[api-minor] Add support for PageLabels in the API

src/shared/util.js

@@ -808,6 +808,42 @@ var Util = PDFJS.Util = (function UtilClosure() {
     return num < 0 ? -1 : 1;
   };
 
+  var ROMAN_NUMBER_MAP = [
+    '', 'C', 'CC', 'CCC', 'CD', 'D', 'DC', 'DCC', 'DCCC', 'CM',
+    '', 'X', 'XX', 'XXX', 'XL', 'L', 'LX', 'LXX', 'LXXX', 'XC',
+    '', 'I', 'II', 'III', 'IV', 'V', 'VI', 'VII', 'VIII', 'IX'
+  ];
+  /**
+   * Converts positive integers to (upper case) Roman numerals.
+   * @param {integer} number - The number that should be converted.
+   * @param {boolean} lowerCase - Indicates if the result should be converted
+   *   to lower case letters. The default is false.
+   * @return {string} The resulting Roman number.
+   */
+  Util.toRoman = function Util_toRoman(number, lowerCase) {
+    assert(isInt(number) && number > 0,
+           'The number should be a positive integer.');
+    var pos, romanBuf = [];
+    // Thousands
+    while (number >= 1000) {
+      number -= 1000;
+      romanBuf.push('M');
+    }
+    // Hundreds
+    pos = (number / 100) | 0;
+    number %= 100;
+    romanBuf.push(ROMAN_NUMBER_MAP[pos]);
+    // Tens
+    pos = (number / 10) | 0;
+    number %= 10;
+    romanBuf.push(ROMAN_NUMBER_MAP[10 + pos]);
+    // Ones
+    romanBuf.push(ROMAN_NUMBER_MAP[20 + number]);
+
+    var romanStr = romanBuf.join('');
+    return (lowerCase ? romanStr.toLowerCase() : romanStr);
+  };
+
   Util.appendToArray = function Util_appendToArray(arr1, arr2) {
     Array.prototype.push.apply(arr1, arr2);
   };