Unity3D Collision Detector + Timer

//Apparently a Unity3D code snippet that times how long it takes for A to collide with B

using UnityEngine;
using System.Collections;

public class CollisionDetector : MonoBehaviour {

    //A new variable named timer.
    // Contains the timing class I made.
    Timer timer;

    //This begins the timing process.
    void Start () {
        timer = new Timer();
    }

    //OnGUI is called every frame.
    // This just makes a box that shows the time.
    // You can delete this and use whatever.
    void OnGUI () {
        //Only try to get the time if the timer isn't null.
        // If it is null, we can't get time from it
        //  because it doesn't exist!
        if(timer != null)
        {
            //Make a new GUI Box.
            // Inside, show the time (which is an integer)
            // We add +"" to make it a string.
            // It's the same as .toString()
            GUILayout.Box(timer.getTime()+"");
        }
    }

    //We're going to start the timer once we move
    // And NOT before.
    //This is a simple true/false variable to store that.
    bool moved = false;

    //Called every frame (basically a loop).
    // In this function, we just want to wait for a move
    //  To be made. Then we start the timer, and don't use this
    //   function ever again.
    void Update()
    {
        //Did we press the left/right arrow keys?
        // If so, we record that data into [delta].
        // That time is multiplied by [Time.deltaTime].
        // This just normalizes the data.
        // Without it, the [delta] variable would be dependant on how
        // quick the computer's frame rate is.
        float delta = Input.GetAxis("Horizontal")*Time.deltaTime;
        //Translate (move) this transform (the gameObject) by the amount.
        // We go to the right, multiplied by the [delta].
        // Note the delta can be negative or positive.
        transform.Translate(Vector3.right*delta);
        //If we haven't moved in any of the past frames BUT
        // the current frame has some (non-zero) movement,
        // then that means we have moved.
        if(moved == false && delta != 0)
        {
            //Set [moved] to true
            // This means the above line (moved == false)
            // will forevermore be untrue. (true == false) -> false
            // We don't need to check if we moved again anyways.
            moved = true;
            //Start the timer by using timer.startTimer().
            timer.startTimer();
        }
    }

    //On trigger enter.
    //
    //Setup in Editor:
    //
    //@Moving Object
    // Add this class to the [moving object].
    //  Add a rigidbody to that object.
    //   Make sure {Gravity} = false.
    //   and {Kinematic} = false.
    //  Use a regular collider.
    //@End GameObject
    // Make sure the [end object] has a collider.
    //  Set [end]'s {trigger} = true.
    //
    // This setup makes [movingObj] collide with walls and stuff (as usual)
    // However, the endObject is a trigger, which means stuff can move through it,
    //  but an event is still sent.
    //
    // When the [movingObj] hits the trigger, OnTriggerEnter is called.
    // The parameter, [other], is the collider script of the end object.
    void OnTriggerEnter(Collider other)
    {
        //Stops the timer.
        // This might get called multiple times
        //  if the triggers hit over and over, but it will be ignored
        //  by the timer code.
        timer.stopTimer();
    }

    //This is a class I just randomly made myself.
    // Its probably worse than the one you gave me, but oh well~
    public class Timer
    {
        int startTime;
        int stopTime;
        bool isRunning = false;
        public Timer(){}
        public int getTime()
        {
            if(isRunning)
            {
                return (int)Time.time-startTime;
            }
            else
            {
                return stopTime-startTime;
            }
        }
        public void startTimer()
        {
            startTime = (int)Time.time;
            isRunning = true;
            Debug.Log("Timer Start");
        }
        public void stopTimer()
        {
            if(isRunning)
            {
                stopTime = (int)Time.time;
                isRunning = false;
                Debug.Log("Stopped Timer at "+getTime()+" seconds.");
            }
        }
    }
}