path: root/catapult/third_party/polymer/components/webcomponentsjs/MutationObserver.js

/**
 * @license
 * Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
 * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
 * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
 * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
 * Code distributed by Google as part of the polymer project is also
 * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
 */
// @version 0.7.24
if (typeof WeakMap === "undefined") {
  (function() {
    var defineProperty = Object.defineProperty;
    var counter = Date.now() % 1e9;
    var WeakMap = function() {
      this.name = "__st" + (Math.random() * 1e9 >>> 0) + (counter++ + "__");
    };
    WeakMap.prototype = {
      set: function(key, value) {
        var entry = key[this.name];
        if (entry && entry[0] === key) entry[1] = value; else defineProperty(key, this.name, {
          value: [ key, value ],
          writable: true
        });
        return this;
      },
      get: function(key) {
        var entry;
        return (entry = key[this.name]) && entry[0] === key ? entry[1] : undefined;
      },
      "delete": function(key) {
        var entry = key[this.name];
        if (!entry || entry[0] !== key) return false;
        entry[0] = entry[1] = undefined;
        return true;
      },
      has: function(key) {
        var entry = key[this.name];
        if (!entry) return false;
        return entry[0] === key;
      }
    };
    window.WeakMap = WeakMap;
  })();
}

(function(global) {
  if (global.JsMutationObserver) {
    return;
  }
  var registrationsTable = new WeakMap();
  var setImmediate;
  if (/Trident|Edge/.test(navigator.userAgent)) {
    setImmediate = setTimeout;
  } else if (window.setImmediate) {
    setImmediate = window.setImmediate;
  } else {
    var setImmediateQueue = [];
    var sentinel = String(Math.random());
    window.addEventListener("message", function(e) {
      if (e.data === sentinel) {
        var queue = setImmediateQueue;
        setImmediateQueue = [];
        queue.forEach(function(func) {
          func();
        });
      }
    });
    setImmediate = function(func) {
      setImmediateQueue.push(func);
      window.postMessage(sentinel, "*");
    };
  }
  var isScheduled = false;
  var scheduledObservers = [];
  function scheduleCallback(observer) {
    scheduledObservers.push(observer);
    if (!isScheduled) {
      isScheduled = true;
      setImmediate(dispatchCallbacks);
    }
  }
  function wrapIfNeeded(node) {
    return window.ShadowDOMPolyfill && window.ShadowDOMPolyfill.wrapIfNeeded(node) || node;
  }
  function dispatchCallbacks() {
    isScheduled = false;
    var observers = scheduledObservers;
    scheduledObservers = [];
    observers.sort(function(o1, o2) {
      return o1.uid_ - o2.uid_;
    });
    var anyNonEmpty = false;
    observers.forEach(function(observer) {
      var queue = observer.takeRecords();
      removeTransientObserversFor(observer);
      if (queue.length) {
        observer.callback_(queue, observer);
        anyNonEmpty = true;
      }
    });
    if (anyNonEmpty) dispatchCallbacks();
  }
  function removeTransientObserversFor(observer) {
    observer.nodes_.forEach(function(node) {
      var registrations = registrationsTable.get(node);
      if (!registrations) return;
      registrations.forEach(function(registration) {
        if (registration.observer === observer) registration.removeTransientObservers();
      });
    });
  }
  function forEachAncestorAndObserverEnqueueRecord(target, callback) {
    for (var node = target; node; node = node.parentNode) {
      var registrations = registrationsTable.get(node);
      if (registrations) {
        for (var j = 0; j < registrations.length; j++) {
          var registration = registrations[j];
          var options = registration.options;
          if (node !== target && !options.subtree) continue;
          var record = callback(options);
          if (record) registration.enqueue(record);
        }
      }
    }
  }
  var uidCounter = 0;
  function JsMutationObserver(callback) {
    this.callback_ = callback;
    this.nodes_ = [];
    this.records_ = [];
    this.uid_ = ++uidCounter;
  }
  JsMutationObserver.prototype = {
    observe: function(target, options) {
      target = wrapIfNeeded(target);
      if (!options.childList && !options.attributes && !options.characterData || options.attributeOldValue && !options.attributes || options.attributeFilter && options.attributeFilter.length && !options.attributes || options.characterDataOldValue && !options.characterData) {
        throw new SyntaxError();
      }
      var registrations = registrationsTable.get(target);
      if (!registrations) registrationsTable.set(target, registrations = []);
      var registration;
      for (var i = 0; i < registrations.length; i++) {
        if (registrations[i].observer === this) {
          registration = registrations[i];
          registration.removeListeners();
          registration.options = options;
          break;
        }
      }
      if (!registration) {
        registration = new Registration(this, target, options);
        registrations.push(registration);
        this.nodes_.push(target);
      }
      registration.addListeners();
    },
    disconnect: function() {
      this.nodes_.forEach(function(node) {
        var registrations = registrationsTable.get(node);
        for (var i = 0; i < registrations.length; i++) {
          var registration = registrations[i];
          if (registration.observer === this) {
            registration.removeListeners();
            registrations.splice(i, 1);
            break;
          }
        }
      }, this);
      this.records_ = [];
    },
    takeRecords: function() {
      var copyOfRecords = this.records_;
      this.records_ = [];
      return copyOfRecords;
    }
  };
  function MutationRecord(type, target) {
    this.type = type;
    this.target = target;
    this.addedNodes = [];
    this.removedNodes = [];
    this.previousSibling = null;
    this.nextSibling = null;
    this.attributeName = null;
    this.attributeNamespace = null;
    this.oldValue = null;
  }
  function copyMutationRecord(original) {
    var record = new MutationRecord(original.type, original.target);
    record.addedNodes = original.addedNodes.slice();
    record.removedNodes = original.removedNodes.slice();
    record.previousSibling = original.previousSibling;
    record.nextSibling = original.nextSibling;
    record.attributeName = original.attributeName;
    record.attributeNamespace = original.attributeNamespace;
    record.oldValue = original.oldValue;
    return record;
  }
  var currentRecord, recordWithOldValue;
  function getRecord(type, target) {
    return currentRecord = new MutationRecord(type, target);
  }
  function getRecordWithOldValue(oldValue) {
    if (recordWithOldValue) return recordWithOldValue;
    recordWithOldValue = copyMutationRecord(currentRecord);
    recordWithOldValue.oldValue = oldValue;
    return recordWithOldValue;
  }
  function clearRecords() {
    currentRecord = recordWithOldValue = undefined;
  }
  function recordRepresentsCurrentMutation(record) {
    return record === recordWithOldValue || record === currentRecord;
  }
  function selectRecord(lastRecord, newRecord) {
    if (lastRecord === newRecord) return lastRecord;
    if (recordWithOldValue && recordRepresentsCurrentMutation(lastRecord)) return recordWithOldValue;
    return null;
  }
  function Registration(observer, target, options) {
    this.observer = observer;
    this.target = target;
    this.options = options;
    this.transientObservedNodes = [];
  }
  Registration.prototype = {
    enqueue: function(record) {
      var records = this.observer.records_;
      var length = records.length;
      if (records.length > 0) {
        var lastRecord = records[length - 1];
        var recordToReplaceLast = selectRecord(lastRecord, record);
        if (recordToReplaceLast) {
          records[length - 1] = recordToReplaceLast;
          return;
        }
      } else {
        scheduleCallback(this.observer);
      }
      records[length] = record;
    },
    addListeners: function() {
      this.addListeners_(this.target);
    },
    addListeners_: function(node) {
      var options = this.options;
      if (options.attributes) node.addEventListener("DOMAttrModified", this, true);
      if (options.characterData) node.addEventListener("DOMCharacterDataModified", this, true);
      if (options.childList) node.addEventListener("DOMNodeInserted", this, true);
      if (options.childList || options.subtree) node.addEventListener("DOMNodeRemoved", this, true);
    },
    removeListeners: function() {
      this.removeListeners_(this.target);
    },
    removeListeners_: function(node) {
      var options = this.options;
      if (options.attributes) node.removeEventListener("DOMAttrModified", this, true);
      if (options.characterData) node.removeEventListener("DOMCharacterDataModified", this, true);
      if (options.childList) node.removeEventListener("DOMNodeInserted", this, true);
      if (options.childList || options.subtree) node.removeEventListener("DOMNodeRemoved", this, true);
    },
    addTransientObserver: function(node) {
      if (node === this.target) return;
      this.addListeners_(node);
      this.transientObservedNodes.push(node);
      var registrations = registrationsTable.get(node);
      if (!registrations) registrationsTable.set(node, registrations = []);
      registrations.push(this);
    },
    removeTransientObservers: function() {
      var transientObservedNodes = this.transientObservedNodes;
      this.transientObservedNodes = [];
      transientObservedNodes.forEach(function(node) {
        this.removeListeners_(node);
        var registrations = registrationsTable.get(node);
        for (var i = 0; i < registrations.length; i++) {
          if (registrations[i] === this) {
            registrations.splice(i, 1);
            break;
          }
        }
      }, this);
    },
    handleEvent: function(e) {
      e.stopImmediatePropagation();
      switch (e.type) {
       case "DOMAttrModified":
        var name = e.attrName;
        var namespace = e.relatedNode.namespaceURI;
        var target = e.target;
        var record = new getRecord("attributes", target);
        record.attributeName = name;
        record.attributeNamespace = namespace;
        var oldValue = e.attrChange === MutationEvent.ADDITION ? null : e.prevValue;
        forEachAncestorAndObserverEnqueueRecord(target, function(options) {
          if (!options.attributes) return;
          if (options.attributeFilter && options.attributeFilter.length && options.attributeFilter.indexOf(name) === -1 && options.attributeFilter.indexOf(namespace) === -1) {
            return;
          }
          if (options.attributeOldValue) return getRecordWithOldValue(oldValue);
          return record;
        });
        break;

       case "DOMCharacterDataModified":
        var target = e.target;
        var record = getRecord("characterData", target);
        var oldValue = e.prevValue;
        forEachAncestorAndObserverEnqueueRecord(target, function(options) {
          if (!options.characterData) return;
          if (options.characterDataOldValue) return getRecordWithOldValue(oldValue);
          return record;
        });
        break;

       case "DOMNodeRemoved":
        this.addTransientObserver(e.target);

       case "DOMNodeInserted":
        var changedNode = e.target;
        var addedNodes, removedNodes;
        if (e.type === "DOMNodeInserted") {
          addedNodes = [ changedNode ];
          removedNodes = [];
        } else {
          addedNodes = [];
          removedNodes = [ changedNode ];
        }
        var previousSibling = changedNode.previousSibling;
        var nextSibling = changedNode.nextSibling;
        var record = getRecord("childList", e.target.parentNode);
        record.addedNodes = addedNodes;
        record.removedNodes = removedNodes;
        record.previousSibling = previousSibling;
        record.nextSibling = nextSibling;
        forEachAncestorAndObserverEnqueueRecord(e.relatedNode, function(options) {
          if (!options.childList) return;
          return record;
        });
      }
      clearRecords();
    }
  };
  global.JsMutationObserver = JsMutationObserver;
  if (!global.MutationObserver) {
    global.MutationObserver = JsMutationObserver;
    JsMutationObserver._isPolyfilled = true;
  }
})(self);