I successfully installed xfce Thunar on Chromebook Linux. Works great!

But, is there a way to associate file types in Thunar with the Chromebook apps?

For example, so PDF's open with Chromebook Chrome web-browser, instead of trying to find an associated app inside Linux.

Hey there,

Fellow Chromebook owner here. Unfortunately, what you're asking for I don't think is possible. The Linux subsystem on Chromebooks runs in a separate container (or sandbox as Google calls it). As such, the programs that run in the Linux container & on the main ChromeOS can't talk with each other. However, you can access files you download from within the Linux container from the Files app (can't remember if you have to enable that or if it's done by default). An example would be that, let's say you download a PDF from a web browser in the Linux container. You could then access that PDF & open it up with ChromeOS's "Gallery" app & view it. Other than that, installing a PDF viewer in the Linux container would be the only other way that I could think of.