Refactor powerline.lint.inspect: do not special-case *ThreadedSegment

Fixes now_playing segment handling in python-3.4

powerline/lib/threaded.py

@@ -2,9 +2,11 @@
 
 from __future__ import absolute_import
 
-from powerline.lib.monotonic import monotonic
-
 from threading import Thread, Lock, Event
+from types import MethodType
+
+from powerline.lib.monotonic import monotonic
+from powerline.segments import Segment
 
 
 class MultiRunnedThread(object):
@@ -28,12 +30,14 @@ class MultiRunnedThread(object):
 		return None
 
 
-class ThreadedSegment(MultiRunnedThread):
+class ThreadedSegment(Segment, MultiRunnedThread):
 	min_sleep_time = 0.1
 	update_first = True
 	interval = 1
 	daemon = False
 
+	argmethods = ('render', 'set_state')
+
 	def __init__(self):
 		super(ThreadedSegment, self).__init__()
 		self.run_once = True
@@ -145,10 +149,34 @@ class ThreadedSegment(MultiRunnedThread):
 	def debug(self, *args, **kwargs):
 		self.pl.debug(prefix=self.__class__.__name__, *args, **kwargs)
 
+	def argspecobjs(self):
+		for name in self.argmethods:
+			try:
+				yield name, getattr(self, name)
+			except AttributeError:
+				pass
+
+	def additional_args(self):
+		return (('interval', self.interval),)
+
+	def omitted_args(self, name, method):
+		if isinstance(getattr(self, name, None), MethodType):
+			omitted_indexes = (0,)
+		else:
+			omitted_indexes = ()
+		if name.startswith('render'):
+			if omitted_indexes:
+				omitted_indexes += (1,)
+			else:
+				omitted_indexes = (0,)
+		return omitted_indexes
+
 
 class KwThreadedSegment(ThreadedSegment):
 	update_first = True
 
+	argmethods = ('render', 'set_state', 'key', 'render_one')
+
 	def __init__(self):
 		super(KwThreadedSegment, self).__init__()
 		self.updated = True

powerline/lint/inspect.py

@@ -1,72 +1,63 @@
 # vim:fileencoding=utf-8:noet
 from __future__ import absolute_import
+
 from inspect import ArgSpec, getargspec
-from powerline.lib.threaded import ThreadedSegment, KwThreadedSegment
 from itertools import count
 
+from powerline.lib.threaded import ThreadedSegment, KwThreadedSegment
+from powerline.segments import Segment
+
 
 def getconfigargspec(obj):
-	if isinstance(obj, ThreadedSegment):
-		args = ['interval']
-		defaults = [getattr(obj, 'interval', 1)]
-		if obj.update_first:
-			args.append('update_first')
-			defaults.append(True)
-		methods = ['render', 'set_state']
-		if isinstance(obj, KwThreadedSegment):
-			methods += ['key', 'render_one']
-
-		for method in methods:
-			if hasattr(obj, method):
-				# Note: on <python-2.6 it may return simple tuple, not 
-				# ArgSpec instance.
-				argspec = getargspec(getattr(obj, method))
-				for i, arg in zip(count(1), reversed(argspec.args)):
-					if (arg == 'self' or
-							(arg == 'segment_info' and
-								getattr(obj, 'powerline_requires_segment_info', None)) or
-							(arg == 'create_watcher' and
-								getattr(obj, 'powerline_requires_filesystem_watcher', None)) or
-							(arg == 'pl') or
-							(method.startswith('render') and (1 if argspec.args[0] == 'self' else 0) + i == len(argspec.args)) or
-							arg in args):
-						continue
-					if argspec.defaults and len(argspec.defaults) >= i:
-						default = argspec.defaults[-i]
-						defaults.append(default)
-						args.append(arg)
-					else:
-						args.insert(0, arg)
-		argspec = ArgSpec(args=args, varargs=None, keywords=None, defaults=tuple(defaults))
+	if hasattr(obj, 'powerline_origin'):
+		obj = obj.powerline_origin
 	else:
-		if hasattr(obj, 'powerline_origin'):
-			obj = obj.powerline_origin
-		else:
-			obj = obj
+		obj = obj
 
-		remove_self = False
-		try:
-			argspec = getargspec(obj)
-		except TypeError:  # Workaround for now_playing segment
-			# TODO For NowPlayingSegment for linter: merge in information about 
-			# player-specific arguments
-			argspec = getargspec(obj.__call__)
-			remove_self = True
-		args = []
-		defaults = []
-		for i, arg in zip(count(1), reversed(argspec.args)):
+	args = []
+	defaults = []
+
+	if isinstance(obj, Segment):
+		additional_args = obj.additional_args()
+		argspecobjs = obj.argspecobjs()
+		get_omitted_args = obj.omitted_args
+	else:
+		additional_args = ()
+		argspecobjs = ((None, obj),)
+		get_omitted_args = lambda *args: ()
+
+	for arg in additional_args:
+		args.append(arg[0])
+		if len(arg) > 1:
+			defaults.append(arg[1])
+
+	requires_segment_info = getattr(obj, 'powerline_requires_segment_info', False)
+	requires_filesystem_watcher = getattr(obj, 'powerline_requires_filesystem_watcher', False)
+
+	for name, method in argspecobjs:
+		argspec = getargspec(method)
+		omitted_args = get_omitted_args(name, method)
+		largs = len(argspec.args)
+		for i, arg in enumerate(reversed(argspec.args)):
 			if (
-				(arg == 'segment_info' and getattr(obj, 'powerline_requires_segment_info', None))
+				largs - (i + 1) in omitted_args
 				or arg == 'pl'
-				or (arg == 'self' and remove_self)
+				or (arg == 'create_watcher' and requires_filesystem_watcher)
+				or (arg == 'segment_info' and requires_segment_info)
 			):
 				continue
-			if argspec.defaults and len(argspec.defaults) >= i:
-				default = argspec.defaults[-i]
+			if argspec.defaults and len(argspec.defaults) > i:
+				if arg in args:
+					idx = args.index(arg)
+					if len(args) - idx > len(defaults):
+						args.pop(idx)
+					else:
+						continue
+				default = argspec.defaults[-(i + 1)]
 				defaults.append(default)
 				args.append(arg)
 			else:
-				args.insert(0, arg)
-		argspec = ArgSpec(args=args, varargs=argspec.varargs, keywords=argspec.keywords, defaults=tuple(defaults))
+				if arg not in args:
+					args.insert(0, arg)
 
-	return argspec
+	return ArgSpec(args=args, varargs=None, keywords=None, defaults=tuple(defaults))

powerline/segment.py

@@ -1,10 +1,10 @@
 # vim:fileencoding=utf-8:noet
-
 from __future__ import absolute_import, unicode_literals, division, print_function
 
-from powerline.lib.file_watcher import create_file_watcher
 import sys
 
+from powerline.lib.file_watcher import create_file_watcher
+
 
 def list_segment_key_values(segment, theme_configs, key, module=None, default=None):
 	try:

powerline/segments/__init__.py

@@ -1,2 +1,51 @@
+# vim:fileencoding=utf-8:noet
+from __future__ import absolute_import
+
+import sys
+
 from pkgutil import extend_path
+from types import MethodType
+
+
 __path__ = extend_path(__path__, __name__)
+
+
+class Segment(object):
+	'''Base class for any segment that is not a function
+
+	Required for powerline.lint.inspect to work properly.
+	'''
+	if sys.version_info < (3, 4):
+		def argspecobjs(self):
+			yield '__call__', self.__call__
+	else:
+		def argspecobjs(self):  # NOQA
+			yield '__call__', self
+
+	argspecobjs.__doc__ = (
+		'''Return a list of valid arguments for inspect.getargspec
+
+		Used to determine function arguments.
+		'''
+	)
+
+	def omitted_args(self, name, method):
+		'''List arguments which should be omitted
+
+		Returns a tuple with indexes of omitted arguments.
+		
+		.. note::``segment_info``, ``create_watcher`` and ``pl`` will be omitted 
+			regardless of the below return (for ``segment_info`` and 
+			``create_watcher``: only if object was marked to require segment 
+			info or filesystem watcher).
+		'''
+		if isinstance(self.__call__, MethodType):
+			return (0,)
+		else:
+			return ()
+
+	@staticmethod
+	def additional_args():
+		'''Returns a list of (additional argument name[, default value]) tuples.
+		'''
+		return ()

powerline/segments/common.py

@@ -19,6 +19,7 @@ from powerline.lib.monotonic import monotonic
 from powerline.lib.humanize_bytes import humanize_bytes
 from powerline.lib.unicode import u
 from powerline.theme import requires_segment_info, requires_filesystem_watcher
+from powerline.segments import Segment
 from collections import namedtuple
 
 
@@ -904,7 +905,7 @@ STATE_SYMBOLS = {
 }
 
 
-class NowPlayingSegment(object):
+class NowPlayingSegment(Segment):
 	def __call__(self, player='mpd', format='{state_symbol} {artist} - {title} ({total})', state_symbols=STATE_SYMBOLS, **kwargs):
 		player_func = getattr(self, 'player_{0}'.format(player))
 		stats = {