onChannel:

openAsMorph

openView

refreshUserList

update the user list from the channel

selectedUser

return the name of the selected user, or nil if none

talkTo

open a window for talking to the selected user

update:

Receive a change notice from an object of whom the receiver is a
dependent. The default behavior is to do nothing; a subclass might want
to change itself in some way.

userIndex

return the index in userList of the user currently selected

userIndex:

change which user is selected

userList

return the current list of user names