State (5.7)

Envision a multilevel computer game that simulates driving a car. In the initial level, the road's condition is "regular". As the player moves to higher levels, new conditions of the road appear, e.g., gravel, wet, ice. The response to the car's controls, steering, braking, etc., varies with the road conditions. The game employs a State pattern to react to the player's use of the car controls.

For the purpose of this exercise, design a small GUI with four buttons (labeled left, accel, right and brake), a choice of conditions (labeled regular, gravel, wet and ice), and a feedback textfield showing the effect (in an arbitrary scale) of pressing a button in a given road ondition as follows:

               Regular   Gravel    Wet     Ice
        left      5        3        4       1
       accel      9        7        9       3
       right      5        3        4       1
       brake      8        6        7       2

Hint: One does not need to use the State pattern to manage such a trivial state. Pretend that the behavior of the car in various conditions is determinted by the simulator using complicated independent algorithms that are better encapsulated in various states.