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// Copyright 2010 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//      http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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 * @fileoverview Browser capability checks for the events package.
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 *
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 */
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goog.provide('goog.events.BrowserFeature');
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goog.require('goog.userAgent');
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/**
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 * Enum of browser capabilities.
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 * @enum {boolean}
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 */
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goog.events.BrowserFeature = {
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  /**
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   * Whether the button attribute of the event is W3C compliant.  False in
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   * Internet Explorer prior to version 9; document-version dependent.
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   */
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  HAS_W3C_BUTTON:
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      !goog.userAgent.IE || goog.userAgent.isDocumentModeOrHigher(9),
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  /**
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   * Whether the browser supports full W3C event model.
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   */
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  HAS_W3C_EVENT_SUPPORT:
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      !goog.userAgent.IE || goog.userAgent.isDocumentModeOrHigher(9),
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  /**
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   * To prevent default in IE7-8 for certain keydown events we need set the
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   * keyCode to -1.
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   */
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  SET_KEY_CODE_TO_PREVENT_DEFAULT:
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      goog.userAgent.IE && !goog.userAgent.isVersionOrHigher('9'),
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  /**
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   * Whether the {@code navigator.onLine} property is supported.
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   */
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  HAS_NAVIGATOR_ONLINE_PROPERTY:
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      !goog.userAgent.WEBKIT || goog.userAgent.isVersionOrHigher('528'),
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  /**
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   * Whether HTML5 network online/offline events are supported.
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   */
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  HAS_HTML5_NETWORK_EVENT_SUPPORT:
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      goog.userAgent.GECKO && goog.userAgent.isVersionOrHigher('1.9b') ||
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      goog.userAgent.IE && goog.userAgent.isVersionOrHigher('8') ||
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      goog.userAgent.OPERA && goog.userAgent.isVersionOrHigher('9.5') ||
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      goog.userAgent.WEBKIT && goog.userAgent.isVersionOrHigher('528'),
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  /**
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   * Whether HTML5 network events fire on document.body, or otherwise the
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   * window.
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   */
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  HTML5_NETWORK_EVENTS_FIRE_ON_BODY:
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      goog.userAgent.GECKO && !goog.userAgent.isVersionOrHigher('8') ||
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      goog.userAgent.IE && !goog.userAgent.isVersionOrHigher('9'),
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  /**
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   * Whether touch is enabled in the browser.
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   */
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  TOUCH_ENABLED:
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      ('ontouchstart' in goog.global ||
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       !!(goog.global['document'] && document.documentElement &&
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          'ontouchstart' in document.documentElement) ||
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       // IE10 uses non-standard touch events, so it has a different check.
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       !!(goog.global['navigator'] &&
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          goog.global['navigator']['msMaxTouchPoints']))
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};
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