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""" Utilities for processing ANSI escape codes and special ASCII characters.
"""
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports
from collections import namedtuple
import re
# System library imports
from IPython.external.qt import QtCore, QtGui
#-----------------------------------------------------------------------------
# Constants and datatypes
#-----------------------------------------------------------------------------
# An action for erase requests (ED and EL commands).
EraseAction = namedtuple('EraseAction', ['action', 'area', 'erase_to'])
# An action for cursor move requests (CUU, CUD, CUF, CUB, CNL, CPL, CHA, CUP,
# and HVP commands).
# FIXME: Not implemented in AnsiCodeProcessor.
MoveAction = namedtuple('MoveAction', ['action', 'dir', 'unit', 'count'])
# An action for scroll requests (SU and ST) and form feeds.
ScrollAction = namedtuple('ScrollAction', ['action', 'dir', 'unit', 'count'])
# An action for the carriage return character
CarriageReturnAction = namedtuple('CarriageReturnAction', ['action'])
# An action for the beep character
BeepAction = namedtuple('BeepAction', ['action'])
# Regular expressions.
CSI_COMMANDS = 'ABCDEFGHJKSTfmnsu'
CSI_SUBPATTERN = '\[(.*?)([%s])' % CSI_COMMANDS
OSC_SUBPATTERN = '\](.*?)[\x07\x1b]'
ANSI_PATTERN = ('\x01?\x1b(%s|%s)\x02?' % \
(CSI_SUBPATTERN, OSC_SUBPATTERN))
ANSI_OR_SPECIAL_PATTERN = re.compile('(\b|\r)|(?:%s)' % ANSI_PATTERN)
SPECIAL_PATTERN = re.compile('([\f])')
#-----------------------------------------------------------------------------
# Classes
#-----------------------------------------------------------------------------
class AnsiCodeProcessor(object):
""" Translates special ASCII characters and ANSI escape codes into readable
attributes. It also supports a few non-standard, xterm-specific codes.
"""
# Whether to increase intensity or set boldness for SGR code 1.
# (Different terminals handle this in different ways.)
bold_text_enabled = False
# We provide an empty default color map because subclasses will likely want
# to use a custom color format.
default_color_map = {}
#---------------------------------------------------------------------------
# AnsiCodeProcessor interface
#---------------------------------------------------------------------------
def __init__(self):
self.actions = []
self.color_map = self.default_color_map.copy()
self.reset_sgr()
def reset_sgr(self):
""" Reset graphics attributs to their default values.
"""
self.intensity = 0
self.italic = False
self.bold = False
self.underline = False
self.foreground_color = None
self.background_color = None
def split_string(self, string):
""" Yields substrings for which the same escape code applies.
"""
self.actions = []
start = 0
for match in ANSI_OR_SPECIAL_PATTERN.finditer(string):
raw = string[start:match.start()]
substring = SPECIAL_PATTERN.sub(self._replace_special, raw)
if substring or self.actions:
yield substring
start = match.end()
self.actions = []
groups = filter(lambda x: x is not None, match.groups())
if groups[0] == '\r':
self.actions.append(CarriageReturnAction('carriage-return'))
yield ''
elif groups[0] == '\b':
self.actions.append(BeepAction('beep'))
yield ''
else:
params = [ param for param in groups[1].split(';') if param ]
if groups[0].startswith('['):
# Case 1: CSI code.
try:
params = map(int, params)
except ValueError:
# Silently discard badly formed codes.
pass
else:
self.set_csi_code(groups[2], params)
elif groups[0].startswith(']'):
# Case 2: OSC code.
self.set_osc_code(params)
raw = string[start:]
substring = SPECIAL_PATTERN.sub(self._replace_special, raw)
if substring or self.actions:
yield substring
def set_csi_code(self, command, params=[]):
""" Set attributes based on CSI (Control Sequence Introducer) code.
Parameters
----------
command : str
The code identifier, i.e. the final character in the sequence.
params : sequence of integers, optional
The parameter codes for the command.
"""
if command == 'm': # SGR - Select Graphic Rendition
if params:
self.set_sgr_code(params)
else:
self.set_sgr_code([0])
elif (command == 'J' or # ED - Erase Data
command == 'K'): # EL - Erase in Line
code = params[0] if params else 0
if 0 <= code <= 2:
area = 'screen' if command == 'J' else 'line'
if code == 0:
erase_to = 'end'
elif code == 1:
erase_to = 'start'
elif code == 2:
erase_to = 'all'
self.actions.append(EraseAction('erase', area, erase_to))
elif (command == 'S' or # SU - Scroll Up
command == 'T'): # SD - Scroll Down
dir = 'up' if command == 'S' else 'down'
count = params[0] if params else 1
self.actions.append(ScrollAction('scroll', dir, 'line', count))
def set_osc_code(self, params):
""" Set attributes based on OSC (Operating System Command) parameters.
Parameters
----------
params : sequence of str
The parameters for the command.
"""
try:
command = int(params.pop(0))
except (IndexError, ValueError):
return
if command == 4:
# xterm-specific: set color number to color spec.
try:
color = int(params.pop(0))
spec = params.pop(0)
self.color_map[color] = self._parse_xterm_color_spec(spec)
except (IndexError, ValueError):
pass
def set_sgr_code(self, params):
""" Set attributes based on SGR (Select Graphic Rendition) codes.
Parameters
----------
params : sequence of ints
A list of SGR codes for one or more SGR commands. Usually this
sequence will have one element per command, although certain
xterm-specific commands requires multiple elements.
"""
# Always consume the first parameter.
if not params:
return
code = params.pop(0)
if code == 0:
self.reset_sgr()
elif code == 1:
if self.bold_text_enabled:
self.bold = True
else:
self.intensity = 1
elif code == 2:
self.intensity = 0
elif code == 3:
self.italic = True
elif code == 4:
self.underline = True
elif code == 22:
self.intensity = 0
self.bold = False
elif code == 23:
self.italic = False
elif code == 24:
self.underline = False
elif code >= 30 and code <= 37:
self.foreground_color = code - 30
elif code == 38 and params and params.pop(0) == 5:
# xterm-specific: 256 color support.
if params:
self.foreground_color = params.pop(0)
elif code == 39:
self.foreground_color = None
elif code >= 40 and code <= 47:
self.background_color = code - 40
elif code == 48 and params and params.pop(0) == 5:
# xterm-specific: 256 color support.
if params:
self.background_color = params.pop(0)
elif code == 49:
self.background_color = None
# Recurse with unconsumed parameters.
self.set_sgr_code(params)
#---------------------------------------------------------------------------
# Protected interface
#---------------------------------------------------------------------------
def _parse_xterm_color_spec(self, spec):
if spec.startswith('rgb:'):
return tuple(map(lambda x: int(x, 16), spec[4:].split('/')))
elif spec.startswith('rgbi:'):
return tuple(map(lambda x: int(float(x) * 255),
spec[5:].split('/')))
elif spec == '?':
raise ValueError('Unsupported xterm color spec')
return spec
def _replace_special(self, match):
special = match.group(1)
if special == '\f':
self.actions.append(ScrollAction('scroll', 'down', 'page', 1))
return ''
class QtAnsiCodeProcessor(AnsiCodeProcessor):
""" Translates ANSI escape codes into QTextCharFormats.
"""
# A map from ANSI color codes to SVG color names or RGB(A) tuples.
darkbg_color_map = {
0 : 'black', # black
1 : 'darkred', # red
2 : 'darkgreen', # green
3 : 'brown', # yellow
4 : 'darkblue', # blue
5 : 'darkviolet', # magenta
6 : 'steelblue', # cyan
7 : 'grey', # white
8 : 'grey', # black (bright)
9 : 'red', # red (bright)
10 : 'lime', # green (bright)
11 : 'yellow', # yellow (bright)
12 : 'deepskyblue', # blue (bright)
13 : 'magenta', # magenta (bright)
14 : 'cyan', # cyan (bright)
15 : 'white' } # white (bright)
# Set the default color map for super class.
default_color_map = darkbg_color_map.copy()
def get_color(self, color, intensity=0):
""" Returns a QColor for a given color code, or None if one cannot be
constructed.
"""
if color is None:
return None
# Adjust for intensity, if possible.
if color < 8 and intensity > 0:
color += 8
constructor = self.color_map.get(color, None)
if isinstance(constructor, basestring):
# If this is an X11 color name, we just hope there is a close SVG
# color name. We could use QColor's static method
# 'setAllowX11ColorNames()', but this is global and only available
# on X11. It seems cleaner to aim for uniformity of behavior.
return QtGui.QColor(constructor)
elif isinstance(constructor, (tuple, list)):
return QtGui.QColor(*constructor)
return None
def get_format(self):
""" Returns a QTextCharFormat that encodes the current style attributes.
"""
format = QtGui.QTextCharFormat()
# Set foreground color
qcolor = self.get_color(self.foreground_color, self.intensity)
if qcolor is not None:
format.setForeground(qcolor)
# Set background color
qcolor = self.get_color(self.background_color, self.intensity)
if qcolor is not None:
format.setBackground(qcolor)
# Set font weight/style options
if self.bold:
format.setFontWeight(QtGui.QFont.Bold)
else:
format.setFontWeight(QtGui.QFont.Normal)
format.setFontItalic(self.italic)
format.setFontUnderline(self.underline)
return format
def set_background_color(self, color):
""" Given a background color (a QColor), attempt to set a color map
that will be aesthetically pleasing.
"""
# Set a new default color map.
self.default_color_map = self.darkbg_color_map.copy()
if color.value() >= 127:
# Colors appropriate for a terminal with a light background. For
# now, only use non-bright colors...
for i in xrange(8):
self.default_color_map[i + 8] = self.default_color_map[i]
# ...and replace white with black.
self.default_color_map[7] = self.default_color_map[15] = 'black'
# Update the current color map with the new defaults.
self.color_map.update(self.default_color_map)
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