How To Limit Chat area (Have A Plugin like This?)

I don't know how to Limit Chat Area
like This:
If a player Chat in a place (20-25 Block), He talk with Someone.. So He needs to get close to the other person about 20 to 25 blocks
and If He get Open to the Other people and He will not Listen and Talk with other people :/

 

You can try to Check if a player Is in the radius of the user who sends the Message. If Yes, the Message will send, of not no Message will send.

 

yes, And Ummm I need Do it with PlayerChatEvent?

 

Yes.