Add support for above lines as described in #462

Support is not mirrored in shell bindings yet

powerline/__init__.py

@@ -413,6 +413,25 @@ class Powerline(object):
 				pass
 			return FailedUnicode(safe_unicode(e))
 
+	def render_above_lines(self, *args, **kwargs):
+		'''Like .render(), but for ``self.renderer.render_above_lines()``
+		'''
+		try:
+			self.update_renderer()
+			for line in self.renderer.render_above_lines(*args, **kwargs):
+				yield line
+		except Exception as e:
+			try:
+				self.exception('Failed to render: {0}', str(e))
+			except Exception as e:
+				# Updates e variable to new value, masking previous one. 
+				# Normally it is the same exception (due to raise in case pl is 
+				# unset), but it may also show error in logger. Note that latter 
+				# is not logged by logger for obvious reasons, thus this also 
+				# prevents us from seeing logger traceback.
+				pass
+			yield FailedUnicode(safe_unicode(e))
+
 	def shutdown(self):
 		'''Shut down all background threads. Must be run only prior to exiting 
 		current application.

powerline/renderer.py

@@ -175,7 +175,20 @@ class Renderer(object):
 			r['getcwd'] = lambda: r['environ']['PWD']
 		return r
 
-	def render(self, mode=None, width=None, side=None, output_raw=False, segment_info=None, matcher_info=None):
+	def render_above_lines(self, **kwargs):
+		'''Render all segments in the {theme}/segments/above list
+
+		Rendering happens in the reversed order. Parameters are the same as in 
+		.render() method.
+
+		:yield: rendered line.
+		'''
+
+		theme = self.get_theme(kwargs.get('matcher_info', None))
+		for line in range(theme.get_line_number() - 1, 0, -1):
+			yield self.render(side=None, line=line, **kwargs)
+
+	def render(self, mode=None, width=None, side=None, line=0, output_raw=False, segment_info=None, matcher_info=None):
 		'''Render all segments.
 
 		When a width is provided, low-priority segments are dropped one at
@@ -193,6 +206,9 @@ class Renderer(object):
 		:param str side:
 			One of ``left``, ``right``. Determines which side will be rendered. 
 			If not present all sides are rendered.
+		:param int line:
+			Line number for which segments should be obtained. Is counted from 
+			zero (botmost line).
 		:param bool output_raw:
 			Changes the output: if this parameter is ``True`` then in place of 
 			one string this method outputs a pair ``(colored_string, 
@@ -203,7 +219,7 @@ class Renderer(object):
 			Matcher information. Is processed in ``.get_theme()`` method.
 		'''
 		theme = self.get_theme(matcher_info)
-		segments = theme.get_segments(side, self.get_segment_info(segment_info, mode))
+		segments = theme.get_segments(side, line, self.get_segment_info(segment_info, mode))
 
 		# Handle excluded/included segments for the current mode
 		segments = [self._get_highlighting(segment, mode) for segment in segments

powerline/shell.py

@@ -51,7 +51,7 @@ def get_argparser(parser=None, *args, **kwargs):
 		parser = argparse.ArgumentParser
 	p = parser(*args, **kwargs)
 	p.add_argument('ext', nargs=1)
-	p.add_argument('side', nargs='?', choices=('left', 'right'))
+	p.add_argument('side', nargs='?', choices=('left', 'right', 'above', 'aboveleft'))
 	p.add_argument('-r', '--renderer_module', metavar='MODULE', type=str)
 	p.add_argument('-w', '--width', type=int)
 	p.add_argument('--last_exit_code', metavar='INT', type=int)

powerline/theme.py

@@ -2,6 +2,7 @@
 
 from powerline.segment import gen_segment_getter
 from powerline.lib.unicode import u
+import itertools
 
 
 def requires_segment_info(func):
@@ -9,6 +10,13 @@ def requires_segment_info(func):
 	return func
 
 
+def new_empty_segment_line():
+	return {
+		'left': [],
+		'right': []
+	}
+
+
 class Theme(object):
 	def __init__(self,
 				ext,
@@ -20,10 +28,7 @@ class Theme(object):
 				shutdown_event=None):
 		self.dividers = theme_config.get('dividers', common_config['dividers'])
 		self.spaces = theme_config.get('spaces', common_config['spaces'])
-		self.segments = {
-			'left': [],
-			'right': [],
-		}
+		self.segments = []
 		self.EMPTY_SEGMENT = {
 			'contents': None,
 			'highlight': {'fg': False, 'bg': False, 'attr': 0}
@@ -33,25 +38,29 @@ class Theme(object):
 		if top_theme_config:
 			theme_configs.append(top_theme_config)
 		get_segment = gen_segment_getter(pl, ext, common_config['paths'], theme_configs, theme_config.get('default_module'))
-		for side in ['left', 'right']:
-			for segment in theme_config['segments'].get(side, []):
-				segment = get_segment(segment, side)
-				if not run_once:
-					if segment['startup']:
-						try:
-							segment['startup'](pl, shutdown_event)
-						except Exception as e:
-							pl.error('Exception during {0} startup: {1}', segment['name'], str(e))
-							continue
-				self.segments[side].append(segment)
+		for segdict in itertools.chain((theme_config['segments'],),
+										theme_config['segments'].get('above', ())):
+			self.segments.append(new_empty_segment_line())
+			for side in ['left', 'right']:
+				for segment in segdict.get(side, []):
+					segment = get_segment(segment, side)
+					if not run_once:
+						if segment['startup']:
+							try:
+								segment['startup'](pl, shutdown_event)
+							except Exception as e:
+								pl.error('Exception during {0} startup: {1}', segment['name'], str(e))
+								continue
+					self.segments[-1][side].append(segment)
 
 	def shutdown(self):
-		for segments in self.segments.values():
-			for segment in segments:
-				try:
-					segment['shutdown']()
-				except TypeError:
-					pass
+		for line in self.segments:
+			for segments in line.values():
+				for segment in segments:
+					try:
+						segment['shutdown']()
+					except TypeError:
+						pass
 
 	def get_divider(self, side='left', type='soft'):
 		'''Return segment divider.'''
@@ -60,15 +69,22 @@ class Theme(object):
 	def get_spaces(self):
 		return self.spaces
 
-	def get_segments(self, side=None, segment_info=None):
+	def get_line_number(self):
+		return len(self.segments)
+
+	def get_segments(self, side=None, line=0, segment_info=None):
 		'''Return all segments.
 
 		Function segments are called, and all segments get their before/after
 		and ljust/rjust properties applied.
+
+		:param int line:
+			Line number for which segments should be obtained. Is counted from 
+			zero (botmost line).
 		'''
 		for side in [side] if side else ['left', 'right']:
 			parsed_segments = []
-			for segment in self.segments[side]:
+			for segment in self.segments[line][side]:
 				if segment['type'] == 'function':
 					self.pl.prefix = segment['name']
 					try:

scripts/powerline

@@ -10,6 +10,12 @@ except ImportError:
 	sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(os.path.realpath(__file__)))))
 	from powerline.shell import ShellPowerline, get_argparser, finish_args  # NOQA
 
+def write(output):
+	try:
+		sys.stdout.write(output)
+	except UnicodeEncodeError:
+		sys.stdout.write(output.encode('utf-8'))
+
 if __name__ == '__main__':
 	args = get_argparser(description=__doc__).parse_args()
 	finish_args(args)
@@ -17,13 +23,21 @@ if __name__ == '__main__':
 	segment_info = {'args': args, 'environ': os.environ}
 	if args.renderer_arg:
 		segment_info.update(args.renderer_arg)
-	rendered = powerline.render(
-		width=args.width,
-		side=args.side,
-		segment_info=segment_info,
-		mode=os.environ.get('_POWERLINE_MODE'),
-	)
-	try:
-		sys.stdout.write(rendered)
-	except UnicodeEncodeError:
-		sys.stdout.write(rendered.encode('utf-8'))
+	if args.side.startswith('above'):
+		for line in powerline.render_above_lines(
+			width=args.width,
+			segment_info=segment_info,
+			mode=os.environ.get('_POWERLINE_MODE'),
+		):
+			write(line)
+			sys.stdout.write('\n')
+		args.side = args.side[len('above'):]
+
+	if args.side:
+		rendered = powerline.render(
+			width=args.width,
+			side=args.side,
+			segment_info=segment_info,
+			mode=os.environ.get('_POWERLINE_MODE'),
+		)
+		write(rendered)