Source code for powerline.renderer

# vim:fileencoding=utf-8:noet
from __future__ import (unicode_literals, division, absolute_import, print_function)

import sys
import os
import re

from itertools import chain

from powerline.theme import Theme
from powerline.lib.unicode import unichr, strwidth_ucs_2, strwidth_ucs_4

NBSP = ' '

np_control_character_translations = dict((
	# Control characters: ^@ … ^Y
	(i1, '^' + unichr(i1 + 0x40)) for i1 in range(0x20)
'''Control character translations

Dictionary that maps characters in range 0x00–0x1F (inclusive) to strings 
``'^@'``, ``'^A'`` and so on.

.. note: maps tab to ``^I`` and newline to ``^J``.

np_invalid_character_translations = dict((
	# Invalid unicode characters obtained using 'surrogateescape' error 
	# handler.
	(i2, '<{0:02x}>'.format(i2 - 0xDC00)) for i2 in range(0xDC80, 0xDD00)
'''Invalid unicode character translations

When using ``surrogateescape`` encoding error handling method characters in 
range 0x80–0xFF (inclusive) are transformed into unpaired surrogate escape 
unicode codepoints 0xDC80–0xDD00. This dictionary maps such characters to 
``<80>``, ``<81>``, and so on: in Python-3 they cannot be printed or 
converted to UTF-8 because UTF-8 standard does not allow surrogate escape 
characters, not even paired ones. Python-2 contains a bug that allows such 
action, but printing them in any case makes no sense.

# XXX: not using `r` because it makes no sense.
np_invalid_character_re = re.compile('(?<![\uD800-\uDBFF])[\uDC80-\uDD00]')
'''Regex that finds unpaired surrogate escape characters

Search is only limited to the ones obtained from ``surrogateescape`` error 
handling method. This regex is only used for UCS-2 Python variants because 
in this case characters above 0xFFFF are represented as surrogate escapes 
characters and are thus subject to partial transformation if 
``np_invalid_character_translations`` translation table is used.

np_character_translations = np_control_character_translations.copy()
'''Dictionary that contains non-printable character translations

In UCS-4 versions of Python this is a union of 
``np_invalid_character_translations`` and ``np_control_character_translations`` 
dictionaries. In UCS-2 for technical reasons ``np_invalid_character_re`` is used 
instead and this dictionary only contains items from 

translate_np = (
		lambda s: (
				lambda match: (
				), s
	) if sys.maxunicode < 0x10FFFF else (
		lambda s: (
'''Function that translates non-printable characters into printable strings

Is used to translate control characters and surrogate escape characters 
obtained from ``surrogateescape`` encoding errors handling method into some 
printable sequences. See documentation for 
``np_invalid_character_translations`` and 
``np_control_character_translations`` for more details.

def construct_returned_value(rendered_highlighted, segments, width, output_raw, output_width):
	if not (output_raw or output_width):
		return rendered_highlighted
		return (
			+ ((''.join((segment['_rendered_raw'] for segment in segments)),) if output_raw else ())
			+ ((width,) if output_width else ())

[docs]class Renderer(object): '''Object that is responsible for generating the highlighted string. :param dict theme_config: Main theme configuration. :param local_themes: Local themes. Is to be used by subclasses from ``.get_theme()`` method, base class only records this parameter to a ``.local_themes`` attribute. :param dict theme_kwargs: Keyword arguments for ``Theme`` class constructor. :param PowerlineLogger pl: Object used for logging. :param int ambiwidth: Width of the characters with east asian width unicode attribute equal to ``A`` (Ambigious). :param dict options: Various options. Are normally not used by base renderer, but all options are recorded as attributes. ''' segment_info = { 'environ': os.environ, 'getcwd': getattr(os, 'getcwdu', os.getcwd), 'home': os.environ.get('HOME'), } '''Basic segment info Is merged with local segment information by :py:meth:`get_segment_info` method. Keys: ``environ`` Object containing environment variables. Must define at least the following methods: ``.__getitem__(var)`` that raises ``KeyError`` in case requested environment variable is not present, ``.get(var, default=None)`` that works like ``dict.get`` and be able to be passed to ``Popen``. ``getcwd`` Function that returns current working directory. Will be called without any arguments, should return ``unicode`` or (in python-2) regular string. ``home`` String containing path to home directory. Should be ``unicode`` or (in python-2) regular string or ``None``. ''' character_translations = {} '''Character translations for use in escape() function. See documentation of ``unicode.translate`` for details. ''' def __init__(self, theme_config, local_themes, theme_kwargs, pl, ambiwidth=1, **options): self.__dict__.update(options) self.theme_config = theme_config theme_kwargs['pl'] = pl = pl if theme_config.get('use_non_breaking_spaces', True): self.character_translations = self.character_translations.copy() self.character_translations[ord(' ')] = NBSP self.theme = Theme(theme_config=theme_config, **theme_kwargs) self.local_themes = local_themes self.theme_kwargs = theme_kwargs self.width_data = { 'N': 1, # Neutral 'Na': 1, # Narrow 'A': ambiwidth, # Ambigious 'H': 1, # Half-width 'W': 2, # Wide 'F': 2, # Fullwidth } strwidth = lambda self, s: ( (strwidth_ucs_2 if sys.maxunicode < 0x10FFFF else strwidth_ucs_4)( self.width_data, s) ) '''Function that returns string width. Is used to calculate the place given string occupies when handling ``width`` argument to ``.render()`` method. Must take east asian width into account. :param unicode string: String whose width will be calculated. :return: unsigned integer. '''
[docs] def get_theme(self, matcher_info): '''Get Theme object. Is to be overridden by subclasses to support local themes, this variant only returns ``.theme`` attribute. :param matcher_info: Parameter ``matcher_info`` that ``.render()`` method received. Unused. ''' return self.theme
[docs] def shutdown(self): '''Prepare for interpreter shutdown. The only job it is supposed to do is calling ``.shutdown()`` method for all theme objects. Should be overridden by subclasses in case they support local themes. ''' self.theme.shutdown()
[docs] def get_segment_info(self, segment_info, mode): '''Get segment information. Must return a dictionary containing at least ``home``, ``environ`` and ``getcwd`` keys (see documentation for ``segment_info`` attribute). This implementation merges ``segment_info`` dictionary passed to ``.render()`` method with ``.segment_info`` attribute, preferring keys from the former. It also replaces ``getcwd`` key with function returning ``segment_info['environ']['PWD']`` in case ``PWD`` variable is available. :param dict segment_info: Segment information that was passed to ``.render()`` method. :return: dict with segment information. ''' r = self.segment_info.copy() r['mode'] = mode if segment_info: r.update(segment_info) if 'PWD' in r['environ']: r['getcwd'] = lambda: r['environ']['PWD'] return r
[docs] 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)
[docs] def render(self, mode=None, width=None, side=None, line=0, output_raw=False, output_width=False, segment_info=None, matcher_info=None): '''Render all segments. When a width is provided, low-priority segments are dropped one at a time until the line is shorter than the width, or only segments with a negative priority are left. If one or more segments with ``"width": "auto"`` are provided they will fill the remaining space until the desired width is reached. :param str mode: Mode string. Affects contents (colors and the set of segments) of rendered string. :param int width: Maximum width text can occupy. May be exceeded if there are too much non-removable segments. :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, colorless_string)``. :param bool output_width: Changes the output: if this parameter is ``True`` then in place of one string this method outputs a pair ``(colored_string, string_width)``. Returns a three-tuple if ``output_raw`` is also ``True``: ``(colored_string, colorless_string, string_width)``. :param dict segment_info: Segment information. See also :py:meth:`get_segment_info` method. :param matcher_info: Matcher information. Is processed in :py:meth:`get_segment_info` method. ''' theme = self.get_theme(matcher_info) return self.do_render( mode=mode, width=width, side=side, line=line, output_raw=output_raw, output_width=output_width, segment_info=self.get_segment_info(segment_info, mode), theme=theme, )
def compute_divider_widths(self, theme): return { 'left': { 'hard': self.strwidth(theme.get_divider('left', 'hard')), 'soft': self.strwidth(theme.get_divider('left', 'soft')), }, 'right': { 'hard': self.strwidth(theme.get_divider('right', 'hard')), 'soft': self.strwidth(theme.get_divider('right', 'soft')), }, }
[docs] def do_render(self, mode, width, side, line, output_raw, output_width, segment_info, theme): '''Like Renderer.render(), but accept theme in place of matcher_info ''' segments = list(theme.get_segments(side, line, segment_info, mode)) current_width = 0 self._prepare_segments(segments, output_width or width) if not width: # No width specified, so we don’t need to crop or pad anything if output_width: current_width = self._render_length(theme, segments, self.compute_divider_widths(theme)) return construct_returned_value(''.join([ segment['_rendered_hl'] for segment in self._render_segments(theme, segments) ]) + self.hlstyle(), segments, current_width, output_raw, output_width) divider_widths = self.compute_divider_widths(theme) # Create an ordered list of segments that can be dropped segments_priority = sorted((segment for segment in segments if segment['priority'] is not None), key=lambda segment: segment['priority'], reverse=True) no_priority_segments = filter(lambda segment: segment['priority'] is None, segments) current_width = self._render_length(theme, segments, divider_widths) if current_width > width: for segment in chain(segments_priority, no_priority_segments): if segment['truncate'] is not None: segment['contents'] = segment['truncate'](, current_width - width, segment) segments_priority = iter(segments_priority) if current_width > width and len(segments) > 100: # When there are too many segments use faster, but less correct # algorythm for width computation diff = current_width - width for segment in segments_priority: segments.remove(segment) diff -= segment['_len'] if diff <= 0: break current_width = self._render_length(theme, segments, divider_widths) if current_width > width: # When there are not too much use more precise, but much slower # width computation. It also finishes computations in case # previous variant did not free enough space. for segment in segments_priority: segments.remove(segment) current_width = self._render_length(theme, segments, divider_widths) if current_width <= width: break del segments_priority # Distribute the remaining space on spacer segments segments_spacers = [segment for segment in segments if segment['expand'] is not None] if segments_spacers: distribute_len, distribute_len_remainder = divmod(width - current_width, len(segments_spacers)) for segment in segments_spacers: segment['contents'] = ( segment['expand'](, 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 elif output_width: current_width = self._render_length(theme, segments, divider_widths) rendered_highlighted = ''.join([segment['_rendered_hl'] for segment in self._render_segments(theme, segments)]) if rendered_highlighted: rendered_highlighted += self.hlstyle() return construct_returned_value(rendered_highlighted, segments, current_width, output_raw, output_width)
def _prepare_segments(self, segments, calculate_contents_len): '''Translate non-printable characters and calculate segment width ''' for segment in segments: segment['contents'] = translate_np(segment['contents']) if calculate_contents_len: for segment in segments: segment['_contents_len'] = self.strwidth(segment['contents']) def _render_length(self, theme, segments, divider_widths): '''Update segments lengths and return them ''' segments_len = len(segments) ret = 0 divider_spaces = theme.get_spaces() for index, segment in enumerate(segments): side = segment['side'] segment_len = segment['_contents_len'] prev_segment = segments[index - 1] if index > 0 else theme.EMPTY_SEGMENT next_segment = segments[index + 1] if index < segments_len - 1 else theme.EMPTY_SEGMENT compare_segment = next_segment if side == 'left' else prev_segment divider_type = 'soft' if compare_segment['highlight']['bg'] == segment['highlight']['bg'] else 'hard' outer_padding = int(bool( (index == 0 and side == 'left') or (index == segments_len - 1 and side == 'right') )) draw_divider = segment['draw_' + divider_type + '_divider'] segment_len += outer_padding if draw_divider: segment_len += divider_widths[side][divider_type] + divider_spaces segment['_len'] = segment_len ret += segment_len return ret def _render_segments(self, theme, segments, render_highlighted=True): '''Internal segment rendering method. This method loops through the segment array and compares the foreground/background colors and divider properties and returns the rendered statusline as a string. The method always renders the raw segment contents (i.e. without highlighting strings added), and only renders the highlighted statusline if render_highlighted is True. ''' segments_len = len(segments) divider_spaces = theme.get_spaces() for index, segment in enumerate(segments): side = segment['side'] prev_segment = segments[index - 1] if index > 0 else theme.EMPTY_SEGMENT next_segment = segments[index + 1] if index < segments_len - 1 else theme.EMPTY_SEGMENT compare_segment = next_segment if side == 'left' else prev_segment outer_padding = int(bool( (index == 0 and side == 'left') or (index == segments_len - 1 and side == 'right') )) * ' ' divider_type = 'soft' if compare_segment['highlight']['bg'] == segment['highlight']['bg'] else 'hard' divider_highlighted = '' contents_raw = segment['contents'] contents_highlighted = '' draw_divider = segment['draw_' + divider_type + '_divider'] # XXX Make sure self.hl() calls are called in the same order # segments are displayed. This is needed for Vim renderer to work. if draw_divider: divider_raw = self.escape(theme.get_divider(side, divider_type)) if side == 'left': contents_raw = outer_padding + contents_raw + (divider_spaces * ' ') else: contents_raw = (divider_spaces * ' ') + contents_raw + outer_padding if divider_type == 'soft': divider_highlight_group_key = 'highlight' if segment['divider_highlight_group'] is None else 'divider_highlight' divider_fg = segment[divider_highlight_group_key]['fg'] divider_bg = segment[divider_highlight_group_key]['bg'] else: divider_fg = segment['highlight']['bg'] divider_bg = compare_segment['highlight']['bg'] if side == 'left': if render_highlighted: contents_highlighted = self.hl(self.escape(contents_raw), **segment['highlight']) divider_highlighted = self.hl(divider_raw, divider_fg, divider_bg, False) segment['_rendered_raw'] = contents_raw + divider_raw segment['_rendered_hl'] = contents_highlighted + divider_highlighted else: if render_highlighted: divider_highlighted = self.hl(divider_raw, divider_fg, divider_bg, False) contents_highlighted = self.hl(self.escape(contents_raw), **segment['highlight']) segment['_rendered_raw'] = divider_raw + contents_raw segment['_rendered_hl'] = divider_highlighted + contents_highlighted else: if side == 'left': contents_raw = outer_padding + contents_raw else: contents_raw = contents_raw + outer_padding contents_highlighted = self.hl(self.escape(contents_raw), **segment['highlight']) segment['_rendered_raw'] = contents_raw segment['_rendered_hl'] = contents_highlighted yield segment
[docs] def escape(self, string): '''Method that escapes segment contents. ''' return string.translate(self.character_translations)
[docs] def hlstyle(fg=None, bg=None, attrs=None): '''Output highlight style string. Assuming highlighted string looks like ``{style}{contents}`` this method should output ``{style}``. If it is called without arguments this method is supposed to reset style to its default. ''' raise NotImplementedError
[docs] def hl(self, contents, fg=None, bg=None, attrs=None): '''Output highlighted chunk. This implementation just outputs :py:meth:`hlstyle` joined with ``contents``. ''' return self.hlstyle(fg, bg, attrs) + (contents or '')