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@zymsys
Created April 14, 2012 19:01
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SRP and OCP example
class TrafficLightDisplay
def showState(state)
puts state == :LIGHT_STATE_RED ? "* RED *" : " red"
puts state == :LIGHT_STATE_AMBER ? "* AMBER *" : " amber"
puts state == :LIGHT_STATE_GREEN ? "* GREEN *" : " green"
puts "---------"
end
end
class TrafficLight
def initialize(schedule)
@state = :LIGHT_STATE_RED
@schedule = schedule
@maxTime = schedule.keys.max
@displays = []
end
def cycle
0.upto @maxTime do |time|
if @schedule.has_key?(time)
@state = @schedule[time]
signalStateChange
end
sleep 1
end
end
def addDisplay(display)
@displays.push display
display.showState @state
end
def signalStateChange
@displays.each do |display|
display.showState @state
end
end
def run
while true
cycle
end
end
end
tl = TrafficLight.new({
5=>:LIGHT_STATE_GREEN,
10=>:LIGHT_STATE_AMBER,
12=>:LIGHT_STATE_RED
})
tl.addDisplay(TrafficLightDisplay.new)
tl.run
class TrafficLightDisplay
def showState(state)
puts state == :LIGHT_STATE_RED ? "* RED *" : " red"
puts state == :LIGHT_STATE_AMBER ? "* AMBER *" : " amber"
puts state == :LIGHT_STATE_GREEN ? "* GREEN *" : " green"
puts "---------"
end
end
class WalkSignalDisplay
def showState(state)
puts state == :LIGHT_STATE_RED ? "* DON'T WALK *" : " don't walk"
puts state == :LIGHT_STATE_AMBER ? "* BLINKING DON'T WALK *" : " blinking don't walk"
puts state == :LIGHT_STATE_GREEN ? "* WALK *" : " walk"
puts "-----------------------"
end
end
class TrafficLight
def initialize(schedule)
@state = :LIGHT_STATE_RED
@schedule = schedule
@maxTime = schedule.keys.max
@displays = []
end
def cycle
0.upto @maxTime do |time|
if @schedule.has_key?(time)
@state = @schedule[time]
signalStateChange
end
sleep 1
end
end
def addDisplay(display)
@displays.push display
display.showState @state
end
def signalStateChange
@displays.each do |display|
display.showState @state
end
end
def run
while true
cycle
end
end
end
tl = TrafficLight.new({
5=>:LIGHT_STATE_GREEN,
10=>:LIGHT_STATE_AMBER,
12=>:LIGHT_STATE_RED
})
tl.addDisplay(TrafficLightDisplay.new)
tl.addDisplay(WalkSignalDisplay.new)
tl.run
class TrafficLight
def initialize(schedule)
setState :LIGHT_STATE_RED
@schedule = schedule
@maxTime = schedule.keys.max
end
def cycle
0.upto @maxTime do |time|
if @schedule.has_key?(time)
setState(@schedule[time])
end
sleep 1
end
end
def setState(newState)
@state = newState
showState()
end
def showState
puts @state == :LIGHT_STATE_RED ? "* RED *" : " red"
puts @state == :LIGHT_STATE_AMBER ? "* AMBER *" : " amber"
puts @state == :LIGHT_STATE_GREEN ? "* GREEN *" : " green"
puts "---------"
end
def run
while true
cycle
end
end
end
TrafficLight.new({
5=>:LIGHT_STATE_GREEN,
10=>:LIGHT_STATE_AMBER,
12=>:LIGHT_STATE_RED
}).run
class TrafficLightDisplay
def showState(state)
puts state == :LIGHT_STATE_RED ? "* RED *" : " red"
puts state == :LIGHT_STATE_AMBER ? "* AMBER *" : " amber"
puts state == :LIGHT_STATE_GREEN ? "* GREEN *" : " green"
puts "---------"
end
end
class TrafficLight
def initialize(schedule)
@schedule = schedule
@maxTime = schedule.keys.max
@display = TrafficLightDisplay.new
setState :LIGHT_STATE_RED
end
def cycle
0.upto @maxTime do |time|
if @schedule.has_key?(time)
setState(@schedule[time])
end
sleep 1
end
end
def setState(newState)
@state = newState
@display.showState(@state)
end
def run
while true
cycle
end
end
end
TrafficLight.new({
5=>:LIGHT_STATE_GREEN,
10=>:LIGHT_STATE_AMBER,
12=>:LIGHT_STATE_RED
}).run
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