Sidebar API to filter files on search

I would really like the ability to filter the files in the sidebar by a search that includes file content. To achieve this, a plugin would need access to the sidebar API.

The current Global Search only provides an extract of the results in a separate buffer but I would like the ability to browse through the results with a quick preview of the files content. This is to achieve a similar search as in Evernote and other similar note-taking software.