Detect Intellij file modifications realtime?

Question

I am writing a plugin for intellij idea.

How do I detect Intellij or Android stdio file modifications realtime?

Solution 1： BulkFileListener

But it works after pressing Ctrl+S. When a character was added or deleted without Ctrl+s, it cannot report this event.

Solution 2： TypedActionHandler

But it only works for adding characters. When a character or a line was deleted, it cannot report this event.

Solution 3： Inspection

May be feasible, but how to do ?

Solutions 1 and 2 are not what I want.

Any other advice?