Tools/pynche/Switchboard.py

   1 """Switchboard class.
   2
   3 This class is used to coordinate updates among all Viewers.  Every Viewer must
   4 conform to the following interface:
   5
   6     - it must include a method called update_yourself() which takes three
   7       arguments; the red, green, and blue values of the selected color.
   8
   9     - When a Viewer selects a color and wishes to update all other Views, it
  10       should call update_views() on the Switchboard object.  Not that the
  11       Viewer typically does *not* update itself before calling update_views(),
  12       since this would cause it to get updated twice.
  13 """
  14
  15 import sys
  16 from types import DictType
  17 import marshal
  18
  19 class Switchboard:
  20     def __init__(self, colordb, initfile):
  21         self.__initfile = initfile
  22         self.__colordb = colordb
  23         self.__optiondb = {}
  24         self.__views = []
  25         self.__red = 0
  26         self.__green = 0
  27         self.__blue = 0
  28         self.__canceled = 0
  29         # read the initialization file
  30         fp = None
  31         if initfile:
  32             try:
  33                 try:
  34                     fp = open(initfile)
  35                     self.__optiondb = marshal.load(fp)
  36                     if type(self.__optiondb) <> DictType:
  37                         sys.stderr.write(
  38                             'Problem reading options from file: %s\n' %
  39                             initfile)
  40                         self.__optiondb = {}
  41                 except (IOError, EOFError):
  42                     pass
  43             finally:
  44                 if fp:
  45                     fp.close()
  46
  47     def add_view(self, view):
  48         self.__views.append(view)
  49
  50     def update_views(self, red, green, blue):
  51         self.__red = red
  52         self.__green = green
  53         self.__blue = blue
  54         for v in self.__views:
  55             v.update_yourself(red, green, blue)
  56
  57     def update_views_current(self):
  58         self.update_views(self.__red, self.__green, self.__blue)
  59
  60     def current_rgb(self):
  61         return self.__red, self.__green, self.__blue
  62
  63     def colordb(self):
  64         return self.__colordb
  65
  66     def optiondb(self):
  67         return self.__optiondb
  68
  69     def save_views(self):
  70         # save the current color
  71         self.__optiondb['RED'] = self.__red
  72         self.__optiondb['GREEN'] = self.__green
  73         self.__optiondb['BLUE'] = self.__blue
  74         for v in self.__views:
  75             if hasattr(v, 'save_options'):
  76                 v.save_options(self.__optiondb)
  77         fp = None
  78         try:
  79             try:
  80                 fp = open(self.__initfile, 'w')
  81             except IOError:
  82                 sys.stderr.write('Cannot write options to file: %s\n' %
  83                                  self.__initfile)
  84             else:
  85                 marshal.dump(self.__optiondb, fp)
  86         finally:
  87             if fp:
  88                 fp.close()
  89
  90     def withdraw_views(self):
  91         for v in self.__views:
  92             if hasattr(v, 'withdraw'):
  93                 v.withdraw()
  94
  95     def canceled(self, flag=1):
  96         self.__canceled = flag
  97
  98     def canceled_p(self):
  99         return self.__canceled