I am trying to figure out if there is a mod/add-on that will open/close new chat windows as I change zones/areas.

For example, I use a standalone chat window for Trade Channel. As a part of the Blizzard default UI, when I enter a city, the trade channel becomes active, and when I leave a city, the trade channel becomes inactive. HOWEVER, this means that whenever I'm not in a city, my "normally trade" chat window is simply a big black box occupying unnecessary space on my screen, that I have to manually change/alter/hide whenever I enter/leave a city.

So I'm looking for an add-on that will let me set trigger events (e.g., entering/leaving a zone, entering/leaving a party or raid group, entering/leaving an instance) that will spawn and despawn (or cause to hide and reappear) the entire window itself, with whatever channels I have configured that window to hold/manage.

Any suggestions?