build: Add option for compiling gnome-shell theme into gresource

Intended to help users who want to add Arc styling to GDM by
replacing the default gnome-shell-theme.gresource. Compiled
gresources are simply installed alongside the shell themes, and
it is up to users to make any use of them.

INSTALL.md

@@ -94,6 +94,7 @@ Option | Default value | Description
 `cinnamon_version` | - | Build Cinnamon theme for specific version
 `gnome_shell_version` | - | Build GNOME Shell theme for specific version
 `gtk3_version` | - | Build GTK 3 theme for specific version
+`gnome_shell_gresource` | `false` | Compile GNOME Shell theme into a gresource file
 
 #### Uninstallation
 

common/gnome-shell/meson.build

@@ -1,6 +1,11 @@
 # supported versions
 gnome_shell_versions = ['3.18', '3.20', '3.22', '3.24', '3.26', '3.28', '3.30', '3.32', '3.34', '3.36', '3.38', '40']
 
+# glib-compile-resources dependency
+if get_option('gnome_shell_gresource')
+  glib_compile_resources = find_program('glib-compile-resources')
+endif
+
 # gnome-shell version
 gnome_shell = find_program('gnome-shell', required : false)
 
@@ -33,7 +38,7 @@ if gnome_shell_ver not in gnome_shell_versions
   endif
 endif
 
-# compile and install
+# dependency files
 
 sass_depend_files = run_command(
   'find', '-L',
@@ -42,6 +47,26 @@ sass_depend_files = run_command(
   check : true
 ).stdout().split()
 
+if get_option('gnome_shell_gresource')
+  gresource_depend_files = []
+
+  gresource_depend_files += [
+    meson.current_source_dir() / gnome_shell_ver / 'pad-osd.css'
+  ]
+
+  gresource_depend_files += run_command(
+    'find', '-L',
+    meson.current_source_dir() / gnome_shell_ver / 'icons',
+    meson.current_source_dir() / gnome_shell_ver / 'common-assets',
+    meson.current_source_dir() / gnome_shell_ver / 'light-assets',
+    meson.current_source_dir() / gnome_shell_ver / 'dark-assets',
+    meson.current_source_dir() / gnome_shell_ver / 'lighter-assets',
+    check : true
+  ).stdout().split()
+endif
+
+# compile and install
+
 foreach variant : get_option('variants')
   if variant != 'darker'
     if not (variant == 'lighter' and gnome_shell_ver.version_compare('<=3.30'))
@@ -63,6 +88,28 @@ foreach variant : get_option('variants')
         depend_files : sass_depend_files
       )
 
+      if get_option('gnome_shell_gresource')
+        gresource_name = (variant == 'light' ? 'gnome-shell-theme' : 'gnome-shell-theme-' + variant)
+
+        gnome_shell_gresource = custom_target(
+        gresource_name + '-gresource',
+        input : meson.current_source_dir() / gnome_shell_ver / 'gresource' / gresource_name + '.gresource.xml',
+        output : gresource_name + '.gresource',
+        command : [
+          glib_compile_resources,
+          '--sourcedir=' + meson.current_source_dir() / gnome_shell_ver,
+          '--sourcedir=' + meson.current_build_dir(),
+          '--target=@OUTPUT@',
+          '@INPUT@'
+        ],
+        build_by_default : true,
+        install : true,
+        install_dir : prefix / install_dir.get(variant) / common_dirs.get('gnome-shell'),
+        depends : gnome_shell_css,
+        depend_files: gresource_depend_files
+      )
+      endif
+
       meson.add_install_script(
         'sh', '-c',
         'install -DT' + ' ' +

meson_options.txt

@@ -36,3 +36,10 @@ option(
   type: 'string',
   description: 'Build GTK 3 theme for specific version',
 )
+
+option(
+  'gnome_shell_gresource',
+  type: 'boolean',
+  value: false,
+  description: 'Compile GNOME Shell theme into a gresource file',
+)