Le 14/03/2018 à 09:44, Arnt Gulbrandsen a écrit :
> Didier Kryn writes:
>>     You're certainly right: it isn't simple. But it's essential,
>> isn't it?. Graphics printing reached the personnal computer probably
>> with the first McIntosh, in 1982. <rant>Not sure it's more
>> feature-rich today than 10 years ago, when it wasn't depending on
>> dbus.</rant>
>
> I wrote a printer driver back then. It used user-bus. "Tell me, dear
> user, whether the printer has and supports. A4 or funny american
> paper? Duplex?"
>
> If I were more ambitious I'd have asked more complicated questions.
> For example, if you want to avoid printer firmware bugs it's generally
> smart to send a large bitmap, but if you aim for high quality output
> and a high page rate, you want to avoid sending bitmaps. Can't ask
> users about such tradeoffs, they will be annoyed and won't be able to
> answer. These days you can ask the printer via d-bus. The printer
> knows more about itself than its users know about it.

    Dear Florian, I agree with you that it is nice to enable the
software to ask the devices what their properties are, by some protocol.
This is nice for the dummy/lazzy user we are all up to some point.

    But here, the device is connected through the network; therefore it
cannot communicate through dbus. Dbus is used between two pieces of
software running on the system and there are simpler alternatives to
this method.

        Didier