Signature of a callback to be used to determine if a given presence status can be set on the connection.
Most users of this mixin do not need to supply an implementation of this callback: the value of
self is enough to determine whether this is a user-settable
presence, so null
should be passed to tp_presence_mixin_class_init
for this callback.
One place where this callback may be needed is on XMPP: not all server implementation support the user becoming invisible. So an XMPP
implementation would implement this function, so that—once connected—the hidden status is only available if the server supports it.
Before the connection is connected, this callback should return true
for every status that might possibly be supported: this
allows the user to at least try to sign in as invisible.
obj |
An instance of a BaseConnection subclass implementing the presence interface with this mixin |
which |
An index into the array of PresenceStatusSpec provided to |
|