/*global self, document, DOMException */

/*! @source http://purl.eligrey.com/github/classList.js/blob/master/classList.js */

// Full polyfill for browsers with no classList support
if (!("classList" in document.createElement("_"))) {
  (function (view) {

  "use strict";

  if (!('Element' in view)) return;

  var
      classListProp = "classList"
    , protoProp = "prototype"
    , elemCtrProto = view.Element[protoProp]
    , objCtr = Object
    , strTrim = String[protoProp].trim || function () {
      return this.replace(/^\s+|\s+$/g, "");
    }
    , arrIndexOf = Array[protoProp].indexOf || function (item) {
      var
          i = 0
        , len = this.length
      ;
      for (; i < len; i++) {
        if (i in this && this[i] === item) {
          return i;
        }
      }
      return -1;
    }
    // Vendors: please allow content code to instantiate DOMExceptions
    , DOMEx = function (type, message) {
      this.name = type;
      this.code = DOMException[type];
      this.message = message;
    }
    , checkTokenAndGetIndex = function (classList, token) {
      if (token === "") {
        throw new DOMEx(
            "SYNTAX_ERR"
          , "An invalid or illegal string was specified"
        );
      }
      if (/\s/.test(token)) {
        throw new DOMEx(
            "INVALID_CHARACTER_ERR"
          , "String contains an invalid character"
        );
      }
      return arrIndexOf.call(classList, token);
    }
    , ClassList = function (elem) {
      var
          trimmedClasses = strTrim.call(elem.getAttribute("class") || "")
        , classes = trimmedClasses ? trimmedClasses.split(/\s+/) : []
        , i = 0
        , len = classes.length
      ;
      for (; i < len; i++) {
        this.push(classes[i]);
      }
      this._updateClassName = function () {
        elem.setAttribute("class", this.toString());
      };
    }
    , classListProto = ClassList[protoProp] = []
    , classListGetter = function () {
      return new ClassList(this);
    }
  ;
  // Most DOMException implementations don't allow calling DOMException's toString()
  // on non-DOMExceptions. Error's toString() is sufficient here.
  DOMEx[protoProp] = Error[protoProp];
  classListProto.item = function (i) {
    return this[i] || null;
  };
  classListProto.contains = function (token) {
    token += "";
    return checkTokenAndGetIndex(this, token) !== -1;
  };
  classListProto.add = function () {
    var
        tokens = arguments
      , i = 0
      , l = tokens.length
      , token
      , updated = false
    ;
    do {
      token = tokens[i] + "";
      if (checkTokenAndGetIndex(this, token) === -1) {
        this.push(token);
        updated = true;
      }
    }
    while (++i < l);

    if (updated) {
      this._updateClassName();
    }
  };
  classListProto.remove = function () {
    var
        tokens = arguments
      , i = 0
      , l = tokens.length
      , token
      , updated = false
      , index
    ;
    do {
      token = tokens[i] + "";
      index = checkTokenAndGetIndex(this, token);
      while (index !== -1) {
        this.splice(index, 1);
        updated = true;
        index = checkTokenAndGetIndex(this, token);
      }
    }
    while (++i < l);

    if (updated) {
      this._updateClassName();
    }
  };
  classListProto.toggle = function (token, force) {
    token += "";

    var
        result = this.contains(token)
      , method = result ?
        force !== true && "remove"
      :
        force !== false && "add"
    ;

    if (method) {
      this[method](token);
    }

    if (force === true || force === false) {
      return force;
    } else {
      return !result;
    }
  };
  classListProto.toString = function () {
    return this.join(" ");
  };

  if (objCtr.defineProperty) {
    var classListPropDesc = {
        get: classListGetter
      , enumerable: true
      , configurable: true
    };
    try {
      objCtr.defineProperty(elemCtrProto, classListProp, classListPropDesc);
    } catch (ex) { // IE 8 doesn't support enumerable:true
      if (ex.number === -0x7FF5EC54) {
        classListPropDesc.enumerable = false;
        objCtr.defineProperty(elemCtrProto, classListProp, classListPropDesc);
      }
    }
  } else if (objCtr[protoProp].__defineGetter__) {
    elemCtrProto.__defineGetter__(classListProp, classListGetter);
  }

  }(self));
}

/* Blob.js
 * A Blob implementation.
 * 2014-07-24
 *
 * By Eli Grey, http://eligrey.com
 * By Devin Samarin, https://github.com/dsamarin
 * License: X11/MIT
 *   See https://github.com/eligrey/Blob.js/blob/master/LICENSE.md
 */

/*global self, unescape */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
  plusplus: true */

/*! @source http://purl.eligrey.com/github/Blob.js/blob/master/Blob.js */

(function (view) {
  "use strict";

  view.URL = view.URL || view.webkitURL;

  if (view.Blob && view.URL) {
    try {
      new Blob;
      return;
    } catch (e) {}
  }

  // Internally we use a BlobBuilder implementation to base Blob off of
  // in order to support older browsers that only have BlobBuilder
  var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || (function(view) {
    var
        get_class = function(object) {
        return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
      }
      , FakeBlobBuilder = function BlobBuilder() {
        this.data = [];
      }
      , FakeBlob = function Blob(data, type, encoding) {
        this.data = data;
        this.size = data.length;
        this.type = type;
        this.encoding = encoding;
      }
      , FBB_proto = FakeBlobBuilder.prototype
      , FB_proto = FakeBlob.prototype
      , FileReaderSync = view.FileReaderSync
      , FileException = function(type) {
        this.code = this[this.name = type];
      }
      , file_ex_codes = (
          "NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR "
        + "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
      ).split(" ")
      , file_ex_code = file_ex_codes.length
      , real_URL = view.URL || view.webkitURL || view
      , real_create_object_URL = real_URL.createObjectURL
      , real_revoke_object_URL = real_URL.revokeObjectURL
      , URL = real_URL
      , btoa = view.btoa
      , atob = view.atob

      , ArrayBuffer = view.ArrayBuffer
      , Uint8Array = view.Uint8Array

      , origin = /^[\w-]+:\/*\[?[\w\.:-]+\]?(?::[0-9]+)?/
    ;
    FakeBlob.fake = FB_proto.fake = true;
    while (file_ex_code--) {
      FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
    }
    // Polyfill URL
    if (!real_URL.createObjectURL) {
      URL = view.URL = function(uri) {
        var
            uri_info = document.createElementNS("http://www.w3.org/1999/xhtml", "a")
          , uri_origin
        ;
        uri_info.href = uri;
        if (!("origin" in uri_info)) {
          if (uri_info.protocol.toLowerCase() === "data:") {
            uri_info.origin = null;
          } else {
            uri_origin = uri.match(origin);
            uri_info.origin = uri_origin && uri_origin[1];
          }
        }
        return uri_info;
      };
    }
    URL.createObjectURL = function(blob) {
      var
          type = blob.type
        , data_URI_header
      ;
      if (type === null) {
        type = "application/octet-stream";
      }
      if (blob instanceof FakeBlob) {
        data_URI_header = "data:" + type;
        if (blob.encoding === "base64") {
          return data_URI_header + ";base64," + blob.data;
        } else if (blob.encoding === "URI") {
          return data_URI_header + "," + decodeURIComponent(blob.data);
        } if (btoa) {
          return data_URI_header + ";base64," + btoa(blob.data);
        } else {
          return data_URI_header + "," + encodeURIComponent(blob.data);
        }
      } else if (real_create_object_URL) {
        return real_create_object_URL.call(real_URL, blob);
      }
    };
    URL.revokeObjectURL = function(object_URL) {
      if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) {
        real_revoke_object_URL.call(real_URL, object_URL);
      }
    };
    FBB_proto.append = function(data/*, endings*/) {
      var bb = this.data;
      // decode data to a binary string
      if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
        var
            str = ""
          , buf = new Uint8Array(data)
          , i = 0
          , buf_len = buf.length
        ;
        for (; i < buf_len; i++) {
          str += String.fromCharCode(buf[i]);
        }
        bb.push(str);
      } else if (get_class(data) === "Blob" || get_class(data) === "File") {
        if (FileReaderSync) {
          var fr = new FileReaderSync;
          bb.push(fr.readAsBinaryString(data));
        } else {
          // async FileReader won't work as BlobBuilder is sync
          throw new FileException("NOT_READABLE_ERR");
        }
      } else if (data instanceof FakeBlob) {
        if (data.encoding === "base64" && atob) {
          bb.push(atob(data.data));
        } else if (data.encoding === "URI") {
          bb.push(decodeURIComponent(data.data));
        } else if (data.encoding === "raw") {
          bb.push(data.data);
        }
      } else {
        if (typeof data !== "string") {
          data += ""; // convert unsupported types to strings
        }
        // decode UTF-16 to binary string
        bb.push(unescape(encodeURIComponent(data)));
      }
    };
    FBB_proto.getBlob = function(type) {
      if (!arguments.length) {
        type = null;
      }
      return new FakeBlob(this.data.join(""), type, "raw");
    };
    FBB_proto.toString = function() {
      return "[object BlobBuilder]";
    };
    FB_proto.slice = function(start, end, type) {
      var args = arguments.length;
      if (args < 3) {
        type = null;
      }
      return new FakeBlob(
          this.data.slice(start, args > 1 ? end : this.data.length)
        , type
        , this.encoding
      );
    };
    FB_proto.toString = function() {
      return "[object Blob]";
    };
    FB_proto.close = function() {
      this.size = 0;
      delete this.data;
    };
    return FakeBlobBuilder;
  }(view));

  view.Blob = function(blobParts, options) {
    var type = options ? (options.type || "") : "";
    var builder = new BlobBuilder();
    if (blobParts) {
      for (var i = 0, len = blobParts.length; i < len; i++) {
        if (Uint8Array && blobParts[i] instanceof Uint8Array) {
          builder.append(blobParts[i].buffer);
        }
        else {
          builder.append(blobParts[i]);
        }
      }
    }
    var blob = builder.getBlob(type);
    if (!blob.slice && blob.webkitSlice) {
      blob.slice = blob.webkitSlice;
    }
    return blob;
  };

  var getPrototypeOf = Object.getPrototypeOf || function(object) {
    return object.__proto__;
  };
  view.Blob.prototype = getPrototypeOf(new view.Blob());
}(typeof self !== "undefined" && self || typeof window !== "undefined" && window || this.content || this));

(function (root, factory) {
    'use strict';
    if (typeof module === 'object') {
        module.exports = factory;
    } else if (typeof define === 'function' && define.amd) {
        define(function () {
            return factory;
        });
    } else {
        root.MediumEditor = factory;
    }
}(this, function () {

    'use strict';

var Util;

(function (window) {
    'use strict';

    function copyInto(overwrite, dest) {
        var prop,
            sources = Array.prototype.slice.call(arguments, 2);
        dest = dest || {};
        for (var i = 0; i < sources.length; i++) {
            var source = sources[i];
            if (source) {
                for (prop in source) {
                    if (source.hasOwnProperty(prop) &&
                        typeof source[prop] !== 'undefined' &&
                        (overwrite || dest.hasOwnProperty(prop) === false)) {
                        dest[prop] = source[prop];
                    }
                }
            }
        }
        return dest;
    }

    Util = {

        // http://stackoverflow.com/questions/17907445/how-to-detect-ie11#comment30165888_17907562
        // by rg89
        isIE: ((navigator.appName === 'Microsoft Internet Explorer') || ((navigator.appName === 'Netscape') && (new RegExp('Trident/.*rv:([0-9]{1,}[.0-9]{0,})').exec(navigator.userAgent) !== null))),

        // http://stackoverflow.com/a/11752084/569101
        isMac: (window.navigator.platform.toUpperCase().indexOf('MAC') >= 0),

        // https://github.com/jashkenas/underscore
        keyCode: {
            BACKSPACE: 8,
            TAB: 9,
            ENTER: 13,
            ESCAPE: 27,
            SPACE: 32,
            DELETE: 46,
            K: 75 // K keycode, and not k
        },

        /**
         * Returns true if it's metaKey on Mac, or ctrlKey on non-Mac.
         * See #591
         */
        isMetaCtrlKey: function (event) {
            if ((this.isMac && event.metaKey) || (!this.isMac && event.ctrlKey)) {
                return true;
            }

            return false;
        },

        /**
         * Returns true if the key associated to the event is inside keys array
         *
         * @see : https://github.com/jquery/jquery/blob/0705be475092aede1eddae01319ec931fb9c65fc/src/event.js#L473-L484
         * @see : http://stackoverflow.com/q/4471582/569101
         */
        isKey: function (event, keys) {
            var keyCode = this.getKeyCode(event);

            // it's not an array let's just compare strings!
            if (false === Array.isArray(keys)) {
                return keyCode === keys;
            }

            if (-1 === keys.indexOf(keyCode)) {
                return false;
            }

            return true;
        },

        getKeyCode: function (event) {
            var keyCode = event.which;

            // getting the key code from event
            if (null === keyCode) {
                keyCode = event.charCode !== null ? event.charCode : event.keyCode;
            }

            return keyCode;
        },

        blockContainerElementNames: ['p', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'blockquote', 'pre'],
        emptyElementNames: ['br', 'col', 'colgroup', 'hr', 'img', 'input', 'source', 'wbr'],

        extend: function extend(/* dest, source1, source2, ...*/) {
            var args = [true].concat(Array.prototype.slice.call(arguments));
            return copyInto.apply(this, args);
        },

        defaults: function defaults(/*dest, source1, source2, ...*/) {
            var args = [false].concat(Array.prototype.slice.call(arguments));
            return copyInto.apply(this, args);
        },

        /*
         * Create a link around the provided text nodes which must be adjacent to each other and all be
         * descendants of the same closest block container. If the preconditions are not met, unexpected
         * behavior will result.
         */
        createLink: function (document, textNodes, href, target) {
            var anchor = document.createElement('a');
            Util.moveTextRangeIntoElement(textNodes[0], textNodes[textNodes.length - 1], anchor);
            anchor.setAttribute('href', href);
            if (target) {
                anchor.setAttribute('target', target);
            }
            return anchor;
        },

        /*
         * Given the provided match in the format {start: 1, end: 2} where start and end are indices into the
         * textContent of the provided element argument, modify the DOM inside element to ensure that the text
         * identified by the provided match can be returned as text nodes that contain exactly that text, without
         * any additional text at the beginning or end of the returned array of adjacent text nodes.
         *
         * The only DOM manipulation performed by this function is splitting the text nodes, non-text nodes are
         * not affected in any way.
         */
        findOrCreateMatchingTextNodes: function (document, element, match) {
            var treeWalker = document.createTreeWalker(element, NodeFilter.SHOW_TEXT, null, false),
                matchedNodes = [],
                currentTextIndex = 0,
                startReached = false,
                currentNode = null,
                newNode = null;

            while ((currentNode = treeWalker.nextNode()) !== null) {
                if (!startReached && match.start < (currentTextIndex + currentNode.nodeValue.length)) {
                    startReached = true;
                    newNode = Util.splitStartNodeIfNeeded(currentNode, match.start, currentTextIndex);
                }
                if (startReached) {
                    Util.splitEndNodeIfNeeded(currentNode, newNode, match.end, currentTextIndex);
                }
                if (startReached && currentTextIndex === match.end) {
                    break; // Found the node(s) corresponding to the link. Break out and move on to the next.
                } else if (startReached && currentTextIndex > (match.end + 1)) {
                    throw new Error('PerformLinking overshot the target!'); // should never happen...
                }

                if (startReached) {
                    matchedNodes.push(newNode || currentNode);
                }

                currentTextIndex += currentNode.nodeValue.length;
                if (newNode !== null) {
                    currentTextIndex += newNode.nodeValue.length;
                    // Skip the newNode as we'll already have pushed it to the matches
                    treeWalker.nextNode();
                }
                newNode = null;
            }
            return matchedNodes;
        },

        /*
         * Given the provided text node and text coordinates, split the text node if needed to make it align
         * precisely with the coordinates.
         *
         * This function is intended to be called from Util.findOrCreateMatchingTextNodes.
         */
        splitStartNodeIfNeeded: function (currentNode, matchStartIndex, currentTextIndex) {
            if (matchStartIndex !== currentTextIndex) {
                return currentNode.splitText(matchStartIndex - currentTextIndex);
            }
            return null;
        },

        /*
         * Given the provided text node and text coordinates, split the text node if needed to make it align
         * precisely with the coordinates. The newNode argument should from the result of Util.splitStartNodeIfNeeded,
         * if that function has been called on the same currentNode.
         *
         * This function is intended to be called from Util.findOrCreateMatchingTextNodes.
         */
        splitEndNodeIfNeeded: function (currentNode, newNode, matchEndIndex, currentTextIndex) {
            var textIndexOfEndOfFarthestNode,
                endSplitPoint;
            textIndexOfEndOfFarthestNode = currentTextIndex + (newNode || currentNode).nodeValue.length +
                    (newNode ? currentNode.nodeValue.length : 0) -
                    1;
            endSplitPoint = (newNode || currentNode).nodeValue.length -
                    (textIndexOfEndOfFarthestNode + 1 - matchEndIndex);
            if (textIndexOfEndOfFarthestNode >= matchEndIndex &&
                    currentTextIndex !== textIndexOfEndOfFarthestNode &&
                    endSplitPoint !== 0) {
                (newNode || currentNode).splitText(endSplitPoint);
            }
        },

        // Find the next node in the DOM tree that represents any text that is being
        // displayed directly next to the targetNode (passed as an argument)
        // Text that appears directly next to the current node can be:
        //  - A sibling text node
        //  - A descendant of a sibling element
        //  - A sibling text node of an ancestor
        //  - A descendant of a sibling element of an ancestor
        findAdjacentTextNodeWithContent: function findAdjacentTextNodeWithContent(rootNode, targetNode, ownerDocument) {
            var pastTarget = false,
                nextNode,
                nodeIterator = ownerDocument.createNodeIterator(rootNode, NodeFilter.SHOW_TEXT, null, false);

            // Use a native NodeIterator to iterate over all the text nodes that are descendants
            // of the rootNode.  Once past the targetNode, choose the first non-empty text node
            nextNode = nodeIterator.nextNode();
            while (nextNode) {
                if (nextNode === targetNode) {
                    pastTarget = true;
                } else if (pastTarget) {
                    if (nextNode.nodeType === 3 && nextNode.nodeValue && nextNode.nodeValue.trim().length > 0) {
                        break;
                    }
                }
                nextNode = nodeIterator.nextNode();
            }

            return nextNode;
        },

        isDescendant: function isDescendant(parent, child, checkEquality) {
            if (!parent || !child) {
                return false;
            }
            if (checkEquality && parent === child) {
                return true;
            }
            var node = child.parentNode;
            while (node !== null) {
                if (node === parent) {
                    return true;
                }
                node = node.parentNode;
            }
            return false;
        },

        // https://github.com/jashkenas/underscore
        isElement: function isElement(obj) {
            return !!(obj && obj.nodeType === 1);
        },

        // https://github.com/jashkenas/underscore
        throttle: function (func, wait) {
            var THROTTLE_INTERVAL = 50,
                context,
                args,
                result,
                timeout = null,
                previous = 0,
                later = function () {
                    previous = Date.now();
                    timeout = null;
                    result = func.apply(context, args);
                    if (!timeout) {
                        context = args = null;
                    }
                };

            if (!wait && wait !== 0) {
                wait = THROTTLE_INTERVAL;
            }

            return function () {
                var now = Date.now(),
                    remaining = wait - (now - previous);

                context = this;
                args = arguments;
                if (remaining <= 0 || remaining > wait) {
                    if (timeout) {
                        clearTimeout(timeout);
                        timeout = null;
                    }
                    previous = now;
                    result = func.apply(context, args);
                    if (!timeout) {
                        context = args = null;
                    }
                } else if (!timeout) {
                    timeout = setTimeout(later, remaining);
                }
                return result;
            };
        },

        traverseUp: function (current, testElementFunction) {
            if (!current) {
                return false;
            }

            do {
                if (current.nodeType === 1) {
                    if (testElementFunction(current)) {
                        return current;
                    }
                    // do not traverse upwards past the nearest containing editor
                    if (Util.isMediumEditorElement(current)) {
                        return false;
                    }
                }

                current = current.parentNode;
            } while (current);

            return false;
        },

        htmlEntities: function (str) {
            // converts special characters (like <) into their escaped/encoded values (like &lt;).
            // This allows you to show to display the string without the browser reading it as HTML.
            return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
        },

        // http://stackoverflow.com/questions/6690752/insert-html-at-caret-in-a-contenteditable-div
        insertHTMLCommand: function (doc, html) {
            var selection, range, el, fragment, node, lastNode, toReplace;

            if (doc.queryCommandSupported('insertHTML')) {
                try {
                    return doc.execCommand('insertHTML', false, html);
                } catch (ignore) {}
            }

            selection = doc.defaultView.getSelection();
            if (selection.getRangeAt && selection.rangeCount) {
                range = selection.getRangeAt(0);
                toReplace = range.commonAncestorContainer;
                // Ensure range covers maximum amount of nodes as possible
                // By moving up the DOM and selecting ancestors whose only child is the range
                if ((toReplace.nodeType === 3 && toReplace.nodeValue === range.toString()) ||
                        (toReplace.nodeType !== 3 && toReplace.innerHTML === range.toString())) {
                    while (toReplace.parentNode &&
                            toReplace.parentNode.childNodes.length === 1 &&
                            !Util.isMediumEditorElement(toReplace.parentNode)) {
                        toReplace = toReplace.parentNode;
                    }
                    range.selectNode(toReplace);
                }
                range.deleteContents();

                el = doc.createElement('div');
                el.innerHTML = html;
                fragment = doc.createDocumentFragment();
                while (el.firstChild) {
                    node = el.firstChild;
                    lastNode = fragment.appendChild(node);
                }
                range.insertNode(fragment);

                // Preserve the selection:
                if (lastNode) {
                    range = range.cloneRange();
                    range.setStartAfter(lastNode);
                    range.collapse(true);
                    selection.removeAllRanges();
                    selection.addRange(range);
                }
            }
        },

        execFormatBlock: function (doc, tagName) {
            // Get the top level block element that contains the selection
            var blockContainer = Util.getTopBlockContainer(Selection.getSelectionStart(doc));

            // Special handling for blockquote
            if (tagName === 'blockquote') {
                if (blockContainer) {
                    var childNodes = Array.prototype.slice.call(blockContainer.childNodes);
                    // Check if the blockquote has a block element as a child (nested blocks)
                    if (childNodes.some(function (childNode) {
                        return Util.isBlockContainer(childNode);
                    })) {
                        // FF handles blockquote differently on formatBlock
                        // allowing nesting, we need to use outdent
                        // https://developer.mozilla.org/en-US/docs/Rich-Text_Editing_in_Mozilla
                        return doc.execCommand('outdent', false, null);
                    }
                }

                // When IE blockquote needs to be called as indent
                // http://stackoverflow.com/questions/1816223/rich-text-editor-with-blockquote-function/1821777#1821777
                if (this.isIE) {
                    return doc.execCommand('indent', false, tagName);
                }
            }

            // If the blockContainer is already the element type being passed in
            // treat it as 'undo' formatting and just convert it to a <p>
            if (blockContainer && tagName === blockContainer.nodeName.toLowerCase()) {
                tagName = 'p';
            }

            // When IE we need to add <> to heading elements
            // http://stackoverflow.com/questions/10741831/execcommand-formatblock-headings-in-ie
            if (this.isIE) {
                tagName = '<' + tagName + '>';
            }
            return doc.execCommand('formatBlock', false, tagName);
        },

        /**
         * Set target to blank on the given el element
         *
         * TODO: not sure if this should be here
         *
         * When creating a link (using core -> createLink) the selection returned by Firefox will be the parent of the created link
         * instead of the created link itself (as it is for Chrome for example), so we retrieve all "a" children to grab the good one by
         * using `anchorUrl` to ensure that we are adding target="_blank" on the good one.
         * This isn't a bulletproof solution anyway ..
         */
        setTargetBlank: function (el, anchorUrl) {
            var i, url = anchorUrl || false;
            if (el.nodeName.toLowerCase() === 'a') {
                el.target = '_blank';
            } else {
                el = el.getElementsByTagName('a');

                for (i = 0; i < el.length; i += 1) {
                    if (false === url || url === el[i].attributes.href.value) {
                        el[i].target = '_blank';
                    }
                }
            }
        },

        addClassToAnchors: function (el, buttonClass) {
            var classes = buttonClass.split(' '),
                i,
                j;
            if (el.nodeName.toLowerCase() === 'a') {
                for (j = 0; j < classes.length; j += 1) {
                    el.classList.add(classes[j]);
                }
            } else {
                el = el.getElementsByTagName('a');
                for (i = 0; i < el.length; i += 1) {
                    for (j = 0; j < classes.length; j += 1) {
                        el[i].classList.add(classes[j]);
                    }
                }
            }
        },

        isListItem: function (node) {
            if (!node) {
                return false;
            }
            if (node.nodeName.toLowerCase() === 'li') {
                return true;
            }

            var parentNode = node.parentNode,
                tagName = parentNode.nodeName.toLowerCase();
            while (!this.isBlockContainer(parentNode) && tagName !== 'div') {
                if (tagName === 'li') {
                    return true;
                }
                parentNode = parentNode.parentNode;
                if (parentNode) {
                    tagName = parentNode.nodeName.toLowerCase();
                } else {
                    return false;
                }
            }
            return false;
        },

        cleanListDOM: function (ownerDocument, element) {
            if (element.nodeName.toLowerCase() !== 'li') {
                return;
            }

            var list = element.parentElement;

            if (list.parentElement.nodeName.toLowerCase() === 'p') { // yes we need to clean up
                this.unwrap(list.parentElement, ownerDocument);

                // move cursor at the end of the text inside the list
                // for some unknown reason, the cursor is moved to end of the "visual" line
                Selection.moveCursor(ownerDocument, element.firstChild, element.firstChild.textContent.length);
            }
        },

        /* splitDOMTree
         *
         * Given a root element some descendant element, split the root element
         * into its own element containing the descendant element and all elements
         * on the left or right side of the descendant ('right' is default)
         *
         * example:
         *
         *         <div>
         *      /    |   \
         *  <span> <span> <span>
         *   / \    / \    / \
         *  1   2  3   4  5   6
         *
         *  If I wanted to split this tree given the <div> as the root and "4" as the leaf
         *  the result would be (the prime ' marks indicates nodes that are created as clones):
         *
         *   SPLITTING OFF 'RIGHT' TREE       SPLITTING OFF 'LEFT' TREE
         *
         *     <div>            <div>'              <div>'      <div>
         *      / \              / \                 / \          |
         * <span> <span>   <span>' <span>       <span> <span>   <span>
         *   / \    |        |      / \           /\     /\       /\
         *  1   2   3        4     5   6         1  2   3  4     5  6
         *
         *  The above example represents splitting off the 'right' or 'left' part of a tree, where
         *  the <div>' would be returned as an element not appended to the DOM, and the <div>
         *  would remain in place where it was
         *
        */
        splitOffDOMTree: function (rootNode, leafNode, splitLeft) {
            var splitOnNode = leafNode,
                createdNode = null,
                splitRight = !splitLeft;

            // loop until we hit the root
            while (splitOnNode !== rootNode) {
                var currParent = splitOnNode.parentNode,
                    newParent = currParent.cloneNode(false),
                    targetNode = (splitRight ? splitOnNode : currParent.firstChild),
                    appendLast;

                // Create a new parent element which is a clone of the current parent
                if (createdNode) {
                    if (splitRight) {
                        // If we're splitting right, add previous created element before siblings
                        newParent.appendChild(createdNode);
                    } else {
                        // If we're splitting left, add previous created element last
                        appendLast = createdNode;
                    }
                }
                createdNode = newParent;

                while (targetNode) {
                    var sibling = targetNode.nextSibling;
                    // Special handling for the 'splitNode'
                    if (targetNode === splitOnNode) {
                        if (!targetNode.hasChildNodes()) {
                            targetNode.parentNode.removeChild(targetNode);
                        } else {
                            // For the node we're splitting on, if it has children, we need to clone it
                            // and not just move it
                            targetNode = targetNode.cloneNode(false);
                        }
                        // If the resulting split node has content, add it
                        if (targetNode.textContent) {
                            createdNode.appendChild(targetNode);
                        }

                        targetNode = (splitRight ? sibling : null);
                    } else {
                        // For general case, just remove the element and only
                        // add it to the split tree if it contains something
                        targetNode.parentNode.removeChild(targetNode);
                        if (targetNode.hasChildNodes() || targetNode.textContent) {
                            createdNode.appendChild(targetNode);
                        }

                        targetNode = sibling;
                    }
                }

                // If we had an element we wanted to append at the end, do that now
                if (appendLast) {
                    createdNode.appendChild(appendLast);
                }

                splitOnNode = currParent;
            }

            return createdNode;
        },

        moveTextRangeIntoElement: function (startNode, endNode, newElement) {
            if (!startNode || !endNode) {
                return false;
            }

            var rootNode = this.findCommonRoot(startNode, endNode);
            if (!rootNode) {
                return false;
            }

            if (endNode === startNode) {
                var temp = startNode.parentNode,
                    sibling = startNode.nextSibling;
                temp.removeChild(startNode);
                newElement.appendChild(startNode);
                if (sibling) {
                    temp.insertBefore(newElement, sibling);
                } else {
                    temp.appendChild(newElement);
                }
                return newElement.hasChildNodes();
            }

            // create rootChildren array which includes all the children
            // we care about
            var rootChildren = [],
                firstChild,
                lastChild,
                nextNode;
            for (var i = 0; i < rootNode.childNodes.length; i++) {
                nextNode = rootNode.childNodes[i];
                if (!firstChild) {
                    if (this.isDescendant(nextNode, startNode, true)) {
                        firstChild = nextNode;
                    }
                } else {
                    if (this.isDescendant(nextNode, endNode, true)) {
                        lastChild = nextNode;
                        break;
                    } else {
                        rootChildren.push(nextNode);
                    }
                }
            }

            var afterLast = lastChild.nextSibling,
                fragment = rootNode.ownerDocument.createDocumentFragment();

            // build up fragment on startNode side of tree
            if (firstChild === startNode) {
                firstChild.parentNode.removeChild(firstChild);
                fragment.appendChild(firstChild);
            } else {
                fragment.appendChild(this.splitOffDOMTree(firstChild, startNode));
            }

            // add any elements between firstChild & lastChild
            rootChildren.forEach(function (element) {
                element.parentNode.removeChild(element);
                fragment.appendChild(element);
            });

            // build up fragment on endNode side of the tree
            if (lastChild === endNode) {
                lastChild.parentNode.removeChild(lastChild);
                fragment.appendChild(lastChild);
            } else {
                fragment.appendChild(this.splitOffDOMTree(lastChild, endNode, true));
            }

            // Add fragment into passed in element
            newElement.appendChild(fragment);

            if (lastChild.parentNode === rootNode) {
                // If last child is in the root, insert newElement in front of it
                rootNode.insertBefore(newElement, lastChild);
            } else if (afterLast) {
                // If last child was removed, but it had a sibling, insert in front of it
                rootNode.insertBefore(newElement, afterLast);
            } else {
                // lastChild was removed and was the last actual element just append
                rootNode.appendChild(newElement);
            }

            return newElement.hasChildNodes();
        },

        /* based on http://stackoverflow.com/a/6183069 */
        depthOfNode: function (inNode) {
            var theDepth = 0,
                node = inNode;
            while (node.parentNode !== null) {
                node = node.parentNode;
                theDepth++;
            }
            return theDepth;
        },

        findCommonRoot: function (inNode1, inNode2) {
            var depth1 = this.depthOfNode(inNode1),
                depth2 = this.depthOfNode(inNode2),
                node1 = inNode1,
                node2 = inNode2;

            while (depth1 !== depth2) {
                if (depth1 > depth2) {
                    node1 = node1.parentNode;
                    depth1 -= 1;
                } else {
                    node2 = node2.parentNode;
                    depth2 -= 1;
                }
            }

            while (node1 !== node2) {
                node1 = node1.parentNode;
                node2 = node2.parentNode;
            }

            return node1;
        },
        /* END - based on http://stackoverflow.com/a/6183069 */

        isElementAtBeginningOfBlock: function (node) {
            var textVal,
                sibling;
            while (!this.isBlockContainer(node) && !this.isMediumEditorElement(node)) {
                sibling = node;
                while (sibling = sibling.previousSibling) {
                    textVal = sibling.nodeType === 3 ? sibling.nodeValue : sibling.textContent;
                    if (textVal.length > 0) {
                        return false;
                    }
                }
                node = node.parentNode;
            }
            return true;
        },

        isMediumEditorElement: function (element) {
            return element && element.getAttribute && !!element.getAttribute('data-medium-editor-element');
        },

        getContainerEditorElement: function (element) {
            return Util.traverseUp(element, function (node) {
                return Util.isMediumEditorElement(node);
            });
        },

        isBlockContainer: function (element) {
            return element && element.nodeType !== 3 && this.blockContainerElementNames.indexOf(element.nodeName.toLowerCase()) !== -1;
        },

        getClosestBlockContainer: function (node) {
            return Util.traverseUp(node, function (node) {
                return Util.isBlockContainer(node);
            });
        },

        getTopBlockContainer: function (element) {
            var topBlock = element;
            this.traverseUp(element, function (el) {
                if (Util.isBlockContainer(el)) {
                    topBlock = el;
                }
                return false;
            });
            return topBlock;
        },

        getFirstSelectableLeafNode: function (element) {
            while (element && element.firstChild) {
                element = element.firstChild;
            }

            // We don't want to set the selection to an element that can't have children, this messes up Gecko.
            element = this.traverseUp(element, function (el) {
                return Util.emptyElementNames.indexOf(el.nodeName.toLowerCase()) === -1;
            });
            // Selecting at the beginning of a table doesn't work in PhantomJS.
            if (element.nodeName.toLowerCase() === 'table') {
                var firstCell = element.querySelector('th, td');
                if (firstCell) {
                    element = firstCell;
                }
            }
            return element;
        },

        getFirstTextNode: function (element) {
            if (element.nodeType === 3) {
                return element;
            }

            for (var i = 0; i < element.childNodes.length; i++) {
                var textNode = this.getFirstTextNode(element.childNodes[i]);
                if (textNode !== null) {
                    return textNode;
                }
            }
            return null;
        },

        ensureUrlHasProtocol: function (url) {
            if (url.indexOf('://') === -1) {
                return 'http://' + url;
            }
            return url;
        },

        warn: function () {
            if (window.console !== undefined && typeof window.console.warn === 'function') {
                window.console.warn.apply(window.console, arguments);
            }
        },

        deprecated: function (oldName, newName, version) {
            // simple deprecation warning mechanism.
            var m = oldName + ' is deprecated, please use ' + newName + ' instead.';
            if (version) {
                m += ' Will be removed in ' + version;
            }
            Util.warn(m);
        },

        deprecatedMethod: function (oldName, newName, args, version) {
            // run the replacement and warn when someone calls a deprecated method
            Util.deprecated(oldName, newName, version);
            if (typeof this[newName] === 'function') {
                this[newName].apply(this, args);
            }
        },

        cleanupAttrs: function (el, attrs) {
            attrs.forEach(function (attr) {
                el.removeAttribute(attr);
            });
        },

        cleanupTags: function (el, tags) {
            tags.forEach(function (tag) {
                if (el.nodeName.toLowerCase() === tag) {
                    el.parentNode.removeChild(el);
                }
            }, this);
        },

        // get the closest parent
        getClosestTag: function (el, tag) {
            return this.traverseUp(el, function (element) {
                return element.nodeName.toLowerCase() === tag.toLowerCase();
            });
        },

        unwrap: function (el, doc) {
            var fragment = doc.createDocumentFragment(),
                nodes = Array.prototype.slice.call(el.childNodes);

            // cast nodeList to array since appending child
            // to a different node will alter length of el.childNodes
            for (var i = 0; i < nodes.length; i++) {
                fragment.appendChild(nodes[i]);
            }

            if (fragment.childNodes.length) {
                el.parentNode.replaceChild(fragment, el);
            } else {
                el.parentNode.removeChild(el);
            }
        }
    };
}(window));

var buttonDefaults;
(function () {
    'use strict';

    buttonDefaults = {
        'bold': {
            name: 'bold',
            action: 'bold',
            aria: 'bold',
            tagNames: ['b', 'strong'],
            style: {
                prop: 'font-weight',
                value: '700|bold'
            },
            useQueryState: true,
            contentDefault: '<b>B</b>',
            contentFA: '<i class="fa fa-bold"></i>'
        },
        'italic': {
            name: 'italic',
            action: 'italic',
            aria: 'italic',
            tagNames: ['i', 'em'],
            style: {
                prop: 'font-style',
                value: 'italic'
            },
            useQueryState: true,
            contentDefault: '<b><i>I</i></b>',
            contentFA: '<i class="fa fa-italic"></i>'
        },
        'underline': {
            name: 'underline',
            action: 'underline',
            aria: 'underline',
            tagNames: ['u'],
            style: {
                prop: 'text-decoration',
                value: 'underline'
            },
            useQueryState: true,
            contentDefault: '<b><u>U</u></b>',
            contentFA: '<i class="fa fa-underline"></i>'
        },
        'strikethrough': {
            name: 'strikethrough',
            action: 'strikethrough',
            aria: 'strike through',
            tagNames: ['strike'],
            style: {
                prop: 'text-decoration',
                value: 'line-through'
            },
            useQueryState: true,
            contentDefault: '<s>A</s>',
            contentFA: '<i class="fa fa-strikethrough"></i>'
        },
        'superscript': {
            name: 'superscript',
            action: 'superscript',
            aria: 'superscript',
            tagNames: ['sup'],
            /* firefox doesn't behave the way we want it to, so we CAN'T use queryCommandState for superscript
               https://github.com/guardian/scribe/blob/master/BROWSERINCONSISTENCIES.md#documentquerycommandstate */
            // useQueryState: true
            contentDefault: '<b>x<sup>1</sup></b>',
            contentFA: '<i class="fa fa-superscript"></i>'
        },
        'subscript': {
            name: 'subscript',
            action: 'subscript',
            aria: 'subscript',
            tagNames: ['sub'],
            /* firefox doesn't behave the way we want it to, so we CAN'T use queryCommandState for subscript
               https://github.com/guardian/scribe/blob/master/BROWSERINCONSISTENCIES.md#documentquerycommandstate */
            // useQueryState: true
            contentDefault: '<b>x<sub>1</sub></b>',
            contentFA: '<i class="fa fa-subscript"></i>'
        },
        'image': {
            name: 'image',
            action: 'image',
            aria: 'image',
            tagNames: ['img'],
            contentDefault: '<b>image</b>',
            contentFA: '<i class="fa fa-picture-o"></i>'
        },
        'orderedlist': {
            name: 'orderedlist',
            action: 'insertorderedlist',
            aria: 'ordered list',
            tagNames: ['ol'],
            useQueryState: true,
            contentDefault: '<b>1.</b>',
            contentFA: '<i class="fa fa-list-ol"></i>'
        },
        'unorderedlist': {
            name: 'unorderedlist',
            action: 'insertunorderedlist',
            aria: 'unordered list',
            tagNames: ['ul'],
            useQueryState: true,
            contentDefault: '<b>&bull;</b>',
            contentFA: '<i class="fa fa-list-ul"></i>'
        },
        'indent': {
            name: 'indent',
            action: 'indent',
            aria: 'indent',
            tagNames: [],
            contentDefault: '<b>&rarr;</b>',
            contentFA: '<i class="fa fa-indent"></i>'
        },
        'outdent': {
            name: 'outdent',
            action: 'outdent',
            aria: 'outdent',
            tagNames: [],
            contentDefault: '<b>&larr;</b>',
            contentFA: '<i class="fa fa-outdent"></i>'
        },
        'justifyCenter': {
            name: 'justifyCenter',
            action: 'justifyCenter',
            aria: 'center justify',
            tagNames: [],
            style: {
                prop: 'text-align',
                value: 'center'
            },
            contentDefault: '<b>C</b>',
            contentFA: '<i class="fa fa-align-center"></i>'
        },
        'justifyFull': {
            name: 'justifyFull',
            action: 'justifyFull',
            aria: 'full justify',
            tagNames: [],
            style: {
                prop: 'text-align',
                value: 'justify'
            },
            contentDefault: '<b>J</b>',
            contentFA: '<i class="fa fa-align-justify"></i>'
        },
        'justifyLeft': {
            name: 'justifyLeft',
            action: 'justifyLeft',
            aria: 'left justify',
            tagNames: [],
            style: {
                prop: 'text-align',
                value: 'left'
            },
            contentDefault: '<b>L</b>',
            contentFA: '<i class="fa fa-align-left"></i>'
        },
        'justifyRight': {
            name: 'justifyRight',
            action: 'justifyRight',
            aria: 'right justify',
            tagNames: [],
            style: {
                prop: 'text-align',
                value: 'right'
            },
            contentDefault: '<b>R</b>',
            contentFA: '<i class="fa fa-align-right"></i>'
        },
        // Known inline elements that are not removed, or not removed consistantly across browsers:
        // <span>, <label>, <br>
        'removeFormat': {
            name: 'removeFormat',
            aria: 'remove formatting',
            action: 'removeFormat',
            contentDefault: '<b>X</b>',
            contentFA: '<i class="fa fa-eraser"></i>'
        },

        /***** Buttons for appending block elements (append-<element> action) *****/

        'quote': {
            name: 'quote',
            action: 'append-blockquote',
            aria: 'blockquote',
            tagNames: ['blockquote'],
            contentDefault: '<b>&ldquo;</b>',
            contentFA: '<i class="fa fa-quote-right"></i>'
        },
        'pre': {
            name: 'pre',
            action: 'append-pre',
            aria: 'preformatted text',
            tagNames: ['pre'],
            contentDefault: '<b>0101</b>',
            contentFA: '<i class="fa fa-code fa-lg"></i>'
        },
        'h1': {
            name: 'h1',
            action: 'append-h1',
            aria: 'header type one',
            tagNames: ['h1'],
            contentDefault: '<b>H1</b>',
            contentFA: '<i class="fa fa-header"><sup>1</sup>'
        },
        'h2': {
            name: 'h2',
            action: 'append-h2',
            aria: 'header type two',
            tagNames: ['h2'],
            contentDefault: '<b>H2</b>',
            contentFA: '<i class="fa fa-header"><sup>2</sup>'
        },
        'h3': {
            name: 'h3',
            action: 'append-h3',
            aria: 'header type three',
            tagNames: ['h3'],
            contentDefault: '<b>H3</b>',
            contentFA: '<i class="fa fa-header"><sup>3</sup>'
        },
        'h4': {
            name: 'h4',
            action: 'append-h4',
            aria: 'header type four',
            tagNames: ['h4'],
            contentDefault: '<b>H4</b>',
            contentFA: '<i class="fa fa-header"><sup>4</sup>'
        },
        'h5': {
            name: 'h5',
            action: 'append-h5',
            aria: 'header type five',
            tagNames: ['h5'],
            contentDefault: '<b>H5</b>',
            contentFA: '<i class="fa fa-header"><sup>5</sup>'
        },
        'h6': {
            name: 'h6',
            action: 'append-h6',
            aria: 'header type six',
            tagNames: ['h6'],
            contentDefault: '<b>H6</b>',
            contentFA: '<i class="fa fa-header"><sup>6</sup>'
        }
    };

})();
var editorDefaults;
(function () {
    // summary: The default options hash used by the Editor

    editorDefaults = {
        activeButtonClass: 'medium-editor-button-active',
        buttonLabels: false,
        delay: 0,
        disableReturn: false,
        disableDoubleReturn: false,
        disableEditing: false,
        autoLink: false,
        elementsContainer: false,
        contentWindow: window,
        ownerDocument: document,
        targetBlank: false,
        extensions: {},
        spellcheck: true
    };
})();

var Extension;
(function () {
    'use strict';

    /* global Util */

    Extension = function (options) {
        Util.extend(this, options);
    };

    Extension.extend = function (protoProps) {
        // magic extender thinger. mostly borrowed from backbone/goog.inherits
        // place this function on some thing you want extend-able.
        //
        // example:
        //
        //      function Thing(args){
        //          this.options = args;
        //      }
        //
        //      Thing.prototype = { foo: "bar" };
        //      Thing.extend = extenderify;
        //
        //      var ThingTwo = Thing.extend({ foo: "baz" });
        //
        //      var thingOne = new Thing(); // foo === "bar"
        //      var thingTwo = new ThingTwo(); // foo === "baz"
        //
        //      which seems like some simply shallow copy nonsense
        //      at first, but a lot more is going on there.
        //
        //      passing a `constructor` to the extend props
        //      will cause the instance to instantiate through that
        //      instead of the parent's constructor.

        var parent = this,
            child;

        // The constructor function for the new subclass is either defined by you
        // (the "constructor" property in your `extend` definition), or defaulted
        // by us to simply call the parent's constructor.

        if (protoProps && protoProps.hasOwnProperty('constructor')) {
            child = protoProps.constructor;
        } else {
            child = function () {
                return parent.apply(this, arguments);
            };
        }

        // das statics (.extend comes over, so your subclass can have subclasses too)
        Util.extend(child, parent);

        // Set the prototype chain to inherit from `parent`, without calling
        // `parent`'s constructor function.
        var Surrogate = function () {
            this.constructor = child;
        };
        Surrogate.prototype = parent.prototype;
        child.prototype = new Surrogate();

        if (protoProps) {
            Util.extend(child.prototype, protoProps);
        }

        // todo: $super?

        return child;
    };

    Extension.prototype = {
        /* init: [function]
         *
         * Called by MediumEditor during initialization.
         * The .base property will already have been set to
         * current instance of MediumEditor when this is called.
         * All helper methods will exist as well
         */
        init: function () {},

        /* base: [MediumEditor instance]
         *
         * If not overriden, this will be set to the current instance
         * of MediumEditor, before the init method is called
         */
        base: undefined,

        /* name: [string]
         *
         * 'name' of the extension, used for retrieving the extension.
         * If not set, MediumEditor will set this to be the key
         * used when passing the extension into MediumEditor via the
         * 'extensions' option
         */
        name: undefined,

        /* checkState: [function (node)]
         *
         * If implemented, this function will be called one or more times
         * the state of the editor & toolbar are updated.
         * When the state is updated, the editor does the following:
         *
         * 1) Find the parent node containing the current selection
         * 2) Call checkState on the extension, passing the node as an argument
         * 3) Get the parent node of the previous node
         * 4) Repeat steps #2 and #3 until we move outside the parent contenteditable
         */
        checkState: undefined,

        /* destroy: [function ()]
         *
         * This method should remove any created html, custom event handlers
         * or any other cleanup tasks that should be performed.
         * If implemented, this function will be called when MediumEditor's
         * destroy method has been called.
         */
        destroy: undefined,

        /* As alternatives to checkState, these functions provide a more structured
         * path to updating the state of an extension (usually a button) whenever
         * the state of the editor & toolbar are updated.
         */

        /* queryCommandState: [function ()]
         *
         * If implemented, this function will be called once on each extension
         * when the state of the editor/toolbar is being updated.
         *
         * If this function returns a non-null value, the extension will
         * be ignored as the code climbs the dom tree.
         *
         * If this function returns true, and the setActive() function is defined
         * setActive() will be called
         */
        queryCommandState: undefined,

        /* isActive: [function ()]
         *
         * If implemented, this function will be called when MediumEditor
         * has determined that this extension is 'active' for the current selection.
         * This may be called when the editor & toolbar are being updated,
         * but only if queryCommandState() or isAlreadyApplied() functions
         * are implemented, and when called, return true.
         */
        isActive: undefined,

        /* isAlreadyApplied: [function (node)]
         *
         * If implemented, this function is similar to checkState() in
         * that it will be called repeatedly as MediumEditor moves up
         * the DOM to update the editor & toolbar after a state change.
         *
         * NOTE: This function will NOT be called if checkState() has
         * been implemented. This function will NOT be called if
         * queryCommandState() is implemented and returns a non-null
         * value when called
         */
        isAlreadyApplied: undefined,

        /* setActive: [function ()]
         *
         * If implemented, this function is called when MediumEditor knows
         * that this extension is currently enabled.  Currently, this
         * function is called when updating the editor & toolbar, and
         * only if queryCommandState() or isAlreadyApplied(node) return
         * true when called
         */
        setActive: undefined,

        /* setInactive: [function ()]
         *
         * If implemented, this function is called when MediumEditor knows
         * that this extension is currently disabled.  Curently, this
         * is called at the beginning of each state change for
         * the editor & toolbar. After calling this, MediumEditor
         * will attempt to update the extension, either via checkState()
         * or the combination of queryCommandState(), isAlreadyApplied(node),
         * isActive(), and setActive()
         */
        setInactive: undefined,

        /************************ Helpers ************************
         * The following are helpers that are either set by MediumEditor
         * during initialization, or are helper methods which either
         * route calls to the MediumEditor instance or provide common
         * functionality for all extensions
         *********************************************************/

        /* window: [Window]
         *
         * If not overriden, this will be set to the window object
         * to be used by MediumEditor and its extensions.  This is
         * passed via the 'contentWindow' option to MediumEditor
         * and is the global 'window' object by default
         */
        'window': undefined,

        /* document: [Document]
         *
         * If not overriden, this will be set to the document object
         * to be used by MediumEditor and its extensions. This is
         * passed via the 'ownerDocument' optin to MediumEditor
         * and is the global 'document' object by default
         */
        'document': undefined,

        /* getEditorElements: [function ()]
         *
         * Helper function which returns an array containing
         * all the contenteditable elements for this instance
         * of MediumEditor
         */
        getEditorElements: function () {
            return this.base.elements;
        },

        /* getEditorId: [function ()]
         *
         * Helper function which returns a unique identifier
         * for this instance of MediumEditor
         */
        getEditorId: function () {
            return this.base.id;
        },

        /* getEditorOptions: [function (option)]
         *
         * Helper function which returns the value of an option
         * used to initialize this instance of MediumEditor
         */
        getEditorOption: function (option) {
            return this.base.options[option];
        }
    };

    /* List of method names to add to the prototype of Extension
     * Each of these methods will be defined as helpers that
     * just call directly into the MediumEditor instance.
     *
     * example for 'on' method:
     * Extension.prototype.on = function () {
     *     return this.base.on.apply(this.base, arguments);
     * }
     */
    [
        // general helpers
        'execAction',

        // event handling
        'on',
        'off',
        'subscribe',
        'trigger'

    ].forEach(function (helper) {
        Extension.prototype[helper] = function () {
            return this.base[helper].apply(this.base, arguments);
        };
    });
})();

var Selection;

(function () {
    'use strict';

    function filterOnlyParentElements(node) {
        if (Util.isBlockContainer(node)) {
            return NodeFilter.FILTER_ACCEPT;
        } else {
            return NodeFilter.FILTER_SKIP;
        }
    }

    Selection = {
        findMatchingSelectionParent: function (testElementFunction, contentWindow) {
            var selection = contentWindow.getSelection(),
                range,
                current;

            if (selection.rangeCount === 0) {
                return false;
            }

            range = selection.getRangeAt(0);
            current = range.commonAncestorContainer;

            return Util.traverseUp(current, testElementFunction);
        },

        getSelectionElement: function (contentWindow) {
            return this.findMatchingSelectionParent(function (el) {
                return Util.isMediumEditorElement(el);
            }, contentWindow);
        },

        // http://stackoverflow.com/questions/17678843/cant-restore-selection-after-html-modify-even-if-its-the-same-html
        // Tim Down
        exportSelection: function (root, doc) {
            if (!root) {
                return null;
            }

            var selectionState = null,
                selection = doc.getSelection();

            if (selection.rangeCount > 0) {
                var range = selection.getRangeAt(0),
                    preSelectionRange = range.cloneRange(),
                    start;

                preSelectionRange.selectNodeContents(root);
                preSelectionRange.setEnd(range.startContainer, range.startOffset);
                start = preSelectionRange.toString().length;

                selectionState = {
                    start: start,
                    end: start + range.toString().length
                };
                // If start = 0 there may still be an empty paragraph before it, but we don't care.
                if (start !== 0) {
                    var emptyBlocksIndex = this.getIndexRelativeToAdjacentEmptyBlocks(doc, root, range.startContainer, range.startOffset);
                    if (emptyBlocksIndex !== 0) {
                        selectionState.emptyBlocksIndex = emptyBlocksIndex;
                    }
                }
            }

            return selectionState;
        },

        // http://stackoverflow.com/questions/17678843/cant-restore-selection-after-html-modify-even-if-its-the-same-html
        // Tim Down
        //
        // {object} selectionState - the selection to import
        // {DOMElement} root - the root element the selection is being restored inside of
        // {Document} doc - the document to use for managing selection
        // {boolean} [favorLaterSelectionAnchor] - defaults to false. If true, import the cursor immediately
        //      subsequent to an anchor tag if it would otherwise be placed right at the trailing edge inside the
        //      anchor. This cursor positioning, even though visually equivalent to the user, can affect behavior
        //      in MS IE.
        importSelection: function (selectionState, root, doc, favorLaterSelectionAnchor) {
            if (!selectionState || !root) {
                return;
            }

            var range = doc.createRange();
            range.setStart(root, 0);
            range.collapse(true);

            var node = root,
                nodeStack = [],
                charIndex = 0,
                foundStart = false,
                stop = false,
                nextCharIndex;

            while (!stop && node) {
                if (node.nodeType === 3) {
                    nextCharIndex = charIndex + node.length;
                    if (!foundStart && selectionState.start >= charIndex && selectionState.start <= nextCharIndex) {
                        range.setStart(node, selectionState.start - charIndex);
                        foundStart = true;
                    }
                    if (foundStart && selectionState.end >= charIndex && selectionState.end <= nextCharIndex) {
                        range.setEnd(node, selectionState.end - charIndex);
                        stop = true;
                    }
                    charIndex = nextCharIndex;
                } else {
                    var i = node.childNodes.length - 1;
                    while (i >= 0) {
                        nodeStack.push(node.childNodes[i]);
                        i -= 1;
                    }
                }
                if (!stop) {
                    node = nodeStack.pop();
                }
            }

            if (selectionState.emptyBlocksIndex && selectionState.end === nextCharIndex) {
                var targetNode = Util.getTopBlockContainer(range.startContainer),
                    index = 0;
                // Skip over empty blocks until we hit the block we want the selection to be in
                while (index < selectionState.emptyBlocksIndex && targetNode.nextSibling) {
                    targetNode = targetNode.nextSibling;
                    index++;
                    // If we find a non-empty block, ignore the emptyBlocksIndex and just put selection here
                    if (targetNode.textContent.length > 0) {
                        break;
                    }
                }

                // We're selecting a high-level block node, so make sure the cursor gets moved into the deepest
                // element at the beginning of the block
                range.setStart(Util.getFirstSelectableLeafNode(targetNode), 0);
                range.collapse(true);
            }

            // If the selection is right at the ending edge of a link, put it outside the anchor tag instead of inside.
            if (favorLaterSelectionAnchor) {
                range = Selection.importSelectionMoveCursorPastAnchor(selectionState, range);
            }

            var sel = doc.getSelection();
            sel.removeAllRanges();
            sel.addRange(range);
        },

        // Utility method called from importSelection only
        importSelectionMoveCursorPastAnchor: function (selectionState, range) {
            var nodeInsideAnchorTagFunction = function (node) {
                return node.nodeName.toLowerCase() === 'a';
            };
            if (selectionState.start === selectionState.end &&
                    range.startContainer.nodeType === 3 &&
                    range.startOffset === range.startContainer.nodeValue.length &&
                    Util.traverseUp(range.startContainer, nodeInsideAnchorTagFunction)) {
                var prevNode = range.startContainer,
                    currentNode = range.startContainer.parentNode;
                while (currentNode !== null && currentNode.nodeName.toLowerCase() !== 'a') {
                    if (currentNode.childNodes[currentNode.childNodes.length - 1] !== prevNode) {
                        currentNode = null;
                    } else {
                        prevNode = currentNode;
                        currentNode = currentNode.parentNode;
                    }
                }
                if (currentNode !== null && currentNode.nodeName.toLowerCase() === 'a') {
                    var currentNodeIndex = null;
                    for (var i = 0; currentNodeIndex === null && i < currentNode.parentNode.childNodes.length; i++) {
                        if (currentNode.parentNode.childNodes[i] === currentNode) {
                            currentNodeIndex = i;
                        }
                    }
                    range.setStart(currentNode.parentNode, currentNodeIndex + 1);
                    range.collapse(true);
                }
            }
            return range;
        },

        // Returns 0 unless the cursor is within or preceded by empty paragraphs/blocks,
        // in which case it returns the count of such preceding paragraphs, including
        // the empty paragraph in which the cursor itself may be embedded.
        getIndexRelativeToAdjacentEmptyBlocks: function (doc, root, cursorContainer, cursorOffset) {
            // If there is text in front of the cursor, that means there isn't only empty blocks before it
            if (cursorContainer.nodeType === 3 && cursorOffset > 0) {
                return 0;
            }

            // Check if the block that contains the cursor has any other text in front of the cursor
            var node = cursorContainer;
            if (node.nodeType !== 3) {
                //node = cursorContainer.childNodes.length === cursorOffset ? null : cursorContainer.childNodes[cursorOffset];
                node = cursorContainer.childNodes[cursorOffset];
            }
            if (node && !Util.isElementAtBeginningOfBlock(node)) {
                return 0;
            }

            // Walk over block elements, counting number of empty blocks between last piece of text
            // and the block the cursor is in
            var treeWalker = doc.createTreeWalker(root, NodeFilter.SHOW_ELEMENT, filterOnlyParentElements, false),
                emptyBlocksCount = 0;
            while (treeWalker.nextNode()) {
                var blockIsEmpty = treeWalker.currentNode.textContent === '';
                if (blockIsEmpty || emptyBlocksCount > 0) {
                    emptyBlocksCount += 1;
                }
                if (Util.isDescendant(treeWalker.currentNode, cursorContainer, true)) {
                    return emptyBlocksCount;
                }
                if (!blockIsEmpty) {
                    emptyBlocksCount = 0;
                }
            }

            return emptyBlocksCount;
        },

        selectionInContentEditableFalse: function (contentWindow) {
            // determine if the current selection is exclusively inside
            // a contenteditable="false", though treat the case of an
            // explicit contenteditable="true" inside a "false" as false.
            var sawtrue,
                sawfalse = this.findMatchingSelectionParent(function (el) {
                    var ce = el && el.getAttribute('contenteditable');
                    if (ce === 'true') {
                        sawtrue = true;
                    }
                    return el.nodeName !== '#text' && ce === 'false';
                }, contentWindow);

            return !sawtrue && sawfalse;
        },

        // http://stackoverflow.com/questions/4176923/html-of-selected-text
        // by Tim Down
        getSelectionHtml: function getSelectionHtml(doc) {
            var i,
                html = '',
                sel = doc.getSelection(),
                len,
                container;
            if (sel.rangeCount) {
                container = doc.createElement('div');
                for (i = 0, len = sel.rangeCount; i < len; i += 1) {
                    container.appendChild(sel.getRangeAt(i).cloneContents());
                }
                html = container.innerHTML;
            }
            return html;
        },

        /**
         *  Find the caret position within an element irrespective of any inline tags it may contain.
         *
         *  @param {DOMElement} An element containing the cursor to find offsets relative to.
         *  @param {Range} A Range representing cursor position. Will window.getSelection if none is passed.
         *  @return {Object} 'left' and 'right' attributes contain offsets from begining and end of Element
         */
        getCaretOffsets: function getCaretOffsets(element, range) {
            var preCaretRange, postCaretRange;

            if (!range) {
                range = window.getSelection().getRangeAt(0);
            }

            preCaretRange = range.cloneRange();
            postCaretRange = range.cloneRange();

            preCaretRange.selectNodeContents(element);
            preCaretRange.setEnd(range.endContainer, range.endOffset);

            postCaretRange.selectNodeContents(element);
            postCaretRange.setStart(range.endContainer, range.endOffset);

            return {
                left: preCaretRange.toString().length,
                right: postCaretRange.toString().length
            };
        },

        // http://stackoverflow.com/questions/15867542/range-object-get-selection-parent-node-chrome-vs-firefox
        rangeSelectsSingleNode: function (range) {
            var startNode = range.startContainer;
            return startNode === range.endContainer &&
                startNode.hasChildNodes() &&
                range.endOffset === range.startOffset + 1;
        },

        getSelectedParentElement: function (range) {
            if (!range) {
                return null;
            }

            // Selection encompasses a single element
            if (this.rangeSelectsSingleNode(range) && range.startContainer.childNodes[range.startOffset].nodeType !== 3) {
                return range.startContainer.childNodes[range.startOffset];
            }

            // Selection range starts inside a text node, so get its parent
            if (range.startContainer.nodeType === 3) {
                return range.startContainer.parentNode;
            }

            // Selection starts inside an element
            return range.startContainer;
        },

        getSelectedElements: function (doc) {
            var selection = doc.getSelection(),
                range,
                toRet,
                currNode;

            if (!selection.rangeCount || selection.isCollapsed || !selection.getRangeAt(0).commonAncestorContainer) {
                return [];
            }

            range = selection.getRangeAt(0);

            if (range.commonAncestorContainer.nodeType === 3) {
                toRet = [];
                currNode = range.commonAncestorContainer;
                while (currNode.parentNode && currNode.parentNode.childNodes.length === 1) {
                    toRet.push(currNode.parentNode);
                    currNode = currNode.parentNode;
                }

                return toRet;
            }

            return [].filter.call(range.commonAncestorContainer.getElementsByTagName('*'), function (el) {
                return (typeof selection.containsNode === 'function') ? selection.containsNode(el, true) : true;
            });
        },

        selectNode: function (node, doc) {
            var range = doc.createRange(),
                sel = doc.getSelection();

            range.selectNodeContents(node);
            sel.removeAllRanges();
            sel.addRange(range);
        },

        select: function (doc, startNode, startOffset, endNode, endOffset) {
            doc.getSelection().removeAllRanges();
            var range = doc.createRange();
            range.setStart(startNode, startOffset);
            if (endNode) {
                range.setEnd(endNode, endOffset);
            } else {
                range.collapse(true);
            }
            doc.getSelection().addRange(range);
            return range;
        },

        /**
         * Move cursor to the given node with the given offset.
         *
         * @param  {DomDocument} doc     Current document
         * @param  {DomElement}  node    Element where to jump
         * @param  {integer}     offset  Where in the element should we jump, 0 by default
         */
        moveCursor: function (doc, node, offset) {
            this.select(doc, node, offset);
        },

        getSelectionRange: function (ownerDocument) {
            var selection = ownerDocument.getSelection();
            if (selection.rangeCount === 0) {
                return null;
            }
            return selection.getRangeAt(0);
        },

        // http://stackoverflow.com/questions/1197401/how-can-i-get-the-element-the-caret-is-in-with-javascript-when-using-contentedi
        // by You
        getSelectionStart: function (ownerDocument) {
            var node = ownerDocument.getSelection().anchorNode,
                startNode = (node && node.nodeType === 3 ? node.parentNode : node);

            return startNode;
        }
    };
}());

var Events;

(function () {
    'use strict';

    Events = function (instance) {
        this.base = instance;
        this.options = this.base.options;
        this.events = [];
        this.customEvents = {};
        this.listeners = {};
    };

    Events.prototype = {
        InputEventOnContenteditableSupported: !Util.isIE,

        // Helpers for event handling

        attachDOMEvent: function (target, event, listener, useCapture) {
            target.addEventListener(event, listener, useCapture);
            this.events.push([target, event, listener, useCapture]);
        },

        detachDOMEvent: function (target, event, listener, useCapture) {
            var index = this.indexOfListener(target, event, listener, useCapture),
                e;
            if (index !== -1) {
                e = this.events.splice(index, 1)[0];
                e[0].removeEventListener(e[1], e[2], e[3]);
            }
        },

        indexOfListener: function (target, event, listener, useCapture) {
            var i, n, item;
            for (i = 0, n = this.events.length; i < n; i = i + 1) {
                item = this.events[i];
                if (item[0] === target && item[1] === event && item[2] === listener && item[3] === useCapture) {
                    return i;
                }
            }
            return -1;
        },

        detachAllDOMEvents: function () {
            var e = this.events.pop();
            while (e) {
                e[0].removeEventListener(e[1], e[2], e[3]);
                e = this.events.pop();
            }
        },

        // custom events
        attachCustomEvent: function (event, listener) {
            this.setupListener(event);
            if (!this.customEvents[event]) {
                this.customEvents[event] = [];
            }
            this.customEvents[event].push(listener);
        },

        detachCustomEvent: function (event, listener) {
            var index = this.indexOfCustomListener(event, listener);
            if (index !== -1) {
                this.customEvents[event].splice(index, 1);
                // TODO: If array is empty, should detach internal listeners via destroyListener()
            }
        },

        indexOfCustomListener: function (event, listener) {
            if (!this.customEvents[event] || !this.customEvents[event].length) {
                return -1;
            }

            return this.customEvents[event].indexOf(listener);
        },

        detachAllCustomEvents: function () {
            this.customEvents = {};
            // TODO: Should detach internal listeners here via destroyListener()
        },

        triggerCustomEvent: function (name, data, editable) {
            if (this.customEvents[name]) {
                this.customEvents[name].forEach(function (listener) {
                    listener(data, editable);
                });
            }
        },

        // Cleaning up

        destroy: function () {
            this.detachAllDOMEvents();
            this.detachAllCustomEvents();
            this.detachExecCommand();

            if (this.base.elements) {
                this.base.elements.forEach(function (element) {
                    element.removeAttribute('data-medium-focused');
                });
            }
        },

        // Listening to calls to document.execCommand

        // Attach a listener to be notified when document.execCommand is called
        attachToExecCommand: function () {
            if (this.execCommandListener) {
                return;
            }

            // Store an instance of the listener so:
            // 1) We only attach to execCommand once
            // 2) We can remove the listener later
            this.execCommandListener = function (execInfo) {
                this.handleDocumentExecCommand(execInfo);
            }.bind(this);

            // Ensure that execCommand has been wrapped correctly
            this.wrapExecCommand();

            // Add listener to list of execCommand listeners
            this.options.ownerDocument.execCommand.listeners.push(this.execCommandListener);
        },

        // Remove our listener for calls to document.execCommand
        detachExecCommand: function () {
            var doc = this.options.ownerDocument;
            if (!this.execCommandListener || !doc.execCommand.listeners) {
                return;
            }

            // Find the index of this listener in the array of listeners so it can be removed
            var index = doc.execCommand.listeners.indexOf(this.execCommandListener);
            if (index !== -1) {
                doc.execCommand.listeners.splice(index, 1);
            }

            // If the list of listeners is now empty, put execCommand back to its original state
            if (!doc.execCommand.listeners.length) {
                this.unwrapExecCommand();
            }
        },

        // Wrap document.execCommand in a custom method so we can listen to calls to it
        wrapExecCommand: function () {
            var doc = this.options.ownerDocument;

            // Ensure all instance of MediumEditor only wrap execCommand once
            if (doc.execCommand.listeners) {
                return;
            }

            // Create a wrapper method for execCommand which will:
            // 1) Call document.execCommand with the correct arguments
            // 2) Loop through any listeners and notify them that execCommand was called
            //    passing extra info on the call
            // 3) Return the result
            var wrapper = function (aCommandName, aShowDefaultUI, aValueArgument) {
                var result = doc.execCommand.orig.apply(this, arguments);

                if (!doc.execCommand.listeners) {
                    return result;
                }

                var args = Array.prototype.slice.call(arguments);
                doc.execCommand.listeners.forEach(function (listener) {
                    listener({
                        command: aCommandName,
                        value: aValueArgument,
                        args: args,
                        result: result
                    });
                });

                return result;
            };

            // Store a reference to the original execCommand
            wrapper.orig = doc.execCommand;

            // Attach an array for storing listeners
            wrapper.listeners = [];

            // Overwrite execCommand
            doc.execCommand = wrapper;
        },

        // Revert document.execCommand back to its original self
        unwrapExecCommand: function () {
            var doc = this.options.ownerDocument;
            if (!doc.execCommand.orig) {
                return;
            }

            // Use the reference to the original execCommand to revert back
            doc.execCommand = doc.execCommand.orig;
        },

        // Listening to browser events to emit events medium-editor cares about
        setupListener: function (name) {
            if (this.listeners[name]) {
                return;
            }

            switch (name) {
                case 'externalInteraction':
                    // Detecting when user has interacted with elements outside of MediumEditor
                    this.attachDOMEvent(this.options.ownerDocument.body, 'mousedown', this.handleBodyMousedown.bind(this), true);
                    this.attachDOMEvent(this.options.ownerDocument.body, 'click', this.handleBodyClick.bind(this), true);
                    this.attachDOMEvent(this.options.ownerDocument.body, 'focus', this.handleBodyFocus.bind(this), true);
                    break;
                case 'blur':
                    // Detecting when focus is lost
                    this.setupListener('externalInteraction');
                    break;
                case 'focus':
                    // Detecting when focus moves into some part of MediumEditor
                    this.setupListener('externalInteraction');
                    break;
                case 'editableInput':
                    // setup cache for knowing when the content has changed
                    this.contentCache = [];
                    this.base.elements.forEach(function (element) {
                        this.contentCache[element.getAttribute('medium-editor-index')] = element.innerHTML;

                        // Attach to the 'oninput' event, handled correctly by most browsers
                        if (this.InputEventOnContenteditableSupported) {
                            this.attachDOMEvent(element, 'input', this.handleInput.bind(this));
                        }
                    }.bind(this));

                    // For browsers which don't support the input event on contenteditable (IE)
                    // we'll attach to 'selectionchange' on the document and 'keypress' on the editables
                    if (!this.InputEventOnContenteditableSupported) {
                        this.setupListener('editableKeypress');
                        this.keypressUpdateInput = true;
                        this.attachDOMEvent(document, 'selectionchange', this.handleDocumentSelectionChange.bind(this));
                        // Listen to calls to execCommand
                        this.attachToExecCommand();
                    }
                    break;
                case 'editableClick':
                    // Detecting click in the contenteditables
                    this.attachToEachElement('click', this.handleClick);
                    break;
                case 'editableBlur':
                    // Detecting blur in the contenteditables
                    this.attachToEachElement('blur', this.handleBlur);
                    break;
                case 'editableKeypress':
                    // Detecting keypress in the contenteditables
                    this.attachToEachElement('keypress', this.handleKeypress);
                    break;
                case 'editableKeyup':
                    // Detecting keyup in the contenteditables
                    this.attachToEachElement('keyup', this.handleKeyup);
                    break;
                case 'editableKeydown':
                    // Detecting keydown on the contenteditables
                    this.attachToEachElement('keydown', this.handleKeydown);
                    break;
                case 'editableKeydownEnter':
                    // Detecting keydown for ENTER on the contenteditables
                    this.setupListener('editableKeydown');
                    break;
                case 'editableKeydownTab':
                    // Detecting keydown for TAB on the contenteditable
                    this.setupListener('editableKeydown');
                    break;
                case 'editableKeydownDelete':
                    // Detecting keydown for DELETE/BACKSPACE on the contenteditables
                    this.setupListener('editableKeydown');
                    break;
                case 'editableMouseover':
                    // Detecting mouseover on the contenteditables
                    this.attachToEachElement('mouseover', this.handleMouseover);
                    break;
                case 'editableDrag':
                    // Detecting dragover and dragleave on the contenteditables
                    this.attachToEachElement('dragover', this.handleDragging);
                    this.attachToEachElement('dragleave', this.handleDragging);
                    break;
                case 'editableDrop':
                    // Detecting drop on the contenteditables
                    this.attachToEachElement('drop', this.handleDrop);
                    break;
                case 'editablePaste':
                    // Detecting paste on the contenteditables
                    this.attachToEachElement('paste', this.handlePaste);
                    break;
            }
            this.listeners[name] = true;
        },

        attachToEachElement: function (name, handler) {
            this.base.elements.forEach(function (element) {
                this.attachDOMEvent(element, name, handler.bind(this));
            }, this);
        },

        focusElement: function (element) {
            element.focus();
            this.updateFocus(element, { target: element, type: 'focus' });
        },

        updateFocus: function (target, eventObj) {
            var toolbar = this.base.getExtensionByName('toolbar'),
                toolbarEl = toolbar ? toolbar.getToolbarElement() : null,
                anchorPreview = this.base.getExtensionByName('anchor-preview'),
                previewEl = (anchorPreview && anchorPreview.getPreviewElement) ? anchorPreview.getPreviewElement() : null,
                hadFocus = this.base.getFocusedElement(),
                toFocus;

            // For clicks, we need to know if the mousedown that caused the click happened inside the existing focused element.
            // If so, we don't want to focus another element
            if (hadFocus &&
                    eventObj.type === 'click' &&
                    this.lastMousedownTarget &&
                    (Util.isDescendant(hadFocus, this.lastMousedownTarget, true) ||
                     Util.isDescendant(toolbarEl, this.lastMousedownTarget, true) ||
                     Util.isDescendant(previewEl, this.lastMousedownTarget, true))) {
                toFocus = hadFocus;
            }

            if (!toFocus) {
                this.base.elements.some(function (element) {
                    // If the target is part of an editor element, this is the element getting focus
                    if (!toFocus && (Util.isDescendant(element, target, true))) {
                        toFocus = element;
                    }

                    // bail if we found an element that's getting focus
                    return !!toFocus;
                }, this);
            }

            // Check if the target is external (not part of the editor, toolbar, or anchorpreview)
            var externalEvent = !Util.isDescendant(hadFocus, target, true) &&
                                !Util.isDescendant(toolbarEl, target, true) &&
                                !Util.isDescendant(previewEl, target, true);

            if (toFocus !== hadFocus) {
                // If element has focus, and focus is going outside of editor
                // Don't blur focused element if clicking on editor, toolbar, or anchorpreview
                if (hadFocus && externalEvent) {
                    // Trigger blur on the editable that has lost focus
                    hadFocus.removeAttribute('data-medium-focused');
                    this.triggerCustomEvent('blur', eventObj, hadFocus);
                }

                // If focus is going into an editor element
                if (toFocus) {
                    // Trigger focus on the editable that now has focus
                    toFocus.setAttribute('data-medium-focused', true);
                    this.triggerCustomEvent('focus', eventObj, toFocus);
                }
            }

            if (externalEvent) {
                this.triggerCustomEvent('externalInteraction', eventObj);
            }
        },

        updateInput: function (target, eventObj) {
            // An event triggered which signifies that the user may have changed someting
            // Look in our cache of input for the contenteditables to see if something changed
            var index = target.getAttribute('medium-editor-index');
            if (target.innerHTML !== this.contentCache[index]) {
                // The content has changed since the last time we checked, fire the event
                this.triggerCustomEvent('editableInput', eventObj, target);
            }
            this.contentCache[index] = target.innerHTML;
        },

        handleDocumentSelectionChange: function (event) {
            // When selectionchange fires, target and current target are set
            // to document, since this is where the event is handled
            // However, currentTarget will have an 'activeElement' property
            // which will point to whatever element has focus.
            if (event.currentTarget && event.currentTarget.activeElement) {
                var activeElement = event.currentTarget.activeElement,
                    currentTarget;
                // We can look at the 'activeElement' to determine if the selectionchange has
                // happened within a contenteditable owned by this instance of MediumEditor
                this.base.elements.some(function (element) {
                    if (Util.isDescendant(element, activeElement, true)) {
                        currentTarget = element;
                        return true;
                    }
                    return false;
                }, this);

                // We know selectionchange fired within one of our contenteditables
                if (currentTarget) {
                    this.updateInput(currentTarget, { target: activeElement, currentTarget: currentTarget });
                }
            }
        },

        handleDocumentExecCommand: function () {
            // document.execCommand has been called
            // If one of our contenteditables currently has focus, we should
            // attempt to trigger the 'editableInput' event
            var target = this.base.getFocusedElement();
            if (target) {
                this.updateInput(target, { target: target, currentTarget: target });
            }
        },

        handleBodyClick: function (event) {
            this.updateFocus(event.target, event);
        },

        handleBodyFocus: function (event) {
            this.updateFocus(event.target, event);
        },

        handleBodyMousedown: function (event) {
            this.lastMousedownTarget = event.target;
        },

        handleInput: function (event) {
            this.updateInput(event.currentTarget, event);
        },

        handleClick: function (event) {
            this.triggerCustomEvent('editableClick', event, event.currentTarget);
        },

        handleBlur: function (event) {
            this.triggerCustomEvent('editableBlur', event, event.currentTarget);
        },

        handleKeypress: function (event) {
            this.triggerCustomEvent('editableKeypress', event, event.currentTarget);

            // If we're doing manual detection of the editableInput event we need
            // to check for input changes during 'keypress'
            if (this.keypressUpdateInput) {
                var eventObj = { target: event.target, currentTarget: event.currentTarget };

                // In IE, we need to let the rest of the event stack complete before we detect
                // changes to input, so using setTimeout here
                setTimeout(function () {
                    this.updateInput(eventObj.currentTarget, eventObj);
                }.bind(this), 0);
            }
        },

        handleKeyup: function (event) {
            this.triggerCustomEvent('editableKeyup', event, event.currentTarget);
        },

        handleMouseover: function (event) {
            this.triggerCustomEvent('editableMouseover', event, event.currentTarget);
        },

        handleDragging: function (event) {
            this.triggerCustomEvent('editableDrag', event, event.currentTarget);
        },

        handleDrop: function (event) {
            this.triggerCustomEvent('editableDrop', event, event.currentTarget);
        },

        handlePaste: function (event) {
            this.triggerCustomEvent('editablePaste', event, event.currentTarget);
        },

        handleKeydown: function (event) {
            this.triggerCustomEvent('editableKeydown', event, event.currentTarget);

            if (Util.isKey(event, Util.keyCode.ENTER)) {
                return this.triggerCustomEvent('editableKeydownEnter', event, event.currentTarget);
            }

            if (Util.isKey(event, Util.keyCode.TAB)) {
                return this.triggerCustomEvent('editableKeydownTab', event, event.currentTarget);
            }

            if (Util.isKey(event, [Util.keyCode.DELETE, Util.keyCode.BACKSPACE])) {
                return this.triggerCustomEvent('editableKeydownDelete', event, event.currentTarget);
            }
        }
    };
}());

var Button;
(function () {
    'use strict';

    /*global Extension, buttonDefaults */

    Button = Extension.extend({

        /* Button Options */

        /* action: [string]
         * The action argument to pass to MediumEditor.execAction()
         * when the button is clicked
         */
        action: undefined,

        /* aria: [string]
         * The value to add as the aria-label attribute of the button
         * element displayed in the toolbar.
         * This is also used as the tooltip for the button
         */
        aria: undefined,

        /* tagNames: [Array]
         * NOTE: This is not used if useQueryState is set to true.
         *
         * Array of element tag names that would indicate that this
         * button has already been applied. If this action has already
         * been applied, the button will be displayed as 'active' in the toolbar
         *
         * Example:
         * For 'bold', if the text is ever within a <b> or <strong>
         * tag that indicates the text is already bold. So the array
         * of tagNames for bold would be: ['b', 'strong']
         */
        tagNames: undefined,

        /* style: [Object]
         * NOTE: This is not used if useQueryState is set to true.
         *
         * A pair of css property & value(s) that indicate that this
         * button has already been applied. If this action has already
         * been applied, the button will be displayed as 'active' in the toolbar
         * Properties of the object:
         *   prop [String]: name of the css property
         *   value [String]: value(s) of the css property
         *                   multiple values can be separated by a '|'
         *
         * Example:
         * For 'bold', if the text is ever within an element with a 'font-weight'
         * style property set to '700' or 'bold', that indicates the text
         * is already bold.  So the style object for bold would be:
         * { prop: 'font-weight', value: '700|bold' }
         */
        style: undefined,

        /* useQueryState: [boolean]
         * Enables/disables whether this button should use the built-in
         * document.queryCommandState() method to determine whether
         * the action has already been applied.  If the action has already
         * been applied, the button will be displayed as 'active' in the toolbar
         *
         * Example:
         * For 'bold', if this is set to true, the code will call:
         * document.queryCommandState('bold') which will return true if the
         * browser thinks the text is already bold, and false otherwise
         */
        useQueryState: undefined,

        /* contentDefault: [string]
         * Default innerHTML to put inside the button
         */
        contentDefault: undefined,

        /* contentFA: [string]
         * The innerHTML to use for the content of the button
         * if the `buttonLabels` option for MediumEditor is set to 'fontawesome'
         */
        contentFA: undefined,

        /* classList: [Array]
         * An array of classNames (strings) to be added to the button
         */
        classList: undefined,

        /* attrs: [object]
         * A set of key-value pairs to add to the button as custom attributes
         */
        attrs: undefined,

        /* buttonDefaults: [Object]
         * Set of default config options for all of the built-in MediumEditor buttons
         */
        defaults: buttonDefaults,

        // The button constructor can optionally accept the name of a built-in button
        // (ie 'bold', 'italic', etc.)
        // When the name of a button is passed, it will initialize itself with the
        // configuration for that button
        constructor: function (options) {
            if (Button.isBuiltInButton(options)) {
                Extension.call(this, this.defaults[options]);
            } else {
                Extension.call(this, options);
            }
        },

        init: function () {
            Extension.prototype.init.apply(this, arguments);

            this.button = this.createButton();
            this.on(this.button, 'click', this.handleClick.bind(this));
        },

        /* getButton: [function ()]
         *
         * If implemented, this function will be called when
         * the toolbar is being created.  The DOM Element returned
         * by this function will be appended to the toolbar along
         * with any other buttons.
         */
        getButton: function () {
            return this.button;
        },

        getAction: function () {
            return (typeof this.action === 'function') ? this.action(this.base.options) : this.action;
        },

        getAria: function () {
            return (typeof this.aria === 'function') ? this.aria(this.base.options) : this.aria;
        },

        getTagNames: function () {
            return (typeof this.tagNames === 'function') ? this.tagNames(this.base.options) : this.tagNames;
        },

        createButton: function () {
            var button = this.document.createElement('button'),
                content = this.contentDefault,
                ariaLabel = this.getAria(),
                buttonLabels = this.getEditorOption('buttonLabels');
            // Add class names
            button.classList.add('medium-editor-action');
            button.classList.add('medium-editor-action-' + this.name);
            if (this.classList) {
                this.classList.forEach(function (className) {
                    button.classList.add(className);
                });
            }

            // Add attributes
            button.setAttribute('data-action', this.getAction());
            if (ariaLabel) {
                button.setAttribute('title', ariaLabel);
                button.setAttribute('aria-label', ariaLabel);
            }
            if (this.attrs) {
                Object.keys(this.attrs).forEach(function (attr) {
                    button.setAttribute(attr, this.attrs[attr]);
                }, this);
            }

            if (buttonLabels === 'fontawesome' && this.contentFA) {
                content = this.contentFA;
            }
            button.innerHTML = content;
            return button;
        },

        handleClick: function (event) {
            event.preventDefault();
            event.stopPropagation();

            var action = this.getAction();

            if (action) {
                this.execAction(action);
            }
        },

        isActive: function () {
            return this.button.classList.contains(this.getEditorOption('activeButtonClass'));
        },

        setInactive: function () {
            this.button.classList.remove(this.getEditorOption('activeButtonClass'));
            delete this.knownState;
        },

        setActive: function () {
            this.button.classList.add(this.getEditorOption('activeButtonClass'));
            delete this.knownState;
        },

        queryCommandState: function () {
            var queryState = null;
            if (this.useQueryState) {
                queryState = this.base.queryCommandState(this.getAction());
            }
            return queryState;
        },

        isAlreadyApplied: function (node) {
            var isMatch = false,
                tagNames = this.getTagNames(),
                styleVals,
                computedStyle;

            if (this.knownState === false || this.knownState === true) {
                return this.knownState;
            }

            if (tagNames && tagNames.length > 0) {
                isMatch = tagNames.indexOf(node.nodeName.toLowerCase()) !== -1;
            }

            if (!isMatch && this.style) {
                styleVals = this.style.value.split('|');
                computedStyle = this.window.getComputedStyle(node, null).getPropertyValue(this.style.prop);
                styleVals.forEach(function (val) {
                    if (!this.knownState) {
                        isMatch = (computedStyle.indexOf(val) !== -1);
                        // text-decoration is not inherited by default
                        // so if the computed style for text-decoration doesn't match
                        // don't write to knownState so we can fallback to other checks
                        if (isMatch || this.style.prop !== 'text-decoration') {
                            this.knownState = isMatch;
                        }
                    }
                }, this);
            }

            return isMatch;
        }
    });

    Button.isBuiltInButton = function (name) {
        return (typeof name === 'string') && Button.prototype.defaults.hasOwnProperty(name);
    };
}());

var FormExtension;
(function () {
    'use strict';

    /* global Button */

    var noop = function () {};

    /* Base functionality for an extension whcih will display
     * a 'form' inside the toolbar
     */
    FormExtension = Button.extend({

        init: function () {
            Button.prototype.init.apply(this, arguments);
        },

        // default labels for the form buttons
        formSaveLabel: '&#10003;',
        formCloseLabel: '&times;',

        /* hasForm: [boolean]
         *
         * Setting this to true will cause getForm() to be called
         * when the toolbar is created, so the form can be appended
         * inside the toolbar container
         */
        hasForm: true,

        /* getForm: [function ()]
         *
         * When hasForm is true, this function must be implemented
         * and return a DOM Element which will be appended to
         * the toolbar container. The form should start hidden, and
         * the extension can choose when to hide/show it
         */
        getForm: noop,

        /* isDisplayed: [function ()]
         *
         * This function should return true/false reflecting
         * whether the form is currently displayed
         */
        isDisplayed: noop,

        /* hideForm: [function ()]
         *
         * This function should hide the form element inside
         * the toolbar container
         */
        hideForm: noop,

        /************************ Helpers ************************
         * The following are helpers that are either set by MediumEditor
         * during initialization, or are helper methods which either
         * route calls to the MediumEditor instance or provide common
         * functionality for all form extensions
         *********************************************************/

        /* showToolbarDefaultActions: [function ()]
         *
         * Helper method which will turn back the toolbar after canceling
         * the customized form
         */
        showToolbarDefaultActions: function () {
            var toolbar = this.base.getExtensionByName('toolbar');
            if (toolbar) {
                toolbar.showToolbarDefaultActions();
            }
        },

        /* hideToolbarDefaultActions: [function ()]
         *
         * Helper function which will hide the default contents of the
         * toolbar, but leave the toolbar container in the same state
         * to allow a form to display its custom contents inside the toolbar
         */
        hideToolbarDefaultActions: function () {
            var toolbar = this.base.getExtensionByName('toolbar');
            if (toolbar) {
                toolbar.hideToolbarDefaultActions();
            }
        },

        /* setToolbarPosition: [function ()]
         *
         * Helper function which will update the size and position
         * of the toolbar based on the toolbar content and the current
         * position of the user's selection
         */
        setToolbarPosition: function () {
            var toolbar = this.base.getExtensionByName('toolbar');
            if (toolbar) {
                toolbar.setToolbarPosition();
            }
        }
    });
})();
var AnchorForm;
(function () {
    'use strict';

    /*global Util, Selection, FormExtension */

    AnchorForm = FormExtension.extend({
        /* Anchor Form Options */

        /* customClassOption: [string]  (previously options.anchorButton + options.anchorButtonClass)
         * Custom class name the user can optionally have added to their created links (ie 'button').
         * If passed as a non-empty string, a checkbox will be displayed allowing the user to choose
         * whether to have the class added to the created link or not.
         */
        customClassOption: null,

        /* customClassOptionText: [string]
         * text to be shown in the checkbox when the __customClassOption__ is being used.
         */
        customClassOptionText: 'Button',

        /* linkValidation: [boolean]  (previously options.checkLinkFormat)
         * enables/disables check for common URL protocols on anchor links.
         */
        linkValidation: false,

        /* placeholderText: [string]  (previously options.anchorInputPlaceholder)
         * text to be shown as placeholder of the anchor input.
         */
        placeholderText: 'Paste or type a link',

        /* targetCheckbox: [boolean]  (previously options.anchorTarget)
         * enables/disables displaying a "Open in new window" checkbox, which when checked
         * changes the `target` attribute of the created link.
         */
        targetCheckbox: false,

        /* targetCheckboxText: [string]  (previously options.anchorInputCheckboxLabel)
         * text to be shown in the checkbox enabled via the __targetCheckbox__ option.
         */
        targetCheckboxText: 'Open in new window',

        // Options for the Button base class
        name: 'anchor',
        action: 'createLink',
        aria: 'link',
        tagNames: ['a'],
        contentDefault: '<b>#</b>',
        contentFA: '<i class="fa fa-link"></i>',

        init: function () {
            FormExtension.prototype.init.apply(this, arguments);

            this.subscribe('editableKeydown', this.handleKeydown.bind(this));
        },

        // Called when the button the toolbar is clicked
        // Overrides ButtonExtension.handleClick
        handleClick: function (event) {
            event.preventDefault();
            event.stopPropagation();

            var selectedParentElement = Selection.getSelectedParentElement(Selection.getSelectionRange(this.document)),
                firstTextNode = Util.getFirstTextNode(selectedParentElement);

            if (Util.getClosestTag(firstTextNode, 'a')) {
                return this.execAction('unlink');
            }

            if (!this.isDisplayed()) {
                this.showForm();
            }

            return false;
        },

        // Called when user hits the defined shortcut (CTRL / COMMAND + K)
        handleKeydown: function (event) {
            if (Util.isKey(event, Util.keyCode.K) && Util.isMetaCtrlKey(event) && !event.shiftKey) {
                this.handleClick(event);
            }
        },

        // Called by medium-editor to append form to the toolbar
        getForm: function () {
            if (!this.form) {
                this.form = this.createForm();
            }
            return this.form;
        },

        getTemplate: function () {
            var template = [
                '<input type="text" class="medium-editor-toolbar-input" placeholder="', this.placeholderText, '">'
            ];

            template.push(
                '<a href="#" class="medium-editor-toolbar-save">',
                this.getEditorOption('buttonLabels') === 'fontawesome' ? '<i class="fa fa-check"></i>' : this.formSaveLabel,
                '</a>'
            );

            template.push('<a href="#" class="medium-editor-toolbar-close">',
                this.getEditorOption('buttonLabels') === 'fontawesome' ? '<i class="fa fa-times"></i>' : this.formCloseLabel,
                '</a>');

            // both of these options are slightly moot with the ability to
            // override the various form buildup/serialize functions.

            if (this.targetCheckbox) {
                // fixme: ideally, this targetCheckboxText would be a formLabel too,
                // figure out how to deprecate? also consider `fa-` icon default implcations.
                template.push(
                    '<input type="checkbox" class="medium-editor-toolbar-anchor-target">',
                    '<label>',
                    this.targetCheckboxText,
                    '</label>'
                );
            }

            if (this.customClassOption) {
                // fixme: expose this `Button` text as a formLabel property, too
                // and provide similar access to a `fa-` icon default.
                template.push(
                    '<input type="checkbox" class="medium-editor-toolbar-anchor-button">',
                    '<label>',
                    this.customClassOptionText,
                    '</label>'
                );
            }

            return template.join('');

        },

        // Used by medium-editor when the default toolbar is to be displayed
        isDisplayed: function () {
            return this.getForm().style.display === 'block';
        },

        hideForm: function () {
            this.getForm().style.display = 'none';
            this.getInput().value = '';
        },

        showForm: function (linkValue) {
            var input = this.getInput();

            this.base.saveSelection();
            this.hideToolbarDefaultActions();
            this.getForm().style.display = 'block';
            this.setToolbarPosition();

            input.value = linkValue || '';
            input.focus();
        },

        // Called by core when tearing down medium-editor (destroy)
        destroy: function () {
            if (!this.form) {
                return false;
            }

            if (this.form.parentNode) {
                this.form.parentNode.removeChild(this.form);
            }

            delete this.form;
        },

        // core methods

        getFormOpts: function () {
            // no notion of private functions? wanted `_getFormOpts`
            var targetCheckbox = this.getForm().querySelector('.medium-editor-toolbar-anchor-target'),
                buttonCheckbox = this.getForm().querySelector('.medium-editor-toolbar-anchor-button'),
                opts = {
                    url: this.getInput().value
                };

            if (this.linkValidation) {
                opts.url = this.checkLinkFormat(opts.url);
            }

            opts.target = '_self';
            if (targetCheckbox && targetCheckbox.checked) {
                opts.target = '_blank';
            }

            if (buttonCheckbox && buttonCheckbox.checked) {
                opts.buttonClass = this.customClassOption;
            }

            return opts;
        },

        doFormSave: function () {
            var opts = this.getFormOpts();
            this.completeFormSave(opts);
        },

        completeFormSave: function (opts) {
            this.base.restoreSelection();
            this.execAction(this.action, opts);
            this.base.checkSelection();
        },

        checkLinkFormat: function (value) {
            var re = /^(https?|ftps?|rtmpt?):\/\/|mailto:/;
            return (re.test(value) ? '' : 'http://') + value;
        },

        doFormCancel: function () {
            this.base.restoreSelection();
            this.base.checkSelection();
        },

        // form creation and event handling
        attachFormEvents: function (form) {
            var close = form.querySelector('.medium-editor-toolbar-close'),
                save = form.querySelector('.medium-editor-toolbar-save'),
                input = form.querySelector('.medium-editor-toolbar-input');

            // Handle clicks on the form itself
            this.on(form, 'click', this.handleFormClick.bind(this));

            // Handle typing in the textbox
            this.on(input, 'keyup', this.handleTextboxKeyup.bind(this));

            // Handle close button clicks
            this.on(close, 'click', this.handleCloseClick.bind(this));

            // Handle save button clicks (capture)
            this.on(save, 'click', this.handleSaveClick.bind(this), true);

        },

        createForm: function () {
            var doc = this.document,
                form = doc.createElement('div');

            // Anchor Form (div)
            form.className = 'medium-editor-toolbar-form';
            form.id = 'medium-editor-toolbar-form-anchor-' + this.getEditorId();
            form.innerHTML = this.getTemplate();
            this.attachFormEvents(form);

            return form;
        },

        getInput: function () {
            return this.getForm().querySelector('input.medium-editor-toolbar-input');
        },

        handleTextboxKeyup: function (event) {
            // For ENTER -> create the anchor
            if (event.keyCode === Util.keyCode.ENTER) {
                event.preventDefault();
                this.doFormSave();
                return;
            }

            // For ESCAPE -> close the form
            if (event.keyCode === Util.keyCode.ESCAPE) {
                event.preventDefault();
                this.doFormCancel();
            }
        },

        handleFormClick: function (event) {
            // make sure not to hide form when clicking inside the form
            event.stopPropagation();
        },

        handleSaveClick: function (event) {
            // Clicking Save -> create the anchor
            event.preventDefault();
            this.doFormSave();
        },

        handleCloseClick: function (event) {
            // Click Close -> close the form
            event.preventDefault();
            this.doFormCancel();
        }
    });
}());
var AnchorPreview;
(function () {
    'use strict';

    /*global Util, Extension */

    AnchorPreview = Extension.extend({
        name: 'anchor-preview',

        // Anchor Preview Options

        /* hideDelay: [number]  (previously options.anchorPreviewHideDelay)
         * time in milliseconds to show the anchor tag preview after the mouse has left the anchor tag.
         */
        hideDelay: 500,

        /* previewValueSelector: [string]
         * the default selector to locate where to put the activeAnchor value in the preview
         */
        previewValueSelector: 'a',

        init: function () {
            this.anchorPreview = this.createPreview();

            this.getEditorOption('elementsContainer').appendChild(this.anchorPreview);

            this.attachToEditables();
        },

        getPreviewElement: function () {
            return this.anchorPreview;
        },

        createPreview: function () {
            var el = this.document.createElement('div');

            el.id = 'medium-editor-anchor-preview-' + this.getEditorId();
            el.className = 'medium-editor-anchor-preview';
            el.innerHTML = this.getTemplate();

            this.on(el, 'click', this.handleClick.bind(this));

            return el;
        },

        getTemplate: function () {
            return '<div class="medium-editor-toolbar-anchor-preview" id="medium-editor-toolbar-anchor-preview">' +
                '    <a class="medium-editor-toolbar-anchor-preview-inner"></a>' +
                '</div>';
        },

        destroy: function () {
            if (this.anchorPreview) {
                if (this.anchorPreview.parentNode) {
                    this.anchorPreview.parentNode.removeChild(this.anchorPreview);
                }
                delete this.anchorPreview;
            }
        },

        hidePreview: function () {
            this.anchorPreview.classList.remove('medium-editor-anchor-preview-active');
            this.activeAnchor = null;
        },

        showPreview: function (anchorEl) {
            if (this.anchorPreview.classList.contains('medium-editor-anchor-preview-active') ||
                    anchorEl.getAttribute('data-disable-preview')) {
                return true;
            }

            if (this.previewValueSelector) {
                this.anchorPreview.querySelector(this.previewValueSelector).textContent = anchorEl.attributes.href.value;
                this.anchorPreview.querySelector(this.previewValueSelector).href = anchorEl.attributes.href.value;
            }

            this.anchorPreview.classList.add('medium-toolbar-arrow-over');
            this.anchorPreview.classList.remove('medium-toolbar-arrow-under');

            if (!this.anchorPreview.classList.contains('medium-editor-anchor-preview-active')) {
                this.anchorPreview.classList.add('medium-editor-anchor-preview-active');
            }

            this.activeAnchor = anchorEl;

            this.positionPreview();
            this.attachPreviewHandlers();

            return this;
        },

        positionPreview: function (activeAnchor) {
            activeAnchor = activeAnchor || this.activeAnchor;
            var buttonHeight = this.anchorPreview.offsetHeight,
                boundary = activeAnchor.getBoundingClientRect(),
                middleBoundary = (boundary.left + boundary.right) / 2,
                diffLeft = this.diffLeft,
                diffTop = this.diffTop,
                halfOffsetWidth,
                defaultLeft;

            halfOffsetWidth = this.anchorPreview.offsetWidth / 2;
            var toolbarExtension = this.base.getExtensionByName('toolbar');
            if (toolbarExtension) {
                diffLeft = toolbarExtension.diffLeft;
                diffTop = toolbarExtension.diffTop;
            }
            defaultLeft = diffLeft - halfOffsetWidth;

            this.anchorPreview.style.top = Math.round(buttonHeight + boundary.bottom - diffTop + this.window.pageYOffset - this.anchorPreview.offsetHeight) + 'px';
            if (middleBoundary < halfOffsetWidth) {
                this.anchorPreview.style.left = defaultLeft + halfOffsetWidth + 'px';
            } else if ((this.window.innerWidth - middleBoundary) < halfOffsetWidth) {
                this.anchorPreview.style.left = this.window.innerWidth + defaultLeft - halfOffsetWidth + 'px';
            } else {
                this.anchorPreview.style.left = defaultLeft + middleBoundary + 'px';
            }
        },

        attachToEditables: function () {
            this.subscribe('editableMouseover', this.handleEditableMouseover.bind(this));
        },

        handleClick: function (event) {
            var anchorExtension = this.base.getExtensionByName('anchor'),
                activeAnchor = this.activeAnchor;

            if (anchorExtension && activeAnchor) {
                event.preventDefault();

                this.base.selectElement(this.activeAnchor);

                // Using setTimeout + delay because:
                // We may actually be displaying the anchor form, which should be controlled by delay
                this.base.delay(function () {
                    if (activeAnchor) {
                        anchorExtension.showForm(activeAnchor.attributes.href.value);
                        activeAnchor = null;
                    }
                }.bind(this));
            }

            this.hidePreview();
        },

        handleAnchorMouseout: function () {
            this.anchorToPreview = null;
            this.off(this.activeAnchor, 'mouseout', this.instanceHandleAnchorMouseout);
            this.instanceHandleAnchorMouseout = null;
        },

        handleEditableMouseover: function (event) {
            var target = Util.getClosestTag(event.target, 'a');

            if (false === target) {
                return;
            }

            // Detect empty href attributes
            // The browser will make href="" or href="#top"
            // into absolute urls when accessed as event.targed.href, so check the html
            if (!/href=["']\S+["']/.test(target.outerHTML) || /href=["']#\S+["']/.test(target.outerHTML)) {
                return true;
            }

            // only show when toolbar is not present
            var toolbar = this.base.getExtensionByName('toolbar');
            if (toolbar && toolbar.isDisplayed && toolbar.isDisplayed()) {
                return true;
            }

            // detach handler for other anchor in case we hovered multiple anchors quickly
            if (this.activeAnchor && this.activeAnchor !== target) {
                this.detachPreviewHandlers();
            }

            this.anchorToPreview = target;

            this.instanceHandleAnchorMouseout = this.handleAnchorMouseout.bind(this);
            this.on(this.anchorToPreview, 'mouseout', this.instanceHandleAnchorMouseout);
            // Using setTimeout + delay because:
            // - We're going to show the anchor preview according to the configured delay
            //   if the mouse has not left the anchor tag in that time
            this.base.delay(function () {
                if (this.anchorToPreview) {
                    this.showPreview(this.anchorToPreview);
                }
            }.bind(this));
        },

        handlePreviewMouseover: function () {
            this.lastOver = (new Date()).getTime();
            this.hovering = true;
        },

        handlePreviewMouseout: function (event) {
            if (!event.relatedTarget || !/anchor-preview/.test(event.relatedTarget.className)) {
                this.hovering = false;
            }
        },

        updatePreview: function () {
            if (this.hovering) {
                return true;
            }
            var durr = (new Date()).getTime() - this.lastOver;
            if (durr > this.hideDelay) {
                // hide the preview 1/2 second after mouse leaves the link
                this.detachPreviewHandlers();
            }
        },

        detachPreviewHandlers: function () {
            // cleanup
            clearInterval(this.intervalTimer);
            if (this.instanceHandlePreviewMouseover) {
                this.off(this.anchorPreview, 'mouseover', this.instanceHandlePreviewMouseover);
                this.off(this.anchorPreview, 'mouseout', this.instanceHandlePreviewMouseout);
                if (this.activeAnchor) {
                    this.off(this.activeAnchor, 'mouseover', this.instanceHandlePreviewMouseover);
                    this.off(this.activeAnchor, 'mouseout', this.instanceHandlePreviewMouseout);
                }
            }

            this.hidePreview();

            this.hovering = this.instanceHandlePreviewMouseover = this.instanceHandlePreviewMouseout = null;
        },

        // TODO: break up method and extract out handlers
        attachPreviewHandlers: function () {
            this.lastOver = (new Date()).getTime();
            this.hovering = true;

            this.instanceHandlePreviewMouseover = this.handlePreviewMouseover.bind(this);
            this.instanceHandlePreviewMouseout = this.handlePreviewMouseout.bind(this);

            this.intervalTimer = setInterval(this.updatePreview.bind(this), 200);

            this.on(this.anchorPreview, 'mouseover', this.instanceHandlePreviewMouseover);
            this.on(this.anchorPreview, 'mouseout', this.instanceHandlePreviewMouseout);
            this.on(this.activeAnchor, 'mouseover', this.instanceHandlePreviewMouseover);
            this.on(this.activeAnchor, 'mouseout', this.instanceHandlePreviewMouseout);
        }
    });
}());

var AutoLink,
    WHITESPACE_CHARS,
    KNOWN_TLDS_FRAGMENT,
    LINK_REGEXP_TEXT;

WHITESPACE_CHARS = [' ', '\t', '\n', '\r', '\u00A0', '\u2000', '\u2001', '\u2002', '\u2003',
                                    '\u2028', '\u2029'];
KNOWN_TLDS_FRAGMENT = 'com|net|org|edu|gov|mil|aero|asia|biz|cat|coop|info|int|jobs|mobi|museum|name|post|pro|tel|travel|' +
    'xxx|ac|ad|ae|af|ag|ai|al|am|an|ao|aq|ar|as|at|au|aw|ax|az|ba|bb|bd|be|bf|bg|bh|bi|bj|bm|bn|bo|br|bs|bt|bv|bw|by|' +
    'bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|cr|cs|cu|cv|cx|cy|cz|dd|de|dj|dk|dm|do|dz|ec|ee|eg|eh|er|es|et|eu|fi|fj|' +
    'fk|fm|fo|fr|ga|gb|gd|ge|gf|gg|gh|gi|gl|gm|gn|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|io|iq|ir|' +
    'is|it|je|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|me|mg|mh|mk|ml|mm|' +
    'mn|mo|mp|mq|mr|ms|mt|mu|mv|mw|mx|my|mz|na|nc|ne|nf|ng|ni|nl|no|np|nr|nu|nz|om|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|ps|' +
    'pt|pw|py|qa|re|ro|rs|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|ja|sk|sl|sm|sn|so|sr|ss|st|su|sv|sx|sy|sz|tc|td|tf|tg|th|' +
    'tj|tk|tl|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw';
LINK_REGEXP_TEXT =
    '(' +
    // Version of Gruber URL Regexp optimized for JS: http://stackoverflow.com/a/17733640
    '((?:(https?://|ftps?://|nntp://)|www\\d{0,3}[.]|[a-z0-9.\\-]+[.](' + KNOWN_TLDS_FRAGMENT + ')\\\/)\\S+(?:[^\\s`!\\[\\]{};:\'\".,?\u00AB\u00BB\u201C\u201D\u2018\u2019]))' +
    // Addition to above Regexp to support bare domains/one level subdomains with common non-i18n TLDs and without www prefix:
    ')|(([a-z0-9\\-]+\\.)?[a-z0-9\\-]+\\.(' + KNOWN_TLDS_FRAGMENT + '))';

(function () {
    'use strict';

    var KNOWN_TLDS_REGEXP = new RegExp('^(' + KNOWN_TLDS_FRAGMENT + ')$', 'i');

    function nodeIsNotInsideAnchorTag(node) {
        return !Util.getClosestTag(node, 'a');
    }

    AutoLink = Extension.extend({
        init: function () {
            Extension.prototype.init.apply(this, arguments);

            this.disableEventHandling = false;
            this.subscribe('editableKeypress', this.onKeypress.bind(this));
            this.subscribe('editableBlur', this.onBlur.bind(this));
            // MS IE has it's own auto-URL detect feature but ours is better in some ways. Be consistent.
            this.document.execCommand('AutoUrlDetect', false, false);
        },

        destroy: function () {
            // Turn AutoUrlDetect back on
            if (this.document.queryCommandSupported('AutoUrlDetect')) {
                this.document.execCommand('AutoUrlDetect', false, true);
            }
        },

        onBlur: function (blurEvent, editable) {
            this.performLinking(editable);
        },

        onKeypress: function (keyPressEvent) {
            if (this.disableEventHandling) {
                return;
            }

            if (Util.isKey(keyPressEvent, [Util.keyCode.SPACE, Util.keyCode.ENTER])) {
                clearTimeout(this.performLinkingTimeout);
                // Saving/restoring the selection in the middle of a keypress doesn't work well...
                this.performLinkingTimeout = setTimeout(function () {
                    try {
                        var sel = this.base.exportSelection();
                        if (this.performLinking(keyPressEvent.target)) {
                            // pass true for favorLaterSelectionAnchor - this is needed for links at the end of a
                            // paragraph in MS IE, or MS IE causes the link to be deleted right after adding it.
                            this.base.importSelection(sel, true);
                        }
                    } catch (e) {
                        if (window.console) {
                            window.console.error('Failed to perform linking', e);
                        }
                        this.disableEventHandling = true;
                    }
                }.bind(this), 0);
            }
        },

        performLinking: function (contenteditable) {
            // Perform linking on a paragraph level basis as otherwise the detection can wrongly find the end
            // of one paragraph and the beginning of another paragraph to constitute a link, such as a paragraph ending
            // "link." and the next paragraph beginning with "my" is interpreted into "link.my" and the code tries to create
            // a link across paragraphs - which doesn't work and is terrible.
            // (Medium deletes the spaces/returns between P tags so the textContent ends up without paragraph spacing)
            var paragraphs = contenteditable.querySelectorAll('p'),
                documentModified = false;
            if (paragraphs.length === 0) {
                paragraphs = [contenteditable];
            }
            for (var i = 0; i < paragraphs.length; i++) {
                documentModified = this.removeObsoleteAutoLinkSpans(paragraphs[i]) || documentModified;
                documentModified = this.performLinkingWithinElement(paragraphs[i]) || documentModified;
            }
            return documentModified;
        },

        removeObsoleteAutoLinkSpans: function (element) {
            var spans = element.querySelectorAll('span[data-auto-link="true"]'),
                documentModified = false;

            for (var i = 0; i < spans.length; i++) {
                var textContent = spans[i].textContent;
                if (textContent.indexOf('://') === -1) {
                    textContent = Util.ensureUrlHasProtocol(textContent);
                }
                if (spans[i].getAttribute('data-href') !== textContent && nodeIsNotInsideAnchorTag(spans[i])) {
                    documentModified = true;
                    var trimmedTextContent = textContent.replace(/\s+$/, '');
                    if (spans[i].getAttribute('data-href') === trimmedTextContent) {
                        var charactersTrimmed = textContent.length - trimmedTextContent.length,
                            subtree = Util.splitOffDOMTree(spans[i], this.splitTextBeforeEnd(spans[i], charactersTrimmed));
                        spans[i].parentNode.insertBefore(subtree, spans[i].nextSibling);
                    } else {
                        // Some editing has happened to the span, so just remove it entirely. The user can put it back
                        // around just the href content if they need to prevent it from linking
                        Util.unwrap(spans[i], this.document);
                    }
                }
            }
            return documentModified;
        },

        splitTextBeforeEnd: function (element, characterCount) {
            var treeWalker = this.document.createTreeWalker(element, NodeFilter.SHOW_TEXT, null, false),
                lastChildNotExhausted = true;

            // Start the tree walker at the last descendant of the span
            while (lastChildNotExhausted) {
                lastChildNotExhausted = treeWalker.lastChild() !== null;
            }

            var currentNode,
                currentNodeValue,
                previousNode;
            while (characterCount > 0 && previousNode !== null) {
                currentNode = treeWalker.currentNode;
                currentNodeValue = currentNode.nodeValue;
                if (currentNodeValue.length > characterCount) {
                    previousNode = currentNode.splitText(currentNodeValue.length - characterCount);
                    characterCount = 0;
                } else {
                    previousNode = treeWalker.previousNode();
                    characterCount -= currentNodeValue.length;
                }
            }
            return previousNode;
        },

        performLinkingWithinElement: function (element) {
            var matches = this.findLinkableText(element),
                linkCreated = false;

            for (var matchIndex = 0; matchIndex < matches.length; matchIndex++) {
                var matchingTextNodes = Util.findOrCreateMatchingTextNodes(this.document, element,
                        matches[matchIndex]);
                if (this.shouldNotLink(matchingTextNodes)) {
                    continue;
                }
                this.createAutoLink(matchingTextNodes, matches[matchIndex].href);
            }
            return linkCreated;
        },

        shouldNotLink: function (textNodes) {
            var shouldNotLink = false;
            for (var i = 0; i < textNodes.length && shouldNotLink === false; i++) {
                // Do not link if the text node is either inside an anchor or inside span[data-auto-link]
                shouldNotLink = !!Util.traverseUp(textNodes[i], function (node) {
                    return node.nodeName.toLowerCase() === 'a' ||
                        (node.getAttribute && node.getAttribute('data-auto-link') === 'true');
                });
            }
            return shouldNotLink;
        },

        findLinkableText: function (contenteditable) {
            var linkRegExp = new RegExp(LINK_REGEXP_TEXT, 'gi'),
                textContent = contenteditable.textContent,
                match = null,
                matches = [];

            while ((match = linkRegExp.exec(textContent)) !== null) {
                var matchOk = true,
                    matchEnd = match.index + match[0].length;
                // If the regexp detected something as a link that has text immediately preceding/following it, bail out.
                matchOk = (match.index === 0 || WHITESPACE_CHARS.indexOf(textContent[match.index - 1]) !== -1) &&
                    (matchEnd === textContent.length || WHITESPACE_CHARS.indexOf(textContent[matchEnd]) !== -1);
                // If the regexp detected a bare domain that doesn't use one of our expected TLDs, bail out.
                matchOk = matchOk && (match[0].indexOf('/') !== -1 ||
                    KNOWN_TLDS_REGEXP.test(match[0].split('.').pop().split('?').shift()));

                if (matchOk) {
                    matches.push({
                        href: match[0],
                        start: match.index,
                        end: matchEnd
                    });
                }
            }
            return matches;
        },

        createAutoLink: function (textNodes, href) {
            href = Util.ensureUrlHasProtocol(href);
            var anchor = Util.createLink(this.document, textNodes, href, this.getEditorOption('targetBlank') ? '_blank' : null),
                span = this.document.createElement('span');
            span.setAttribute('data-auto-link', 'true');
            span.setAttribute('data-href', href);
            anchor.insertBefore(span, anchor.firstChild);
            while (anchor.childNodes.length > 1) {
                span.appendChild(anchor.childNodes[1]);
            }
        }

    });
}());
var FileDragging;

(function () {
    'use strict';

    var CLASS_DRAG_OVER = 'medium-editor-dragover';

    function clearClassNames(element) {
        var editable = Util.getContainerEditorElement(element),
            existing = Array.prototype.slice.call(editable.parentElement.querySelectorAll('.' + CLASS_DRAG_OVER));

        existing.forEach(function (el) {
            el.classList.remove(CLASS_DRAG_OVER);
        });
    }

    FileDragging = Extension.extend({
        name: 'fileDragging',

        allowedTypes: ['image'],

        init: function () {
            Extension.prototype.init.apply(this, arguments);

            this.subscribe('editableDrag', this.handleDrag.bind(this));
            this.subscribe('editableDrop', this.handleDrop.bind(this));
        },

        handleDrag: function (event) {
            event.preventDefault();
            event.dataTransfer.dropEffect = 'copy';

            var target = event.target.classList ? event.target : event.target.parentElement;

            // Ensure the class gets removed from anything that had it before
            clearClassNames(target);

            if (event.type === 'dragover') {
                target.classList.add(CLASS_DRAG_OVER);
            }
        },

        handleDrop: function (event) {
            // Prevent file from opening in the current window
            event.preventDefault();
            event.stopPropagation();

            // IE9 does not support the File API, so prevent file from opening in the window
            // but also don't try to actually get the file
            if (event.dataTransfer.files) {
                Array.prototype.slice.call(event.dataTransfer.files).forEach(function (file) {
                    if (this.isAllowedFile(file)) {
                        if (file.type.match('image')) {
                            this.insertImageFile(file);
                        }
                    }
                }, this);
            }

            // Make sure we remove our class from everything
            clearClassNames(event.target);
        },

        isAllowedFile: function (file) {
            return this.allowedTypes.some(function (fileType) {
                return !!file.type.match(fileType);
            });
        },

        insertImageFile: function (file) {
            var fileReader = new FileReader();
            fileReader.readAsDataURL(file);

            var id = 'medium-img-' + (+new Date());
            Util.insertHTMLCommand(this.document, '<img class="medium-editor-image-loading" id="' + id + '" />');

            fileReader.onload = function () {
                var img = this.document.getElementById(id);
                if (img) {
                    img.removeAttribute('id');
                    img.removeAttribute('class');
                    img.src = fileReader.result;
                }
            }.bind(this);
        }
    });
}());

var KeyboardCommands;
(function () {
    'use strict';

    /*global Extension, Util */

    KeyboardCommands = Extension.extend({
        name: 'keyboard-commands',

        /* KeyboardCommands Options */

        /* commands: [Array]
         * Array of objects describing each command and the combination of keys that will trigger it
         * Required for each object:
         *   command [String] (argument passed to editor.execAction())
         *   key [String] (keyboard character that triggers this command)
         *   meta [boolean] (whether the ctrl/meta key has to be active or inactive)
         *   shift [boolean] (whether the shift key has to be active or inactive)
         *   alt [boolean] (whether the alt key has to be active or inactive)
         */
        commands: [
            {
                command: 'bold',
                key: 'B',
                meta: true,
                shift: false,
                alt: false
            },
            {
                command: 'italic',
                key: 'I',
                meta: true,
                shift: false,
                alt: false
            },
            {
                command: 'underline',
                key: 'U',
                meta: true,
                shift: false,
                alt: false
            }
        ],

        init: function () {
            Extension.prototype.init.apply(this, arguments);

            this.subscribe('editableKeydown', this.handleKeydown.bind(this));
            this.keys = {};
            this.commands.forEach(function (command) {
                var keyCode = command.key.charCodeAt(0);
                if (!this.keys[keyCode]) {
                    this.keys[keyCode] = [];
                }
                this.keys[keyCode].push(command);
            }, this);
        },

        handleKeydown: function (event) {
            var keyCode = Util.getKeyCode(event);
            if (!this.keys[keyCode]) {
                return;
            }

            var isMeta = Util.isMetaCtrlKey(event),
                isShift = !!event.shiftKey,
                isAlt = !!event.altKey;

            this.keys[keyCode].forEach(function (data) {
                if (data.meta === isMeta &&
                    data.shift === isShift &&
                    data.alt === isAlt) {
                    event.preventDefault();
                    event.stopPropagation();

                    // command can be false so the shortcurt is just disabled
                    if (false !== data.command) {
                        this.execAction(data.command);
                    }
                }
            }, this);
        }
    });
}());

var FontSizeForm;
(function () {
    'use strict';

    /*global FormExtension, Selection */

    FontSizeForm = FormExtension.extend({

        name: 'fontsize',
        action: 'fontSize',
        aria: 'increase/decrease font size',
        contentDefault: '&#xB1;', // ±
        contentFA: '<i class="fa fa-text-height"></i>',

        init: function () {
            FormExtension.prototype.init.apply(this, arguments);
        },

        // Called when the button the toolbar is clicked
        // Overrides ButtonExtension.handleClick
        handleClick: function (event) {
            event.preventDefault();
            event.stopPropagation();

            if (!this.isDisplayed()) {
                // Get fontsize of current selection (convert to string since IE returns this as number)
                var fontSize = this.document.queryCommandValue('fontSize') + '';
                this.showForm(fontSize);
            }

            return false;
        },

        // Called by medium-editor to append form to the toolbar
        getForm: function () {
            if (!this.form) {
                this.form = this.createForm();
            }
            return this.form;
        },

        // Used by medium-editor when the default toolbar is to be displayed
        isDisplayed: function () {
            return this.getForm().style.display === 'block';
        },

        hideForm: function () {
            this.getForm().style.display = 'none';
            this.getInput().value = '';
        },

        showForm: function (fontSize) {
            var input = this.getInput();

            this.base.saveSelection();
            this.hideToolbarDefaultActions();
            this.getForm().style.display = 'block';
            this.setToolbarPosition();

            input.value = fontSize || '';
            input.focus();
        },

        // Called by core when tearing down medium-editor (destroy)
        destroy: function () {
            if (!this.form) {
                return false;
            }

            if (this.form.parentNode) {
                this.form.parentNode.removeChild(this.form);
            }

            delete this.form;
        },

        // core methods

        doFormSave: function () {
            this.base.restoreSelection();
            this.base.checkSelection();
        },

        doFormCancel: function () {
            this.base.restoreSelection();
            this.clearFontSize();
            this.base.checkSelection();
        },

        // form creation and event handling
        createForm: function () {
            var doc = this.document,
                form = doc.createElement('div'),
                input = doc.createElement('input'),
                close = doc.createElement('a'),
                save = doc.createElement('a');

            // Font Size Form (div)
            form.className = 'medium-editor-toolbar-form';
            form.id = 'medium-editor-toolbar-form-fontsize-' + this.getEditorId();

            // Handle clicks on the form itself
            this.on(form, 'click', this.handleFormClick.bind(this));

            // Add font size slider
            input.setAttribute('type', 'range');
            input.setAttribute('min', '1');
            input.setAttribute('max', '7');
            input.className = 'medium-editor-toolbar-input';
            form.appendChild(input);

            // Handle typing in the textbox
            this.on(input, 'change', this.handleSliderChange.bind(this));

            // Add save buton
            save.setAttribute('href', '#');
            save.className = 'medium-editor-toobar-save';
            save.innerHTML = this.getEditorOption('buttonLabels') === 'fontawesome' ?
                             '<i class="fa fa-check"></i>' :
                             '&#10003;';
            form.appendChild(save);

            // Handle save button clicks (capture)
            this.on(save, 'click', this.handleSaveClick.bind(this), true);

            // Add close button
            close.setAttribute('href', '#');
            close.className = 'medium-editor-toobar-close';
            close.innerHTML = this.getEditorOption('buttonLabels') === 'fontawesome' ?
                              '<i class="fa fa-times"></i>' :
                              '&times;';
            form.appendChild(close);

            // Handle close button clicks
            this.on(close, 'click', this.handleCloseClick.bind(this));

            return form;
        },

        getInput: function () {
            return this.getForm().querySelector('input.medium-editor-toolbar-input');
        },

        clearFontSize: function () {
            Selection.getSelectedElements(this.document).forEach(function (el) {
                if (el.nodeName.toLowerCase() === 'font' && el.hasAttribute('size')) {
                    el.removeAttribute('size');
                }
            });
        },

        handleSliderChange: function () {
            var size = this.getInput().value;
            if (size === '4') {
                this.clearFontSize();
            } else {
                this.execAction('fontSize', { size: size });
            }
        },

        handleFormClick: function (event) {
            // make sure not to hide form when clicking inside the form
            event.stopPropagation();
        },

        handleSaveClick: function (event) {
            // Clicking Save -> create the font size
            event.preventDefault();
            this.doFormSave();
        },

        handleCloseClick: function (event) {
            // Click Close -> close the form
            event.preventDefault();
            this.doFormCancel();
        }
    });
}());
var PasteHandler;

(function () {
    'use strict';
    /*jslint regexp: true*/
    /*
        jslint does not allow character negation, because the negation
        will not match any unicode characters. In the regexes in this
        block, negation is used specifically to match the end of an html
        tag, and in fact unicode characters *should* be allowed.
    */
    function createReplacements() {
        return [

            // replace two bogus tags that begin pastes from google docs
            [new RegExp(/<[^>]*docs-internal-guid[^>]*>/gi), ''],
            [new RegExp(/<\/b>(<br[^>]*>)?$/gi), ''],

             // un-html spaces and newlines inserted by OS X
            [new RegExp(/<span class="Apple-converted-space">\s+<\/span>/g), ' '],
            [new RegExp(/<br class="Apple-interchange-newline">/g), '<br>'],

            // replace google docs italics+bold with a span to be replaced once the html is inserted
            [new RegExp(/<span[^>]*(font-style:italic;font-weight:bold|font-weight:bold;font-style:italic)[^>]*>/gi), '<span class="replace-with italic bold">'],

            // replace google docs italics with a span to be replaced once the html is inserted
            [new RegExp(/<span[^>]*font-style:italic[^>]*>/gi), '<span class="replace-with italic">'],

            //[replace google docs bolds with a span to be replaced once the html is inserted
            [new RegExp(/<span[^>]*font-weight:bold[^>]*>/gi), '<span class="replace-with bold">'],

             // replace manually entered b/i/a tags with real ones
            [new RegExp(/&lt;(\/?)(i|b|a)&gt;/gi), '<$1$2>'],

             // replace manually a tags with real ones, converting smart-quotes from google docs
            [new RegExp(/&lt;a(?:(?!href).)+href=(?:&quot;|&rdquo;|&ldquo;|"|“|”)(((?!&quot;|&rdquo;|&ldquo;|"|“|”).)*)(?:&quot;|&rdquo;|&ldquo;|"|“|”)(?:(?!&gt;).)*&gt;/gi), '<a href="$1">'],

            // Newlines between paragraphs in html have no syntactic value,
            // but then have a tendency to accidentally become additional paragraphs down the line
            [new RegExp(/<\/p>\n+/gi), '</p>'],
            [new RegExp(/\n+<p/gi), '<p'],

            // Microsoft Word makes these odd tags, like <o:p></o:p>
            [new RegExp(/<\/?o:[a-z]*>/gi), '']
        ];
    }
    /*jslint regexp: false*/

    PasteHandler = Extension.extend({
        /* Paste Options */

        /* forcePlainText: [boolean]
         * Forces pasting as plain text.
         */
        forcePlainText: true,

        /* cleanPastedHTML: [boolean]
         * cleans pasted content from different sources, like google docs etc.
         */
        cleanPastedHTML: false,

        /* cleanReplacements: [Array]
         * custom pairs (2 element arrays) of RegExp and replacement text to use during paste when
         * __forcePlainText__ or __cleanPastedHTML__ are `true` OR when calling `cleanPaste(text)` helper method.
         */
        cleanReplacements: [],

        /* cleanAttrs:: [Array]
         * list of element attributes to remove during paste when __cleanPastedHTML__ is `true` or when
         * calling `cleanPaste(text)` or `pasteHTML(html, options)` helper methods.
         */
        cleanAttrs: ['class', 'style', 'dir'],

        /* cleanTags: [Array]
         * list of element tag names to remove during paste when __cleanPastedHTML__ is `true` or when
         * calling `cleanPaste(text)` or `pasteHTML(html, options)` helper methods.
         */
        cleanTags: ['meta'],

        init: function () {
            Extension.prototype.init.apply(this, arguments);

            if (this.forcePlainText || this.cleanPastedHTML) {
                this.subscribe('editablePaste', this.handlePaste.bind(this));
            }
        },

        handlePaste: function (event, element) {
            var paragraphs,
                html = '',
                p,
                dataFormatHTML = 'text/html',
                dataFormatPlain = 'text/plain',
                pastedHTML,
                pastedPlain;

            if (this.window.clipboardData && event.clipboardData === undefined) {
                event.clipboardData = this.window.clipboardData;
                // If window.clipboardData exists, but event.clipboardData doesn't exist,
                // we're probably in IE. IE only has two possibilities for clipboard
                // data format: 'Text' and 'URL'.
                //
                // Of the two, we want 'Text':
                dataFormatHTML = 'Text';
                dataFormatPlain = 'Text';
            }

            if (event.clipboardData &&
                    event.clipboardData.getData &&
                    !event.defaultPrevented) {
                event.preventDefault();

                pastedHTML = event.clipboardData.getData(dataFormatHTML);
                pastedPlain = event.clipboardData.getData(dataFormatPlain);

                if (this.cleanPastedHTML && pastedHTML) {
                    return this.cleanPaste(pastedHTML);
                }

                if (!(this.getEditorOption('disableReturn') || element.getAttribute('data-disable-return'))) {
                    paragraphs = pastedPlain.split(/[\r\n]+/g);
                    // If there are no \r\n in data, don't wrap in <p>
                    if (paragraphs.length > 1) {
                        for (p = 0; p < paragraphs.length; p += 1) {
                            if (paragraphs[p] !== '') {
                                html += '<p>' + Util.htmlEntities(paragraphs[p]) + '</p>';
                            }
                        }
                    } else {
                        html = Util.htmlEntities(paragraphs[0]);
                    }
                } else {
                    html = Util.htmlEntities(pastedPlain);
                }
                Util.insertHTMLCommand(this.document, html);
            }
        },

        cleanPaste: function (text) {
            var i, elList, workEl,
                el = Selection.getSelectionElement(this.window),
                multiline = /<p|<br|<div/.test(text),
                replacements = createReplacements().concat(this.cleanReplacements || []);

            for (i = 0; i < replacements.length; i += 1) {
                text = text.replace(replacements[i][0], replacements[i][1]);
            }

            if (!multiline) {
                return this.pasteHTML(text);
            }

            // double br's aren't converted to p tags, but we want paragraphs.
            elList = text.split('<br><br>');

            this.pasteHTML('<p>' + elList.join('</p><p>') + '</p>');

            try {
                this.document.execCommand('insertText', false, '\n');
            } catch (ignore) { }

            // block element cleanup
            elList = el.querySelectorAll('a,p,div,br');
            for (i = 0; i < elList.length; i += 1) {
                workEl = elList[i];

                // Microsoft Word replaces some spaces with newlines.
                // While newlines between block elements are meaningless, newlines within
                // elements are sometimes actually spaces.
                workEl.innerHTML = workEl.innerHTML.replace(/\n/gi, ' ');

                switch (workEl.nodeName.toLowerCase()) {
                    case 'p':
                    case 'div':
                        this.filterCommonBlocks(workEl);
                        break;
                    case 'br':
                        this.filterLineBreak(workEl);
                        break;
                }
            }
        },

        pasteHTML: function (html, options) {
            options = Util.defaults({}, options, {
                cleanAttrs: this.cleanAttrs,
                cleanTags: this.cleanTags
            });

            var elList, workEl, i, fragmentBody, pasteBlock = this.document.createDocumentFragment();

            pasteBlock.appendChild(this.document.createElement('body'));

            fragmentBody = pasteBlock.querySelector('body');
            fragmentBody.innerHTML = html;

            this.cleanupSpans(fragmentBody);

            elList = fragmentBody.querySelectorAll('*');

            for (i = 0; i < elList.length; i += 1) {
                workEl = elList[i];

                if ('a' === workEl.nodeName.toLowerCase() && this.getEditorOption('targetBlank')) {
                    Util.setTargetBlank(workEl);
                }

                Util.cleanupAttrs(workEl, options.cleanAttrs);
                Util.cleanupTags(workEl, options.cleanTags);
            }

            Util.insertHTMLCommand(this.document, fragmentBody.innerHTML.replace(/&nbsp;/g, ' '));
        },

        isCommonBlock: function (el) {
            return (el && (el.nodeName.toLowerCase() === 'p' || el.nodeName.toLowerCase() === 'div'));
        },

        filterCommonBlocks: function (el) {
            if (/^\s*$/.test(el.textContent) && el.parentNode) {
                el.parentNode.removeChild(el);
            }
        },

        filterLineBreak: function (el) {
            if (this.isCommonBlock(el.previousElementSibling)) {
                // remove stray br's following common block elements
                this.removeWithParent(el);
            } else if (this.isCommonBlock(el.parentNode) && (el.parentNode.firstChild === el || el.parentNode.lastChild === el)) {
                // remove br's just inside open or close tags of a div/p
                this.removeWithParent(el);
            } else if (el.parentNode && el.parentNode.childElementCount === 1 && el.parentNode.textContent === '') {
                // and br's that are the only child of elements other than div/p
                this.removeWithParent(el);
            }
        },

        // remove an element, including its parent, if it is the only element within its parent
        removeWithParent: function (el) {
            if (el && el.parentNode) {
                if (el.parentNode.parentNode && el.parentNode.childElementCount === 1) {
                    el.parentNode.parentNode.removeChild(el.parentNode);
                } else {
                    el.parentNode.removeChild(el);
                }
            }
        },

        cleanupSpans: function (containerEl) {
            var i,
                el,
                newEl,
                spans = containerEl.querySelectorAll('.replace-with'),
                isCEF = function (el) {
                    return (el && el.nodeName !== '#text' && el.getAttribute('contenteditable') === 'false');
                };

            for (i = 0; i < spans.length; i += 1) {
                el = spans[i];
                newEl = this.document.createElement(el.classList.contains('bold') ? 'b' : 'i');

                if (el.classList.contains('bold') && el.classList.contains('italic')) {
                    // add an i tag as well if this has both italics and bold
                    newEl.innerHTML = '<i>' + el.innerHTML + '</i>';
                } else {
                    newEl.innerHTML = el.innerHTML;
                }
                el.parentNode.replaceChild(newEl, el);
            }

            spans = containerEl.querySelectorAll('span');
            for (i = 0; i < spans.length; i += 1) {
                el = spans[i];

                // bail if span is in contenteditable = false
                if (Util.traverseUp(el, isCEF)) {
                    return false;
                }

                // remove empty spans, replace others with their contents
                Util.unwrap(el, this.document);
            }
        }
    });
}());

var Placeholder;

(function () {
    'use strict';

    /*global Extension */

    Placeholder = Extension.extend({
        name: 'placeholder',

        /* Placeholder Options */

        /* text: [string]
         * Text to display in the placeholder
         */
        text: 'Type your text',

        /* hideOnClick: [boolean]
         * Should we hide the placeholder on click (true) or when user starts typing (false)
         */
        hideOnClick: true,

        init: function () {
            Extension.prototype.init.apply(this, arguments);

            this.initPlaceholders();
            this.attachEventHandlers();
        },

        initPlaceholders: function () {
            this.getEditorElements().forEach(function (el) {
                if (!el.getAttribute('data-placeholder')) {
                    el.setAttribute('data-placeholder', this.text);
                }
                this.updatePlaceholder(el);
            }, this);
        },

        destroy: function () {
            this.getEditorElements().forEach(function (el) {
                if (el.getAttribute('data-placeholder') === this.text) {
                    el.removeAttribute('data-placeholder');
                }
            }, this);
        },

        showPlaceholder: function (el) {
            if (el) {
                el.classList.add('medium-editor-placeholder');
            }
        },

        hidePlaceholder: function (el) {
            if (el) {
                el.classList.remove('medium-editor-placeholder');
            }
        },

        updatePlaceholder: function (el) {
            // if one of these element ('img, blockquote, ul, ol') are found inside the given element, we won't display the placeholder
            if (!(el.querySelector('img, blockquote, ul, ol')) && el.textContent.replace(/^\s+|\s+$/g, '') === '') {
                return this.showPlaceholder(el);
            }

            this.hidePlaceholder(el);
        },

        attachEventHandlers: function () {
            // Custom events
            this.subscribe('blur', this.handleExternalInteraction.bind(this));

            // Check placeholder on blur
            this.subscribe('editableBlur', this.handleBlur.bind(this));

            // if we don't want the placeholder to be removed on click but when user start typing
            if (this.hideOnClick) {
                this.subscribe('editableClick', this.handleHidePlaceholderEvent.bind(this));
            } else {
                this.subscribe('editableKeyup', this.handleBlur.bind(this));
            }

            // Events where we always hide the placeholder
            this.subscribe('editableKeypress', this.handleHidePlaceholderEvent.bind(this));
            this.subscribe('editablePaste', this.handleHidePlaceholderEvent.bind(this));
        },

        handleHidePlaceholderEvent: function (event, element) {
            // Events where we hide the placeholder
            this.hidePlaceholder(element);
        },

        handleBlur: function (event, element) {
            // Update placeholder for element that lost focus
            this.updatePlaceholder(element);
        },

        handleExternalInteraction: function () {
            // Update all placeholders
            this.initPlaceholders();
        }
    });
}());

var Toolbar;
(function () {
    'use strict';

    /*global Util, Selection, Extension */

    Toolbar = Extension.extend({
        name: 'toolbar',

        /* Toolbar Options */

        /* align: ['left'|'center'|'right']
         * When the __static__ option is true, this aligns the static toolbar
         * relative to the medium-editor element.
         */
        align: 'center',

        /* allowMultiParagraphSelection: [boolean]
         * enables/disables whether the toolbar should be displayed when
         * selecting multiple paragraphs/block elements
         */
        allowMultiParagraphSelection: true,

        /* buttons: [Array]
         * the names of the set of buttons to display on the toolbar.
         */
        buttons: ['bold', 'italic', 'underline', 'anchor', 'h2', 'h3', 'quote'],

        /* diffLeft: [Number]
         * value in pixels to be added to the X axis positioning of the toolbar.
         */
        diffLeft: 0,

        /* diffTop: [Number]
         * value in pixels to be added to the Y axis positioning of the toolbar.
         */
        diffTop: -10,

        /* firstButtonClass: [string]
         * CSS class added to the first button in the toolbar.
         */
        firstButtonClass: 'medium-editor-button-first',

        /* lastButtonClass: [string]
         * CSS class added to the last button in the toolbar.
         */
        lastButtonClass: 'medium-editor-button-last',

        /* standardizeSelectionStart: [boolean]
         * enables/disables standardizing how the beginning of a range is decided
         * between browsers whenever the selected text is analyzed for updating toolbar buttons status.
         */
        standardizeSelectionStart: false,

        /* static: [boolean]
         * enable/disable the toolbar always displaying in the same location
         * relative to the medium-editor element.
         */
        static: false,

        /* sticky: [boolean]
         * When the __static__ option is true, this enables/disables the toolbar
         * "sticking" to the viewport and staying visible on the screen while
         * the page scrolls.
         */
        sticky: false,

        /* updateOnEmptySelection: [boolean]
         * When the __static__ option is true, this enables/disables updating
         * the state of the toolbar buttons even when the selection is collapsed
         * (there is no selection, just a cursor).
         */
        updateOnEmptySelection: false,

        init: function () {
            Extension.prototype.init.apply(this, arguments);

            this.initThrottledMethods();
            this.getEditorOption('elementsContainer').appendChild(this.getToolbarElement());
        },

        // Helper method to execute method for every extension, but ignoring the toolbar extension
        forEachExtension: function (iterator, context) {
            return this.base.extensions.forEach(function (command) {
                if (command === this) {
                    return;
                }
                return iterator.apply(context || this, arguments);
            }, this);
        },

        // Toolbar creation/deletion

        createToolbar: function () {
            var toolbar = this.document.createElement('div');

            toolbar.id = 'medium-editor-toolbar-' + this.getEditorId();
            toolbar.className = 'medium-editor-toolbar';

            if (this.static) {
                toolbar.className += ' static-toolbar';
            } else {
                toolbar.className += ' medium-editor-stalker-toolbar';
            }

            toolbar.appendChild(this.createToolbarButtons());

            // Add any forms that extensions may have
            this.forEachExtension(function (extension) {
                if (extension.hasForm) {
                    toolbar.appendChild(extension.getForm());
                }
            });

            this.attachEventHandlers();

            return toolbar;
        },

        createToolbarButtons: function () {
            var ul = this.document.createElement('ul'),
                li,
                btn,
                buttons,
                extension,
                buttonName,
                buttonOpts;

            ul.id = 'medium-editor-toolbar-actions' + this.getEditorId();
            ul.className = 'medium-editor-toolbar-actions';
            ul.style.display = 'block';

            this.buttons.forEach(function (button) {
                if (typeof button === 'string') {
                    buttonName = button;
                    buttonOpts = null;
                } else {
                    buttonName = button.name;
                    buttonOpts = button;
                }

                // If the button already exists as an extension, it'll be returned
                // othwerise it'll create the default built-in button
                extension = this.base.addBuiltInExtension(buttonName, buttonOpts);

                if (extension && typeof extension.getButton === 'function') {
                    btn = extension.getButton(this.base);
                    li = this.document.createElement('li');
                    if (Util.isElement(btn)) {
                        li.appendChild(btn);
                    } else {
                        li.innerHTML = btn;
                    }
                    ul.appendChild(li);
                }
            }, this);

            buttons = ul.querySelectorAll('button');
            if (buttons.length > 0) {
                buttons[0].classList.add(this.firstButtonClass);
                buttons[buttons.length - 1].classList.add(this.lastButtonClass);
            }

            return ul;
        },

        destroy: function () {
            if (this.toolbar) {
                if (this.toolbar.parentNode) {
                    this.toolbar.parentNode.removeChild(this.toolbar);
                }
                delete this.toolbar;
            }
        },

        // Toolbar accessors

        getToolbarElement: function () {
            if (!this.toolbar) {
                this.toolbar = this.createToolbar();
            }

            return this.toolbar;
        },

        getToolbarActionsElement: function () {
            return this.getToolbarElement().querySelector('.medium-editor-toolbar-actions');
        },

        // Toolbar event handlers

        initThrottledMethods: function () {
            // throttledPositionToolbar is throttled because:
            // - It will be called when the browser is resizing, which can fire many times very quickly
            // - For some event (like resize) a slight lag in UI responsiveness is OK and provides performance benefits
            this.throttledPositionToolbar = Util.throttle(function () {
                if (this.base.isActive) {
                    this.positionToolbarIfShown();
                }
            }.bind(this));
        },

        attachEventHandlers: function () {
            // MediumEditor custom events for when user beings and ends interaction with a contenteditable and its elements
            this.subscribe('blur', this.handleBlur.bind(this));
            this.subscribe('focus', this.handleFocus.bind(this));

            // Updating the state of the toolbar as things change
            this.subscribe('editableClick', this.handleEditableClick.bind(this));
            this.subscribe('editableKeyup', this.handleEditableKeyup.bind(this));

            // Handle mouseup on document for updating the selection in the toolbar
            this.on(this.document.documentElement, 'mouseup', this.handleDocumentMouseup.bind(this));

            // Add a scroll event for sticky toolbar
            if (this.static && this.sticky) {
                // On scroll (capture), re-position the toolbar
                this.on(this.window, 'scroll', this.handleWindowScroll.bind(this), true);
            }

            // On resize, re-position the toolbar
            this.on(this.window, 'resize', this.handleWindowResize.bind(this));
        },

        handleWindowScroll: function () {
            this.positionToolbarIfShown();
        },

        handleWindowResize: function () {
            this.throttledPositionToolbar();
        },

        handleDocumentMouseup: function (event) {
            // Do not trigger checkState when mouseup fires over the toolbar
            if (event &&
                    event.target &&
                    Util.isDescendant(this.getToolbarElement(), event.target)) {
                return false;
            }
            this.checkState();
        },

        handleEditableClick: function () {
            // Delay the call to checkState to handle bug where selection is empty
            // immediately after clicking inside a pre-existing selection
            setTimeout(function () {
                this.checkState();
            }.bind(this), 0);
        },

        handleEditableKeyup: function () {
            this.checkState();
        },

        handleBlur: function () {
            // Kill any previously delayed calls to hide the toolbar
            clearTimeout(this.hideTimeout);

            // Blur may fire even if we have a selection, so we want to prevent any delayed showToolbar
            // calls from happening in this specific case
            clearTimeout(this.delayShowTimeout);

            // Delay the call to hideToolbar to handle bug with multiple editors on the page at once
            this.hideTimeout = setTimeout(function () {
                this.hideToolbar();
            }.bind(this), 1);
        },

        handleFocus: function () {
            this.checkState();
        },

        // Hiding/showing toolbar

        isDisplayed: function () {
            return this.getToolbarElement().classList.contains('medium-editor-toolbar-active');
        },

        showToolbar: function () {
            clearTimeout(this.hideTimeout);
            if (!this.isDisplayed()) {
                this.getToolbarElement().classList.add('medium-editor-toolbar-active');
                this.trigger('showToolbar', {}, this.base.getFocusedElement());
            }
        },

        hideToolbar: function () {
            if (this.isDisplayed()) {
                this.getToolbarElement().classList.remove('medium-editor-toolbar-active');
                this.trigger('hideToolbar', {}, this.base.getFocusedElement());
            }
        },

        isToolbarDefaultActionsDisplayed: function () {
            return this.getToolbarActionsElement().style.display === 'block';
        },

        hideToolbarDefaultActions: function () {
            if (this.isToolbarDefaultActionsDisplayed()) {
                this.getToolbarActionsElement().style.display = 'none';
            }
        },

        showToolbarDefaultActions: function () {
            this.hideExtensionForms();

            if (!this.isToolbarDefaultActionsDisplayed()) {
                this.getToolbarActionsElement().style.display = 'block';
            }

            // Using setTimeout + options.delay because:
            // We will actually be displaying the toolbar, which should be controlled by options.delay
            this.delayShowTimeout = this.base.delay(function () {
                this.showToolbar();
            }.bind(this));
        },

        hideExtensionForms: function () {
            // Hide all extension forms
            this.forEachExtension(function (extension) {
                if (extension.hasForm && extension.isDisplayed()) {
                    extension.hideForm();
                }
            });
        },

        // Responding to changes in user selection

        // Checks for existance of multiple block elements in the current selection
        multipleBlockElementsSelected: function () {
            var regexEmptyHTMLTags = /<[^\/>][^>]*><\/[^>]+>/gim, // http://stackoverflow.com/questions/3129738/remove-empty-tags-using-regex
                regexBlockElements = new RegExp('<(' + Util.blockContainerElementNames.join('|') + ')[^>]*>', 'g'),
                selectionHTML = Selection.getSelectionHtml(this.document).replace(regexEmptyHTMLTags, ''), // Filter out empty blocks from selection
                hasMultiParagraphs = selectionHTML.match(regexBlockElements); // Find how many block elements are within the html

            return !!hasMultiParagraphs && hasMultiParagraphs.length > 1;
        },

        modifySelection: function () {
            var selection = this.window.getSelection(),
                selectionRange = selection.getRangeAt(0);

            /*
            * In firefox, there are cases (ie doubleclick of a word) where the selectionRange start
            * will be at the very end of an element.  In other browsers, the selectionRange start
            * would instead be at the very beginning of an element that actually has content.
            * example:
            *   <span>foo</span><span>bar</span>
            *
            * If the text 'bar' is selected, most browsers will have the selectionRange start at the beginning
            * of the 'bar' span.  However, there are cases where firefox will have the selectionRange start
            * at the end of the 'foo' span.  The contenteditable behavior will be ok, but if there are any
            * properties on the 'bar' span, they won't be reflected accurately in the toolbar
            * (ie 'Bold' button wouldn't be active)
            *
            * So, for cases where the selectionRange start is at the end of an element/node, find the next
            * adjacent text node that actually has content in it, and move the selectionRange start there.
            */
            if (this.standardizeSelectionStart &&
                    selectionRange.startContainer.nodeValue &&
                    (selectionRange.startOffset === selectionRange.startContainer.nodeValue.length)) {
                var adjacentNode = Util.findAdjacentTextNodeWithContent(Selection.getSelectionElement(this.window), selectionRange.startContainer, this.document);
                if (adjacentNode) {
                    var offset = 0;
                    while (adjacentNode.nodeValue.substr(offset, 1).trim().length === 0) {
                        offset = offset + 1;
                    }
                    selectionRange = Selection.select(this.document, adjacentNode, offset,
                        selectionRange.endContainer, selectionRange.offset);
                }
            }
        },

        checkState: function () {
            if (this.base.preventSelectionUpdates) {
                return;
            }

            // If no editable has focus OR selection is inside contenteditable = false
            // hide toolbar
            if (!this.base.getFocusedElement() ||
                    Selection.selectionInContentEditableFalse(this.window)) {
                return this.hideToolbar();
            }

            // If there's no selection element, selection element doesn't belong to this editor
            // or toolbar is disabled for this selection element
            // hide toolbar
            var selectionElement = Selection.getSelectionElement(this.window);
            if (!selectionElement ||
                    this.getEditorElements().indexOf(selectionElement) === -1 ||
                    selectionElement.getAttribute('data-disable-toolbar')) {
                return this.hideToolbar();
            }

            // Now we know there's a focused editable with a selection

            // If the updateOnEmptySelection option is true, show the toolbar
            if (this.updateOnEmptySelection && this.static) {
                return this.showAndUpdateToolbar();
            }

            // If we don't have a 'valid' selection -> hide toolbar
            if (this.window.getSelection().toString().trim() === '' ||
                (this.allowMultiParagraphSelection === false && this.multipleBlockElementsSelected())) {
                return this.hideToolbar();
            }

            this.showAndUpdateToolbar();
        },

        // Updating the toolbar

        showAndUpdateToolbar: function () {
            this.modifySelection();
            this.setToolbarButtonStates();
            this.trigger('positionToolbar', {}, this.base.getFocusedElement());
            this.showToolbarDefaultActions();
            this.setToolbarPosition();
        },

        setToolbarButtonStates: function () {
            this.forEachExtension(function (extension) {
                if (typeof extension.isActive === 'function' &&
                    typeof extension.setInactive === 'function') {
                    extension.setInactive();
                }
            });

            this.checkActiveButtons();
        },

        checkActiveButtons: function () {
            var manualStateChecks = [],
                queryState = null,
                selectionRange = Selection.getSelectionRange(this.document),
                parentNode,
                updateExtensionState = function (extension) {
                    if (typeof extension.checkState === 'function') {
                        extension.checkState(parentNode);
                    } else if (typeof extension.isActive === 'function' &&
                               typeof extension.isAlreadyApplied === 'function' &&
                               typeof extension.setActive === 'function') {
                        if (!extension.isActive() && extension.isAlreadyApplied(parentNode)) {
                            extension.setActive();
                        }
                    }
                };

            if (!selectionRange) {
                return;
            }

            // Loop through all extensions
            this.forEachExtension(function (extension) {
                // For those extensions where we can use document.queryCommandState(), do so
                if (typeof extension.queryCommandState === 'function') {
                    queryState = extension.queryCommandState();
                    // If queryCommandState returns a valid value, we can trust the browser
                    // and don't need to do our manual checks
                    if (queryState !== null) {
                        if (queryState && typeof extension.setActive === 'function') {
                            extension.setActive();
                        }
                        return;
                    }
                }
                // We can't use queryCommandState for this extension, so add to manualStateChecks
                manualStateChecks.push(extension);
            });

            parentNode = Selection.getSelectedParentElement(selectionRange);

            // Make sure the selection parent isn't outside of the contenteditable
            if (!this.getEditorElements().some(function (element) {
                    return Util.isDescendant(element, parentNode, true);
                })) {
                return;
            }

            // Climb up the DOM and do manual checks for whether a certain extension is currently enabled for this node
            while (parentNode) {
                manualStateChecks.forEach(updateExtensionState);

                // we can abort the search upwards if we leave the contentEditable element
                if (Util.isMediumEditorElement(parentNode)) {
                    break;
                }
                parentNode = parentNode.parentNode;
            }
        },

        // Positioning toolbar

        positionToolbarIfShown: function () {
            if (this.isDisplayed()) {
                this.setToolbarPosition();
            }
        },

        setToolbarPosition: function () {
            var container = this.base.getFocusedElement(),
                selection = this.window.getSelection(),
                anchorPreview;

            // If there isn't a valid selection, bail
            if (!container) {
                return this;
            }

            if (this.static) {
                this.showToolbar();
                this.positionStaticToolbar(container);
            } else if (!selection.isCollapsed) {
                this.showToolbar();
                this.positionToolbar(selection);
            }

            anchorPreview = this.base.getExtensionByName('anchor-preview');

            if (anchorPreview && typeof anchorPreview.hidePreview === 'function') {
                anchorPreview.hidePreview();
            }
        },

        positionStaticToolbar: function (container) {
            // position the toolbar at left 0, so we can get the real width of the toolbar
            this.getToolbarElement().style.left = '0';

            // document.documentElement for IE 9
            var scrollTop = (this.document.documentElement && this.document.documentElement.scrollTop) || this.document.body.scrollTop,
                windowWidth = this.window.innerWidth,
                toolbarElement = this.getToolbarElement(),
                containerRect = container.getBoundingClientRect(),
                containerTop = containerRect.top + scrollTop,
                containerCenter = (containerRect.left + (containerRect.width / 2)),
                toolbarHeight = toolbarElement.offsetHeight,
                toolbarWidth = toolbarElement.offsetWidth,
                halfOffsetWidth = toolbarWidth / 2,
                targetLeft;

            if (this.sticky) {
                // If it's beyond the height of the editor, position it at the bottom of the editor
                if (scrollTop > (containerTop + container.offsetHeight - toolbarHeight)) {
                    toolbarElement.style.top = (containerTop + container.offsetHeight - toolbarHeight) + 'px';
                    toolbarElement.classList.remove('medium-editor-sticky-toolbar');

                // Stick the toolbar to the top of the window
                } else if (scrollTop > (containerTop - toolbarHeight)) {
                    toolbarElement.classList.add('medium-editor-sticky-toolbar');
                    toolbarElement.style.top = '0px';

                // Normal static toolbar position
                } else {
                    toolbarElement.classList.remove('medium-editor-sticky-toolbar');
                    toolbarElement.style.top = containerTop - toolbarHeight + 'px';
                }
            } else {
                toolbarElement.style.top = containerTop - toolbarHeight + 'px';
            }

            switch (this.align) {
                case 'left':
                    targetLeft = containerRect.left;
                    break;

                case 'right':
                    targetLeft = containerRect.right - toolbarWidth;
                    break;

                case 'center':
                    targetLeft = containerCenter - halfOffsetWidth;
                    break;
            }

            if (targetLeft < 0) {
                targetLeft = 0;
            } else if ((targetLeft + toolbarWidth) > windowWidth) {
                targetLeft = (windowWidth - Math.ceil(toolbarWidth) - 1);
            }

            toolbarElement.style.left = targetLeft + 'px';
        },

        positionToolbar: function (selection) {
            // position the toolbar at left 0, so we can get the real width of the toolbar
            this.getToolbarElement().style.left = '0';

            var windowWidth = this.window.innerWidth,
                range = selection.getRangeAt(0),
                boundary = range.getBoundingClientRect(),
                middleBoundary = (boundary.left + boundary.right) / 2,
                toolbarElement = this.getToolbarElement(),
                toolbarHeight = toolbarElement.offsetHeight,
                toolbarWidth = toolbarElement.offsetWidth,
                halfOffsetWidth = toolbarWidth / 2,
                buttonHeight = 50,
                defaultLeft = this.diffLeft - halfOffsetWidth;

            if (boundary.top < buttonHeight) {
                toolbarElement.classList.add('medium-toolbar-arrow-over');
                toolbarElement.classList.remove('medium-toolbar-arrow-under');
                toolbarElement.style.top = buttonHeight + boundary.bottom - this.diffTop + this.window.pageYOffset - toolbarHeight + 'px';
            } else {
                toolbarElement.classList.add('medium-toolbar-arrow-under');
                toolbarElement.classList.remove('medium-toolbar-arrow-over');
                toolbarElement.style.top = boundary.top + this.diffTop + this.window.pageYOffset - toolbarHeight + 'px';
            }

            if (middleBoundary < halfOffsetWidth) {
                toolbarElement.style.left = defaultLeft + halfOffsetWidth + 'px';
            } else if ((windowWidth - middleBoundary) < halfOffsetWidth) {
                toolbarElement.style.left = windowWidth + defaultLeft - halfOffsetWidth + 'px';
            } else {
                toolbarElement.style.left = defaultLeft + middleBoundary + 'px';
            }
        }
    });
}());

var ImageDragging;

(function () {
    'use strict';

    ImageDragging = Extension.extend({
        init: function () {
            Extension.prototype.init.apply(this, arguments);

            this.subscribe('editableDrag', this.handleDrag.bind(this));
            this.subscribe('editableDrop', this.handleDrop.bind(this));
        },

        handleDrag: function (event) {
            var className = 'medium-editor-dragover';
            event.preventDefault();
            event.dataTransfer.dropEffect = 'copy';

            if (event.type === 'dragover') {
                event.target.classList.add(className);
            } else if (event.type === 'dragleave') {
                event.target.classList.remove(className);
            }
        },

        handleDrop: function (event) {
            var className = 'medium-editor-dragover',
                files;
            event.preventDefault();
            event.stopPropagation();

            // IE9 does not support the File API, so prevent file from opening in a new window
            // but also don't try to actually get the file
            if (event.dataTransfer.files) {
                files = Array.prototype.slice.call(event.dataTransfer.files, 0);
                files.some(function (file) {
                    if (file.type.match('image')) {
                        var fileReader, id;
                        fileReader = new FileReader();
                        fileReader.readAsDataURL(file);

                        id = 'medium-img-' + (+new Date());
                        Util.insertHTMLCommand(this.document, '<img class="medium-editor-image-loading" id="' + id + '" />');

                        fileReader.onload = function () {
                            var img = this.document.getElementById(id);
                            if (img) {
                                img.removeAttribute('id');
                                img.removeAttribute('class');
                                img.src = fileReader.result;
                            }
                        }.bind(this);
                    }
                }.bind(this));
            }
            event.target.classList.remove(className);
        }
    });
}());

var extensionDefaults;
(function () {
    // for now this is empty because nothing interally uses an Extension default.
    // as they are converted, provide them here.
    extensionDefaults = {
        button: Button,
        form: FormExtension,

        anchor: AnchorForm,
        anchorPreview: AnchorPreview,
        autoLink: AutoLink,
        fileDragging: FileDragging,
        fontSize: FontSizeForm,
        imageDragging: ImageDragging, // deprecated
        keyboardCommands: KeyboardCommands,
        paste: PasteHandler,
        placeholder: Placeholder,
        toolbar: Toolbar
    };
})();

function MediumEditor(elements, options) {
    'use strict';
    return this.init(elements, options);
}

(function () {
    'use strict';

    // Event handlers that shouldn't be exposed externally

    function handleDisabledEnterKeydown(event, element) {
        if (this.options.disableReturn || element.getAttribute('data-disable-return')) {
            event.preventDefault();
        } else if (this.options.disableDoubleReturn || element.getAttribute('data-disable-double-return')) {
            var node = Selection.getSelectionStart(this.options.ownerDocument);

            // if current text selection is empty OR previous sibling text is empty
            if ((node && node.textContent.trim() === '') ||
                (node.previousElementSibling && node.previousElementSibling.textContent.trim() === '')) {
                event.preventDefault();
            }
        }
    }

    function handleTabKeydown(event) {
        // Override tab only for pre nodes
        var node = Selection.getSelectionStart(this.options.ownerDocument),
            tag = node && node.nodeName.toLowerCase();

        if (tag === 'pre') {
            event.preventDefault();
            Util.insertHTMLCommand(this.options.ownerDocument, '    ');
        }

        // Tab to indent list structures!
        if (Util.isListItem(node)) {
            event.preventDefault();

            // If Shift is down, outdent, otherwise indent
            if (event.shiftKey) {
                this.options.ownerDocument.execCommand('outdent', false, null);
            } else {
                this.options.ownerDocument.execCommand('indent', false, null);
            }
        }
    }

    function handleBlockDeleteKeydowns(event) {
        var p, node = Selection.getSelectionStart(this.options.ownerDocument),
            tagName = node.nodeName.toLowerCase(),
            isEmpty = /^(\s+|<br\/?>)?$/i,
            isHeader = /h\d/i;

        if (Util.isKey(event, [Util.keyCode.BACKSPACE, Util.keyCode.ENTER]) &&
                // has a preceeding sibling
                node.previousElementSibling &&
                // in a header
                isHeader.test(tagName) &&
                // at the very end of the block
                Selection.getCaretOffsets(node).left === 0) {
            if (Util.isKey(event, Util.keyCode.BACKSPACE) && isEmpty.test(node.previousElementSibling.innerHTML)) {
                // backspacing the begining of a header into an empty previous element will
                // change the tagName of the current node to prevent one
                // instead delete previous node and cancel the event.
                node.previousElementSibling.parentNode.removeChild(node.previousElementSibling);
                event.preventDefault();
            } else if (Util.isKey(event, Util.keyCode.ENTER)) {
                // hitting return in the begining of a header will create empty header elements before the current one
                // instead, make "<p><br></p>" element, which are what happens if you hit return in an empty paragraph
                p = this.options.ownerDocument.createElement('p');
                p.innerHTML = '<br>';
                node.previousElementSibling.parentNode.insertBefore(p, node);
                event.preventDefault();
            }
        } else if (Util.isKey(event, Util.keyCode.DELETE) &&
                    // between two sibling elements
                    node.nextElementSibling &&
                    node.previousElementSibling &&
                    // not in a header
                    !isHeader.test(tagName) &&
                    // in an empty tag
                    isEmpty.test(node.innerHTML) &&
                    // when the next tag *is* a header
                    isHeader.test(node.nextElementSibling.nodeName.toLowerCase())) {
            // hitting delete in an empty element preceding a header, ex:
            //  <p>[CURSOR]</p><h1>Header</h1>
            // Will cause the h1 to become a paragraph.
            // Instead, delete the paragraph node and move the cursor to the begining of the h1

            // remove node and move cursor to start of header
            Selection.moveCursor(this.options.ownerDocument, node.nextElementSibling);

            node.previousElementSibling.parentNode.removeChild(node);

            event.preventDefault();
        } else if (Util.isKey(event, Util.keyCode.BACKSPACE) &&
                tagName === 'li' &&
                // hitting backspace inside an empty li
                isEmpty.test(node.innerHTML) &&
                // is first element (no preceeding siblings)
                !node.previousElementSibling &&
                // parent also does not have a sibling
                !node.parentElement.previousElementSibling &&
                // is not the only li in a list
                node.nextElementSibling &&
                node.nextElementSibling.nodeName.toLowerCase() === 'li') {
            // backspacing in an empty first list element in the first list (with more elements) ex:
            //  <ul><li>[CURSOR]</li><li>List Item 2</li></ul>
            // will remove the first <li> but add some extra element before (varies based on browser)
            // Instead, this will:
            // 1) remove the list element
            // 2) create a paragraph before the list
            // 3) move the cursor into the paragraph

            // create a paragraph before the list
            p = this.options.ownerDocument.createElement('p');
            p.innerHTML = '<br>';
            node.parentElement.parentElement.insertBefore(p, node.parentElement);

            // move the cursor into the new paragraph
            Selection.moveCursor(this.options.ownerDocument, p);

            // remove the list element
            node.parentElement.removeChild(node);

            event.preventDefault();
        }
    }

    function handleKeyup(event) {
        var node = Selection.getSelectionStart(this.options.ownerDocument),
            tagName;

        if (!node) {
            return;
        }

        if (Util.isMediumEditorElement(node) && node.children.length === 0) {
            this.options.ownerDocument.execCommand('formatBlock', false, 'p');
        }

        if (Util.isKey(event, Util.keyCode.ENTER) && !Util.isListItem(node)) {
            tagName = node.nodeName.toLowerCase();
            // For anchor tags, unlink
            if (tagName === 'a') {
                this.options.ownerDocument.execCommand('unlink', false, null);
            } else if (!event.shiftKey && !event.ctrlKey) {
                // only format block if this is not a header tag
                if (!/h\d/.test(tagName)) {
                    this.options.ownerDocument.execCommand('formatBlock', false, 'p');
                }
            }
        }
    }

    // Internal helper methods which shouldn't be exposed externally

    function addToEditors(win) {
        if (!win._mediumEditors) {
            // To avoid breaking users who are assuming that the unique id on
            // medium-editor elements will start at 1, inserting a 'null' in the
            // array so the unique-id can always map to the index of the editor instance
            win._mediumEditors = [null];
        }

        // If this already has a unique id, re-use it
        if (!this.id) {
            this.id = win._mediumEditors.length;
        }

        win._mediumEditors[this.id] = this;
    }

    function removeFromEditors(win) {
        if (!win._mediumEditors || !win._mediumEditors[this.id]) {
            return;
        }

        /* Setting the instance to null in the array instead of deleting it allows:
         * 1) Each instance to preserve its own unique-id, even after being destroyed
         *    and initialized again
         * 2) The unique-id to always correspond to an index in the array of medium-editor
         *    instances. Thus, we will be able to look at a contenteditable, and determine
         *    which instance it belongs to, by indexing into the global array.
         */
        win._mediumEditors[this.id] = null;
    }

    function createElementsArray(selector) {
        if (!selector) {
            selector = [];
        }
        // If string, use as query selector
        if (typeof selector === 'string') {
            selector = this.options.ownerDocument.querySelectorAll(selector);
        }
        // If element, put into array
        if (Util.isElement(selector)) {
            selector = [selector];
        }
        // Convert NodeList (or other array like object) into an array
        var elements = Array.prototype.slice.apply(selector);

        // Loop through elements and convert textarea's into divs
        this.elements = [];
        elements.forEach(function (element, index) {
            if (element.nodeName.toLowerCase() === 'textarea') {
                this.elements.push(createContentEditable.call(this, element, index));
            } else {
                this.elements.push(element);
            }
        }, this);
    }

    function setExtensionDefaults(extension, defaults) {
        Object.keys(defaults).forEach(function (prop) {
            if (extension[prop] === undefined) {
                extension[prop] = defaults[prop];
            }
        });
        return extension;
    }

    function initExtension(extension, name, instance) {
        var extensionDefaults = {
            'window': instance.options.contentWindow,
            'document': instance.options.ownerDocument,
            'base': instance
        };

        // Add default options into the extension
        extension = setExtensionDefaults(extension, extensionDefaults);

        // Call init on the extension
        if (typeof extension.init === 'function') {
            extension.init();
        }

        // Set extension name (if not already set)
        if (!extension.name) {
            extension.name = name;
        }
        return extension;
    }

    function isToolbarEnabled() {
        // If any of the elements don't have the toolbar disabled
        // We need a toolbar
        if (this.elements.every(function (element) {
                return !!element.getAttribute('data-disable-toolbar');
            })) {
            return false;
        }

        return this.options.toolbar !== false;
    }

    function isAnchorPreviewEnabled() {
        // If toolbar is disabled, don't add
        if (!isToolbarEnabled.call(this)) {
            return false;
        }

        return this.options.anchorPreview !== false;
    }

    function isPlaceholderEnabled() {
        return this.options.placeholder !== false;
    }

    function isAutoLinkEnabled() {
        return this.options.autoLink !== false;
    }

    function isImageDraggingEnabled() {
        return this.options.imageDragging !== false;
    }

    function isKeyboardCommandsEnabled() {
        return this.options.keyboardCommands !== false;
    }

    function shouldUseFileDraggingExtension() {
        // Since the file-dragging extension replaces the image-dragging extension,
        // we need to check if the user passed an overrided image-dragging extension.
        // If they have, to avoid breaking users, we won't use file-dragging extension.
        return !this.options.extensions['imageDragging'];
    }

    function createContentEditable(textarea, id) {
        var div = this.options.ownerDocument.createElement('div'),
            uniqueId = 'medium-editor-' + Date.now() + '-' + id,
            attributesToClone = [
                'data-disable-editing',
                'data-disable-toolbar',
                'data-placeholder',
                'data-disable-return',
                'data-disable-double-return',
                'data-disable-preview',
                'spellcheck'
            ];

        div.className = textarea.className;
        div.id = uniqueId;
        div.innerHTML = textarea.value;
        div.setAttribute('medium-editor-textarea-id', id);
        attributesToClone.forEach(function (attr) {
            if (textarea.hasAttribute(attr)) {
                div.setAttribute(attr, textarea.getAttribute(attr));
            }
        });

        textarea.classList.add('medium-editor-hidden');
        textarea.setAttribute('medium-editor-textarea-id', id);
        textarea.parentNode.insertBefore(
            div,
            textarea
        );

        return div;
    }

    function initElements() {
        this.elements.forEach(function (element, index) {
            if (!this.options.disableEditing && !element.getAttribute('data-disable-editing')) {
                element.setAttribute('contentEditable', true);
                element.setAttribute('spellcheck', this.options.spellcheck);
            }
            element.setAttribute('data-medium-editor-element', true);
            element.setAttribute('role', 'textbox');
            element.setAttribute('aria-multiline', true);
            element.setAttribute('medium-editor-index', index);

            if (element.hasAttribute('medium-editor-textarea-id')) {
                this.on(element, 'input', function (event) {
                    var target = event.target,
                        textarea = target.parentNode.querySelector('textarea[medium-editor-textarea-id="' + target.getAttribute('medium-editor-textarea-id') + '"]');
                    if (textarea) {
                        textarea.value = this.serialize()[target.id].value;
                    }
                }.bind(this));
            }
        }, this);
    }

    function attachHandlers() {
        var i;

        // attach to tabs
        this.subscribe('editableKeydownTab', handleTabKeydown.bind(this));

        // Bind keys which can create or destroy a block element: backspace, delete, return
        this.subscribe('editableKeydownDelete', handleBlockDeleteKeydowns.bind(this));
        this.subscribe('editableKeydownEnter', handleBlockDeleteKeydowns.bind(this));

        // disabling return or double return
        if (this.options.disableReturn || this.options.disableDoubleReturn) {
            this.subscribe('editableKeydownEnter', handleDisabledEnterKeydown.bind(this));
        } else {
            for (i = 0; i < this.elements.length; i += 1) {
                if (this.elements[i].getAttribute('data-disable-return') || this.elements[i].getAttribute('data-disable-double-return')) {
                    this.subscribe('editableKeydownEnter', handleDisabledEnterKeydown.bind(this));
                    break;
                }
            }
        }

        // if we're not disabling return, add a handler to help handle cleanup
        // for certain cases when enter is pressed
        if (!this.options.disableReturn) {
            this.elements.forEach(function (element) {
                if (!element.getAttribute('data-disable-return')) {
                    this.on(element, 'keyup', handleKeyup.bind(this));
                }
            }, this);
        }
    }

    function initExtensions() {

        this.extensions = [];

        // Passed in extensions
        Object.keys(this.options.extensions).forEach(function (name) {
            // Always save the toolbar extension for last
            if (name !== 'toolbar' && this.options.extensions[name]) {
                this.extensions.push(initExtension(this.options.extensions[name], name, this));
            }
        }, this);

        // 4 Cases for imageDragging + fileDragging extensons:
        //
        // 1. ImageDragging ON + No Custom Image Dragging Extension:
        //    * Use fileDragging extension (default options)
        // 2. ImageDragging OFF + No Custom Image Dragging Extension:
        //    * Use fileDragging extension w/ images turned off
        // 3. ImageDragging ON + Custom Image Dragging Extension:
        //    * Don't use fileDragging (could interfere with custom image dragging extension)
        // 4. ImageDragging OFF + Custom Image Dragging:
        //    * Don't use fileDragging (could interfere with custom image dragging extension)
        if (shouldUseFileDraggingExtension.call(this)) {
            var opts = this.options.fileDragging;
            if (!opts) {
                opts = {};

                // Image is in the 'allowedTypes' list by default.
                // If imageDragging is off override the 'allowedTypes' list with an empty one
                if (!isImageDraggingEnabled.call(this)) {
                    opts.allowedTypes = [];
                }
            }
            this.addBuiltInExtension('fileDragging', opts);
        }

        // Built-in extensions
        var builtIns = {
            paste: true,
            anchorPreview: isAnchorPreviewEnabled.call(this),
            autoLink: isAutoLinkEnabled.call(this),
            keyboardCommands: isKeyboardCommandsEnabled.call(this),
            placeholder: isPlaceholderEnabled.call(this)
        };
        Object.keys(builtIns).forEach(function (name) {
            if (builtIns[name]) {
                this.addBuiltInExtension(name);
            }
        }, this);

        // Users can pass in a custom toolbar extension
        // so check for that first and if it's not present
        // just create the default toolbar
        var toolbarExtension = this.options.extensions['toolbar'];
        if (!toolbarExtension && isToolbarEnabled.call(this)) {
            // Backwards compatability
            var toolbarOptions = Util.extend({}, this.options.toolbar, {
                allowMultiParagraphSelection: this.options.allowMultiParagraphSelection // deprecated
            });
            toolbarExtension = new MediumEditor.extensions.toolbar(toolbarOptions);
        }

        // If the toolbar is not disabled, so we actually have an extension
        // initialize it and add it to the extensions array
        if (toolbarExtension) {
            this.extensions.push(initExtension(toolbarExtension, 'toolbar', this));
        }
    }

    function mergeOptions(defaults, options) {
        var deprecatedProperties = [
            ['allowMultiParagraphSelection', 'toolbar.allowMultiParagraphSelection']
        ];
        // warn about using deprecated properties
        if (options) {
            deprecatedProperties.forEach(function (pair) {
                if (options.hasOwnProperty(pair[0]) && options[pair[0]] !== undefined) {
                    Util.deprecated(pair[0], pair[1], 'v6.0.0');
                }
            });
        }

        return Util.defaults({}, options, defaults);
    }

    function execActionInternal(action, opts) {
        /*jslint regexp: true*/
        var appendAction = /^append-(.+)$/gi,
            justifyAction = /justify([A-Za-z]*)$/g, /* Detecting if is justifyCenter|Right|Left */
            match;
        /*jslint regexp: false*/

        // Actions starting with 'append-' should attempt to format a block of text ('formatBlock') using a specific
        // type of block element (ie append-blockquote, append-h1, append-pre, etc.)
        match = appendAction.exec(action);
        if (match) {
            return Util.execFormatBlock(this.options.ownerDocument, match[1]);
        }

        if (action === 'fontSize') {
            return this.options.ownerDocument.execCommand('fontSize', false, opts.size);
        }

        if (action === 'createLink') {
            return this.createLink(opts);
        }

        if (action === 'image') {
            return this.options.ownerDocument.execCommand('insertImage', false, this.options.contentWindow.getSelection());
        }

        /* Issue: https://github.com/yabwe/medium-editor/issues/595
         * If the action is to justify the text */
        if (justifyAction.exec(action)) {
            var result = this.options.ownerDocument.execCommand(action, false, null),
                parentNode = Selection.getSelectedParentElement(Selection.getSelectionRange(this.options.ownerDocument));
            if (parentNode) {
                cleanupJustifyDivFragments.call(this, Util.getTopBlockContainer(parentNode));
            }

            return result;
        }

        return this.options.ownerDocument.execCommand(action, false, null);
    }

    /* If we've just justified text within a container block
     * Chrome may have removed <br> elements and instead wrapped lines in <div> elements
     * with a text-align property.  If so, we want to fix this
     */
    function cleanupJustifyDivFragments(blockContainer) {
        if (!blockContainer) {
            return;
        }

        var textAlign,
            childDivs = Array.prototype.slice.call(blockContainer.childNodes).filter(function (element) {
                var isDiv = element.nodeName.toLowerCase() === 'div';
                if (isDiv && !textAlign) {
                    textAlign = element.style.textAlign;
                }
                return isDiv;
            });

        /* If we found child <div> elements with text-align style attributes
         * we should fix this by:
         *
         * 1) Unwrapping each <div> which has a text-align style
         * 2) Insert a <br> element after each set of 'unwrapped' div children
         * 3) Set the text-align style of the parent block element
         */
        if (childDivs.length) {
            // Since we're mucking with the HTML, preserve selection
            this.saveSelection();
            childDivs.forEach(function (div) {
                if (div.style.textAlign === textAlign) {
                    var lastChild = div.lastChild;
                    if (lastChild) {
                        // Instead of a div, extract the child elements and add a <br>
                        Util.unwrap(div, this.options.ownerDocument);
                        var br = this.options.ownerDocument.createElement('BR');
                        lastChild.parentNode.insertBefore(br, lastChild.nextSibling);
                    }
                }
            }, this);
            blockContainer.style.textAlign = textAlign;
            // We're done, so restore selection
            this.restoreSelection();
        }
    }

    MediumEditor.Extension = Extension;

    MediumEditor.extensions = extensionDefaults;
    MediumEditor.util = Util;
    MediumEditor.selection = Selection;

    MediumEditor.prototype = {
        defaults: editorDefaults,

        // NOT DOCUMENTED - exposed for backwards compatability
        init: function (elements, options) {
            this.options = mergeOptions.call(this, this.defaults, options);
            this.origElements = elements;

            if (!this.options.elementsContainer) {
                this.options.elementsContainer = this.options.ownerDocument.body;
            }

            return this.setup();
        },

        setup: function () {
            if (this.isActive) {
                return;
            }

            createElementsArray.call(this, this.origElements);

            if (this.elements.length === 0) {
                return;
            }

            this.isActive = true;
            addToEditors.call(this, this.options.contentWindow);

            this.events = new Events(this);

            // Call initialization helpers
            initElements.call(this);
            initExtensions.call(this);
            attachHandlers.call(this);
        },

        destroy: function () {
            if (!this.isActive) {
                return;
            }

            this.isActive = false;

            this.extensions.forEach(function (extension) {
                if (typeof extension.destroy === 'function') {
                    extension.destroy();
                }
            }, this);

            this.events.destroy();

            this.elements.forEach(function (element) {
                // Reset elements content, fix for issue where after editor destroyed the red underlines on spelling errors are left
                if (this.options.spellcheck) {
                    element.innerHTML = element.innerHTML;
                }

                // cleanup extra added attributes
                element.removeAttribute('contentEditable');
                element.removeAttribute('spellcheck');
                element.removeAttribute('data-medium-editor-element');
                element.removeAttribute('role');
                element.removeAttribute('aria-multiline');
                element.removeAttribute('medium-editor-index');

                // Remove any elements created for textareas
                if (element.hasAttribute('medium-editor-textarea-id')) {
                    var textarea = element.parentNode.querySelector('textarea[medium-editor-textarea-id="' + element.getAttribute('medium-editor-textarea-id') + '"]');
                    if (textarea) {
                        // Un-hide the textarea
                        textarea.classList.remove('medium-editor-hidden');
                    }
                    if (element.parentNode) {
                        element.parentNode.removeChild(element);
                    }
                }
            }, this);
            this.elements = [];

            removeFromEditors.call(this, this.options.contentWindow);
        },

        on: function (target, event, listener, useCapture) {
            this.events.attachDOMEvent(target, event, listener, useCapture);
        },

        off: function (target, event, listener, useCapture) {
            this.events.detachDOMEvent(target, event, listener, useCapture);
        },

        subscribe: function (event, listener) {
            this.events.attachCustomEvent(event, listener);
        },

        unsubscribe: function (event, listener) {
            this.events.detachCustomEvent(event, listener);
        },

        trigger: function (name, data, editable) {
            this.events.triggerCustomEvent(name, data, editable);
        },

        delay: function (fn) {
            var self = this;
            return setTimeout(function () {
                if (self.isActive) {
                    fn();
                }
            }, this.options.delay);
        },

        serialize: function () {
            var i,
                elementid,
                content = {};
            for (i = 0; i < this.elements.length; i += 1) {
                elementid = (this.elements[i].id !== '') ? this.elements[i].id : 'element-' + i;
                content[elementid] = {
                    value: this.elements[i].innerHTML.trim()
                };
            }
            return content;
        },

        getExtensionByName: function (name) {
            var extension;
            if (this.extensions && this.extensions.length) {
                this.extensions.some(function (ext) {
                    if (ext.name === name) {
                        extension = ext;
                        return true;
                    }
                    return false;
                });
            }
            return extension;
        },

        /**
         * NOT DOCUMENTED - exposed as a helper for other extensions to use
         */
        addBuiltInExtension: function (name, opts) {
            var extension = this.getExtensionByName(name),
                merged;
            if (extension) {
                return extension;
            }

            switch (name) {
                case 'anchor':
                    merged = Util.extend({}, this.options.anchor, opts);
                    extension = new MediumEditor.extensions.anchor(merged);
                    break;
                case 'anchorPreview':
                    extension = new MediumEditor.extensions.anchorPreview(this.options.anchorPreview);
                    break;
                case 'autoLink':
                    extension = new MediumEditor.extensions.autoLink();
                    break;
                case 'fileDragging':
                    extension = new MediumEditor.extensions.fileDragging(opts);
                    break;
                case 'fontsize':
                    extension = new MediumEditor.extensions.fontSize(opts);
                    break;
                case 'keyboardCommands':
                    extension = new MediumEditor.extensions.keyboardCommands(this.options.keyboardCommands);
                    break;
                case 'paste':
                    extension = new MediumEditor.extensions.paste(this.options.paste);
                    break;
                case 'placeholder':
                    extension = new MediumEditor.extensions.placeholder(this.options.placeholder);
                    break;
                default:
                    // All of the built-in buttons for MediumEditor are extensions
                    // so check to see if the extension we're creating is a built-in button
                    if (MediumEditor.extensions.button.isBuiltInButton(name)) {
                        if (opts) {
                            merged = Util.defaults({}, opts, MediumEditor.extensions.button.prototype.defaults[name]);
                            extension = new MediumEditor.extensions.button(merged);
                        } else {
                            extension = new MediumEditor.extensions.button(name);
                        }
                    }
            }

            if (extension) {
                this.extensions.push(initExtension(extension, name, this));
            }

            return extension;
        },

        stopSelectionUpdates: function () {
            this.preventSelectionUpdates = true;
        },

        startSelectionUpdates: function () {
            this.preventSelectionUpdates = false;
        },

        checkSelection: function () {
            var toolbar = this.getExtensionByName('toolbar');
            if (toolbar) {
                toolbar.checkState();
            }
            return this;
        },

        // Wrapper around document.queryCommandState for checking whether an action has already
        // been applied to the current selection
        queryCommandState: function (action) {
            var fullAction = /^full-(.+)$/gi,
                match,
                queryState = null;

            // Actions starting with 'full-' need to be modified since this is a medium-editor concept
            match = fullAction.exec(action);
            if (match) {
                action = match[1];
            }

            try {
                queryState = this.options.ownerDocument.queryCommandState(action);
            } catch (exc) {
                queryState = null;
            }

            return queryState;
        },

        execAction: function (action, opts) {
            /*jslint regexp: true*/
            var fullAction = /^full-(.+)$/gi,
                match,
                result;
            /*jslint regexp: false*/

            // Actions starting with 'full-' should be applied to to the entire contents of the editable element
            // (ie full-bold, full-append-pre, etc.)
            match = fullAction.exec(action);
            if (match) {
                // Store the current selection to be restored after applying the action
                this.saveSelection();
                // Select all of the contents before calling the action
                this.selectAllContents();
                result = execActionInternal.call(this, match[1], opts);
                // Restore the previous selection
                this.restoreSelection();
            } else {
                result = execActionInternal.call(this, action, opts);
            }

            // do some DOM clean-up for known browser issues after the action
            if (action === 'insertunorderedlist' || action === 'insertorderedlist') {
                Util.cleanListDOM(this.options.ownerDocument, this.getSelectedParentElement());
            }

            this.checkSelection();
            return result;
        },

        getSelectedParentElement: function (range) {
            if (range === undefined) {
                range = this.options.contentWindow.getSelection().getRangeAt(0);
            }
            return Selection.getSelectedParentElement(range);
        },

        selectAllContents: function () {
            var currNode = Selection.getSelectionElement(this.options.contentWindow);

            if (currNode) {
                // Move to the lowest descendant node that still selects all of the contents
                while (currNode.children.length === 1) {
                    currNode = currNode.children[0];
                }

                this.selectElement(currNode);
            }
        },

        selectElement: function (element) {
            Selection.selectNode(element, this.options.ownerDocument);

            var selElement = Selection.getSelectionElement(this.options.contentWindow);
            if (selElement) {
                this.events.focusElement(selElement);
            }
        },

        getFocusedElement: function () {
            var focused;
            this.elements.some(function (element) {
                // Find the element that has focus
                if (!focused && element.getAttribute('data-medium-focused')) {
                    focused = element;
                }

                // bail if we found the element that had focus
                return !!focused;
            }, this);

            return focused;
        },

        // Export the state of the selection in respect to one of this
        // instance of MediumEditor's elements
        exportSelection: function () {
            var selectionElement = Selection.getSelectionElement(this.options.contentWindow),
                editableElementIndex = this.elements.indexOf(selectionElement),
                selectionState = null;

            if (editableElementIndex >= 0) {
                selectionState = Selection.exportSelection(selectionElement, this.options.ownerDocument);
            }

            if (selectionState !== null && editableElementIndex !== 0) {
                selectionState.editableElementIndex = editableElementIndex;
            }

            return selectionState;
        },

        saveSelection: function () {
            this.selectionState = this.exportSelection();
        },

        // Restore a selection based on a selectionState returned by a call
        // to MediumEditor.exportSelection
        importSelection: function (selectionState, favorLaterSelectionAnchor) {
            if (!selectionState) {
                return;
            }

            var editableElement = this.elements[selectionState.editableElementIndex || 0];
            Selection.importSelection(selectionState, editableElement, this.options.ownerDocument, favorLaterSelectionAnchor);
        },

        restoreSelection: function () {
            this.importSelection(this.selectionState);
        },

        createLink: function (opts) {
            var customEvent,
                i;

            if (opts.url && opts.url.trim().length > 0) {
                var currentSelection = this.options.contentWindow.getSelection();
                if (currentSelection) {
                    var exportedSelection,
                        startContainerParentElement,
                        endContainerParentElement,
                        textNodes;

                    startContainerParentElement = Util.getClosestBlockContainer(
                        currentSelection.getRangeAt(0).startContainer);
                    endContainerParentElement = Util.getClosestBlockContainer(
                        currentSelection.getRangeAt(0).endContainer);

                    if (startContainerParentElement === endContainerParentElement) {
                        var currentEditor = Selection.getSelectionElement(this.options.contentWindow),
                            parentElement = (startContainerParentElement || currentEditor),
                            fragment = this.options.ownerDocument.createDocumentFragment();
                        exportedSelection = this.exportSelection();
                        fragment.appendChild(parentElement.cloneNode(true));
                        if (currentEditor === parentElement) {
                            // We have to avoid the editor itself being wiped out when it's the only block element,
                            // as our reference inside this.elements gets detached from the page when insertHTML runs.
                            // If we just use [parentElement, 0] and [parentElement, parentElement.childNodes.length]
                            // as the range boundaries, this happens whenever parentElement === currentEditor.
                            // The tradeoff to this workaround is that a orphaned tag can sometimes be left behind at
                            // the end of the editor's content.
                            // In Gecko:
                            // as an empty <strong></strong> if parentElement.lastChild is a <strong> tag.
                            // In WebKit:
                            // an invented <br /> tag at the end in the same situation

                            Selection.select(this.options.ownerDocument,
                                parentElement.firstChild, 0,
                                parentElement.lastChild, parentElement.lastChild.nodeType === 3 ?
                                parentElement.lastChild.nodeValue.length : parentElement.lastChild.childNodes.length);
                        } else {
                            Selection.select(this.options.ownerDocument,
                                parentElement, 0,
                                parentElement, parentElement.childNodes.length);
                        }
                        var modifiedExportedSelection = this.exportSelection();

                        textNodes = Util.findOrCreateMatchingTextNodes(this.options.ownerDocument,
                                fragment,
                                {
                                    start: exportedSelection.start - modifiedExportedSelection.start,
                                    end: exportedSelection.end - modifiedExportedSelection.start,
                                    editableElementIndex: exportedSelection.editableElementIndex
                                });
                        // Creates the link in the document fragment
                        Util.createLink(this.options.ownerDocument, textNodes, opts.url.trim());
                        // Chrome trims the leading whitespaces when inserting HTML, which messes up restoring the selection.
                        var leadingWhitespacesCount = (fragment.firstChild.innerHTML.match(/^\s+/) || [''])[0].length;
                        // Now move the created link back into the original document in a way to preserve undo/redo history
                        Util.insertHTMLCommand(this.options.ownerDocument,
                            fragment.firstChild.innerHTML.replace(/^\s+/, ''));
                        exportedSelection.start -= leadingWhitespacesCount;
                        exportedSelection.end -= leadingWhitespacesCount;
                        this.importSelection(exportedSelection);
                    } else {
                        this.options.ownerDocument.execCommand('createLink', false, opts.url);
                    }
                    if (this.options.targetBlank || opts.target === '_blank') {
                        Util.setTargetBlank(Selection.getSelectionStart(this.options.ownerDocument), opts.url);
                    }

                    if (opts.buttonClass) {
                        Util.addClassToAnchors(Selection.getSelectionStart(this.options.ownerDocument), opts.buttonClass);
                    }
                }
            }

            if (this.options.targetBlank || opts.target === '_blank' || opts.buttonClass) {
                customEvent = this.options.ownerDocument.createEvent('HTMLEvents');
                customEvent.initEvent('input', true, true, this.options.contentWindow);
                for (i = 0; i < this.elements.length; i += 1) {
                    this.elements[i].dispatchEvent(customEvent);
                }
            }
        },

        cleanPaste: function (text) {
            this.getExtensionByName('paste').cleanPaste(text);
        },

        pasteHTML: function (html, options) {
            this.getExtensionByName('paste').pasteHTML(html, options);
        }
    };
}());

MediumEditor.parseVersionString = function (release) {
    var split = release.split('-'),
        version = split[0].split('.'),
        preRelease = (split.length > 1) ? split[1] : '';
    return {
        major: parseInt(version[0], 10),
        minor: parseInt(version[1], 10),
        revision: parseInt(version[2], 10),
        preRelease: preRelease,
        toString: function () {
            return [version[0], version[1], version[2]].join('.') + (preRelease ? '-' + preRelease : '');
        }
    };
};

MediumEditor.version = MediumEditor.parseVersionString.call(this, ({
    // grunt-bump looks for this:
    'version': '5.4.0'
}).version);

    return MediumEditor;
}()));