pysize/ui/utils.py

   1 # This program is free software; you can redistribute it and/or modify
   2 # it under the terms of the GNU General Public License as published by
   3 # the Free Software Foundation; either version 2 of the License, or
   4 # (at your option) any later version.
   5 #
   6 # This program is distributed in the hope that it will be useful,
   7 # but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 # GNU Library General Public License for more details.
  10 #
  11 # You should have received a copy of the GNU General Public License
  12 # along with this program; if not, write to the Free Software
  13 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  14 #
  15 # See the COPYING file for license information.
  16 #
  17 # Copyright (c) 2006, 2007 Guillaume Chazarain <guichaz@yahoo.fr>
  18
  19 import re
  20 import time
  21
  22 UNITS = ['B', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB']
  23
  24 def human_unit(size):
  25     """Return a string of the form '12.34 MiB' given a size in bytes."""
  26     for i in xrange(len(UNITS) - 1, 0, -1):
  27         base = 1 << (10 * i)
  28         if 2 * base < size:
  29             return '%.2f %s' % ((float(size) / base), UNITS[i])
  30     return str(size) + ' ' + UNITS[0]
  31
  32 def short_string(string, length):
  33     """Returned a cut copy of the string, replace the middle with '~'."""
  34     if len(string) > length:
  35         middle = length / 2
  36         return string[:middle] + '~' + string[middle - length:]
  37     return string
  38
  39 def sanitize_string(string):
  40     def clean_blank(c):
  41         if c != ' ' and c.isspace():
  42             return '?'
  43         return c
  44     def robust_char_decode(c):
  45         try:
  46             return c.decode('UTF-8')
  47         except UnicodeDecodeError:
  48             return '?'
  49     blank_cleaned = ''.join(map(clean_blank, string))
  50     try:
  51         return blank_cleaned.decode('UTF-8')
  52     except UnicodeDecodeError:
  53         return ''.join(map(robust_char_decode, blank_cleaned))
  54
  55 MIN_SIZE_REGEXP = re.compile('^([0-9]+)(.?)(.*)$')
  56
  57 def min_size_to_consider(min_size='auto', height=0):
  58     if min_size == 'auto':
  59         return 1.0 / height
  60     match = MIN_SIZE_REGEXP.match(min_size)
  61     if not match:
  62         raise Exception, 'Cannot parse: ' + min_size
  63     min_size, letter, suffix = match.groups()
  64     units_letters = [u[0] for u in UNITS]
  65     if not letter:
  66         letter = 'B'
  67     letter = letter.upper()
  68     if not (letter in units_letters and suffix in ('iB', '')):
  69         raise Exception, 'Cannot parse unit in: ' + min_size
  70     return int(min_size) * 1024 ** units_letters.index(letter)
  71
  72 PROGRESS_CHARS = ['/', '-', '\\', '|']
  73 last_progress_char = 0
  74 last_progress_time = time.time()
  75
  76 def update_progress():
  77     global last_progress_char, last_progress_time
  78     now = time.time()
  79     if now - last_progress_time > 0.04:
  80             last_progress_char = (last_progress_char + 1) % len(PROGRESS_CHARS)
  81             last_progress_time = now
  82             return PROGRESS_CHARS[last_progress_char]
  83
  84 class UINotAvailableException(Exception):
  85     pass