Re: Making a phone call with GNOME

[Simon McVittie <smcv collabora com>]

On Mon, 19 Mar 2018 at 12:18:30 +0000, Bob Ham wrote:
> On 15/03/18 19:13, Simon McVittie wrote:
> > the hard division between one-to-one
> > messages and chatrooms in XMPP is unlike the variable-number-of-users
> > "switchboards" in the now-defunct MSNP.)
>
> Out of interest, does Telepathy expose that difference?  To me, that
> kind of distinction seems like an implementation detail that I would
> expect to be abstracted away.

Yes, Telepathy exposes that difference, because it matters. You can't[1]
have an XMPP conversation with two peers without joining a (named)
chatroom. Even if *you* send every message to both of those peers,
their clients won't know that they should send replies to both you and
the other peer.

In contrast, on MSNP, you could start a two-party conversation and later
decide to invite a third person. A high-quality client would provide
UI for this (I think Empathy does, or did); and even if your UI doesn't
expose a menu option for that, it still needs to be able to deal with
the other party inviting a third person, and indicate to you that your
messages are now going to them as well.

There's no way we could have designed this correctly in Telepathy without
being aware of protocol quirks like these, and indeed this API wasn't
present in our first attempts (initially we could only represent
one-to-one conversations and named chatrooms, like in XMPP and IRC).

    smcv

[1] using baseline XMPP without uncommon extensions that, in practice,
    result in creating an XMPP MUC chatroom with a meaningless
    machine-generated name (which a high-quality UX should hide from
    the user because it means nothing to them)