| /* |
| * Copyright 2013 The Polymer Authors. All rights reserved. |
| * Use of this source code is goverened by a BSD-style |
| * license that can be found in the LICENSE file. |
| */ |
| |
| // TODO(jmesserly): polyfill does not have feature testing or the definition of |
| // SideTable. The extra code is from: |
| // https://github.com/Polymer/CustomElements/blob/master/src/MutationObserver.js |
| // https://github.com/Polymer/CustomElements/blob/master/src/sidetable.js |
| // I also renamed JsMutationObserver -> MutationObserver to correctly interact |
| // with dart2js interceptors. |
| |
| if (!window.MutationObserver && !window.WebKitMutationObserver) { |
| |
| (function(global) { |
| // SideTable is a weak map where possible. If WeakMap is not available the |
| // association is stored as an expando property. |
| var SideTable; |
| // TODO(arv): WeakMap does not allow for Node etc to be keys in Firefox |
| if (typeof WeakMap !== 'undefined' && navigator.userAgent.indexOf('Firefox/') < 0) { |
| SideTable = WeakMap; |
| } else { |
| (function() { |
| var defineProperty = Object.defineProperty; |
| var hasOwnProperty = Object.hasOwnProperty; |
| var counter = new Date().getTime() % 1e9; |
| |
| SideTable = function() { |
| this.name = '__st' + (Math.random() * 1e9 >>> 0) + (counter++ + '__'); |
| }; |
| |
| SideTable.prototype = { |
| set: function(key, value) { |
| defineProperty(key, this.name, {value: value, writable: true}); |
| }, |
| get: function(key) { |
| return hasOwnProperty.call(key, this.name) ? key[this.name] : undefined; |
| }, |
| delete: function(key) { |
| this.set(key, undefined); |
| } |
| } |
| })(); |
| } |
| |
| var registrationsTable = new SideTable(); |
| |
| // We use setImmediate or postMessage for our future callback. |
| var setImmediate = window.msSetImmediate; |
| |
| // Use post message to emulate setImmediate. |
| if (!setImmediate) { |
| 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, '*'); |
| }; |
| } |
| |
| // This is used to ensure that we never schedule 2 callas to setImmediate |
| var isScheduled = false; |
| |
| // Keep track of observers that needs to be notified next time. |
| var scheduledObservers = []; |
| |
| /** |
| * Schedules |dispatchCallback| to be called in the future. |
| * @param {MutationObserver} observer |
| */ |
| 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() { |
| // http://dom.spec.whatwg.org/#mutation-observers |
| |
| isScheduled = false; // Used to allow a new setImmediate call above. |
| |
| var observers = scheduledObservers; |
| scheduledObservers = []; |
| // Sort observers based on their creation UID (incremental). |
| observers.sort(function(o1, o2) { |
| return o1.uid_ - o2.uid_; |
| }); |
| |
| var anyNonEmpty = false; |
| observers.forEach(function(observer) { |
| |
| // 2.1, 2.2 |
| var queue = observer.takeRecords(); |
| // 2.3. Remove all transient registered observers whose observer is mo. |
| removeTransientObserversFor(observer); |
| |
| // 2.4 |
| if (queue.length) { |
| observer.callback_(queue, observer); |
| anyNonEmpty = true; |
| } |
| }); |
| |
| // 3. |
| 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(); |
| }); |
| }); |
| } |
| |
| /** |
| * This function is used for the "For each registered observer observer (with |
| * observer's options as options) in target's list of registered observers, |
| * run these substeps:" and the "For each ancestor ancestor of target, and for |
| * each registered observer observer (with options options) in ancestor's list |
| * of registered observers, run these substeps:" part of the algorithms. The |
| * |options.subtree| is checked to ensure that the callback is called |
| * correctly. |
| * |
| * @param {Node} target |
| * @param {function(MutationObserverInit):MutationRecord} callback |
| */ |
| 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; |
| |
| // Only target ignores subtree. |
| if (node !== target && !options.subtree) |
| continue; |
| |
| var record = callback(options); |
| if (record) |
| registration.enqueue(record); |
| } |
| } |
| } |
| } |
| |
| var uidCounter = 0; |
| |
| /** |
| * The class that maps to the DOM MutationObserver interface. |
| * @param {Function} callback. |
| * @constructor |
| */ |
| function MutationObserver(callback) { |
| this.callback_ = callback; |
| this.nodes_ = []; |
| this.records_ = []; |
| this.uid_ = ++uidCounter; |
| } |
| |
| MutationObserver.prototype = { |
| observe: function(target, options) { |
| target = wrapIfNeeded(target); |
| |
| // 1.1 |
| if (!options.childList && !options.attributes && !options.characterData || |
| |
| // 1.2 |
| options.attributeOldValue && !options.attributes || |
| |
| // 1.3 |
| options.attributeFilter && options.attributeFilter.length && |
| !options.attributes || |
| |
| // 1.4 |
| options.characterDataOldValue && !options.characterData) { |
| |
| throw new SyntaxError(); |
| } |
| |
| var registrations = registrationsTable.get(target); |
| if (!registrations) |
| registrationsTable.set(target, registrations = []); |
| |
| // 2 |
| // If target's list of registered observers already includes a registered |
| // observer associated with the context object, replace that registered |
| // observer's options with options. |
| var registration; |
| for (var i = 0; i < registrations.length; i++) { |
| if (registrations[i].observer === this) { |
| registration = registrations[i]; |
| registration.removeListeners(); |
| registration.options = options; |
| break; |
| } |
| } |
| |
| // 3. |
| // Otherwise, add a new registered observer to target's list of registered |
| // observers with the context object as the observer and options as the |
| // options, and add target to context object's list of nodes on which it |
| // is registered. |
| 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); |
| // Each node can only have one registered observer associated with |
| // this observer. |
| break; |
| } |
| } |
| }, this); |
| this.records_ = []; |
| }, |
| |
| takeRecords: function() { |
| var copyOfRecords = this.records_; |
| this.records_ = []; |
| return copyOfRecords; |
| } |
| }; |
| |
| /** |
| * @param {string} type |
| * @param {Node} target |
| * @constructor |
| */ |
| 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; |
| } |
| |
| // TODO(jmesserly): this fixes the interceptor dispatch on IE. |
| // Not sure why this is necessary. |
| MutationObserver.prototype.constructor = MutationObserver; |
| MutationObserver.name = 'MutationObserver'; |
| MutationRecord.prototype.constructor = MutationRecord; |
| MutationRecord.name = 'MutationRecord'; |
| |
| 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; |
| }; |
| |
| // We keep track of the two (possibly one) records used in a single mutation. |
| var currentRecord, recordWithOldValue; |
| |
| /** |
| * Creates a record without |oldValue| and caches it as |currentRecord| for |
| * later use. |
| * @param {string} oldValue |
| * @return {MutationRecord} |
| */ |
| function getRecord(type, target) { |
| return currentRecord = new MutationRecord(type, target); |
| } |
| |
| /** |
| * Gets or creates a record with |oldValue| based in the |currentRecord| |
| * @param {string} oldValue |
| * @return {MutationRecord} |
| */ |
| function getRecordWithOldValue(oldValue) { |
| if (recordWithOldValue) |
| return recordWithOldValue; |
| recordWithOldValue = copyMutationRecord(currentRecord); |
| recordWithOldValue.oldValue = oldValue; |
| return recordWithOldValue; |
| } |
| |
| function clearRecords() { |
| currentRecord = recordWithOldValue = undefined; |
| } |
| |
| /** |
| * @param {MutationRecord} record |
| * @return {boolean} Whether the record represents a record from the current |
| * mutation event. |
| */ |
| function recordRepresentsCurrentMutation(record) { |
| return record === recordWithOldValue || record === currentRecord; |
| } |
| |
| /** |
| * Selects which record, if any, to replace the last record in the queue. |
| * This returns |null| if no record should be replaced. |
| * |
| * @param {MutationRecord} lastRecord |
| * @param {MutationRecord} newRecord |
| * @param {MutationRecord} |
| */ |
| function selectRecord(lastRecord, newRecord) { |
| if (lastRecord === newRecord) |
| return lastRecord; |
| |
| // Check if the the record we are adding represents the same record. If |
| // so, we keep the one with the oldValue in it. |
| if (recordWithOldValue && recordRepresentsCurrentMutation(lastRecord)) |
| return recordWithOldValue; |
| |
| return null; |
| } |
| |
| /** |
| * Class used to represent a registered observer. |
| * @param {MutationObserver} observer |
| * @param {Node} target |
| * @param {MutationObserverInit} options |
| * @constructor |
| */ |
| 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; |
| |
| // There are cases where we replace the last record with the new record. |
| // For example if the record represents the same mutation we need to use |
| // the one with the oldValue. If we get same record (this can happen as we |
| // walk up the tree) we ignore the new record. |
| 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); |
| }, |
| |
| /** |
| * Adds a transient observer on node. The transient observer gets removed |
| * next time we deliver the change records. |
| * @param {Node} node |
| */ |
| addTransientObserver: function(node) { |
| // Don't add transient observers on the target itself. We already have all |
| // the required listeners set up on the target. |
| if (node === this.target) |
| return; |
| |
| this.addListeners_(node); |
| this.transientObservedNodes.push(node); |
| var registrations = registrationsTable.get(node); |
| if (!registrations) |
| registrationsTable.set(node, registrations = []); |
| |
| // We know that registrations does not contain this because we already |
| // checked if node === this.target. |
| registrations.push(this); |
| }, |
| |
| removeTransientObservers: function() { |
| var transientObservedNodes = this.transientObservedNodes; |
| this.transientObservedNodes = []; |
| |
| transientObservedNodes.forEach(function(node) { |
| // Transient observers are never added to the target. |
| this.removeListeners_(node); |
| |
| var registrations = registrationsTable.get(node); |
| for (var i = 0; i < registrations.length; i++) { |
| if (registrations[i] === this) { |
| registrations.splice(i, 1); |
| // Each node can only have one registered observer associated with |
| // this observer. |
| break; |
| } |
| } |
| }, this); |
| }, |
| |
| handleEvent: function(e) { |
| // Stop propagation since we are managing the propagation manually. |
| // This means that other mutation events on the page will not work |
| // correctly but that is by design. |
| e.stopImmediatePropagation(); |
| |
| switch (e.type) { |
| case 'DOMAttrModified': |
| // http://dom.spec.whatwg.org/#concept-mo-queue-attributes |
| |
| var name = e.attrName; |
| var namespace = e.relatedNode.namespaceURI; |
| var target = e.target; |
| |
| // 1. |
| var record = new getRecord('attributes', target); |
| record.attributeName = name; |
| record.attributeNamespace = namespace; |
| |
| // 2. |
| var oldValue = |
| e.attrChange === MutationEvent.ADDITION ? null : e.prevValue; |
| |
| forEachAncestorAndObserverEnqueueRecord(target, function(options) { |
| // 3.1, 4.2 |
| if (!options.attributes) |
| return; |
| |
| // 3.2, 4.3 |
| if (options.attributeFilter && options.attributeFilter.length && |
| options.attributeFilter.indexOf(name) === -1 && |
| options.attributeFilter.indexOf(namespace) === -1) { |
| return; |
| } |
| // 3.3, 4.4 |
| if (options.attributeOldValue) |
| return getRecordWithOldValue(oldValue); |
| |
| // 3.4, 4.5 |
| return record; |
| }); |
| |
| break; |
| |
| case 'DOMCharacterDataModified': |
| // http://dom.spec.whatwg.org/#concept-mo-queue-characterdata |
| var target = e.target; |
| |
| // 1. |
| var record = getRecord('characterData', target); |
| |
| // 2. |
| var oldValue = e.prevValue; |
| |
| |
| forEachAncestorAndObserverEnqueueRecord(target, function(options) { |
| // 3.1, 4.2 |
| if (!options.characterData) |
| return; |
| |
| // 3.2, 4.3 |
| if (options.characterDataOldValue) |
| return getRecordWithOldValue(oldValue); |
| |
| // 3.3, 4.4 |
| return record; |
| }); |
| |
| break; |
| |
| case 'DOMNodeRemoved': |
| this.addTransientObserver(e.target); |
| // Fall through. |
| case 'DOMNodeInserted': |
| // http://dom.spec.whatwg.org/#concept-mo-queue-childlist |
| var target = e.relatedNode; |
| 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; |
| |
| // 1. |
| var record = getRecord('childList', target); |
| record.addedNodes = addedNodes; |
| record.removedNodes = removedNodes; |
| record.previousSibling = previousSibling; |
| record.nextSibling = nextSibling; |
| |
| forEachAncestorAndObserverEnqueueRecord(target, function(options) { |
| // 2.1, 3.2 |
| if (!options.childList) |
| return; |
| |
| // 2.2, 3.3 |
| return record; |
| }); |
| |
| } |
| |
| clearRecords(); |
| } |
| }; |
| |
| global.MutationObserver = MutationObserver; |
| })(window); |
| |
| } |