Create basic vim segment renderer

This commit also includes a basic proof-of-concept demo for creating vim
statuslines. When creating vim statuslines you basically need to first
create the statusline the same way as the terminal demo, use the vim
renderer and then afterwards loop through the collected highlight groups
in the vim renderer and write those as vim highlight statements.

Vim obviously needs a ton of wrapper code to make everything work
properly (separate modes, callbacks, all that stuff) so the current demo
only shows some basic statusline highlighting.

lib/renderers/__init__.py

@@ -3,3 +3,4 @@ class SegmentRenderer:
 		raise NotImplementedError
 
 from lib.renderers.terminal import TerminalSegmentRenderer
+from lib.renderers.vim import VimSegmentRenderer

lib/renderers/vim.py

@@ -0,0 +1,59 @@
+#!/usr/bin/env python
+
+from lib.core import Segment
+from lib.renderers import SegmentRenderer
+
+
+class VimSegmentRenderer(SegmentRenderer):
+	'''Powerline vim segment renderer.
+	'''
+	def __init__(self):
+		self.hl_groups = {}
+
+	def hl(self, fg=None, bg=None, attr=None):
+		'''Highlight a segment.
+
+		If an argument is None, the argument is ignored. If an argument is
+		False, the argument is reset to the terminal defaults. If an argument
+		is a valid color or attribute, it's added to the vim highlight group.
+		'''
+		hl_group = {
+			'ctermfg': 'NONE',
+			'guifg': 'NONE',
+			'ctermbg': 'NONE',
+			'guibg': 'NONE',
+			'attr': ['NONE'],
+		}
+
+		# We don't need to explicitly reset attributes in vim, so skip those calls
+		if not attr and not bg and not fg:
+			return ''
+
+		if fg is not None and fg is not False:
+			hl_group['ctermfg'] = fg[0]
+			hl_group['guifg'] = fg[1]
+
+		if bg is not None and bg is not False:
+			hl_group['ctermbg'] = bg[0]
+			hl_group['guibg'] = bg[1]
+
+		if attr is not None and attr is not False and attr != 0:
+			hl_group['attr'] = []
+			if attr & Segment.ATTR_BOLD:
+				hl_group['attr'].append('bold')
+			if attr & Segment.ATTR_ITALIC:
+				hl_group['attr'].append('italic')
+			if attr & Segment.ATTR_UNDERLINE:
+				hl_group['attr'].append('underline')
+
+		hl_group_name = 'Pl_{ctermfg}_{guifg}_{ctermbg}_{guibg}_{attr}'.format(
+			ctermfg=hl_group['ctermfg'],
+			guifg=hl_group['guifg'],
+			ctermbg=hl_group['ctermbg'],
+			guibg=hl_group['guibg'],
+			attr=''.join(attr[0] for attr in hl_group['attr']),
+		)
+
+		self.hl_groups[hl_group_name] = hl_group
+
+		return '%#{0}#'.format(hl_group_name)

powerline-vim-example.py

@@ -3,7 +3,7 @@
 '''
 
 from lib.core import Segment
-from lib.renderers import TerminalSegmentRenderer
+from lib.renderers import VimSegmentRenderer
 
 powerline = Segment([
 	Segment('NORMAL', 22, 148, attr=Segment.ATTR_BOLD),
@@ -12,12 +12,12 @@ powerline = Segment([
 		Segment(' ~/projects/powerline/lib/'),
 		Segment('core.py ', 231, attr=Segment.ATTR_BOLD),
 	], 250, 240, separate=False, padding=''),
-	Segment(),
+	Segment('%<%='),
 	Segment([
 		Segment('unix'),
 		Segment('utf-8'),
 		Segment('python'),
-		Segment(' 83%', 247, 240),
+		Segment(' 83%%', 247, 240),
 		Segment([
 			Segment(' ⭡ ', 239),
 			Segment('23', attr=Segment.ATTR_BOLD),
@@ -26,4 +26,17 @@ powerline = Segment([
 	], 245, side='r'),
 ], bg=236)
 
-print(powerline.render(TerminalSegmentRenderer()))
+renderer = VimSegmentRenderer()
+stl = powerline.render(renderer)
+
+for group, hl in renderer.hl_groups.items():
+	print('hi {group} ctermfg={ctermfg} guifg={guifg} guibg={guibg} ctermbg={ctermbg} cterm={attr} gui={attr}'.format(
+		group=group,
+		ctermfg=hl['ctermfg'],
+		guifg='#{0:06x}'.format(hl['guifg']) if hl['guifg'] != 'NONE' else 'NONE',
+		ctermbg=hl['ctermbg'],
+		guibg='#{0:06x}'.format(hl['guibg']) if hl['guibg'] != 'NONE' else 'NONE',
+		attr=','.join(hl['attr']),
+	))
+
+print('let &stl = "{0}"'.format(stl))