extjs源码分析-003(js获取系统或者客户端信息)

(function(){
    var idSeed = 0,
        ua = navigator.userAgent.toLowerCase(),//客户端信息
        check = function(r){
            return r.test(ua);
        },
        DOC = document,
        isStrict = DOC.compatMode == "CSS1Compat",
        isOpera = check(/opera/),
        isChrome = check(/\bchrome\b/),//
        isWebKit = check(/webkit/),
        isSafari = !isChrome && check(/safari/),
        isSafari2 = isSafari && check(/applewebkit\/4/),
        isSafari3 = isSafari && check(/version\/3/),
        isSafari4 = isSafari && check(/version\/4/),
        isIE = !isOpera && check(/msie/),
        isIE7 = isIE && check(/msie 7/),
        isIE8 = isIE && check(/msie 8/),
        isIE6 = isIE && !isIE7 && !isIE8,
        isGecko = !isWebKit && check(/gecko/),
        isGecko2 = isGecko && check(/rv:1\.8/),
        isGecko3 = isGecko && check(/rv:1\.9/),
        isBorderBox = isIE && !isStrict,//ie盒子模型
        isWindows = check(/windows|win32/),
        isMac = check(/macintosh|mac os x/),
        isAir = check(/adobeair/),//是否为adobe air应用程序
        isLinux = check(/linux/),
        isSecure = /^https/i.test(window.location.protocol);//是否为https
})()