lib/python/Components/Sources/Boolean.py

   1 from Source import Source
   2 from Components.Element import cached
   3 from enigma import eTimer
   4
   5 # a small warning:
   6 # you can use that boolean well to express screen-private
   7 # conditional expressions.
   8 #
   9 # however, if you think that there is ANY interest that another
  10 # screen could use your expression, please put your calculation
  11 # into a seperate Source, providing a "boolean"-property.
  12 class Boolean(Source, object):
  13         def __init__(self, fixed = False, function = None, poll = 0):
  14                 Source.__init__(self)
  15                 self.function = function
  16                 self.fixed = fixed
  17                 if poll > 0:
  18                         self.poll_timer = eTimer()
  19                         self.poll_timer.callback.append(self.poll)
  20                         self.poll_timer.start(poll)
  21                 else:
  22                         self.poll_timer = None
  23
  24         @cached
  25         def getBoolean(self):
  26                 if self.function is not None:
  27                         return self.function()
  28                 else:
  29                         return self.fixed
  30
  31         def setBoolean(self, value):
  32                 assert self.function is None
  33                 self.fixed = value
  34                 self.poll()
  35
  36         boolean = property(getBoolean, setBoolean)
  37
  38         def poll(self):
  39                 self.changed((self.CHANGED_ALL,))
  40
  41         def destroy(self):
  42                 if self.poll_timer:
  43                         self.poll_timer.callback.remove(self.poll)
  44                 Source.destroy(self)