roman_elevator.js
var DIRECTION_DOWN = -1
var DIRECTION_NONE = 0
var DIRECTION_UP = 1

function HardwareElevator(){};
HardwareElevator.prototype = {
    moveUp:function(){console.log('moving up');},
    moveDown:function(){console.log('moving down');},
    stopAndOpenDoors:function(){console.log('stopping and opening doors');},
    getCurrentFloor:function(){console.log('getting current floor');},
    getCurrentDirection:function(){console.log('getting current drection');}
}

function Elevator() {
    this.hw = new HardwareElevator();
    this.hw.addEventListener("doorsClosed", _.bind(this.onDoorsClosed, this));
    this.hw.addEventListener("beforeFloor", _.bind(this.onBeforeFloor, this));

    this.destinationFloor = 0;
}
Elevator.prototype = {
    onDoorsClosed: function(floor) {
        if (this.destinationFloor > floor) {
            this.hw.moveUp();
        } else if (this.destinationFloor < floor) {
            this.hw.moveDown();
        }
    },
    onBeforeFloor: function(floor, direction) {
        if (this.destinationFloor === floor) {
            this.hw.stopAndOpenDoors();
        }
    },
    floorButtonPressed: function(floor, direction) {
        if (this.hw.getCurrentDirection === DIRECTION_NONE) {
            this.destinationFloor = floor;

            if (this.hw.getCurrentFloor > floor) {
                this.hw.moveDown();
            } else if (this.hw.getCurrentFloor < floor) {
                this.hw.moveUp();
            } else {
                this.stopAndOpenDoors();
            }
        }
    },
    cabinButtonPressed: function(floor) {
        if (this.hw.getCurrentDirection === DIRECTION_NONE) {
            this.destinationFloor = floor;

            if (this.hw.getCurrentFloor > floor) {
                this.hw.moveDown();
            } else if (this.hw.getCurrentFloor < floor) {
                this.hw.moveUp();
            } else {
                this.hw.stopAndOpenDoors();
            }
        }
    }
}