def restorePriorities(self):
for task, oldPriority in zip(self.items, self.oldPriorities):
task.setPriority(oldPriority)
def changePriorities(self, delta):
for task in self.items:
task.setPriority(task.priority() + delta)
def setNewExtremePriority(self):
newExtremePriority = self.oldExtremePriority + self.delta
for task in self.items:
task.setPriority(newExtremePriority)
