The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 "use strict";

 this.EXPORTED_SYMBOLS = ["ContentUtil"];

 const XHTML_NS = "http://www.w3.org/1999/xhtml";

 const nsIDOMKeyEvent = Components.interfaces.nsIDOMKeyEvent;

 this.ContentUtil = {

   populateFragmentFromString: function populateFragmentFromString(fragment, str) {

     let re = /^([^#]*)#(\d+)\b([^#]*)/,

         document = fragment.ownerDocument,

         // the remaining arguments are our {text, className} values

         replacements = Array.slice(arguments, 2),

         match;

     // walk over the string, building textNode/spans as nec. with replacement content

     // note that #1,#2 etc. may not appear in numerical order in the string

     while ((match = re.exec(str))) {

       let [mstring,pre,num,post] = match,

           replaceText = "",

           replaceClass,

           idx = num-1; // markers are 1-based, replacement indices 0 based

       str = str.substring(re.lastIndex+mstring.length);

       if (pre)

           fragment.appendChild(document.createTextNode(pre));

       if (replacements[idx]) {

         replaceText = replacements[idx].text;

         let spanNode = document.createElementNS(XHTML_NS, "span");

         spanNode.appendChild(document.createTextNode(replaceText));

         // add class to the span when provided

         if(replacements[idx].className)

           spanNode.classList.add(replacements[idx].className);

         fragment.appendChild(spanNode);

       } else {

         // put it back if no replacement was provided

         fragment.appendChild(document.createTextNode("#"+num));

       }

       if(post)

         fragment.appendChild(document.createTextNode(post));

     }

     if(str)

       fragment.appendChild(document.createTextNode(str));

     return fragment;

   },

   // Pass several objects in and it will combine them all into the first object and return it.

   // NOTE: Deep copy is not supported

   extend: function extend() {

     // copy reference to target object

     let target = arguments[0] || {};

     let length = arguments.length;

     if (length === 1) {

       return target;

     }

     // Handle case when target is a string or something

     if (typeof target != "object" && typeof target != "function") {

       target = {};

     }

     for (let i = 1; i < length; i++) {

       // Only deal with non-null/undefined values

       let options = arguments[i];

       if (options != null) {

         // Extend the base object

         for (let name in options) {

           let copy = options[name];

           // Prevent never-ending loop

           if (target === copy)

             continue;

           if (copy !== undefined)

             target[name] = copy;

         }

       }

     }

     // Return the modified object

     return target;

   },

   // Checks if a keycode is used for list navigation.

   isNavigationKey: function (keyCode) {

     let navigationKeys = [

       nsIDOMKeyEvent.DOM_VK_DOWN,

       nsIDOMKeyEvent.DOM_VK_UP,

       nsIDOMKeyEvent.DOM_VK_LEFT,

       nsIDOMKeyEvent.DOM_VK_RIGHT,

       nsIDOMKeyEvent.DOM_VK_PAGE_UP,

       nsIDOMKeyEvent.DOM_VK_PAGE_DOWN,

       nsIDOMKeyEvent.DOM_VK_ESCAPE];

     return navigationKeys.indexOf(keyCode) != -1;

   }

 };