[gtk/dist-css] dist: Add a dist script to generate css

[Matthias Clasen <matthiasc src gnome org>]

commit 13ef82fc4d9a245e9e925f8c86b598d62cfd1954
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jan 12 08:18:47 2021 -0500

    dist: Add a dist script to generate css
    
    When I added the sassc option, I failed to ensure that
    the theme css is included in the tarballs. This is required
    to make tarball builds with -Dsassc=disabled work.

 build-aux/meson/dist-theme.py | 19 +++++++++++++++++++
 meson.build                   |  2 ++
 2 files changed, 21 insertions(+)
---
diff --git a/build-aux/meson/dist-theme.py b/build-aux/meson/dist-theme.py
new file mode 100644
index 0000000000..1582057113
--- /dev/null
+++ b/build-aux/meson/dist-theme.py
@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+
+import os
+from pathlib import PurePath
+import subprocess
+
+stylesheets = [ 'gtk/theme/Adwaita/Adwaita.css',
+                'gtk/theme/Adwaita/Adwaita-dark.css',
+                'gtk/theme/HighContrast/HighContrast.css',
+                'gtk/theme/HighContrast/HighContrast-inverse.css' ]
+
+sourceroot = os.environ.get('MESON_SOURCE_ROOT')
+distroot = os.environ.get('MESON_DIST_ROOT')
+
+for stylesheet in stylesheets:
+  stylesheet_path = PurePath(stylesheet)
+  src = PurePath(sourceroot, stylesheet_path.with_suffix('.scss'))
+  dst = PurePath(distroot, stylesheet_path)
+  subprocess.call(['sassc', '-a', '-M', '-t', 'compact', src, dst])
diff --git a/meson.build b/meson.build
index 9fe9cd5acf..3edb716efc 100644
--- a/meson.build
+++ b/meson.build
@@ -803,6 +803,8 @@ else
   message('Not executing post-install steps automatically when cross compiling')
 endif
 
+meson.add_dist_script('build-aux/meson/dist-theme.py')
+
 if host_machine.system() != 'windows'
   # Install Valgrind suppression files (except on Windows,
   # as Valgrind is currently not supported on Windows)