I'm trying to make our custom language plugin to correctly handle files which are not under the source root folder.
First, their icon must be changed. I implemented a FileIconPatcher but only icons in the editor tabs get changed, not the ones in the files tree. Any clues why?
Next, they should be excluded from error highlighting. I implemented both problemFileHighlightingFilter and problemHighlightingFilter and it did the trick. Do I actually need both and what's the difference?