##(see the SpecSpec for an explanation)

 * '''Launchpad Entry''': UbuntuSpec:jockey-printer-driver-support
 * '''Created''': 2008-06-05
 * '''Contributors''': Till Kamppeter, Martin Pitt
 * '''Packages affected''': jockey

== Summary ==

Instead of reimplementing a lot of Jockey's purpose/already existing
features in system-config-printer, we will make Jockey more generic to
also work for printer drivers.

Jockey will be able to look for available LSB-package drivers on
[[http://www.linuxfoundation.org/en/OpenPrinting|OpenPrinting.org]], and
expose its services through a generic D-BUS API for requesting and
querying device drivers. This API can then be used by
system-config-printer and possibly other components of the desktop.

== Release Note ==

TODO when spec is nearing beta.

== Rationale ==

We can only ship a limited number of printer drivers by default, for
CD size reasons, and also because new printer models are constantly
appearing on the market which need drivers which were not yet
available at the time of the Ubuntu release.

From the UI and workflow perspective, a printer driver is not much
different from a kernel driver. Jockey and its planned online driver
DB support is an ideal place to integrate support for printer drivers.

== Use Cases ==

 * Jane has a home computer, at which  she enabled the checkbox for
 "check for unsupported community drivers". The other day she
 returns home with a shiny new $99 printer and plugs it in.
 `system-config-printer` picks it up, but does not find an available
 driver. In 8.04 nothing happens now. In Intrepid she gets the offer
 to install a driver from openprinting.org, and a note that it is free
 (thus unproblematic to try out). She clicks on "Enable", from then on
 she can use her printer without further fuss.

== Assumptions ==

This specification relies on the implementation of
UbuntuSpec:printerdriverautodownload, in particular that
openprinting.org will provide Debian-style package repositories.

== Design ==

=== Printer detection ===

A printer is identified by stating its "IEEE-1284 device ID" (which,
despite the name, is also available for USB and network printers).
Printers generally return it as identification.

=== openprinting.org query ===

[[http://www.linuxfoundation.org/en/OpenPrinting|OpenPrinting.org]]
already has a [[http://www.linuxfoundation.org/en/OpenPrinting/Database/Query|web query protocol]].
A new subclass of Jockey's `DriverDB` interface will
be written which talks to that printer database to find out about
available drivers for a given printer device ID.

=== D-BUS interface ===

Add a session D-BUS function for requesting a driver, identified by driver type
(`printer-id`, or the already supported `modalias` for kernel modules)
and the printer device ID. Jockey will check all available DriverDBs
as usual and offer to install it if one is found.

It needs to be on the session bus, because Jockey needs to
interactively present some driver details (license, description,
confirmation). Jockey already has a built-in gksu support (this will
eventually be fixed with a system D-BUS interface, but this is outside
the range of this spec).

While being at it, the D-BUS interface will also get methods for
getting a list of locally installed hardware, all available drivers,
and for enabling/disabling a particular driver.

== Implementation ==

=== Printer detection ===

`lpinfo -l -v` returns a list of locally connected printers and their
device IDs, for example:

 {{{
 Device: uri = usb://Samsung/ML-1610
     class = direct
     info = Samsung ML-1610 USB #1
     make-and-model = Samsung ML-1610
     device-id = MFG:Samsung;CMD:GDI;MDL:ML-1610;CLS:PRINTER;MODE:GDI;STATUS:IDLE;@
}}}

=== D-BUS interface ===

=== UI Changes ===

 * Display freeness of a driver in the UI, and provide a button to
 read the entire license if it is not free.

== Test/Demo Plan ==

TODO when spec is nearing beta.
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CategorySpec