Function $SnifferProvider

test/angular/1.4/angular.js:17955–18026

* !!! This is an undocumented "private" service !!! * * @name $sniffer * @requires $window * @requires $document * * @property {boolean} history Does the browser support html5 history api ? * @property {boolean} transitions Does the browser support CSS transition events ? * @property {boolea

()

 * This is very simple implementation of testing browser's features.
 */
function $SnifferProvider() {
  this.$get = ['$window', '$document', function($window, $document) {
    var eventSupport = {},
        android =
          toInt((/android (\d+)/.exec(lowercase(($window.navigator || {}).userAgent)) || [])[1]),
        boxee = /Boxee/i.test(($window.navigator || {}).userAgent),
        document = $document[0] || {},
        vendorPrefix,
        vendorRegex = /^(Moz|webkit|ms)(?=[A-Z])/,
        bodyStyle = document.body && document.body.style,
        transitions = false,
        animations = false,
        match;

    if (bodyStyle) {
      for (var prop in bodyStyle) {
        if (match = vendorRegex.exec(prop)) {
          vendorPrefix = match[0];
          vendorPrefix = vendorPrefix.substr(0, 1).toUpperCase() + vendorPrefix.substr(1);
          break;
        }
      }

      if (!vendorPrefix) {
        vendorPrefix = ('WebkitOpacity' in bodyStyle) && 'webkit';
      }

      transitions = !!(('transition' in bodyStyle) || (vendorPrefix + 'Transition' in bodyStyle));
      animations  = !!(('animation' in bodyStyle) || (vendorPrefix + 'Animation' in bodyStyle));

      if (android && (!transitions ||  !animations)) {
        transitions = isString(bodyStyle.webkitTransition);
        animations = isString(bodyStyle.webkitAnimation);
      }
    }


    return {
      // Android has history.pushState, but it does not update location correctly
      // so let's not use the history API at all.
      // http://code.google.com/p/android/issues/detail?id=17471
      // https://github.com/angular/angular.js/issues/904

      // older webkit browser (533.9) on Boxee box has exactly the same problem as Android has
      // so let's not use the history API also
      // We are purposefully using `!(android < 4)` to cover the case when `android` is undefined
      // jshint -W018
      history: !!($window.history && $window.history.pushState && !(android < 4) && !boxee),
      // jshint +W018
      hasEvent: function(event) {
        // IE9 implements 'input' event it's so fubared that we rather pretend that it doesn't have
        // it. In particular the event is not fired when backspace or delete key are pressed or
        // when cut operation is performed.
        // IE10+ implements 'input' event but it erroneously fires under various situations,
        // e.g. when placeholder changes, or a form is focused.
        if (event === 'input' && msie <= 11) return false;

        if (isUndefined(eventSupport[event])) {