import time

class desktop_SequentialTimer():
  def __init__(self):
    self.activeTimeout = None
    self.callback = None
    self.queue = []
  #}

  def update(self):
    # Get current time in milliseconds.
    now = time.time_ns() // 1000000

    # Schedule an item.
    if (
      self.activeTimeout == None and
      len(self.queue) > 0
    ):
      self.activeTimeout = now + self.queue[0][0]
    elif (
      self.activeTimeout != None and
      now >= self.activeTimeout
    ):
      # Report when the time is up.
      key = self.queue[0][1]
      value = self.queue[0][2]
      self.queue.pop(0)
      self.activeTimeout = None
      self.callback(key, value)
    #}
  #}

  def schedule(self, key, value, timeout):
    self.queue.append([timeout, key, value])
  #}