/* Copyright 2015 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

'use strict';

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    define('pdfjs/display/dom_utils', ['exports', 'pdfjs/shared/global'],
      factory);
  } else if (typeof exports !== 'undefined') {
    factory(exports, require('../shared/global.js'));
  } else {
    factory((root.pdfjsDisplayDOMUtils = {}), root.pdfjsSharedGlobal);
  }
}(this, function (exports, sharedGlobal) {

var PDFJS = sharedGlobal.PDFJS;

/**
 * Optimised CSS custom property getter/setter.
 * @class
 */
var CustomStyle = (function CustomStyleClosure() {

  // As noted on: http://www.zachstronaut.com/posts/2009/02/17/
  //              animate-css-transforms-firefox-webkit.html
  // in some versions of IE9 it is critical that ms appear in this list
  // before Moz
  var prefixes = ['ms', 'Moz', 'Webkit', 'O'];
  var _cache = {};

  function CustomStyle() {}

  CustomStyle.getProp = function get(propName, element) {
    // check cache only when no element is given
    if (arguments.length === 1 && typeof _cache[propName] === 'string') {
      return _cache[propName];
    }

    element = element || document.documentElement;
    var style = element.style, prefixed, uPropName;

    // test standard property first
    if (typeof style[propName] === 'string') {
      return (_cache[propName] = propName);
    }

    // capitalize
    uPropName = propName.charAt(0).toUpperCase() + propName.slice(1);

    // test vendor specific properties
    for (var i = 0, l = prefixes.length; i < l; i++) {
      prefixed = prefixes[i] + uPropName;
      if (typeof style[prefixed] === 'string') {
        return (_cache[propName] = prefixed);
      }
    }

    //if all fails then set to undefined
    return (_cache[propName] = 'undefined');
  };

  CustomStyle.setProp = function set(propName, element, str) {
    var prop = this.getProp(propName);
    if (prop !== 'undefined') {
      element.style[prop] = str;
    }
  };

  return CustomStyle;
})();

PDFJS.CustomStyle = CustomStyle;

exports.CustomStyle = CustomStyle;
}));
