Add support for full powerline reloading at runtime

Is not guaranteed to work in all cases.

powerline/__init__.py

@@ -336,7 +336,11 @@ class Powerline(object):
 		Instance of the class that manages (re)loading of the configuration.
 	'''
 
-	def __init__(self,
+	def __init__(self, *args, **kwargs):
+		self.init_args = (args, kwargs)
+		self.init(*args, **kwargs)
+
+	def init(self,
 	         ext,
 	         renderer_module=None,
 	         run_once=False,
@@ -344,6 +348,10 @@ class Powerline(object):
 	         use_daemon_threads=True,
 	         shutdown_event=None,
 	         config_loader=None):
+		'''Do actual initialization.
+		
+		__init__ function only stores the arguments.
+		'''
 		self.ext = ext
 		self.run_once = run_once
 		self.logger = logger
@@ -732,10 +740,42 @@ class Powerline(object):
 	def setup(self, *args, **kwargs):
 		'''Setup the environment to use powerline.
 
-		To be overridden by subclasses, this one only saves args and kwargs.
+		To be overridden by subclasses, this one only saves args and kwargs and 
+		unsets shutdown_event.
 		'''
+		self.shutdown_event.clear()
 		self.setup_args = (args, kwargs)
 
+	def reload(self):
+		'''Reload powerline after update.
+
+		Should handle most (but not all) powerline updates.
+
+		Purges out all powerline modules and modules imported by powerline for 
+		segment and matcher functions. Requires defining ``setup`` function that 
+		updates reference to main powerline object.
+
+		.. warning::
+			Not guaranteed to work properly, use it at your own risk. It 
+			may break your python code.
+		'''
+		from imp import reload
+		modules = self.imported_modules | set((module for module in sys.modules if module.startswith('powerline')))
+		modules_holder = []
+		for module in modules:
+			try:
+				# Needs to hold module to prevent garbage collecting until they 
+				# are all reloaded.
+				modules_holder.append(sys.modules.pop(module))
+			except KeyError:
+				pass
+		PowerlineClass = getattr(__import__(self.__module__, fromlist=(self.__class__.__name__,)), self.__class__.__name__)
+		self.shutdown(set_event=True)
+		init_args, init_kwargs = self.init_args
+		powerline = PowerlineClass(*init_args, **init_kwargs)
+		setup_args, setup_kwargs = self.setup_args
+		powerline.setup(*setup_args, **setup_kwargs)
+
 	def shutdown(self, set_event=True):
 		'''Shut down all background threads.
 

powerline/bindings/ipython/post_0_11.py

@@ -43,12 +43,12 @@ class PowerlinePromptManager(PromptManager):
 
 
 class ConfigurableIpythonPowerline(IpythonPowerline):
-	def __init__(self, ip, is_prompt, old_widths):
+	def init(self, ip, is_prompt, old_widths):
 		config = ip.config.Powerline
 		self.config_overrides = config.get('config_overrides')
 		self.theme_overrides = config.get('theme_overrides', {})
 		self.paths = config.get('paths')
-		super(ConfigurableIpythonPowerline, self).__init__(is_prompt, old_widths)
+		super(ConfigurableIpythonPowerline, self).init(is_prompt, old_widths)
 
 
 old_prompt_manager = None

powerline/bindings/ipython/pre_0_11.py

@@ -86,11 +86,11 @@ class PowerlinePrompt2(PowerlinePromptOut):
 
 
 class ConfigurableIpythonPowerline(IpythonPowerline):
-	def __init__(self, is_prompt, old_widths, config_overrides=None, theme_overrides={}, paths=None):
+	def init(self, is_prompt, old_widths, config_overrides=None, theme_overrides={}, paths=None):
 		self.config_overrides = config_overrides
 		self.theme_overrides = theme_overrides
 		self.paths = paths
-		super(ConfigurableIpythonPowerline, self).__init__(is_prompt, old_widths)
+		super(ConfigurableIpythonPowerline, self).init(is_prompt, old_widths)
 
 
 def setup(**kwargs):

powerline/ipython.py

@@ -23,8 +23,8 @@ class RewriteResult(object):
 
 
 class IpythonPowerline(Powerline):
-	def __init__(self, is_prompt, old_widths):
-		super(IpythonPowerline, self).__init__(
+	def init(self, is_prompt, old_widths):
+		super(IpythonPowerline, self).init(
 			'ipython',
 			renderer_module=('.prompt' if is_prompt else None),
 			use_daemon_threads=True

powerline/shell.py

@@ -14,10 +14,10 @@ def mergeargs(argvalue):
 
 
 class ShellPowerline(Powerline):
-	def __init__(self, args, **kwargs):
+	def init(self, args, **kwargs):
 		self.args = args
 		self.theme_option = args.theme_option
-		super(ShellPowerline, self).__init__(args.ext[0], args.renderer_module, **kwargs)
+		super(ShellPowerline, self).init(args.ext[0], args.renderer_module, **kwargs)
 
 	def load_main_config(self):
 		r = super(ShellPowerline, self).load_main_config()

powerline/vim.py

@@ -23,8 +23,8 @@ def _override_from(config, override_varname):
 
 
 class VimPowerline(Powerline):
-	def __init__(self, pyeval='PowerlinePyeval', **kwargs):
-		super(VimPowerline, self).__init__('vim', **kwargs)
+	def init(self, pyeval='PowerlinePyeval', **kwargs):
+		super(VimPowerline, self).init('vim', **kwargs)
 		self.last_window_id = 1
 		self.pyeval = pyeval
 		self.window_statusline = '%!' + pyeval + '(\'powerline.statusline({0})\')'