chiark - git - mdw - stgit/blob - stgit/out.py

   1 # -*- coding: utf-8 -*-
   2
   3 __copyright__ = """
   4 Copyright (C) 2007, Karl Hasselström <kha@treskal.com>
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License version 2 as
   8 published by the Free Software Foundation.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18 """
  19
  20 import sys, textwrap
  21
  22 class MessagePrinter(object):
  23     def __init__(self, file = None):
  24         class Output(object):
  25             def __init__(self, write, flush):
  26                 self.write = write
  27                 self.flush = flush
  28                 self.at_start_of_line = True
  29                 self.level = 0
  30             def new_line(self):
  31                 """Ensure that we're at the beginning of a line."""
  32                 if not self.at_start_of_line:
  33                     self.write('\n')
  34                     self.at_start_of_line = True
  35             def single_line(self, msg, print_newline = True,
  36                             need_newline = True):
  37                 """Write a single line. Newline before and after are
  38                 separately configurable."""
  39                 if need_newline:
  40                     self.new_line()
  41                 if self.at_start_of_line:
  42                     self.write('  '*self.level)
  43                 self.write(msg)
  44                 if print_newline:
  45                     self.write('\n')
  46                     self.at_start_of_line = True
  47                 else:
  48                     self.flush()
  49                     self.at_start_of_line = False
  50             def tagged_lines(self, tag, lines):
  51                 tag += ': '
  52                 width = 79 - 2*self.level - len(tag)
  53                 lines = [wl for line in lines
  54                          for wl in textwrap.wrap(line, width,
  55                                                  break_long_words = False)]
  56                 for line in lines:
  57                     self.single_line(tag + line)
  58                     tag = ' '*len(tag)
  59             def write_line(self, line):
  60                 """Write one line of text on a lines of its own, not
  61                 indented."""
  62                 self.new_line()
  63                 self.write('%s\n' % line)
  64                 self.at_start_of_line = True
  65             def write_raw(self, string):
  66                 """Write an arbitrary string, possibly containing
  67                 newlines."""
  68                 self.new_line()
  69                 self.write(string)
  70                 self.at_start_of_line = string.endswith('\n')
  71         if file:
  72             self.__stdout = self.__stderr = Output(file.write, file.flush)
  73         else:
  74             self.__stdout = Output(sys.stdout.write, sys.stdout.flush)
  75             self.__stderr = Output(sys.stdout.write, sys.stdout.flush)
  76         if file or sys.stdout.isatty():
  77             self.__out = self.__stdout
  78             self.__err = self.__stdout
  79         else:
  80             self.__out = Output(lambda msg: None, lambda: None)
  81             self.__err = self.__stderr
  82     def stdout(self, line):
  83         """Write a line to stdout."""
  84         self.__stdout.write_line(line)
  85     def stdout_raw(self, string):
  86         """Write a string possibly containing newlines to stdout."""
  87         self.__stdout.write_raw(string)
  88     def err_raw(self, string):
  89         """Write a string possibly containing newlines to the error
  90         output."""
  91         self.__err.write_raw(string)
  92     def info(self, *msgs):
  93         for msg in msgs:
  94             self.__out.single_line(msg)
  95     def note(self, *msgs, **kw):
  96         self.__out.tagged_lines(kw.get('title', 'Notice'), msgs)
  97     def warn(self, *msgs, **kw):
  98         self.__err.tagged_lines(kw.get('title', 'Warning'), msgs)
  99     def error(self, *msgs, **kw):
 100         self.__err.tagged_lines(kw.get('title', 'Error'), msgs)
 101     def start(self, msg):
 102         """Start a long-running operation."""
 103         self.__out.single_line('%s ... ' % msg, print_newline = False)
 104         self.__out.level += 1
 105     def done(self, extramsg = None):
 106         """Finish long-running operation."""
 107         self.__out.level -= 1
 108         if extramsg:
 109             msg = 'done (%s)' % extramsg
 110         else:
 111             msg = 'done'
 112         self.__out.single_line(msg, need_newline = False)
 113
 114 out = MessagePrinter()