[gnome-tweaks] appearance: Search for themes and icons in system data dirs

[Jeremy Bicha <jbicha src gnome org>]

commit 878b4c0db6b5a53c70f6844eb258d5ec48dd859c
Author: Jascha Geerds <jascha jgeerds name>
Date:   Sun Dec 17 09:35:09 2017 +0100

    appearance: Search for themes and icons in system data dirs
    
    https://gitlab.gnome.org/GNOME/gnome-tweaks/issues/114

 gtweak/tweaks/tweak_group_appearance.py | 17 ++++-------------
 gtweak/utils.py                         | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 13 deletions(-)
---
diff --git a/gtweak/tweaks/tweak_group_appearance.py b/gtweak/tweaks/tweak_group_appearance.py
index 8227089..db3fbd1 100644
--- a/gtweak/tweaks/tweak_group_appearance.py
+++ b/gtweak/tweaks/tweak_group_appearance.py
@@ -13,7 +13,7 @@ from gi.repository import Gtk
 from gi.repository import GLib
 
 import gtweak
-from gtweak.utils import walk_directories, make_combo_list_with_default, extract_zip_file
+from gtweak.utils import walk_directories, make_combo_list_with_default, extract_zip_file, get_resource_dirs
 from gtweak.tweakmodel import Tweak
 from gtweak.gshellwrapper import GnomeShellFactory
 from gtweak.gsettings import GSettingsSetting
@@ -41,11 +41,8 @@ class GtkThemeSwitcher(GSettingsComboTweak):
         if gtk_ver % 2: # Want even number
             gtk_ver += 1
 
-        dirs = ( os.path.join(gtweak.DATA_DIR, "themes"),
-                 os.path.join(GLib.get_user_data_dir(), "themes"),
-                 os.path.join(os.path.expanduser("~"), ".themes"))
         valid = ['Adwaita', 'HighContrast', 'HighContrastInverse']
-        valid += walk_directories(dirs, lambda d:
+        valid += walk_directories(get_resource_dirs("themes"), lambda d:
                     os.path.exists(os.path.join(d, "gtk-3.0", "gtk.css")) or \
                          os.path.exists(os.path.join(d, "gtk-3.{}".format(gtk_ver))))
         return set(valid)
@@ -76,10 +73,7 @@ class IconThemeSwitcher(GSettingsComboTweak):
             **options)
 
     def _get_valid_icon_themes(self):
-        dirs = ( os.path.join(gtweak.DATA_DIR, "icons"),
-                 os.path.join(GLib.get_user_data_dir(), "icons"),
-                 os.path.join(os.path.expanduser("~"), ".icons"))
-        valid = walk_directories(dirs, lambda d:
+        valid = walk_directories(get_resource_dirs("icons"), lambda d:
                     os.path.isdir(d) and \
                        os.path.exists(os.path.join(d, "index.theme")))
         return set(valid)
@@ -94,10 +88,7 @@ class CursorThemeSwitcher(GSettingsComboTweak):
             **options)
 
     def _get_valid_cursor_themes(self):
-        dirs = ( os.path.join(gtweak.DATA_DIR, "icons"),
-                 os.path.join(GLib.get_user_data_dir(), "icons"),
-                 os.path.join(os.path.expanduser("~"), ".icons"))
-        valid = walk_directories(dirs, lambda d:
+        valid = walk_directories(get_resource_dirs("icons"), lambda d:
                     os.path.isdir(d) and \
                         os.path.exists(os.path.join(d, "cursors")))
         return set(valid)
diff --git a/gtweak/utils.py b/gtweak/utils.py
index 2f2ebf2..6f0c25c 100644
--- a/gtweak/utils.py
+++ b/gtweak/utils.py
@@ -8,6 +8,7 @@ import tempfile
 import shutil
 import subprocess
 import glob
+import itertools
 
 import gtweak
 from gtweak.gsettings import GSettingsSetting
@@ -104,6 +105,22 @@ def execute_subprocess(cmd_then_args, block=True):
         stdout, stderr = p.communicate()
         return stdout, stderr, p.returncode
 
+def get_resource_dirs(resource):
+    """Returns a list of all known resource dirs for a given resource.
+
+    :param str resource:
+        Name of the resource (e.g. "themes")
+    :return:
+        A list of resource dirs
+    """
+    dirs = [os.path.join(dir, resource)
+            for dir in itertools.chain(GLib.get_system_data_dirs(),
+                                       (gtweak.DATA_DIR,
+                                        GLib.get_user_data_dir()))]
+    dirs += [os.path.join(os.path.expanduser("~"), ".{}".format(resource))]
+
+    return [dir for dir in dirs if os.path.isdir(dir)]
+
 @singleton
 class AutostartManager: