Add support for reloading configuration in the main thread

docs/source/configuration.rst

@@ -168,7 +168,13 @@ Common configuration is a subdictionary that is a value of ``common`` key in
 
 ``interval``
     Number, determines time (in seconds) between checks for changed 
-    configuration. Use ``null`` to disable. Defaults to 10.
+    configuration. Checks are done in a seprate thread. Use ``null`` to check 
+    for configuration changes on ``.render()`` call in main thread.
+    Defaults to ``None``.
+
+``reload_config``
+    Boolean, determines whether configuration should be reloaded at all. 
+    Defaults to ``True``.
 
 Extension-specific configuration
 --------------------------------

powerline/__init__.py

@@ -121,6 +121,7 @@ class Powerline(object):
 		}
 		self.shutdown_event = shutdown_event or Event()
 		self.config_loader = config_loader or ConfigLoader(shutdown_event=self.shutdown_event)
+		self.run_loader_update = False
 
 		self.renderer_options = {}
 
@@ -191,9 +192,10 @@ class Powerline(object):
 					},
 				)
 
-				if not self.run_once:
-					interval = self.common_config.get('interval', 10)
+				if not self.run_once and self.common_config.get('reload_config', True):
+					interval = self.common_config.get('interval', None)
 					self.config_loader.set_interval(interval)
+					self.run_loader_update = (interval is None)
 					if interval is not None and not self.config_loader.is_alive():
 						self.config_loader.start()
 
@@ -347,6 +349,8 @@ class Powerline(object):
 
 	def update_renderer(self):
 		'''Updates/creates a renderer if needed.'''
+		if self.run_loader_update:
+			self.config_loader.update()
 		create_renderer_kwargs = None
 		with self.cr_kwargs_lock:
 			if self.create_renderer_kwargs:

powerline/lib/config.py

@@ -107,39 +107,41 @@ class ConfigLoader(MultiRunnedThread):
 			return self.loaded[path]
 		except KeyError:
 			r = self._load(path)
-			if self.interval is not None:
-				self.loaded[path] = r
+			self.loaded[path] = r
 			return r
 
+	def update(self):
+		toload = []
+		with self.lock:
+			for path, functions in self.watched.items():
+				for function in functions:
+					if self.watcher(path):
+						function(path)
+						toload.append(path)
+		with self.lock:
+			for key, functions in list(self.missing.items()):
+				remove = False
+				for condition_function, function in list(functions):
+					try:
+						path = condition_function(key)
+					except Exception as e:
+						self.exception('Error while running condition function for key {0}: {1}', key, str(e))
+					else:
+						if path:
+							toload.append(path)
+							function(path)
+							functions.remove((condition_function, function))
+				if not functions:
+					self.missing.pop(key)
+		for path in toload:
+			try:
+				self.loaded[path] = self._load(path)
+			except Exception as e:
+				self.exception('Error while loading {0}: {1}', path, str(e))
+
 	def run(self):
 		while self.interval is not None and not self.shutdown_event.is_set():
-			toload = []
-			with self.lock:
-				for path, functions in self.watched.items():
-					for function in functions:
-						if self.watcher(path):
-							function(path)
-							toload.append(path)
-			with self.lock:
-				for key, functions in list(self.missing.items()):
-					remove = False
-					for condition_function, function in list(functions):
-						try:
-							path = condition_function(key)
-						except Exception as e:
-							self.exception('Error while running condition function for key {0}: {1}', key, str(e))
-						else:
-							if path:
-								toload.append(path)
-								function(path)
-								functions.remove((condition_function, function))
-					if not functions:
-						self.missing.pop(key)
-			for path in toload:
-				try:
-					self.loaded[path] = self._load(path)
-				except Exception as e:
-					self.exception('Error while loading {0}: {1}', path, str(e))
+			self.update()
 			self.shutdown_event.wait(self.interval)
 
 	def exception(self, msg, *args, **kwargs):

powerline/lint/__init__.py

@@ -419,6 +419,7 @@ main_spec = (Spec(
 										lambda value: 'unknown debugging level {0}'.format(value)).optional(),
 		log_format=Spec().type(str).optional(),
 		interval=Spec().either(Spec().cmp('gt', 0.0), Spec().type(type(None))).optional(),
+		reload_config=Spec().type(bool).optional(),
 	).context_message('Error while loading common configuration (key {key})'),
 	ext=Spec(
 		vim=Spec(

tests/test_config_reload.py

@@ -242,6 +242,20 @@ class TestConfigReload(TestCase):
 				self.assertEqual(p.logger._pop_msgs(), [])
 		pop_events()
 
+	def test_reload_theme_main(self):
+		with replace_item(globals(), 'config', deepcopy(config)):
+			config['config']['common']['interval'] = None
+			with get_powerline(run_once=False) as p:
+				self.assertEqual(p.render(), '<1 2 1> s<2 4 False>>><3 4 4>g<4 False False>>><None None None>')
+				self.assertAccessEvents('config', 'colors', 'colorschemes/test/default', 'themes/test/default')
+
+				config['themes/test/default']['segments']['left'][0]['contents'] = 'col3'
+				add_watcher_events(p, 'themes/test/default', wait=False)
+				self.assertEqual(p.render(), '<1 2 1> col3<2 4 False>>><3 4 4>g<4 False False>>><None None None>')
+				self.assertAccessEvents('themes/test/default')
+				self.assertEqual(p.logger._pop_msgs(), [])
+		pop_events()
+
 
 replaces = {}