A traffic light application to drive home some Ruby OOP principles.
- Get a copy of Shoes running, resources online at:
I had to add the following line to my ~/.bashrc to get this running on OSX:
PATH=/Applications/Shoes.app/Contents/MacOS:$PATH
- Fork your own copy of this exercise and clone it
git clone https://github.com/dmgarland/TrafficLight.git
cd TrafficLight
- Run it!
shoes traffic.rb
We'll be modifying a Shoes application that models a traffic light.
- Using inheritance, implement 3 subclasses of Bulb: GoBulb, WaitBulb and StopBulb. Change the subclasses so that when we define them, the correct colour is displayed. Suggest that the following colours are used:
| State | Colour |
|---|---|
| Go | "#00FF30" |
| Wait | "#FFFC00" |
| Stop | "#FF0000" |
- Refactor the implementation so that the colours are defined once in a module called TL, and we can refer to colours with the following syntax:
| State | Colour |
|---|---|
| TL:Go | "#00FF30" |
| TL:Wait | "#FFFC00" |
| TL:Stop | "#FF0000" |
- Refactor the implementation so that a bulb only shows its true colour when it is switched on, otherwise it shows grey. Fix the application so that it shows the TL::Stop state on startup.
- Implement the click method, so that every time the traffic light is clicked, the colours cycle through the states given in the TrafficLight class
- Change the TrafficLight class so the pattern matches US-style traffic lights.
- When you're done, submit a pull request so that I can review your work.