sniffer.js

'use strict';

/**
 * !!! 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 {boolean} animations Does the browser support CSS animation events ?
 *
 * @description
 * This is very simple implementation of testing browser's features.
 */
function $SnifferProvider() {
  this.$get = ['$window', '$document', function($window, $document) {
    var eventSupport = {},
        // Chrome Packaged Apps are not allowed to access `history.pushState`. They can be detected by
        // the presence of `chrome.app.runtime` (see https://developer.chrome.com/apps/api_index)
        isChromePackagedApp = $window.chrome && $window.chrome.app && $window.chrome.app.runtime,
        hasHistoryPushState = !isChromePackagedApp && $window.history && $window.history.pushState,
        android =
          toInt((/android (\d+)/.exec(lowercase(($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[0].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: !!(hasHistoryPushState && !(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 <= 9) return false;

        if (isUndefined(eventSupport[event])) {
          var divElm = document.createElement('div');
          eventSupport[event] = 'on' + event in divElm;
        }

        return eventSupport[event];
      },
      csp: csp(),
      vendorPrefix: vendorPrefix,
      transitions: transitions,
      animations: animations,
      android: android
    };
  }];
}