.

Any Google chrome issue would be unrelated to this bug since Chrome does not use webview but we'll check it out.

[Erhannis]

It appears that arrow marks (like, over vector names) are affected, as well. Has anyone found a full workaround or fix, yet?

[pkra]

@dpvc I've added this to the milestone. Are you still unable to reproduce this?