How to modify tokens tree programmatically with BaseListener?

[yasamprom]

In my language I have TAB and UNTAB tokens (it is important like in Python). It is impossible to process TAB and UNTAB in grammar.g4 correctly so I need special class (I guess it is BaseListener) for processing TAB/UNTAB when I enter some rules.
How to make my BaseListener work in background? This class now is highlighted with grey color, it is not used. Where should I create it?

[parrt]

Do you mean's plugin's parse tree view or arbitrary antlr code altering parse tree? It's typically modified by constructing new parse tree or other from auto-generated tree.

[yasamprom]

Do you mean's plugin's parse tree view or arbitrary antlr code altering parse tree? It's typically modified by constructing new parse tree or other from auto-generated tree.

I guess I need ParseTreeView. My purpose is to add TAB and UNTUB in my PSI programmatically. And I want to do it in background, while user is typing characters. I didn't find examples how to do that

[parrt]

Hmm...ok, yeah, I'm afraid I just can't remember how all this works :( Sorry!
Ter

[l-Luna]

In my current project parsing Haskell, I found that actually letting IJ see the synthetic tokens caused issues with the consistency of the token stream (i.e. IJ complains a lot); instead I use a custom token stream that adds tokens just before the parser sees them, and then a modified tree converter that doesn't use up physical tokens on these fake tokens (alongside some other extensions that would be nice to upstream sometime).