[js]Stopwatch

Stopwatch.js

var Stopwatch = function() {
    this.initialize.apply(this, arguments);
};
Stopwatch.prototype = {
    initialize: function() {
        this.reset();
    },
    start: function() {
        this.startTime = new Date();
    },
    stop: function() {
        this.stamp = this.getStamp();
        this.startTime = null;
    },
    reset: function() {
        this.stamp = 0;
        this.startTime = null;
    },
    getStamp: function() {
        if (this.startTime == null) { return this.stamp; }
        return new Date() - this.startTime + this.stamp;
    },
    getStampString: function() {
        var stamp = this.getStamp(), pl = function(v) { return v < 10 ? "0" + v : v; };
        var s = (stamp % (60 * 1000))  / 1000;
        var m = ((stamp  / (60 * 1000)) | 0) % 60;
        var h = ((stamp  / (60 * 60 * 1000)) | 0) % 60;
        return "" + pl(h) + ":" + pl(m) + ":" + pl(s);
    }
};