gnu: Add emacs-theme-magic.

* gnu/packages/emacs-xyz.scm (emacs-theme-magic): New variable.

Signed-off-by: Nicolas Goaziou <mail@nicolasgoaziou.fr>

gnu/packages/emacs-xyz.scm

@@ -76,7 +76,7 @@
 ;;; Copyright © 2020 Fredrik Salomonsson <plattfot@gmail.com>
 ;;; Copyright © 2020 Ryan Desfosses <rdes@protonmail.com>
 ;;; Copyright © 2020 Eric Bavier <bavier@posteo.net>
-;;; Copyright © 2020 Morgan Smith <Morgan.J.Smith@outlook.com>
+;;; Copyright © 2020, 2021 Morgan Smith <Morgan.J.Smith@outlook.com>
 ;;; Copyright © 2020 Peng Mei Yu <i@pengmeiyu.com>
 ;;; Copyright © 2020 Niklas Eklund <niklas.eklund@posteo.net>
 ;;; Copyright © 2020 Marco Grassi <marco.au.grassi98@protonmail.com>
@@ -725,6 +725,50 @@ (define-public emacs-moody
 then only the color of the mode line changes when a window becomes in-/active.")
     (license license:gpl3+)))
 
+(define-public emacs-theme-magic
+  ;; No tagged release upstream, but the commit below correspond to the 0.2.3
+  ;; release.
+  (let ((commit "844c4311bd26ebafd4b6a1d72ddcc65d87f074e3")
+        (revision "0"))
+    (package
+      (name "emacs-theme-magic")
+      (version "0.2.3")
+      (source
+       (origin
+         (method git-fetch)
+         (uri (git-reference
+               (url "https://github.com/jcaw/theme-magic")
+               (commit commit)))
+         (file-name (git-file-name name version))
+         (sha256
+          (base32 "10gkg7jh1s1484gm66a87zr7x8vmv00s7gfd0w2pj47nqf98g8hz"))))
+      (build-system emacs-build-system)
+      (arguments
+       `(
+         ;; Include Pywal interaction scripts.
+         #:include (cons "^python/" %default-include)
+         #:phases
+         (modify-phases %standard-phases
+           (add-after 'unpack 'patch-exec-paths
+             (lambda* (#:key inputs #:allow-other-keys)
+               (let ((files '("theme-magic.el" "python/wal_change_colors.py"))
+                     (python (assoc-ref inputs "python"))
+                     (python-pywal (assoc-ref inputs "python-pywal")))
+                 (substitute* files
+                   (("\"python\"") (string-append "\"" python "/bin/python3\""))
+                   (("\"wal\"") (string-append "\"" python-pywal "/bin/wal\""))))
+               #t)))))
+      (inputs
+       `(("python" ,python)
+         ("python-pywal" ,python-pywal)))
+      (home-page "https://github.com/jcaw/theme-magic")
+      (synopsis "Generate and apply color palettes based on your Emacs theme")
+      (description
+       "This package provides a command to extract the colors from your Emacs
+theme and apply them to the rest of Linux with Pywal.  Pywal only applies your
+theme to the current session.")
+      (license license:gpl3+))))
+
 (define-public emacs-treepy
   (package
     (name "emacs-treepy")