gnu: Add t4k-common.

* gnu/packages/education.scm (t4k-common): New variable.

gnu/packages/education.scm

@@ -36,6 +36,7 @@
   #:use-module (gnu packages glib)
   #:use-module (gnu packages gnome)
   #:use-module (gnu packages gtk)
+  #:use-module (gnu packages image)
   #:use-module (gnu packages javascript)
   #:use-module (gnu packages kde)
   #:use-module (gnu packages kde-frameworks) ; extra-cmake-modules
@@ -713,3 +714,49 @@ each key.  A collection of lessons are included for a wide range of different
 languages and keyboard layouts, and typing statistics are used to dynamically
 adjust the level of difficulty.")
     (license license:gpl2)))
+
+(define-public t4k-common
+  (package
+    (name "t4k-common")
+    (version "0.1.1")
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/tux4kids/t4kcommon")
+             (commit (string-append "upstream/" version))))
+       (file-name (git-file-name name version))
+       (sha256
+        (base32 "13q02xpmps9qg8zrzzy2gzv4a6afgi28lxk4z242j780v0gphchp"))
+       (patches
+        (search-patches "t4k-common-libpng16.patch"))))
+    (build-system cmake-build-system)
+    (arguments
+     `(#:tests? #f                      ;FIXME: cannot find how to run tests
+       #:phases
+       (modify-phases %standard-phases
+         (add-after 'set-paths 'set-sdl-paths
+           (lambda* (#:key inputs #:allow-other-keys)
+             (setenv "CPATH" (string-append (assoc-ref inputs "sdl")
+                                            "/include/SDL:"
+                                            (or (getenv "CPATH") "")))))
+         (add-after 'unpack 'fix-andika-font-path
+           (lambda* (#:key inputs #:allow-other-keys)
+             (substitute* "src/t4k_sdl.c"
+               (("(/usr/share/.*?)/AndikaDesRevG\\.ttf")
+                (string-append (assoc-ref inputs "font-andika")
+                               "/share/fonts/truetype")))
+             #t)))))
+    (native-inputs
+     `(("pkg-config" ,pkg-config)))
+    (inputs
+     `(("font-andika" ,font-sil-andika)
+       ("libpng" ,libpng)
+       ("librsvg" ,librsvg)
+       ("libxml2" ,libxml2)
+       ("sdl" ,(sdl-union (list sdl sdl-image sdl-mixer sdl-net sdl-pango)))))
+    (home-page "https://github.com/tux4kids/t4kcommon")
+    (synopsis "Library of code shared between TuxMath and TuxType")
+    (description "Tux4Kids-Common is a library of code shared between
+TuxMath and TuxType.")
+    (license license:gpl3+)))