Use `expand` key to fill segments

powerline/renderer.py

@@ -269,7 +269,7 @@ class Renderer(object):
 			segments.remove(segment)
 
 		# Distribute the remaining space on spacer segments
-		segments_spacers = [segment for segment in segments if segment['width'] == 'auto']
+		segments_spacers = [segment for segment in segments if segment['expand'] is not None]
 		if segments_spacers:
 			if not segments_priority:
 				# Update segment['_len'] and current_width if not already done 
@@ -278,15 +278,12 @@ class Renderer(object):
 				current_width = self._render_length(theme, segments, divider_widths)
 			distribute_len, distribute_len_remainder = divmod(width - current_width, len(segments_spacers))
 			for segment in segments_spacers:
-				if segment['align'] == 'l':
-					segment['_space_right'] += distribute_len
-				elif segment['align'] == 'r':
-					segment['_space_left'] += distribute_len
-				elif segment['align'] == 'c':
-					space_side, space_side_remainder = divmod(distribute_len, 2)
-					segment['_space_left'] += space_side + space_side_remainder
-					segment['_space_right'] += space_side
-			segments_spacers[0]['_space_right'] += distribute_len_remainder
+				segment['contents'] = (
+					segment['expand'](
+						self.pl,
+						distribute_len + (1 if distribute_len_remainder > 0 else 0),
+						segment))
+				distribute_len_remainder -= 1
 			# `_len` key is not needed anymore, but current_width should have an 
 			# actual value for various bindings.
 			current_width = width
@@ -321,7 +318,7 @@ class Renderer(object):
 			))
 
 			draw_divider = segment['draw_' + divider_type + '_divider']
-			segment_len += segment['_space_left'] + segment['_space_right'] + outer_padding
+			segment_len += outer_padding
 			if draw_divider:
 				segment_len += divider_widths[side][divider_type] + divider_spaces
 
@@ -363,30 +360,14 @@ class Renderer(object):
 			if draw_divider:
 				divider_raw = self.escape(theme.get_divider(side, divider_type))
 				if side == 'left':
-					contents_raw = (
-						outer_padding + (segment['_space_left'] * ' ')
-						+ contents_raw
-						+ ((divider_spaces + segment['_space_right']) * ' ')
-					)
+					contents_raw = outer_padding + contents_raw + (divider_spaces * ' ')
 				else:
-					contents_raw = (
-						((divider_spaces + segment['_space_left']) * ' ')
-						+ contents_raw
-						+ (segment['_space_right'] * ' ') + outer_padding
-					)
+					contents_raw = (divider_spaces * ' ') + contents_raw + outer_padding
 			else:
 				if side == 'left':
-					contents_raw = (
-						outer_padding + (segment['_space_left'] * ' ')
-						+ contents_raw
-						+ (segment['_space_right'] * ' ')
-					)
+					contents_raw = outer_padding + contents_raw
 				else:
-					contents_raw = (
-						(segment['_space_left'] * ' ')
-						+ contents_raw
-						+ (segment['_space_right'] * ' ') + outer_padding
-					)
+					contents_raw = contents_raw + outer_padding
 
 			# Replace spaces with no-break spaces
 			contents_raw = contents_raw.translate(self.np_character_translations)

powerline/segment.py

@@ -285,6 +285,7 @@ def gen_segment_getter(pl, ext, common_config, theme_configs, default_module, ge
 				'include_modes': segment.get('include_modes', []),
 				'width': None,
 				'align': None,
+				'expand': None,
 				'startup': None,
 				'shutdown': None,
 				'mode': None,
@@ -292,8 +293,6 @@ def gen_segment_getter(pl, ext, common_config, theme_configs, default_module, ge
 				'_rendered_hl': '',
 				'_len': None,
 				'_contents_len': None,
-				'_space_left': 0,
-				'_space_right': 0,
 			}
 
 		if segment_type == 'function':
@@ -331,6 +330,7 @@ def gen_segment_getter(pl, ext, common_config, theme_configs, default_module, ge
 			'include_modes': segment.get('include_modes', []),
 			'width': segment.get('width'),
 			'align': segment.get('align', 'l'),
+			'expand': None,
 			'startup': startup_func,
 			'shutdown': shutdown_func,
 			'mode': None,
@@ -338,8 +338,6 @@ def gen_segment_getter(pl, ext, common_config, theme_configs, default_module, ge
 			'_rendered_hl': '',
 			'_len': None,
 			'_contents_len': None,
-			'_space_left': 0,
-			'_space_right': 0,
 		}
 
 	return get

powerline/theme.py

@@ -23,6 +23,26 @@ def new_empty_segment_line():
 	}
 
 
+def add_spaces_left(pl, amount, segment):
+	return (' ' * amount) + segment['contents']
+
+
+def add_spaces_right(pl, amount, segment):
+	return segment['contents'] + (' ' * amount)
+
+
+def add_spaces_center(pl, amount, segment):
+	amount, remainder = divmod(amount, 2)
+	return (' ' * (amount + remainder)) + segment['contents'] + (' ' * amount)
+
+
+expand_functions = {
+	'l': add_spaces_right,
+	'r': add_spaces_left,
+	'c': add_spaces_center,
+}
+
+
 class Theme(object):
 	def __init__(self,
 	             ext,
@@ -128,6 +148,13 @@ class Theme(object):
 						self.colorscheme,
 					)
 			for segment in parsed_segments:
+				width = segment['width']
+				align = segment['align']
+				if width == 'auto':
+					segment['expand'] = expand_functions.get(align)
+					if segment['expand'] is None:
+						self.pl.error('Align argument must be “r”, “l” or “c”, not “{0}”', align)
+
 				segment['contents'] = segment['before'] + u(segment['contents'] if segment['contents'] is not None else '') + segment['after']
 				# Align segment contents
 				if segment['width'] and segment['width'] != 'auto':