# Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
#
# This file is part of attoconf.
#
# attoconf is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# attoconf 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with attoconf. If not, see <http://www.gnu.org/licenses/>.
def put_line_in_width(file, line, width, indent):
''' Print a line with wrapping.
'''
line = line.rstrip(' ')
if len(line) <= width or ' ' not in line.lstrip(' '):
# this is not just an optimization
file.writelines([line, '\n'])
return
line += ' '
indents = indent * ' '
initial_spaces = len(line) - len(line.lstrip(' '))
while line.lstrip():
space = line.rfind(' ', initial_spaces, width + 1)
if space == -1:
space = line.find(' ', initial_spaces)
if space == -1:
space = len(line)
file.writelines([line[:space], '\n'])
line = indents + line[space+1:].lstrip(' ')
initial_spaces = indent
class HelpSection(object):
''' A help section contains some header lines and some related options.
'''
__slots__ = (
'headers',
'options',
)
def __init__(self):
''' Create an empty help section.
'''
self.headers = []
self.options = []
def add_text(self, text, hidden):
''' Add a header line.
'''
self.headers.append((hidden, text))
def add_option(self, name, text, hidden):
''' Add an option with its description.
'''
self.options.append((hidden, name, text))
def print(self, file, hidden, width):
''' Format (some of) the help text prettily.
'''
if self.options:
for oh, name, ht in self.options:
if oh <= hidden:
break
else:
return False
# options longer than this will be split into multiple lines
split_width = width / 4 - 2
# longest option
longest_opt = 0
for oh, name, ht in self.options:
if oh > hidden:
continue
l = len(name) + 2
if l > split_width:
continue
if l > longest_opt:
longest_opt = l
if longest_opt == 0:
longest_opt = int(split_width)
for oh, ht in self.headers:
if oh > hidden:
continue
put_line_in_width(file, ht, width, 0)
for oh, name, ht in self.options:
if oh > hidden:
continue
# no, it's not really that simple
if len(name) > longest_opt:
file.writelines([' ', name, '\n'])
name = ''
line = ' %-*s%s' % (longest_opt, name, ht)
put_line_in_width(file, line, width, longest_opt + 2)
return True
def detect_terminal_width(fd, DEFAULT_WIDTH=float('inf')):
''' Detect the width of a terminal.
'''
if not isinstance(fd, int):
fd = getattr(fd, 'fileno', lambda: -1)()
if fd == -1:
return DEFAULT_WIDTH
import fcntl
import termios
try:
buf = fcntl.ioctl(fd, termios.TIOCGWINSZ, b'xx' * 4)
except IOError as e:
import errno
if e.errno != errno.ENOTTY:
raise
return DEFAULT_WIDTH
import struct
ws_row, ws_col, ws_xpixel, ws_ypixel = struct.unpack('HHHH', buf)
return ws_col
class Help(object):
''' Help collects the set of flavor text and option descriptions
related to arguments.
'''
__slots__ = (
'sections',
)
def __init__(self):
''' Help does not take any arguments during construction.
'''
self.sections = []
def add_text(self, help, hidden):
''' Add a header line.
This creates a new section if the last line wasn't a header.
'''
if not self.sections or self.sections[-1].options:
self.sections.append(HelpSection())
self.sections[-1].add_text(help, hidden)
def add_option(self, name, help, hidden):
''' Add an option with its description to the current section.
This creates a new section only if it is first.
'''
if not self.sections:
self.sections.append(HelpSection())
self.sections[-1].add_option(name, help, hidden)
def print(self, file, hidden, width=0):
''' Print all the help at the given level of hidden-ness.
'''
if width == 0:
width = detect_terminal_width(file)
if width < 20:
width = 80
for s in self.sections:
if s.print(file, hidden, width):
file.write('\n')
