gnu: Add and use sane-backends.

* gnu/packages/scanner.scm (sane-backends): New variable.
* gnu/packages/gnome.scm (colord, simple-scan): Use it instead of
'sane-backends-minimal'.
* gnu/packages/libreoffice.scm (libreoffice): Likewise.
* gnu/packages/wine.scm (wine): Likewise.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/gnome.scm

@@ -2433,7 +2433,7 @@ keyboard shortcuts.")
        ("libusb" ,libusb)
        ("sqlite" ,sqlite)
        ("polkit" ,polkit)
-       ("sane-backends" ,sane-backends-minimal)))
+       ("sane-backends" ,sane-backends)))
     (home-page "http://www.freedesktop.org/software/colord/")
     (synopsis "Color management service")
     (description "Colord is a system service that makes it easy to manage,
@@ -3570,7 +3570,7 @@ USB transfers with your high-level application or system daemon.")
        ("cairo" ,cairo)
        ("gdk-pixbuf" ,gdk-pixbuf)
        ("gusb" ,gusb)
-       ("libsane" ,sane-backends-minimal)))
+       ("libsane" ,sane-backends)))
     (native-inputs
      `(("gettext" ,gettext-minimal)
        ("itstool" ,itstool)

gnu/packages/libreoffice.scm

@@ -784,7 +784,7 @@ and to return information on pronunciations, meanings and synonyms.")
        ("postgresql" ,postgresql)
        ("python" ,python)
        ("redland" ,redland)
-       ("sane-backends" ,sane-backends-minimal)
+       ("sane-backends" ,sane-backends)
        ("unixodbc" ,unixodbc)
        ("unzip" ,unzip)
        ("vigra" ,vigra)

gnu/packages/scanner.scm

@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2014 John Darrington <jmd@gnu.org>
 ;;; Copyright © 2015 Andy Wingo <wingo@igalia.com>
+;;; Copyright © 2016 Andy Patterson <ajpatter@uwaterloo.ca>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -20,6 +21,7 @@
 (define-module (gnu packages scanner)
   #:use-module (guix packages)
   #:use-module (guix download)
+  #:use-module (guix utils)
   #:use-module (guix build-system gnu)
   #:use-module (gnu packages pkg-config)
   #:use-module (gnu packages libusb)
@@ -78,3 +80,41 @@ proving access to any raster image scanner hardware (flatbed scanner,
 hand-held scanner, video- and still-cameras, frame-grabbers, etc.).  The
 package contains the library, but no drivers.")
     (license licence:gpl2+))) ; plus linking exception
+
+;; This variant links in the hpaio backend, provided by hplip, which adds
+;; support for HP scanners whose backends are not maintained by
+;; 'sane-backends'. It also builds all of those backends.
+(define-public sane-backends
+  (package
+    (inherit sane-backends-minimal)
+    (name "sane-backends")
+    (inputs
+     `(("hplip" ,(@ (gnu packages cups) hplip))
+       ,@(package-inputs sane-backends-minimal)))
+    (arguments
+     (substitute-keyword-arguments (package-arguments sane-backends-minimal)
+       ((#:phases phases)
+        `(modify-phases ,phases
+           (delete 'disable-backends)
+           (add-after 'unpack 'add-backends
+             (lambda _
+               (substitute* "backend/dll.conf.in"
+                 (("hp5590" all) (format #f "~a~%~a" all "hpaio")))
+               #t))
+           (add-after 'install 'install-hpaio
+             (lambda* (#:key inputs outputs #:allow-other-keys)
+               (define hplip (string-append (assoc-ref inputs "hplip")
+                                            "/lib/sane"))
+               (define out (string-append (assoc-ref outputs "out")
+                                          "/lib/sane"))
+               (for-each
+                (lambda (file)
+                  (symlink file (string-append out "/" (basename file))))
+                (find-files hplip))
+               #t))))))
+    (synopsis
+     "Raster image scanner library and drivers, with scanner support")
+    (description "SANE stands for \"Scanner Access Now Easy\" and is an API
+proving access to any raster image scanner hardware (flatbed scanner,
+hand-held scanner, video- and still-cameras, frame-grabbers, etc.).  The
+package contains the library and drivers.")))

gnu/packages/wine.scm

@@ -83,7 +83,7 @@
        ("libmpg123" ,mpg123)
        ("libldap" ,openldap)
        ("libnetapi" ,samba)
-       ("libsane" ,sane-backends-minimal)
+       ("libsane" ,sane-backends)
        ("libpng" ,libpng)
        ("libjpeg" ,libjpeg)
        ("libtiff" ,libtiff)