Display page as 'active' when that page is generated by a plugin

I’ve asked this question on StackOverflow, but nobody answered there, so i thought I would try asking it here.

I’m writing a plugin that generates and manages a set of page content from a small SQLite database. In my page structure, I’ve created a page at mysite.com/plugin_page. This pulls data from the plugin and has links that show pages such as mysite.com/plugin_page/view/$1. Once you enter the view/$1 structure though, all pages are built by the plugin.

When the user is viewing mysite.com/plugin_page, the active page highlighting works fine in my navigation menu. When you go to the viewing page though, no page is listed as ‘active’ and the correct page isn’t highlighted in the navigation menu.

Is there something I need to do within the plugin to account for this? If interested in looking at the code itself, here is the repository link.