stoplight.py

SMC takes a state machine stored in a .sm file and generates a State pattern in twelve programming l

				cv.itemconfigure(self._south_light['GREEN'], fill='green')
			elif color == 'yellow':
				cv.itemconfigure(self._north_light['GREEN'], fill='white')
				cv.itemconfigure(self._south_light['GREEN'], fill='white')
				cv.itemconfigure(self._north_light['YELLOW'], fill='yellow')
				cv.itemconfigure(self._south_light['YELLOW'], fill='yellow')

	def SetTimer(self, timer):
		self._timerID = self._canvas.after(self._timeouts[timer], self.Timeout)

	def StopTimer(self):
		if self._timerID >= 0:
			self._canvas.after_cancel(self._timerID)
			self._timerID = -1

	def Timeout(self):
		self._timerID = -1
		self._fsm.Timeout()

	def ResetLights(self):
		cv = self._canvas

		cv.itemconfigure(self._east_light['YELLOW'], fill='white')
		cv.itemconfigure(self._west_light['YELLOW'], fill='white')
		cv.itemconfigure(self._east_light['RED'], fill='white')
		cv.itemconfigure(self._west_light['RED'], fill='white')
		cv.itemconfigure(self._east_light['GREEN'], fill='white')
		cv.itemconfigure(self._west_light['GREEN'], fill='white')

		cv.itemconfigure(self._north_light['YELLOW'], fill='white')
		cv.itemconfigure(self._south_light['YELLOW'], fill='white')
		cv.itemconfigure(self._north_light['RED'], fill='white')
		cv.itemconfigure(self._south_light['RED'], fill='white')
		cv.itemconfigure(self._north_light['GREEN'], fill='white')
		cv.itemconfigure(self._south_light['GREEN'], fill='white')

	# InformVehicles --
	#
	#   Tell the vehicles that were waiting on the green light
	#   that they can go now.
	#
	# Arguments:
	#   direction   Which light turned green.

	def InformVehicles(self, direction):
		if      direction == 'north':
			for vehicle in self._northVehicleList:
				vehicle.lightGreen()
			self._northVehicleList = []
		elif direction == 'south':
			for vehicle in self._southVehicleList:
				vehicle.lightGreen()
			self._southVehicleList = []
		elif direction == 'east':
			for vehicle in self._eastVehicleList:
				vehicle.lightGreen()
			self._eastVehicleList = []
		elif direction == 'west':
			for vehicle in self._westVehicleList:
				vehicle.lightGreen()
			self._westVehicleList = []

	def DrawRoads(self):
		cv = self._canvas
		# The roads are drawn as follows:
		#
		#        (x2,y1)   (x4,y1)
		#             |  |  |
		#             |     |
		#             |  |  |
		# (x1,y2)     |     |       (x5,y2)
		# ------------+  |  +------------
		#         (x2,y2) (x4,y2)
		# - - - - - -        - - - - - -
		#         (x2,y4) (x4,y4)   (x5,y4)
		# ------------+     +------------
		# (x1,y4)     |  |  |
		#             |     |
		#             |  |  |
		#             |     |
		#        (x2,y5) |(x4,y5)

		# Calculate the line segment's length.
		XLength = (self.getRoadLengthX() / 2) - self._roadWidth / 2
		YLength = (self.getRoadLengthY() / 2) - self._roadWidth / 2

		# Calculate the major coordinates.
		X1 = 0
		Y1 = 0
		X2 = XLength
		Y2 = YLength
		X3 = int(cv.cget('width')) / 2
		Y3 = int(cv.cget('height')) / 2
		X4 = int(cv.cget('width')) - XLength
		Y4 = int(cv.cget('height')) - YLength
		X5 = int(cv.cget('width'))
		Y5 = int(cv.cget('height'))

		# Put green lawns around the road.
		cv.create_rectangle(X1, Y1, X2, Y2,
			outline="",
			fill='green',
		)
		cv.create_rectangle(X1, Y4, X2, Y5,
			outline="",
			fill='green',
		)
		cv.create_rectangle(X4, Y4, X5, Y5,
			outline="",
			fill='green',
		)
		cv.create_rectangle(X4, Y1, X5, Y2,
			outline="",
			fill='green',
		)

		# Draw four connected lines where each drawing uses three
		# coordinates.
		cv.create_line(X1, Y2, X2, Y2, X2, Y1)
		cv.create_line(X4, Y1, X4, Y2, X5, Y2)
		cv.create_line(X1, Y4, X2, Y4, X2, Y5)
		cv.create_line(X4, Y5, X4, Y4, X5, Y4)

		# Now draw the lane markings.
		cv.create_line(X1, Y3, X2, Y3)
		cv.create_line(X3, Y1, X3, Y2)
		cv.create_line(X4, Y3, X5, Y3)
		cv.create_line(X3, Y4, X3, Y5)

	def DrawLights(self):
		cv = self._canvas
		# The lights are drawns as follows:
		#
		#  y1          +---+
		#              | o |green
		#              | o |yellow
		#              | o |red
		#  y2  +-------+---+-------+
		#      | o o o |   | o o o |
		#  y3  +-------+---+-------+
		#              | o |red
		#              | o |yellow
		#              | o |green
		#  y4          +---+
		#
		#    x1       x2   x3     x4
		# Store each light as a separate element in a table.

		# Figure out the coordinates for the stoplights.
		X1 = int(cv.cget('width')) / 2 - self._lightWidth / 2 - self._lightHeight
		Y1 = int(cv.cget('height')) / 2 - self._lightWidth / 2 - self._lightHeight
		X2 = X1 + self._lightHeight
		Y2 = Y1 + self._lightHeight
		X3 = X2 + self._lightWidth
		Y3 = Y2 + self._lightWidth
		X4 = X3 + self._lightHeight
		Y4 = Y3 + self._lightHeight

		# Draw the four stop lights boxes.
		cv.create_rectangle(X2, Y1, X3, Y2,
				outline='black',
				fill='black',
				width=1,
		)
		cv.create_rectangle(X1, Y2, X2, Y3,
				outline='black',
				fill='black',
				width=1,
		)
		cv.create_rectangle(X2, Y3, X3, Y4,
				outline='black',
				fill='black',
				width=1,
		)
		cv.create_rectangle(X3, Y2, X4, Y3,
				outline='black',
				fill='black',
				width=1,
		)

		# Draw the lights within the stoplights. Save the
		# canvas items into an array because they will be
		# referenced later. Because there are two lights
		self._north_light['RED'] = cv.create_oval(
				X2 + self._lightSpace,
				Y1 + self._lightSpace,
				X3 - self._lightSpace,
				Y1 + self._lightSpace + self._lightDiameter,
				outline='black',
				fill='white'
		)
		self._north_light['YELLOW'] = cv.create_oval(
				X2 + self._lightSpace,
				Y1 + self._lightSpace * 2 + self._lightDiameter,
				X3 - self._lightSpace,
				Y1 + self._lightSpace * 2 + self._lightDiameter * 2,
				outline='black',
				fill='white'
		)
		self._north_light['GREEN'] = cv.create_oval(
				X2 + self._lightSpace,
				Y1 + self._lightSpace * 3 + self._lightDiameter * 2,
				X3 - self._lightSpace,
				Y1 + self._lightSpace * 3 + self._lightDiameter * 3,
				outline='black',
				fill='white'
		)

		self._west_light['RED'] = cv.create_oval(
				X1 + self._lightSpace,
				Y2 + self._lightSpace,
				X1 + self._lightSpace + self._lightDiameter,
				Y3 - self._lightSpace,
				outline='black',
				fill='white'
		)
		self._west_light['YELLOW'] = cv.create_oval(
				X1 + self._lightSpace * 2 + self._lightDiameter,
				Y2 + self._lightSpace,
				X1 + self._lightSpace * 2 + self._lightDiameter * 2,
				Y3 - self._lightSpace,
				outline='black',
				fill='white'
		)
		self._west_light['GREEN'] = cv.create_oval(
				X1 + self._lightSpace * 3 + self._lightDiameter * 2,
				Y2 + self._lightSpace,
				X1 + self._lightSpace * 3 + self._lightDiameter * 3,
				Y3 - self._lightSpace,
				outline='black',
				fill='white'
		)

		self._south_light['GREEN'] = cv.create_oval(
				X2 + self._lightSpace,
				Y3 + self._lightSpace,
				X3 - self._lightSpace,
				Y3 + self._lightSpace + self._lightDiameter,
				outline='black',
				fill='white'
		)
		self._south_light['YELLOW'] = cv.create_oval(
				X2 + self._lightSpace,
				Y3 + self._lightSpace * 2 + self._lightDiameter,
				X3 - self._lightSpace,
				Y3 + self._lightSpace * 2 + self._lightDiameter * 2,
				outline='black',
				fill='white'
		)
		self._south_light['RED'] = cv.create_oval(
				X2 + self._lightSpace,
				Y3 + self._lightSpace * 3 + self._lightDiameter * 2,
				X3 - self._lightSpace,
				Y3 + self._lightSpace * 3 + self._lightDiameter * 3,
				outline='black',
				fill='white'
		)

		self._east_light['GREEN'] = cv.create_oval(
				X3 + self._lightSpace,
				Y2 + self._lightSpace,
				X3 + self._lightSpace + self._lightDiameter,
				Y3 - self._lightSpace,
				outline='black',
				fill='white'
		)
		self._east_light['YELLOW'] = cv.create_oval(
				X3 + self._lightSpace * 2 + self._lightDiameter,
				Y2 + self._lightSpace,
				X3 + self._lightSpace * 2 + self._lightDiameter * 2,
				Y3 - self._lightSpace,
				outline='black',
				fill='white'
		)
		self._east_light['RED'] = cv.create_oval(
				X3 + self._lightSpace * 3 + self._lightDiameter * 2,
				Y2 + self._lightSpace,
				X3 + self._lightSpace * 3 + self._lightDiameter * 3,
				Y3 - self._lightSpace,
				outline='black',
				fill='white'
		)