text: /* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
  /* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
  /* Copyright 2012 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.
   */
  /* globals VBArray, PDFJS */
  
  'use strict';
  
  // Initializing PDFJS global object here, it case if we need to change/disable
  // some PDF.js features, e.g. range requests
  if (typeof PDFJS === 'undefined') {
    (typeof window !== 'undefined' ? window : this).PDFJS = {};
  }
  
  // Checking if the typed arrays are supported
  // Support: iOS<6.0 (subarray), IE<10, Android<4.0
  (function checkTypedArrayCompatibility() {
    if (typeof Uint8Array !== 'undefined') {
      // Support: iOS<6.0
      if (typeof Uint8Array.prototype.subarray === 'undefined') {
          Uint8Array.prototype.subarray = function subarray(start, end) {
            return new Uint8Array(this.slice(start, end));
          };
          Float32Array.prototype.subarray = function subarray(start, end) {
            return new Float32Array(this.slice(start, end));
          };
      }
  
      // Support: Android<4.1
      if (typeof Float64Array === 'undefined') {
        window.Float64Array = Float32Array;
      }
      return;
    }
  
    function subarray(start, end) {
      return new TypedArray(this.slice(start, end));
    }
  
    function setArrayOffset(array, offset) {
      if (arguments.length < 2) {
        offset = 0;
      }
      for (var i = 0, n = array.length; i < n; ++i, ++offset) {
        this[offset] = array[i] & 0xFF;
      }
    }
  
    function TypedArray(arg1) {
      var result, i, n;
      if (typeof arg1 === 'number') {
        result = [];
        for (i = 0; i < arg1; ++i) {
          result[i] = 0;
        }
      } else if ('slice' in arg1) {
        result = arg1.slice(0);
      } else {
        result = [];
        for (i = 0, n = arg1.length; i < n; ++i) {
          result[i] = arg1[i];
        }
      }
  
      result.subarray = subarray;
      result.buffer = result;
      result.byteLength = result.length;
      result.set = setArrayOffset;
  
      if (typeof arg1 === 'object' && arg1.buffer) {
        result.buffer = arg1.buffer;
      }
      return result;
    }
  
    window.Uint8Array = TypedArray;
    window.Int8Array = TypedArray;
  
    // we don't need support for set, byteLength for 32-bit array
    // so we can use the TypedArray as well
    window.Uint32Array = TypedArray;
    window.Int32Array = TypedArray;
    window.Uint16Array = TypedArray;
    window.Float32Array = TypedArray;
    window.Float64Array = TypedArray;
  })();
  
  // URL = URL || webkitURL
  // Support: Safari<7, Android 4.2+
  (function normalizeURLObject() {
    if (!window.URL) {
      window.URL = window.webkitURL;
    }
  })();
  
  // Object.defineProperty()?
  // Support: Android<4.0, Safari<5.1
  (function checkObjectDefinePropertyCompatibility() {
    if (typeof Object.defineProperty !== 'undefined') {
      var definePropertyPossible = true;
      try {
        // some browsers (e.g. safari) cannot use defineProperty() on DOM objects
        // and thus the native version is not sufficient
        Object.defineProperty(new Image(), 'id', { value: 'test' });
        // ... another test for android gb browser for non-DOM objects
        var Test = function Test() {};
        Test.prototype = { get id() { } };
        Object.defineProperty(new Test(), 'id',
          { value: '', configurable: true, enumerable: true, writable: false });
      } catch (e) {
        definePropertyPossible = false;
      }
      if (definePropertyPossible) {
        return;
      }
    }
  
    Object.defineProperty = function objectDefineProperty(obj, name, def) {
      delete obj[name];
      if ('get' in def) {
        obj.__defineGetter__(name, def['get']);
      }
      if ('set' in def) {
        obj.__defineSetter__(name, def['set']);
      }
      if ('value' in def) {
        obj.__defineSetter__(name, function objectDefinePropertySetter(value) {
          this.__defineGetter__(name, function objectDefinePropertyGetter() {
            return value;
          });
          return value;
        });
        obj[name] = def.value;
      }
    };
  })();
  
  
  // No XMLHttpRequest#response?
  // Support: IE<11, Android <4.0
  (function checkXMLHttpRequestResponseCompatibility() {
    var xhrPrototype = XMLHttpRequest.prototype;
    var xhr = new XMLHttpRequest();
    if (!('overrideMimeType' in xhr)) {
      // IE10 might have response, but not overrideMimeType
      // Support: IE10
      Object.defineProperty(xhrPrototype, 'overrideMimeType', {
        value: function xmlHttpRequestOverrideMimeType(mimeType) {}
      });
    }
    if ('responseType' in xhr) {
      return;
    }
  
    // The worker will be using XHR, so we can save time and disable worker.
    PDFJS.disableWorker = true;
  
    Object.defineProperty(xhrPrototype, 'responseType', {
      get: function xmlHttpRequestGetResponseType() {
        return this._responseType || 'text';
      },
      set: function xmlHttpRequestSetResponseType(value) {
        if (value === 'text' || value === 'arraybuffer') {
          this._responseType = value;
          if (value === 'arraybuffer' &&
              typeof this.overrideMimeType === 'function') {
            this.overrideMimeType('text/plain; charset=x-user-defined');
          }
        }
      }
    });
  
    // Support: IE9
    if (typeof VBArray !== 'undefined') {
      Object.defineProperty(xhrPrototype, 'response', {
        get: function xmlHttpRequestResponseGet() {
          if (this.responseType === 'arraybuffer') {
            return new Uint8Array(new VBArray(this.responseBody).toArray());
          } else {
            return this.responseText;
          }
        }
      });
      return;
    }
  
    Object.defineProperty(xhrPrototype, 'response', {
      get: function xmlHttpRequestResponseGet() {
        if (this.responseType !== 'arraybuffer') {
          return this.responseText;
        }
        var text = this.responseText;
        var i, n = text.length;
        var result = new Uint8Array(n);
        for (i = 0; i < n; ++i) {
          result[i] = text.charCodeAt(i) & 0xFF;
        }
        return result.buffer;
      }
    });
  })();
  
  // window.btoa (base64 encode function) ?
  // Support: IE<10
  (function checkWindowBtoaCompatibility() {
    if ('btoa' in window) {
      return;
    }
  
    var digits =
      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
  
    window.btoa = function windowBtoa(chars) {
      var buffer = '';
      var i, n;
      for (i = 0, n = chars.length; i < n; i += 3) {
        var b1 = chars.charCodeAt(i) & 0xFF;
        var b2 = chars.charCodeAt(i + 1) & 0xFF;
        var b3 = chars.charCodeAt(i + 2) & 0xFF;
        var d1 = b1 >> 2, d2 = ((b1 & 3) << 4) | (b2 >> 4);
        var d3 = i + 1 < n ? ((b2 & 0xF) << 2) | (b3 >> 6) : 64;
        var d4 = i + 2 < n ? (b3 & 0x3F) : 64;
        buffer += (digits.charAt(d1) + digits.charAt(d2) +
                   digits.charAt(d3) + digits.charAt(d4));
      }
      return buffer;
    };
  })();
  
  // window.atob (base64 encode function)?
  // Support: IE<10
  (function checkWindowAtobCompatibility() {
    if ('atob' in window) {
      return;
    }
  
    // https://github.com/davidchambers/Base64.js
    var digits =
      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
    window.atob = function (input) {
      input = input.replace(/=+$/, '');
      if (input.length % 4 === 1) {
        throw new Error('bad atob input');
      }
      for (
        // initialize result and counters
        var bc = 0, bs, buffer, idx = 0, output = '';
        // get next character
        buffer = input.charAt(idx++);
        // character found in table?
        // initialize bit storage and add its ascii value
        ~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
          // and if not first of each 4 characters,
          // convert the first 8 bits to one ascii character
          bc++ % 4) ? output += String.fromCharCode(255 & bs >> (-2 * bc & 6)) : 0
      ) {
        // try to find character in table (0-63, not found => -1)
        buffer = digits.indexOf(buffer);
      }
      return output;
    };
  })();
  
  // Function.prototype.bind?
  // Support: Android<4.0, iOS<6.0
  (function checkFunctionPrototypeBindCompatibility() {
    if (typeof Function.prototype.bind !== 'undefined') {
      return;
    }
  
    Function.prototype.bind = function functionPrototypeBind(obj) {
      var fn = this, headArgs = Array.prototype.slice.call(arguments, 1);
      var bound = function functionPrototypeBindBound() {
        var args = headArgs.concat(Array.prototype.slice.call(arguments));
        return fn.apply(obj, args);
      };
      return bound;
    };
  })();
  
  // HTMLElement dataset property
  // Support: IE<11, Safari<5.1, Android<4.0
  (function checkDatasetProperty() {
    var div = document.createElement('div');
    if ('dataset' in div) {
      return; // dataset property exists
    }
  
    Object.defineProperty(HTMLElement.prototype, 'dataset', {
      get: function() {
        if (this._dataset) {
          return this._dataset;
        }
  
        var dataset = {};
        for (var j = 0, jj = this.attributes.length; j < jj; j++) {
          var attribute = this.attributes[j];
          if (attribute.name.substring(0, 5) !== 'data-') {
            continue;
          }
          var key = attribute.name.substring(5).replace(/\-([a-z])/g,
            function(all, ch) {
              return ch.toUpperCase();
            });
          dataset[key] = attribute.value;
        }
  
        Object.defineProperty(this, '_dataset', {
          value: dataset,
          writable: false,
          enumerable: false
        });
        return dataset;
      },
      enumerable: true
    });
  })();
  
  // HTMLElement classList property
  // Support: IE<10, Android<4.0, iOS<5.0
  (function checkClassListProperty() {
    var div = document.createElement('div');
    if ('classList' in div) {
      return; // classList property exists
    }
  
    function changeList(element, itemName, add, remove) {
      var s = element.className || '';
      var list = s.split(/\s+/g);
      if (list[0] === '') {
        list.shift();
      }
      var index = list.indexOf(itemName);
      if (index < 0 && add) {
        list.push(itemName);
      }
      if (index >= 0 && remove) {
        list.splice(index, 1);
      }
      element.className = list.join(' ');
      return (index >= 0);
    }
  
    var classListPrototype = {
      add: function(name) {
        changeList(this.element, name, true, false);
      },
      contains: function(name) {
        return changeList(this.element, name, false, false);
      },
      remove: function(name) {
        changeList(this.element, name, false, true);
      },
      toggle: function(name) {
        changeList(this.element, name, true, true);
      }
    };
  
    Object.defineProperty(HTMLElement.prototype, 'classList', {
      get: function() {
        if (this._classList) {
          return this._classList;
        }
  
        var classList = Object.create(classListPrototype, {
          element: {
            value: this,
            writable: false,
            enumerable: true
          }
        });
        Object.defineProperty(this, '_classList', {
          value: classList,
          writable: false,
          enumerable: false
        });
        return classList;
      },
      enumerable: true
    });
  })();
  
  // Check console compatibility
  // In older IE versions the console object is not available
  // unless console is open.
  // Support: IE<10
  (function checkConsoleCompatibility() {
    if (!('console' in window)) {
      window.console = {
        log: function() {},
        error: function() {},
        warn: function() {}
      };
    } else if (!('bind' in //console.log)) {
      // native functions in IE9 might not have bind
      //console.log = (function(fn) {
        return function(msg) { return fn(msg); };
      })(//console.log);
      //console.error = (function(fn) {
        return function(msg) { return fn(msg); };
      })(//console.error);
      //console.warn = (function(fn) {
        return function(msg) { return fn(msg); };
      })(//console.warn);
    }
  })();
  
  // Check onclick compatibility in Opera
  // Support: Opera<15
  (function checkOnClickCompatibility() {
    // workaround for reported Opera bug DSK-354448:
    // onclick fires on disabled buttons with opaque content
    function ignoreIfTargetDisabled(event) {
      if (isDisabled(event.target)) {
        event.stopPropagation();
      }
    }
    function isDisabled(node) {
      return node.disabled || (node.parentNode && isDisabled(node.parentNode));
    }
    if (navigator.userAgent.indexOf('Opera') !== -1) {
      // use browser detection since we cannot feature-check this bug
      document.addEventListener('click', ignoreIfTargetDisabled, true);
    }
  })();
  
  // Checks if possible to use URL.createObjectURL()
  // Support: IE
  (function checkOnBlobSupport() {
    // sometimes IE loosing the data created with createObjectURL(), see #3977
    if (navigator.userAgent.indexOf('Trident') >= 0) {
      PDFJS.disableCreateObjectURL = true;
    }
  })();
  
  // Checks if navigator.language is supported
  (function checkNavigatorLanguage() {
    if ('language' in navigator) {
      return;
    }
    PDFJS.locale = navigator.userLanguage || 'en-US';
  })();
  
  (function checkRangeRequests() {
    // Safari has issues with cached range requests see:
    // https://github.com/mozilla/pdf.js/issues/3260
    // Last tested with version 6.0.4.
    // Support: Safari 6.0+
    var isSafari = Object.prototype.toString.call(
                    window.HTMLElement).indexOf('Constructor') > 0;
  
    // Older versions of Android (pre 3.0) has issues with range requests, see:
    // https://github.com/mozilla/pdf.js/issues/3381.
    // Make sure that we only match webkit-based Android browsers,
    // since Firefox/Fennec works as expected.
    // Support: Android<3.0
    var regex = /Android\s[0-2][^\d]/;
    var isOldAndroid = regex.test(navigator.userAgent);
  
    // Range requests are broken in Chrome 39 and 40, https://crbug.com/442318
    var isChromeWithRangeBug = /Chrome\/(39|40)\./.test(navigator.userAgent);
  
    if (isSafari || isOldAndroid || isChromeWithRangeBug) {
      PDFJS.disableRange = true;
      PDFJS.disableStream = true;
    }
  })();
  
  // Check if the browser supports manipulation of the history.
  // Support: IE<10, Android<4.2
  (function checkHistoryManipulation() {
    // Android 2.x has so buggy pushState support that it was removed in
    // Android 3.0 and restored as late as in Android 4.2.
    // Support: Android 2.x
    if (!history.pushState || navigator.userAgent.indexOf('Android 2.') >= 0) {
      PDFJS.disableHistory = true;
    }
  })();
  
  // Support: IE<11, Chrome<21, Android<4.4, Safari<6
  (function checkSetPresenceInImageData() {
    // IE < 11 will use window.CanvasPixelArray which lacks set function.
    if (window.CanvasPixelArray) {
      if (typeof window.CanvasPixelArray.prototype.set !== 'function') {
        window.CanvasPixelArray.prototype.set = function(arr) {
          for (var i = 0, ii = this.length; i < ii; i++) {
            this[i] = arr[i];
          }
        };
      }
    } else {
      // Old Chrome and Android use an inaccessible CanvasPixelArray prototype.
      // Because we cannot feature detect it, we rely on user agent parsing.
      var polyfill = false, versionMatch;
      if (navigator.userAgent.indexOf('Chrom') >= 0) {
        versionMatch = navigator.userAgent.match(/Chrom(e|ium)\/([0-9]+)\./);
        // Chrome < 21 lacks the set function.
        polyfill = versionMatch && parseInt(versionMatch[2]) < 21;
      } else if (navigator.userAgent.indexOf('Android') >= 0) {
        // Android < 4.4 lacks the set function.
        // Android >= 4.4 will contain Chrome in the user agent,
        // thus pass the Chrome check above and not reach this block.
        polyfill = /Android\s[0-4][^\d]/g.test(navigator.userAgent);
      } else if (navigator.userAgent.indexOf('Safari') >= 0) {
        versionMatch = navigator.userAgent.
          match(/Version\/([0-9]+)\.([0-9]+)\.([0-9]+) Safari\//);
        // Safari < 6 lacks the set function.
        polyfill = versionMatch && parseInt(versionMatch[1]) < 6;
      }
  
      if (polyfill) {
        var contextPrototype = window.CanvasRenderingContext2D.prototype;
        contextPrototype._createImageData = contextPrototype.createImageData;
        contextPrototype.createImageData = function(w, h) {
          var imageData = this._createImageData(w, h);
          imageData.data.set = function(arr) {
            for (var i = 0, ii = this.length; i < ii; i++) {
              this[i] = arr[i];
            }
          };
          return imageData;
        };
      }
    }
  })();
  
  // Support: IE<10, Android<4.0, iOS
  (function checkRequestAnimationFrame() {
    function fakeRequestAnimationFrame(callback) {
      window.setTimeout(callback, 20);
    }
  
    var isIOS = /(iPad|iPhone|iPod)/g.test(navigator.userAgent);
    if (isIOS) {
      // requestAnimationFrame on iOS is broken, replacing with fake one.
      window.requestAnimationFrame = fakeRequestAnimationFrame;
      return;
    }
    if ('requestAnimationFrame' in window) {
      return;
    }
    window.requestAnimationFrame =
      window.mozRequestAnimationFrame ||
      window.webkitRequestAnimationFrame ||
      fakeRequestAnimationFrame;
  })();
  
  (function checkCanvasSizeLimitation() {
    var isIOS = /(iPad|iPhone|iPod)/g.test(navigator.userAgent);
    var isAndroid = /Android/g.test(navigator.userAgent);
    if (isIOS || isAndroid) {
      // 5MP
      PDFJS.maxCanvasPixels = 5242880;
    }
  })();
  
  // Disable fullscreen support for certain problematic configurations.
  // Support: IE11+ (when embedded).
  (function checkFullscreenSupport() {
    var isEmbeddedIE = (navigator.userAgent.indexOf('Trident') >= 0 &&
                        window.parent !== window);
    if (isEmbeddedIE) {
      PDFJS.disableFullscreen = true;
    }
  })();
  