'''
Task Coach - Your friendly task manager
Copyright (C) 2004-2009 Frank Niessink <frank@niessink.com>
Task Coach 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.
Task Coach 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 this program. If not, see <http://www.gnu.org/licenses/>.
'''
import singleton as patterns
class Command(object):
def __init__(self, *args, **kwargs):
super(Command, self).__init__() # object.__init__ takes no arguments
def do(self):
CommandHistory().append(self)
def undo(self):
pass
def redo(self):
pass
def __str__(self):
return 'command'
class CommandHistory(object):
__metaclass__ = patterns.Singleton
def __init__(self):
self.__history = []
self.__future = []
def append(self, command):
self.__history.append(command)
del self.__future[:]
def undo(self):
if self.__history:
command = self.__history.pop()
command.undo()
self.__future.append(command)
def redo(self):
if self.__future:
command = self.__future.pop()
command.redo()
self.__history.append(command)
def clear(self):
del self.__history[:]
del self.__future[:]
def hasHistory(self):
return self.__history
def getHistory(self):
return self.__history
def hasFuture(self):
return self.__future
def getFuture(self):
return self.__future
def _extendLabel(self, label, commandList):
if commandList:
commandName = u' %s'%commandList[-1]
label += commandName.lower()
return label
def undostr(self, label='Undo'):
return self._extendLabel(label, self.__history)
def redostr(self, label='Redo'):
return self._extendLabel(label, self.__future)
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