macKeys.js

/**
 * (c) Michael Zelensky 2015
 *
 * DESCRIPTION
 *
 * Ctrl, Shift, Alt, Cmd buttons detector for Mac
 * to support corresponding event.ctrlKey, event.shiftKey, event.altKey which do not work on Mac
 *
 * LICENSE
 *
 * Distributed under MIT License
 * You can use this code in your project without limitation, no matter if it is commercial or not,
 * with all copyright marks intact
 *
 * USAGE
 *
 * Just include this code into your JS or HTML and then check if key is pressed in your code, e.g.:
 *
 * window.onclick = function (event) {
 *     if (event.ctrlKey || macKeys.ctrlKey) {
 *         //do something
 *     }
 * }
 *
 */

(function(){
    var saywho, isMac, webkit, mozilla, opera, kC;
    isMac = navigator.platform.toUpperCase().indexOf('MAC') >= 0;
    window.macKeys = {
        cmdKey : false,
        ctrlKey : false,
        shiftKey : false,
        altKey : false,
        reset : function(){
            this.cmdKey = false;
            this.ctrlKey = false;
            this.shiftKey = false;
            this.altKey = false;
        }
    };
    if (isMac) {
        //browser detection, originates from: http://stackoverflow.com/questions/2400935/browser-detection-in-javascript
        saywho = (function(){
            var ua = navigator.userAgent, tem,
                M = ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [];
            if (/trident/i.test(M[1])) {
                tem = /\brv[ :]+(\d+)/g.exec(ua) || [];
                return { 'browser': 'IE', 'version': (tem[1] || '') };
            }
            if (M[1] === 'Chrome') {
                tem = ua.match(/\b(OPR|Edge)\/(\d+)/);
                //if(tem != null) return tem.slice(1).join(' ').replace('OPR', 'Opera');
                if (tem != null) return {'browser':tem.slice(1)[0].replace('OPR', 'Opera'), 'version': tem.slice(1)[1]}
            }
            M = M[2] ? [M[1], M[2]]: [navigator.appName, navigator.appVersion, '-?'];
            if ((tem = ua.match(/version\/(\d+)/i))!= null) M.splice(1, 1, tem[1]);
            return { 'browser': M[0], 'version': M[1] };
        })();
        webkit = (saywho.browser === 'Chrome' || saywho.browser === 'Safari');
        mozilla = saywho.browser === 'Firefox';
        opera = saywho.browser === 'Opera';
        window.onkeydown = function(e){
            kC = e.keyCode;
            if (((webkit || opera) && (kC === 91 || kC === 93)) || (mozilla && kC === 224)) {
                macKeys.cmdKey = true;
            } else if (kC === 16) {
                macKeys.shiftKey = true;
            } else if (kC === 17) {
                macKeys.ctrlKey = true;
            } else if (kC === 18) {
                macKeys.altKey = true;
            }
        };
        window.onkeyup = function(e){
            kC = e.keyCode;
            if (((webkit || opera) && (kC === 91 || kC === 93)) || (mozilla && kC === 224)) {
                macKeys.cmdKey = false;
            } else if (kC === 16) {
                macKeys.shiftKey = false;
            } else if (kC === 17) {
                macKeys.ctrlKey = false;
            } else if (kC === 18) {
                macKeys.altKey = false;
            }
        };
        window.onblur = function(){
            macKeys.reset();
        };
    }
})();