helpers.js

"use strict"

var Helpers = (function(){

    function getEarthCircumference() { return 2 * Math.PI * (6378.1 * 1000); }
    function getColor(colorName) { return colors[colorName];}

//map of all default CSS color names
    var colors = {
    "aliceblue":"#f0f8ff","antiquewhite":"#faebd7","aqua":"#00ffff","aquamarine":"#7fffd4",
    "azure":"#f0ffff", "beige":"#f5f5dc","bisque":"#ffe4c4","black":"#000000",
    "blanchedalmond":"#ffebcd","blue":"#0000ff","blueviolet":"#8a2be2","brown":"#a52a2a",
    "burlywood":"#deb887","cadetblue":"#5f9ea0","chartreuse":"#7fff00","chocolate":"#d2691e",
    "coral":"#ff7f50","cornflowerblue":"#6495ed","cornsilk":"#fff8dc","crimson":"#dc143c",
    "cyan":"#00ffff","darkblue":"#00008b","darkcyan":"#008b8b","darkgoldenrod":"#b8860b",
    "darkgray":"#a9a9a9", "darkgreen":"#006400","darkkhaki":"#bdb76b","darkmagenta":"#8b008b",
    "darkolivegreen":"#556b2f","darkorange":"#ff8c00","darkorchid":"#9932cc","darkred":"#8b0000",
    "darksalmon":"#e9967a","darkseagreen":"#8fbc8f","darkslateblue":"#483d8b",
    "darkslategray":"#2f4f4f","darkturquoise":"#00ced1","darkviolet":"#9400d3","deeppink":"#ff1493",
    "deepskyblue":"#00bfff", "dimgray":"#696969","dodgerblue":"#1e90ff","firebrick":"#b22222",
    "floralwhite":"#fffaf0","forestgreen":"#228b22","fuchsia":"#ff00ff","gainsboro":"#dcdcdc",
    "ghostwhite":"#f8f8ff","gold":"#ffd700","goldenrod":"#daa520","gray":"#808080",
    "green":"#008000","greenyellow":"#adff2f","honeydew":"#f0fff0","hotpink":"#ff69b4",
    "indianred":"#cd5c5c","indigo":"#4b0082","ivory":"#fffff0","khaki":"#f0e68c",
    "lavender":"#e6e6fa","lavenderblush":"#fff0f5","lawngreen":"#7cfc00","lemonchiffon":"#fffacd",
    "lightblue":"#add8e6","lightcoral":"#f08080","lightcyan":"#e0ffff",
    "lightgoldenrodyellow":"#fafad2","lightgrey":"#d3d3d3","lightgreen":"#90ee90",
    "lightpink":"#ffb6c1","lightsalmon":"#ffa07a","lightseagreen":"#20b2aa",
    "lightskyblue":"#87cefa","lightslategray":"#778899","lightsteelblue":"#b0c4de",
    "lightyellow":"#ffffe0","lime":"#00ff00","limegreen":"#32cd32","linen":"#faf0e6",
    "magenta":"#ff00ff","maroon":"#800000","mediumaquamarine":"#66cdaa","mediumblue":"#0000cd",
    "mediumorchid":"#ba55d3","mediumpurple":"#9370d8","mediumseagreen":"#3cb371",
    "mediumslateblue":"#7b68ee","mediumspringgreen":"#00fa9a","mediumturquoise":"#48d1cc",
    "mediumvioletred":"#c71585","midnightblue":"#191970","mintcream":"#f5fffa",
    "mistyrose":"#ffe4e1","moccasin":"#ffe4b5","navajowhite":"#ffdead","navy":"#000080",
    "oldlace":"#fdf5e6","olive":"#808000","olivedrab":"#6b8e23","orange":"#ffa500",
    "orangered":"#ff4500","orchid":"#da70d6","palegoldenrod":"#eee8aa","palegreen":"#98fb98",
    "paleturquoise":"#afeeee","palevioletred":"#d87093","papayawhip":"#ffefd5",
    "peachpuff":"#ffdab9","peru":"#cd853f","pink":"#ffc0cb","plum":"#dda0dd","powderblue":"#b0e0e6",
    "purple":"#800080","red":"#ff0000","rosybrown":"#bc8f8f","royalblue":"#4169e1",
    "saddlebrown":"#8b4513","salmon":"#fa8072","sandybrown":"#f4a460","seagreen":"#2e8b57",
    "seashell":"#fff5ee","sienna":"#a0522d","silver":"#c0c0c0","skyblue":"#87ceeb",
    "slateblue":"#6a5acd","slategray":"#708090","snow":"#fffafa","springgreen":"#00ff7f",
    "steelblue":"#4682b4","tan":"#d2b48c","teal":"#008080","thistle":"#d8bfd8","tomato":"#ff6347",
    "turquoise":"#40e0d0","violet":"#ee82ee","wheat":"#f5deb3","white":"#ffffff",
    "whitesmoke":"#f5f5f5","yellow":"#ffff00","yellowgreen":"#9acd32"}
    
    var daysPerMonth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
    
    var webGlFailMessage = {
        DEVICE_TOO_OLD: "Ihr Gerät ist vermutlich zu alt und unterstützt keine 3D-Grafik im Browser (WebGL)",
        ANDROID_UNSUPPORTED_BROWSER: "Ihr Android-Browser unterstützt anscheinend keine 3D-Grafiken (WebGL). Mögliche Lösung: Installieren und benutzen sie ein aktuelle Version der Browser 'Chrome' oder 'Firefox Mobile'",
        IOS_VERSION_TOO_OLD: "Ihr iPhone/iPad unterstützt keine 3D-Grafik im Browser (WebGL). Mögliche Lösung: Aktualisieren sie das Betriebssystem ('iOS') auf Version 8 oder höher.",
        IE_TOO_OLD: "Ihr Internet Explorer unterstützt keine 3D-Grafik im Brwoser (WebGL). Mögliche Lösung: Aktualisieren sie den Internet Explorer auf Version 11 oder höher",
        GENERIC: "Ihr Browser oder ihr Gerät unterstützt keine 3D-Grafik im Browser (WebGL)."
    }
    
    function getWebGlFailReason()
    {
        var ua = navigator.userAgent.toLowerCase();
        var isAndroid = ua.indexOf("android") > -1;
        var isWebkit  = ua.indexOf("webkit")  > -1;
        var isChrome  = ua.indexOf("chrome")  > -1;
        var isFirefox = ua.indexOf("firefox") > -1;
        var isSafari  = (ua.indexOf("safari")  > -1) && (ua.indexOf("chrome")  == -1);  //Chrome's user agent also contains the "Safari" string
        var isMsie    = ua.indexOf("msie ")   > -1;
       
        var isMobile  = ua.indexOf("mobile")  > -1; //for firefox, this only means "phone", not "tablet"
        var isTablet  = ua.indexOf("tablet")  > -1;
        var isIphone  = ua.indexOf("iphone")  > -1;
        var isIpad    = ua.indexOf("ipad")  > -1;
        var isIos     = isIphone || isIpad;
        
        if (isAndroid && !(isChrome || isFirefox)) return webGlFailMessage.ANDROID_UNSUPPORTED_BROWSER;
        if (isAndroid &&  (isChrome || isFirefox)) return webGlFailMessage.DEVICE_TOO_OLD;
        if (isIos) return webGlFailMessage.IOS_VERSION_TOO_OLD;
        if (isMsie) return webGlFailMessage.IE_TOO_OLD;

        return webGlFailMessage.GENERIC;
    }

    function getDayString(dayOfYear)
    {
        var day = ((dayOfYear % 366) | 0)+1;
        var monthNames = ["Januar","Februar","März","April","Mai","Juni","Juli","August","September","Oktober","November","Dezember"];
        
        for (var month = 0; day > daysPerMonth[month]; month++)
            day -= daysPerMonth[month];
            
        return "" + day + ". " + monthNames[month];
    }

    function getDayOfYear(date)
    {
        var month = date.getMonth();        //Note the JavaScript Date API is 0-based for the getMonth(),
        var dayOfYear = date.getDate()-1;   //but 1-based for getDate()
        
        for (var i = 0; i < month; i++)
            dayOfYear += daysPerMonth[i];

        //for now, we just ignore leap years altogether        
        //var year = date.getFullYear();
        //var isLeapYear =  (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
        
        //in a leap year, every day after February 28th is one day further from the beginning of that year than normal
        //if (isLeapYear && dayOfYear > daysPerMonth[0] + daysPerMonth[1])
        //    dayOfYear += 1;
            
        return dayOfYear;
    }
    
    function ajaxGet( url, onReceivedHandler) {
        var req = new XMLHttpRequest();
        req.open("GET", url );
        req.overrideMimeType("text/plain");    //necessary to stop Firefox from logging spurious errors on some documents
        req.responseType = "";
        req.onreadystatechange = function() 
        { 
            if (req.readyState != 4 || req.response == null)
                return;

            onReceivedHandler(req.responseText);
        }
        req.send();
    
    }
    

    return {getEarthCircumference: getEarthCircumference, 
            getDayString:          getDayString, 
            getColor:              getColor, 
            getWebGlFailReason:    getWebGlFailReason,
            ajaxGet:               ajaxGet};

})();