[core/theme] Add iconset support

Allow themes to specify iconsets. To do so, add a new util library
"util.algorithm", which currently contains support for deep merging of
dicts.

core/theme.py

@@ -3,6 +3,7 @@ import io
 import json
 
 import core.event
+import util.algorithm
 
 THEME_BASE_DIR=os.path.dirname(os.path.realpath(__file__))
 PATHS=[
@@ -19,6 +20,11 @@ class Theme(object):
             self.__data = raw_data
         else:
             self.__data = self.load(name)
+            for icons in self.__data['icons']:
+                util.algorithm.merge(self.__data, self.load(icons, 'icons'))
+            if iconset:
+                util.algorithm.merge(self.__data, iconset)
+
         core.event.register('update', self.__start)
         core.event.register('next-widget', self.__next_widget)
 
@@ -34,9 +40,9 @@ class Theme(object):
         ]:
             setattr(self, attr.replace('-', '_'), lambda widget=None, default=default, attr=attr: self.__get(widget, attr, default))
 
-    def load(self, name):
+    def load(self, name, subdir=''):
         for path in PATHS:
-            theme_file = os.path.join(path, '{}.json'.format(name))
+            theme_file = os.path.join(path, subdir, '{}.json'.format(name))
             if os.path.isfile(theme_file):
                 with io.open(theme_file, encoding='utf-8') as data:
                     return json.load(data)

tests/util/test_algorithm.py

@@ -0,0 +1,40 @@
+import unittest
+
+from util.algorithm import *
+
+class algorithm(unittest.TestCase):
+    def setUp(self):
+        self.someData = {'a': 100, 'b': 200, 'c': [1,2,3]}
+        self.differentData = {'x': 20, 'y': 'bla', 'z': ['a','b']}
+        self.moreData = {'n': 100}
+        self.overlapData = {'a': 200, 'c': [1,2,4]}
+
+    def test_merge_with_empty(self):
+        self.assertEqual(self.someData, merge(self.someData, {}))
+        self.assertEqual(None, merge(self.someData, None))
+
+    def test_merge_no_overwrite(self):
+        result = merge(self.someData, self.differentData)
+        for k in self.someData:
+            self.assertEqual(result[k], self.someData[k])
+        for k in self.differentData:
+            self.assertEqual(result[k], self.differentData[k])
+
+    def test_merge_multiple(self):
+        result = merge(self.someData, self.differentData, self.moreData)
+        for k in self.someData:
+            self.assertEqual(result[k], self.someData[k])
+        for k in self.differentData:
+            self.assertEqual(result[k], self.differentData[k])
+        for k in self.moreData:
+            self.assertEqual(result[k], self.moreData[k])
+
+    def merge_overlap(self):
+        result = merge(self.someData, self.overlapData)
+        for k in self.someData:
+            if not k in self.overlapData:
+                self.assertEqual(result[k], self.someData[k])
+        for k in self.overlapData:
+            self.assertEqual(result[k], self.overlapData[k])
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

util/algorithm.py

@@ -0,0 +1,23 @@
+import copy
+
+# algorithm copied from
+# http://blog.impressiver.com/post/31434674390/deep-merge-multiple-python-dicts
+# nicely done :)
+def merge(target, *args):
+    if len(args) > 1:
+        for item in args:
+            merge(target, item)
+        return target
+
+    item = args[0]
+    if not isinstance(item, dict):
+        return item
+    for key, value in item.items():
+        if key in target and isinstance(target[key], dict):
+            merge(target[key], value)
+        else:
+            if not key in target:
+                target[key] = copy.deepcopy(value)
+    return target
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4