Does a Web Worker run on the main ui android thread or a separate thread?

Question

I have an OLD application for the Android that uses WebChromeClient

public class MyWebViewClient extends WebChromeClient

to run a web page on the Android as an application . The original intent was to keep the displays for apps (browser, ios, and android) identical . As usually happens, the application grew more complicated over time (5 years) and a local web database is used to store state for faster startup.

With the latest version of the Android Oreo OS, my app gets a ANR warning. I realize it is time to redesign but have a super tight schedule. If I move the initialization code (web database that uses callbacks (promises), ...) into a html 5 web worker, will that code run on a separate thread in Android application (other than the main ui thread?) Will this solve the ANR? Or do I have to totally redesign?

Does a Web Worker run on the main ui android thread or a separate thread? BTW - how about in the latest IOS, are web workers run on the main thread or separate thread?

Thanks in advance for your input.

Answer 1

The webview does not run on the Android UI thread. The problem had nothing to do with the web view at all. Instead the ANR is a known Android Oreo change. And I was able to fix it by following this post