ponysay/src/colourstack.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

'''
ponysay - Ponysay, cowsay reimplementation for ponies
Copyright (C) 2012, 2013  Erkin Batu Altunbaş et al.

This program is free software. It comes without any warranty, to
the extent permitted by applicable law. You can redistribute it
and/or modify it under the terms of the Do What The Fuck You Want
To Public License, Version 2, as published by Sam Hocevar. See
http://sam.zoy.org/wtfpl/COPYING for more details.
'''
from common import *



'''
ANSI colour stack

This is used to make layers with independent coloursations
'''
class ColourStack():
    '''
    Constructor
    
    @param  autopush:str  String that, when used, will create a new independently colourised layer
    @param  autopop:str   String that, when used, will end the current layer and continue of the previous layer
    '''
    def __init__(self, autopush, autopop):
        self.autopush = autopush
        self.autopop  = autopop
        self.lenpush  = len(autopush)
        self.lenpop   = len(autopop)
        self.bufproto = ' ' * (self.lenpush if self.lenpush > self.lenpop else self.lenpop)
        self.stack    = []
        self.push()
        self.seq      = None
    
    
    '''
    Create a new independently colourised layer
    
    @return  :str  String that should be inserted into your buffer
    '''
    def push(self):
        self.stack.insert(0, [self.bufproto, None, None, [False] * 9])
        if len(self.stack) == 1:
            return None
        return '\033[0m'
    
    
    '''
    End the current layer and continue of the previous layer
    
    @return  :str  String that should be inserted into your buffer
    '''
    def pop(self):
        old = self.stack.pop(0)
        rc = '\033[0;'
        if len(self.stack) == 0: # last resort in case something made it pop too mush
            push()
        new = self.stack[0]
        if new[1] is not None:  rc += new[1] + ';'
        if new[2] is not None:  rc += new[2] + ';'
        for i in range(0, 9):
            if new[3][i]:
                rc += str(i + 1) + ';'
        return rc[:-1] + 'm'
    
    
    '''
    Use this, in sequence, for which character in your buffer that contains yor autopush and autopop
    string, the automatically get push and pop string to insert after each character
    
    @param   :chr  One character in your buffer
    @return  :str  The text to insert after the input character
    '''
    def feed(self, char):
        if self.seq is not None:
            self.seq += char
            if (char == '~') or (('a' <= char) and (char <= 'z')) or (('A' <= char) and (char <= 'Z')):
                if (self.seq[0] == '[') and (self.seq[-1] == 'm'):
                    self.seq = self.seq[1:-1].split(';')
                    (i, n) = (0, len(self.seq))
                    while i < n:
                        part = self.seq[i]
                        p = 0 if part == '' else int(part)
                        i += 1
                        if p == 0:                       self.stack[0][1:] = [None, None, [False] * 9]
                        elif (1 <= p) and (p <= 9):      self.stack[0][3][p - 1] = True
                        elif (21 <= p) and (p <= 29):    self.stack[0][3][p - 21] = False
                        elif p == 39:                    self.stack[0][1] = None
                        elif p == 49:                    self.stack[0][2] = None
                        elif (30 <= p) and (p <= 37):    self.stack[0][1] = part
                        elif (90 <= p) and (p <= 97):    self.stack[0][1] = part
                        elif (40 <= p) and (p <= 47):    self.stack[0][2] = part
                        elif (100 <= p) and (p <= 107):  self.stack[0][2] = part
                        elif p == 38:
                            self.stack[0][1] = '%s;%s;%s' % (part, self.seq[i], self.seq[i + 1])
                            i += 2
                        elif p == 48:
                            self.stack[0][2] = '%s;%s;%s' % (part, self.seq[i], self.seq[i + 1])
                            i += 2
                self.seq = None
        elif char == '\033':
            self.seq = ''
        buf = self.stack[0][0]
        buf = buf[1:] + char
        rc = ''
        if   buf[-self.lenpush:] == self.autopush:  rc = self.push()
        elif buf[-self.lenpop:]  == self.autopop:   rc = self.pop()
        self.stack[0][0] = buf
        return rc