@atlassian/aui/src/js/aui/internal/browser.js

Atlassian User Interface library

var ua = navigator.userAgent.toLowerCase();
var isIE = /msie/.test(ua);
var isWinXP = /windows nt 5.1/.test(ua);
var isWinVista = /windows nt 6.0/.test(ua);
var isWin7 = /windows nt 6.1/.test(ua);
var isMacOSX = /mac os x/.test(ua);
var doesSupportHtml5DateInput;
var doesSupportFocusWithin;

/**
 * Layered elements can get obscured by <object>, <embed>, <select> or sometimes even <iframe>
 * on older versions of Windows + Internet Explorer.
 * From manual testing, all IE versions on Windows 7 appear to have the bug,
 * but no IE versions on Windows 8 have it.
 */
export function needsLayeringShim() {
    return isIE && (isWinXP || isWinVista || isWin7);
}

export function supportsVoiceOver() {
    return isMacOSX;
}

export function supportsDateField() {
    if (typeof doesSupportHtml5DateInput === 'undefined') {
        var el = document.createElement('input');
        el.setAttribute('type', 'date');
        doesSupportHtml5DateInput = el.type === 'date';
    }
    return doesSupportHtml5DateInput;
}

export function supportsFocusWithin() {
    if (typeof doesSupportFocusWithin === 'undefined') {
        try {
            document.querySelector(':focus-within');
            doesSupportFocusWithin = true;
            // eslint-disable-next-line no-unused-vars
        } catch (e) {
            doesSupportFocusWithin = false;
        }
    }
    return doesSupportFocusWithin;
}