ansi.py   [plain text]

# Twisted, the Framework of Your Internet
# Copyright (C) 2001-2002 Matthew W. Lefkowitz
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
"""Module to parse ANSI escape sequences

Maintainer: U(Jean-Paul Calderone <exarkun@twistedmatrix.com>
"""

import string

# Twisted imports
from twisted.python import log

class ColorText:
    """
    Represents an element of text along with the texts colors and
    additional attributes.
    """

    # The colors to use
    COLORS = ('b', 'r', 'g', 'y', 'l', 'm', 'c', 'w')
    BOLD_COLORS = tuple([x.upper() for x in COLORS])
    BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = range(len(COLORS))

    # Color names
    COLOR_NAMES = (
        'Black', 'Red', 'Green', 'Yellow', 'Blue', 'Magenta', 'Cyan', 'White'
    )

    def __init__(self, text, fg, bg, display, bold, underline, flash, reverse):
        self.text, self.fg, self.bg = text, fg, bg
        self.display = display
        self.bold = bold
        self.underline = underline
        self.flash = flash
        self.reverse = reverse
        if self.reverse:
            self.fg, self.bg = self.bg, self.fg


class AnsiParser:
    """
    Parser class for ANSI codes.
    """

    # Terminators for cursor movement ansi controls - unsupported
    CURSOR_SET = ('H', 'f', 'A', 'B', 'C', 'D', 'R', 's', 'u', 'd','G')

    # Terminators for erasure ansi controls - unsupported
    ERASE_SET = ('J', 'K', 'P')
    
    # Terminators for mode change ansi controls - unsupported
    MODE_SET = ('h', 'l')
    
    # Terminators for keyboard assignment ansi controls - unsupported
    ASSIGN_SET = ('p',)
    
    # Terminators for color change ansi controls - supported
    COLOR_SET = ('m',)

    SETS = (CURSOR_SET, ERASE_SET, MODE_SET, ASSIGN_SET, COLOR_SET)

    def __init__(self, defaultFG, defaultBG):
        self.defaultFG, self.defaultBG = defaultFG, defaultBG
        self.currentFG, self.currentBG = self.defaultFG, self.defaultBG
        self.bold, self.flash, self.underline, self.reverse = 0, 0, 0, 0
        self.display = 1
        self.prepend = ''

    
    def stripEscapes(self, string):
        """
        Remove all ANSI color escapes from the given string.
        """
        result = ''
        show = 1
        i = 0
        L = len(string)
        while i < L:
            if show == 0 and string[i] in _sets:
                show = 1
            elif show:
                n = string.find('\x1B', i)
                if n == -1:
                    return result + string[i:]
                else:
                    result = result + string[i:n]
                    i = n
                    show = 0
            i = i + 1
        return result

    def writeString(self, colorstr):
        pass

    def parseString(self, str):
        """
        Turn a string input into a list of ColorText elements.
        """

        if self.prepend:
            str = self.prepend + str
            self.prepend = ''
        parts = str.split('\x1B')
        
        if len(parts) == 1:
            self.writeString(self.formatText(parts[0]))
        else:
            self.writeString(self.formatText(parts[0]))
            for s in parts[1:]:
                L = len(s)
                i = 0 
                type = None
                while i < L:
                    if s[i] not in string.digits+'[;?':
                        break
                    i+=1
                if not s:
                    self.prepend = '\x1b'
                    return
                if s[0]!='[':
                    self.writeString(self.formatText(s[i+1:]))
                    continue
                else:
                    s=s[1:]
                    i-=1
                if i==L-1:
                    self.prepend = '\x1b['
                    return
                type = _setmap.get(s[i], None)
                if type is None:
                    continue 

                if type == AnsiParser.COLOR_SET:
                    self.parseColor(s[:i + 1])
                    s = s[i + 1:]
                    self.writeString(self.formatText(s))
                elif type == AnsiParser.CURSOR_SET:
                    cursor, s = s[:i+1], s[i+1:]
                    self.parseCursor(cursor)
                    self.writeString(self.formatText(s))
                elif type == AnsiParser.ERASE_SET:
                    erase, s = s[:i+1], s[i+1:]
                    self.parseErase(erase)
                    self.writeString(self.formatText(s))
                elif type == AnsiParser.MODE_SET:
                    mode, s = s[:i+1], s[i+1:]
                    #self.parseErase('2J')
                    self.writeString(self.formatText(s))
                elif i == L:
                    self.prepend = '\x1B[' + s
                else:
                    log.msg('Unhandled ANSI control type: %c' % (s[i],))
                    s = s[i + 1:]
                    self.writeString(self.formatText(s))

    def parseColor(self, str):
        """
        Handle a single ANSI color sequence
        """
        # Drop the trailing 'm'
        str = str[:-1]

        if not str:
            str = '0'

        try:
            parts = map(int, str.split(';'))
        except ValueError:
            log.msg('Invalid ANSI color sequence (%d): %s' % (len(str), str))
            self.currentFG, self.currentBG = self.defaultFG, self.defaultBG
            return

        for x in parts:
            if x == 0:
                self.currentFG, self.currentBG = self.defaultFG, self.defaultBG
                self.bold, self.flash, self.underline, self.reverse = 0, 0, 0, 0
                self.display = 1
            elif x == 1:
                self.bold = 1
            elif 30 <= x <= 37:
                self.currentFG = x - 30
            elif 40 <= x <= 47:
                self.currentBG = x - 40
            elif x == 39:
                self.currentFG = self.defaultFG
            elif x == 49:
                self.currentBG = self.defaultBG
            elif x == 4:
                self.underline = 1
            elif x == 5:
                self.flash = 1
            elif x == 7:
                self.reverse = 1
            elif x == 8:
                self.display = 0
            elif x == 22:
                self.bold = 0
            elif x == 24:
                self.underline = 0
            elif x == 25:
                self.blink = 0
            elif x == 27:
                self.reverse = 0
            elif x == 28:
                self.display = 1
            else:
                log.msg('Unrecognised ANSI color command: %d' % (x,))

    def parseCursor(self, cursor):
        pass

    def parseErase(self, erase):
        pass


    def pickColor(self, value, mode, BOLD = ColorText.BOLD_COLORS):
        if mode:
            return ColorText.COLORS[value]
        else:
            return self.bold and BOLD[value] or ColorText.COLORS[value]


    def formatText(self, text):
        return ColorText(
            text,
            self.pickColor(self.currentFG, 0),
            self.pickColor(self.currentBG, 1),
            self.display, self.bold, self.underline, self.flash, self.reverse
        )


_sets = ''.join(map(''.join, AnsiParser.SETS))

_setmap = {}
for s in AnsiParser.SETS:
    for r in s:
        _setmap[r] = s
del s