"""Switchboard class.
This class is used to coordinate updates among all Viewers. Every Viewer must
conform to the following interface:
- it must include a method called update_yourself() which takes three
arguments; the red, green, and blue values of the selected color.
- When a Viewer selects a color and wishes to update all other Views, it
should call update_views() on the Switchboard object. Not that the
Viewer typically does *not* update itself before calling update_views(),
since this would cause it to get updated twice.
"""
import sys
from types import DictType
import marshal
class Switchboard:
def __init__(self, colordb, initfile):
self.__initfile = initfile
self.__colordb = colordb
self.__optiondb = {}
self.__views = []
self.__red = 0
self.__green = 0
self.__blue = 0
self.__canceled = 0
# read the initialization file
fp = None
if initfile:
try:
try:
fp = open(initfile)
self.__optiondb = marshal.load(fp)
if type(self.__optiondb) <> DictType:
sys.stderr.write(
'Problem reading options from file: %s\n' %
initfile)
self.__optiondb = {}
except (IOError, EOFError):
pass
finally:
if fp:
fp.close()
def add_view(self, view):
self.__views.append(view)
def update_views(self, red, green, blue):
self.__red = red
self.__green = green
self.__blue = blue
for v in self.__views:
v.update_yourself(red, green, blue)
def update_views_current(self):
self.update_views(self.__red, self.__green, self.__blue)
def current_rgb(self):
return self.__red, self.__green, self.__blue
def colordb(self):
return self.__colordb
def optiondb(self):
return self.__optiondb
def save_views(self):
# save the current color
self.__optiondb['RED'] = self.__red
self.__optiondb['GREEN'] = self.__green
self.__optiondb['BLUE'] = self.__blue
for v in self.__views:
if hasattr(v, 'save_options'):
v.save_options(self.__optiondb)
fp = None
try:
try:
fp = open(self.__initfile, 'w')
except IOError:
sys.stderr.write('Cannot write options to file: %s\n' %
self.__initfile)
else:
marshal.dump(self.__optiondb, fp)
finally:
if fp:
fp.close()
def withdraw_views(self):
for v in self.__views:
if hasattr(v, 'withdraw'):
v.withdraw()
def canceled(self, flag=1):
self.__canceled = flag
def canceled_p(self):
return self.__canceled
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