Automatic scrolling when playing sheet music doesn't work in certain browsers or horizontal mode

[chris-saunders]

Your environment

• Version used: (master branch + Dev branch)
• Platform used: JavaScript
• Rendering engine used: SVG (default)
• Browser Name and Version: Safari 12.0, Android webView (Chromium), iOS UIWebView, iOS WKWebView
• Operating System and version (desktop or mobile): Android, iOS, Mac OSX (10.13.6)

Expected Results

As the music plays and the seek bar goes offscreen the browser scrolls automatically to keep up

Observed Results

In any browser with layout mode set to horizontal it does not scroll, and in the listed browsers above it will not scroll regardless of layout.

Possible Solution

It seems to work for chrome, both on mobile devices and desktops. May be a browser specific issue.

[Danielku15]

Thanks to BrowserStack I could make some tests on various devices and could identify the issue. The problem is that alphaTab by default scrolls on document.documentElement which is the html tag.

Various mobile browsers seem to not be able to scroll on html but need to scroll on body instead. I also found this blog post on that topic. Changing the scrolling to document.body fixes the issue.