# lib/goog/labs/useragent/engine.js

1 | // Copyright 2013 The Closure Library Authors. All Rights Reserved.
2 | //
3 | // Licensed under the Apache License, Version 2.0 (the "License");
4 | // you may not use this file except in compliance with the License.
5 | // You may obtain a copy of the License at
6 | //
7 | // http://www.apache.org/licenses/LICENSE-2.0
8 | //
9 | // Unless required by applicable law or agreed to in writing, software
10 | // distributed under the License is distributed on an "AS-IS" BASIS,
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 | // See the License for the specific language governing permissions and
13 | // limitations under the License.
14 |
15 | /**
16 | * @fileoverview Closure user agent detection.
17 | * @see http://en.wikipedia.org/wiki/User_agent
18 | * For more information on browser brand, platform, or device see the other
19 | * sub-namespaces in goog.labs.userAgent (browser, platform, and device).
20 | *
21 | */
22 |
23 | goog.provide('goog.labs.userAgent.engine');
24 |
25 | goog.require('goog.array');
26 | goog.require('goog.labs.userAgent.util');
27 | goog.require('goog.string');
28 |
29 |
30 | /**
31 | * @return {boolean} Whether the rendering engine is Presto.
32 | */
33 | goog.labs.userAgent.engine.isPresto = function() {
34 | return goog.labs.userAgent.util.matchUserAgent('Presto');
35 | };
36 |
37 |
38 | /**
39 | * @return {boolean} Whether the rendering engine is Trident.
40 | */
41 | goog.labs.userAgent.engine.isTrident = function() {
42 | // IE only started including the Trident token in IE8.
43 | return goog.labs.userAgent.util.matchUserAgent('Trident') ||
44 | goog.labs.userAgent.util.matchUserAgent('MSIE');
45 | };
46 |
47 |
48 | /**
49 | * @return {boolean} Whether the rendering engine is WebKit.
50 | */
51 | goog.labs.userAgent.engine.isWebKit = function() {
52 | return goog.labs.userAgent.util.matchUserAgentIgnoreCase('WebKit');
53 | };
54 |
55 |
56 | /**
57 | * @return {boolean} Whether the rendering engine is Gecko.
58 | */
59 | goog.labs.userAgent.engine.isGecko = function() {
60 | return goog.labs.userAgent.util.matchUserAgent('Gecko') &&
61 | !goog.labs.userAgent.engine.isWebKit() &&
62 | !goog.labs.userAgent.engine.isTrident();
63 | };
64 |
65 |
66 | /**
67 | * @return {string} The rendering engine's version or empty string if version
68 | * can't be determined.
69 | */
70 | goog.labs.userAgent.engine.getVersion = function() {
71 | var userAgentString = goog.labs.userAgent.util.getUserAgent();
72 | if (userAgentString) {
73 | var tuples = goog.labs.userAgent.util.extractVersionTuples(
74 | userAgentString);
75 |
76 | var engineTuple = tuples[1];
77 | if (engineTuple) {
78 | // In Gecko, the version string is either in the browser info or the
79 | // Firefox version. See Gecko user agent string reference:
80 | // http://goo.gl/mULqa
81 | if (engineTuple[0] == 'Gecko') {
82 | return goog.labs.userAgent.engine.getVersionForKey_(
83 | tuples, 'Firefox');
84 | }
85 |
86 | return engineTuple[1];
87 | }
88 |
89 | // IE has only one version identifier, and the Trident version is
90 | // specified in the parenthetical.
91 | var browserTuple = tuples[0];
92 | var info;
93 | if (browserTuple && (info = browserTuple[2])) {
94 | var match = /Trident\/([^\s;]+)/.exec(info);
95 | if (match) {
96 | return match[1];
97 | }
98 | }
99 | }
100 | return '';
101 | };
102 |
103 |
104 | /**
105 | * @param {string|number} version The version to check.
106 | * @return {boolean} Whether the rendering engine version is higher or the same
107 | * as the given version.
108 | */
109 | goog.labs.userAgent.engine.isVersionOrHigher = function(version) {
110 | return goog.string.compareVersions(goog.labs.userAgent.engine.getVersion(),
111 | version) >= 0;
112 | };
113 |
114 |
115 | /**
116 | * @param {!Array<!Array<string>>} tuples Version tuples.
117 | * @param {string} key The key to look for.
118 | * @return {string} The version string of the given key, if present.
119 | * Otherwise, the empty string.
120 | * @private
121 | */
122 | goog.labs.userAgent.engine.getVersionForKey_ = function(tuples, key) {
123 | // TODO(nnaze): Move to util if useful elsewhere.
124 |
125 | var pair = goog.array.find(tuples, function(pair) {
126 | return key == pair[0];
127 | });
128 |
129 | return pair && pair[1] || '';
130 | };