lib/goog/dom/dom.js

1	// Copyright 2006 The Closure Library Authors. All Rights Reserved.
2	//
3	// Licensed under the Apache License, Version 2.0 (the "License");
4	// you may not use this file except in compliance with the License.
5	// You may obtain a copy of the License at
6	//
7	// http://www.apache.org/licenses/LICENSE-2.0
8	//
9	// Unless required by applicable law or agreed to in writing, software
10	// distributed under the License is distributed on an "AS-IS" BASIS,
11	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12	// See the License for the specific language governing permissions and
13	// limitations under the License.
14
15	/**
16	* @fileoverview Utilities for manipulating the browser's Document Object Model
17	* Inspiration taken heavily from mochikit (http://mochikit.com/).
18	*
19	* You can use {@link goog.dom.DomHelper} to create new dom helpers that refer
20	* to a different document object. This is useful if you are working with
21	* frames or multiple windows.
22	*
23	* @author arv@google.com (Erik Arvidsson)
24	*/
25
26
27	// TODO(arv): Rename/refactor getTextContent and getRawTextContent. The problem
28	// is that getTextContent should mimic the DOM3 textContent. We should add a
29	// getInnerText (or getText) which tries to return the visible text, innerText.
30
31
32	goog.provide('goog.dom');
33	goog.provide('goog.dom.Appendable');
34	goog.provide('goog.dom.DomHelper');
35
36	goog.require('goog.array');
37	goog.require('goog.asserts');
38	goog.require('goog.dom.BrowserFeature');
39	goog.require('goog.dom.NodeType');
40	goog.require('goog.dom.TagName');
41	goog.require('goog.math.Coordinate');
42	goog.require('goog.math.Size');
43	goog.require('goog.object');
44	goog.require('goog.string');
45	goog.require('goog.userAgent');
46
47
48	/**
49	* @define {boolean} Whether we know at compile time that the browser is in
50	* quirks mode.
51	*/
52	goog.define('goog.dom.ASSUME_QUIRKS_MODE', false);
53
54
55	/**
56	* @define {boolean} Whether we know at compile time that the browser is in
57	* standards compliance mode.
58	*/
59	goog.define('goog.dom.ASSUME_STANDARDS_MODE', false);
60
61
62	/**
63	* Whether we know the compatibility mode at compile time.
64	* @type {boolean}
65	* @private
66	*/
67	goog.dom.COMPAT_MODE_KNOWN_ =
68	goog.dom.ASSUME_QUIRKS_MODE \|\| goog.dom.ASSUME_STANDARDS_MODE;
69
70
71	/**
72	* Gets the DomHelper object for the document where the element resides.
73	* @param {(Node\|Window)=} opt_element If present, gets the DomHelper for this
74	* element.
75	* @return {!goog.dom.DomHelper} The DomHelper.
76	*/
77	goog.dom.getDomHelper = function(opt_element) {
78	return opt_element ?
79	new goog.dom.DomHelper(goog.dom.getOwnerDocument(opt_element)) :
80	(goog.dom.defaultDomHelper_ \|\|
81	(goog.dom.defaultDomHelper_ = new goog.dom.DomHelper()));
82	};
83
84
85	/**
86	* Cached default DOM helper.
87	* @type {goog.dom.DomHelper}
88	* @private
89	*/
90	goog.dom.defaultDomHelper_;
91
92
93	/**
94	* Gets the document object being used by the dom library.
95	* @return {!Document} Document object.
96	*/
97	goog.dom.getDocument = function() {
98	return document;
99	};
100
101
102	/**
103	* Gets an element from the current document by element id.
104	*
105	* If an Element is passed in, it is returned.
106	*
107	* @param {string\|Element} element Element ID or a DOM node.
108	* @return {Element} The element with the given ID, or the node passed in.
109	*/
110	goog.dom.getElement = function(element) {
111	return goog.dom.getElementHelper_(document, element);
112	};
113
114
115	/**
116	* Gets an element by id from the given document (if present).
117	* If an element is given, it is returned.
118	* @param {!Document} doc
119	* @param {string\|Element} element Element ID or a DOM node.
120	* @return {Element} The resulting element.
121	* @private
122	*/
123	goog.dom.getElementHelper_ = function(doc, element) {
124	return goog.isString(element) ?
125	doc.getElementById(element) :
126	element;
127	};
128
129
130	/**
131	* Gets an element by id, asserting that the element is found.
132	*
133	* This is used when an element is expected to exist, and should fail with
134	* an assertion error if it does not (if assertions are enabled).
135	*
136	* @param {string} id Element ID.
137	* @return {!Element} The element with the given ID, if it exists.
138	*/
139	goog.dom.getRequiredElement = function(id) {
140	return goog.dom.getRequiredElementHelper_(document, id);
141	};
142
143
144	/**
145	* Helper function for getRequiredElementHelper functions, both static and
146	* on DomHelper. Asserts the element with the given id exists.
147	* @param {!Document} doc
148	* @param {string} id
149	* @return {!Element} The element with the given ID, if it exists.
150	* @private
151	*/
152	goog.dom.getRequiredElementHelper_ = function(doc, id) {
153	// To prevent users passing in Elements as is permitted in getElement().
154	goog.asserts.assertString(id);
155	var element = goog.dom.getElementHelper_(doc, id);
156	element = goog.asserts.assertElement(element,
157	'No element found with id: ' + id);
158	return element;
159	};
160
161
162	/**
163	* Alias for getElement.
164	* @param {string\|Element} element Element ID or a DOM node.
165	* @return {Element} The element with the given ID, or the node passed in.
166	* @deprecated Use {@link goog.dom.getElement} instead.
167	*/
168	goog.dom.$ = goog.dom.getElement;
169
170
171	/**
172	* Looks up elements by both tag and class name, using browser native functions
173	* ({@code querySelectorAll}, {@code getElementsByTagName} or
174	* {@code getElementsByClassName}) where possible. This function
175	* is a useful, if limited, way of collecting a list of DOM elements
176	* with certain characteristics. {@code goog.dom.query} offers a
177	* more powerful and general solution which allows matching on CSS3
178	* selector expressions, but at increased cost in code size. If all you
179	* need is particular tags belonging to a single class, this function
180	* is fast and sleek.
181	*
182	* Note that tag names are case sensitive in the SVG namespace, and this
183	* function converts opt_tag to uppercase for comparisons. For queries in the
184	* SVG namespace you should use querySelector or querySelectorAll instead.
185	* https://bugzilla.mozilla.org/show_bug.cgi?id=963870
186	* https://bugs.webkit.org/show_bug.cgi?id=83438
187	*
188	* @see {goog.dom.query}
189	*
190	* @param {?string=} opt_tag Element tag name.
191	* @param {?string=} opt_class Optional class name.
192	* @param {(Document\|Element)=} opt_el Optional element to look in.
193	* @return { {length: number} } Array-like list of elements (only a length
194	* property and numerical indices are guaranteed to exist).
195	*/
196	goog.dom.getElementsByTagNameAndClass = function(opt_tag, opt_class, opt_el) {
197	return goog.dom.getElementsByTagNameAndClass_(document, opt_tag, opt_class,
198	opt_el);
199	};
200
201
202	/**
203	* Returns a static, array-like list of the elements with the provided
204	* className.
205	* @see {goog.dom.query}
206	* @param {string} className the name of the class to look for.
207	* @param {(Document\|Element)=} opt_el Optional element to look in.
208	* @return { {length: number} } The items found with the class name provided.
209	*/
210	goog.dom.getElementsByClass = function(className, opt_el) {
211	var parent = opt_el \|\| document;
212	if (goog.dom.canUseQuerySelector_(parent)) {
213	return parent.querySelectorAll('.' + className);
214	}
215	return goog.dom.getElementsByTagNameAndClass_(
216	document, '*', className, opt_el);
217	};
218
219
220	/**
221	* Returns the first element with the provided className.
222	* @see {goog.dom.query}
223	* @param {string} className the name of the class to look for.
224	* @param {Element\|Document=} opt_el Optional element to look in.
225	* @return {Element} The first item with the class name provided.
226	*/
227	goog.dom.getElementByClass = function(className, opt_el) {
228	var parent = opt_el \|\| document;
229	var retVal = null;
230	if (goog.dom.canUseQuerySelector_(parent)) {
231	retVal = parent.querySelector('.' + className);
232	} else {
233	retVal = goog.dom.getElementsByTagNameAndClass_(
234	document, '*', className, opt_el)[0];
235	}
236	return retVal \|\| null;
237	};
238
239
240	/**
241	* Ensures an element with the given className exists, and then returns the
242	* first element with the provided className.
243	* @see {goog.dom.query}
244	* @param {string} className the name of the class to look for.
245	* @param {!Element\|!Document=} opt_root Optional element or document to look
246	* in.
247	* @return {!Element} The first item with the class name provided.
248	* @throws {goog.asserts.AssertionError} Thrown if no element is found.
249	*/
250	goog.dom.getRequiredElementByClass = function(className, opt_root) {
251	var retValue = goog.dom.getElementByClass(className, opt_root);
252	return goog.asserts.assert(retValue,
253	'No element found with className: ' + className);
254	};
255
256
257	/**
258	* Prefer the standardized (http://www.w3.org/TR/selectors-api/), native and
259	* fast W3C Selectors API.
260	* @param {!(Element\|Document)} parent The parent document object.
261	* @return {boolean} whether or not we can use parent.querySelector* APIs.
262	* @private
263	*/
264	goog.dom.canUseQuerySelector_ = function(parent) {
265	return !!(parent.querySelectorAll && parent.querySelector);
266	};
267
268
269	/**
270	* Helper for {@code getElementsByTagNameAndClass}.
271	* @param {!Document} doc The document to get the elements in.
272	* @param {?string=} opt_tag Element tag name.
273	* @param {?string=} opt_class Optional class name.
274	* @param {(Document\|Element)=} opt_el Optional element to look in.
275	* @return { {length: number} } Array-like list of elements (only a length
276	* property and numerical indices are guaranteed to exist).
277	* @private
278	*/
279	goog.dom.getElementsByTagNameAndClass_ = function(doc, opt_tag, opt_class,
280	opt_el) {
281	var parent = opt_el \|\| doc;
282	var tagName = (opt_tag && opt_tag != '*') ? opt_tag.toUpperCase() : '';
283
284	if (goog.dom.canUseQuerySelector_(parent) &&
285	(tagName \|\| opt_class)) {
286	var query = tagName + (opt_class ? '.' + opt_class : '');
287	return parent.querySelectorAll(query);
288	}
289
290	// Use the native getElementsByClassName if available, under the assumption
291	// that even when the tag name is specified, there will be fewer elements to
292	// filter through when going by class than by tag name
293	if (opt_class && parent.getElementsByClassName) {
294	var els = parent.getElementsByClassName(opt_class);
295
296	if (tagName) {
297	var arrayLike = {};
298	var len = 0;
299
300	// Filter for specific tags if requested.
301	for (var i = 0, el; el = els[i]; i++) {
302	if (tagName == el.nodeName) {
303	arrayLike[len++] = el;
304	}
305	}
306	arrayLike.length = len;
307
308	return arrayLike;
309	} else {
310	return els;
311	}
312	}
313
314	var els = parent.getElementsByTagName(tagName \|\| '*');
315
316	if (opt_class) {
317	var arrayLike = {};
318	var len = 0;
319	for (var i = 0, el; el = els[i]; i++) {
320	var className = el.className;
321	// Check if className has a split function since SVG className does not.
322	if (typeof className.split == 'function' &&
323	goog.array.contains(className.split(/\s+/), opt_class)) {
324	arrayLike[len++] = el;
325	}
326	}
327	arrayLike.length = len;
328	return arrayLike;
329	} else {
330	return els;
331	}
332	};
333
334
335	/**
336	* Alias for {@code getElementsByTagNameAndClass}.
337	* @param {?string=} opt_tag Element tag name.
338	* @param {?string=} opt_class Optional class name.
339	* @param {Element=} opt_el Optional element to look in.
340	* @return { {length: number} } Array-like list of elements (only a length
341	* property and numerical indices are guaranteed to exist).
342	* @deprecated Use {@link goog.dom.getElementsByTagNameAndClass} instead.
343	*/
344	goog.dom.$$ = goog.dom.getElementsByTagNameAndClass;
345
346
347	/**
348	* Sets multiple properties on a node.
349	* @param {Element} element DOM node to set properties on.
350	* @param {Object} properties Hash of property:value pairs.
351	*/
352	goog.dom.setProperties = function(element, properties) {
353	goog.object.forEach(properties, function(val, key) {
354	if (key == 'style') {
355	element.style.cssText = val;
356	} else if (key == 'class') {
357	element.className = val;
358	} else if (key == 'for') {
359	element.htmlFor = val;
360	} else if (key in goog.dom.DIRECT_ATTRIBUTE_MAP_) {
361	element.setAttribute(goog.dom.DIRECT_ATTRIBUTE_MAP_[key], val);
362	} else if (goog.string.startsWith(key, 'aria-') \|\|
363	goog.string.startsWith(key, 'data-')) {
364	element.setAttribute(key, val);
365	} else {
366	element[key] = val;
367	}
368	});
369	};
370
371
372	/**
373	* Map of attributes that should be set using
374	* element.setAttribute(key, val) instead of element[key] = val. Used
375	* by goog.dom.setProperties.
376	*
377	* @private {!Object<string, string>}
378	* @const
379	*/
380	goog.dom.DIRECT_ATTRIBUTE_MAP_ = {
381	'cellpadding': 'cellPadding',
382	'cellspacing': 'cellSpacing',
383	'colspan': 'colSpan',
384	'frameborder': 'frameBorder',
385	'height': 'height',
386	'maxlength': 'maxLength',
387	'role': 'role',
388	'rowspan': 'rowSpan',
389	'type': 'type',
390	'usemap': 'useMap',
391	'valign': 'vAlign',
392	'width': 'width'
393	};
394
395
396	/**
397	* Gets the dimensions of the viewport.
398	*
399	* Gecko Standards mode:
400	* docEl.clientWidth Width of viewport excluding scrollbar.
401	* win.innerWidth Width of viewport including scrollbar.
402	* body.clientWidth Width of body element.
403	*
404	* docEl.clientHeight Height of viewport excluding scrollbar.
405	* win.innerHeight Height of viewport including scrollbar.
406	* body.clientHeight Height of document.
407	*
408	* Gecko Backwards compatible mode:
409	* docEl.clientWidth Width of viewport excluding scrollbar.
410	* win.innerWidth Width of viewport including scrollbar.
411	* body.clientWidth Width of viewport excluding scrollbar.
412	*
413	* docEl.clientHeight Height of document.
414	* win.innerHeight Height of viewport including scrollbar.
415	* body.clientHeight Height of viewport excluding scrollbar.
416	*
417	* IE6/7 Standards mode:
418	* docEl.clientWidth Width of viewport excluding scrollbar.
419	* win.innerWidth Undefined.
420	* body.clientWidth Width of body element.
421	*
422	* docEl.clientHeight Height of viewport excluding scrollbar.
423	* win.innerHeight Undefined.
424	* body.clientHeight Height of document element.
425	*
426	* IE5 + IE6/7 Backwards compatible mode:
427	* docEl.clientWidth 0.
428	* win.innerWidth Undefined.
429	* body.clientWidth Width of viewport excluding scrollbar.
430	*
431	* docEl.clientHeight 0.
432	* win.innerHeight Undefined.
433	* body.clientHeight Height of viewport excluding scrollbar.
434	*
435	* Opera 9 Standards and backwards compatible mode:
436	* docEl.clientWidth Width of viewport excluding scrollbar.
437	* win.innerWidth Width of viewport including scrollbar.
438	* body.clientWidth Width of viewport excluding scrollbar.
439	*
440	* docEl.clientHeight Height of document.
441	* win.innerHeight Height of viewport including scrollbar.
442	* body.clientHeight Height of viewport excluding scrollbar.
443	*
444	* WebKit:
445	* Safari 2
446	* docEl.clientHeight Same as scrollHeight.
447	* docEl.clientWidth Same as innerWidth.
448	* win.innerWidth Width of viewport excluding scrollbar.
449	* win.innerHeight Height of the viewport including scrollbar.
450	* frame.innerHeight Height of the viewport exluding scrollbar.
451	*
452	* Safari 3 (tested in 522)
453	*
454	* docEl.clientWidth Width of viewport excluding scrollbar.
455	* docEl.clientHeight Height of viewport excluding scrollbar in strict mode.
456	* body.clientHeight Height of viewport excluding scrollbar in quirks mode.
457	*
458	* @param {Window=} opt_window Optional window element to test.
459	* @return {!goog.math.Size} Object with values 'width' and 'height'.
460	*/
461	goog.dom.getViewportSize = function(opt_window) {
462	// TODO(arv): This should not take an argument
463	return goog.dom.getViewportSize_(opt_window \|\| window);
464	};
465
466
467	/**
468	* Helper for {@code getViewportSize}.
469	* @param {Window} win The window to get the view port size for.
470	* @return {!goog.math.Size} Object with values 'width' and 'height'.
471	* @private
472	*/
473	goog.dom.getViewportSize_ = function(win) {
474	var doc = win.document;
475	var el = goog.dom.isCss1CompatMode_(doc) ? doc.documentElement : doc.body;
476	return new goog.math.Size(el.clientWidth, el.clientHeight);
477	};
478
479
480	/**
481	* Calculates the height of the document.
482	*
483	* @return {number} The height of the current document.
484	*/
485	goog.dom.getDocumentHeight = function() {
486	return goog.dom.getDocumentHeight_(window);
487	};
488
489
490	/**
491	* Calculates the height of the document of the given window.
492	*
493	* Function code copied from the opensocial gadget api:
494	* gadgets.window.adjustHeight(opt_height)
495	*
496	* @private
497	* @param {!Window} win The window whose document height to retrieve.
498	* @return {number} The height of the document of the given window.
499	*/
500	goog.dom.getDocumentHeight_ = function(win) {
501	// NOTE(eae): This method will return the window size rather than the document
502	// size in webkit quirks mode.
503	var doc = win.document;
504	var height = 0;
505
506	if (doc) {
507	// Calculating inner content height is hard and different between
508	// browsers rendering in Strict vs. Quirks mode. We use a combination of
509	// three properties within document.body and document.documentElement:
510	// - scrollHeight
511	// - offsetHeight
512	// - clientHeight
513	// These values differ significantly between browsers and rendering modes.
514	// But there are patterns. It just takes a lot of time and persistence
515	// to figure out.
516
517	var body = doc.body;
518	var docEl = doc.documentElement;
519	if (!(docEl && body)) {
520	return 0;
521	}
522
523	// Get the height of the viewport
524	var vh = goog.dom.getViewportSize_(win).height;
525	if (goog.dom.isCss1CompatMode_(doc) && docEl.scrollHeight) {
526	// In Strict mode:
527	// The inner content height is contained in either:
528	// document.documentElement.scrollHeight
529	// document.documentElement.offsetHeight
530	// Based on studying the values output by different browsers,
531	// use the value that's NOT equal to the viewport height found above.
532	height = docEl.scrollHeight != vh ?
533	docEl.scrollHeight : docEl.offsetHeight;
534	} else {
535	// In Quirks mode:
536	// documentElement.clientHeight is equal to documentElement.offsetHeight
537	// except in IE. In most browsers, document.documentElement can be used
538	// to calculate the inner content height.
539	// However, in other browsers (e.g. IE), document.body must be used
540	// instead. How do we know which one to use?
541	// If document.documentElement.clientHeight does NOT equal
542	// document.documentElement.offsetHeight, then use document.body.
543	var sh = docEl.scrollHeight;
544	var oh = docEl.offsetHeight;
545	if (docEl.clientHeight != oh) {
546	sh = body.scrollHeight;
547	oh = body.offsetHeight;
548	}
549
550	// Detect whether the inner content height is bigger or smaller
551	// than the bounding box (viewport). If bigger, take the larger
552	// value. If smaller, take the smaller value.
553	if (sh > vh) {
554	// Content is larger
555	height = sh > oh ? sh : oh;
556	} else {
557	// Content is smaller
558	height = sh < oh ? sh : oh;
559	}
560	}
561	}
562
563	return height;
564	};
565
566
567	/**
568	* Gets the page scroll distance as a coordinate object.
569	*
570	* @param {Window=} opt_window Optional window element to test.
571	* @return {!goog.math.Coordinate} Object with values 'x' and 'y'.
572	* @deprecated Use {@link goog.dom.getDocumentScroll} instead.
573	*/
574	goog.dom.getPageScroll = function(opt_window) {
575	var win = opt_window \|\| goog.global \|\| window;
576	return goog.dom.getDomHelper(win.document).getDocumentScroll();
577	};
578
579
580	/**
581	* Gets the document scroll distance as a coordinate object.
582	*
583	* @return {!goog.math.Coordinate} Object with values 'x' and 'y'.
584	*/
585	goog.dom.getDocumentScroll = function() {
586	return goog.dom.getDocumentScroll_(document);
587	};
588
589
590	/**
591	* Helper for {@code getDocumentScroll}.
592	*
593	* @param {!Document} doc The document to get the scroll for.
594	* @return {!goog.math.Coordinate} Object with values 'x' and 'y'.
595	* @private
596	*/
597	goog.dom.getDocumentScroll_ = function(doc) {
598	var el = goog.dom.getDocumentScrollElement_(doc);
599	var win = goog.dom.getWindow_(doc);
600	if (goog.userAgent.IE && goog.userAgent.isVersionOrHigher('10') &&
601	win.pageYOffset != el.scrollTop) {
602	// The keyboard on IE10 touch devices shifts the page using the pageYOffset
603	// without modifying scrollTop. For this case, we want the body scroll
604	// offsets.
605	return new goog.math.Coordinate(el.scrollLeft, el.scrollTop);
606	}
607	return new goog.math.Coordinate(win.pageXOffset \|\| el.scrollLeft,
608	win.pageYOffset \|\| el.scrollTop);
609	};
610
611
612	/**
613	* Gets the document scroll element.
614	* @return {!Element} Scrolling element.
615	*/
616	goog.dom.getDocumentScrollElement = function() {
617	return goog.dom.getDocumentScrollElement_(document);
618	};
619
620
621	/**
622	* Helper for {@code getDocumentScrollElement}.
623	* @param {!Document} doc The document to get the scroll element for.
624	* @return {!Element} Scrolling element.
625	* @private
626	*/
627	goog.dom.getDocumentScrollElement_ = function(doc) {
628	// WebKit needs body.scrollLeft in both quirks mode and strict mode. We also
629	// default to the documentElement if the document does not have a body (e.g.
630	// a SVG document).
631	if (!goog.userAgent.WEBKIT && goog.dom.isCss1CompatMode_(doc)) {
632	return doc.documentElement;
633	}
634	return doc.body \|\| doc.documentElement;
635	};
636
637
638	/**
639	* Gets the window object associated with the given document.
640	*
641	* @param {Document=} opt_doc Document object to get window for.
642	* @return {!Window} The window associated with the given document.
643	*/
644	goog.dom.getWindow = function(opt_doc) {
645	// TODO(arv): This should not take an argument.
646	return opt_doc ? goog.dom.getWindow_(opt_doc) : window;
647	};
648
649
650	/**
651	* Helper for {@code getWindow}.
652	*
653	* @param {!Document} doc Document object to get window for.
654	* @return {!Window} The window associated with the given document.
655	* @private
656	*/
657	goog.dom.getWindow_ = function(doc) {
658	return doc.parentWindow \|\| doc.defaultView;
659	};
660
661
662	/**
663	* Returns a dom node with a set of attributes. This function accepts varargs
664	* for subsequent nodes to be added. Subsequent nodes will be added to the
665	* first node as childNodes.
666	*
667	* So:
668	* <code>createDom('div', null, createDom('p'), createDom('p'));</code>
669	* would return a div with two child paragraphs
670	*
671	* @param {string} tagName Tag to create.
672	* @param {(Object\|Array<string>\|string)=} opt_attributes If object, then a map
673	* of name-value pairs for attributes. If a string, then this is the
674	* className of the new element. If an array, the elements will be joined
675	* together as the className of the new element.
676	* @param {...(Object\|string\|Array\|NodeList)} var_args Further DOM nodes or
677	* strings for text nodes. If one of the var_args is an array or NodeList,i
678	* its elements will be added as childNodes instead.
679	* @return {!Element} Reference to a DOM node.
680	*/
681	goog.dom.createDom = function(tagName, opt_attributes, var_args) {
682	return goog.dom.createDom_(document, arguments);
683	};
684
685
686	/**
687	* Helper for {@code createDom}.
688	* @param {!Document} doc The document to create the DOM in.
689	* @param {!Arguments} args Argument object passed from the callers. See
690	* {@code goog.dom.createDom} for details.
691	* @return {!Element} Reference to a DOM node.
692	* @private
693	*/
694	goog.dom.createDom_ = function(doc, args) {
695	var tagName = args[0];
696	var attributes = args[1];
697
698	// Internet Explorer is dumb: http://msdn.microsoft.com/workshop/author/
699	// dhtml/reference/properties/name_2.asp
700	// Also does not allow setting of 'type' attribute on 'input' or 'button'.
701	if (!goog.dom.BrowserFeature.CAN_ADD_NAME_OR_TYPE_ATTRIBUTES && attributes &&
702	(attributes.name \|\| attributes.type)) {
703	var tagNameArr = ['<', tagName];
704	if (attributes.name) {
705	tagNameArr.push(' name="', goog.string.htmlEscape(attributes.name),
706	'"');
707	}
708	if (attributes.type) {
709	tagNameArr.push(' type="', goog.string.htmlEscape(attributes.type),
710	'"');
711
712	// Clone attributes map to remove 'type' without mutating the input.
713	var clone = {};
714	goog.object.extend(clone, attributes);
715
716	// JSCompiler can't see how goog.object.extend added this property,
717	// because it was essentially added by reflection.
718	// So it needs to be quoted.
719	delete clone['type'];
720
721	attributes = clone;
722	}
723	tagNameArr.push('>');
724	tagName = tagNameArr.join('');
725	}
726
727	var element = doc.createElement(tagName);
728
729	if (attributes) {
730	if (goog.isString(attributes)) {
731	element.className = attributes;
732	} else if (goog.isArray(attributes)) {
733	element.className = attributes.join(' ');
734	} else {
735	goog.dom.setProperties(element, attributes);
736	}
737	}
738
739	if (args.length > 2) {
740	goog.dom.append_(doc, element, args, 2);
741	}
742
743	return element;
744	};
745
746
747	/**
748	* Appends a node with text or other nodes.
749	* @param {!Document} doc The document to create new nodes in.
750	* @param {!Node} parent The node to append nodes to.
751	* @param {!Arguments} args The values to add. See {@code goog.dom.append}.
752	* @param {number} startIndex The index of the array to start from.
753	* @private
754	*/
755	goog.dom.append_ = function(doc, parent, args, startIndex) {
756	function childHandler(child) {
757	// TODO(user): More coercion, ala MochiKit?
758	if (child) {
759	parent.appendChild(goog.isString(child) ?
760	doc.createTextNode(child) : child);
761	}
762	}
763
764	for (var i = startIndex; i < args.length; i++) {
765	var arg = args[i];
766	// TODO(attila): Fix isArrayLike to return false for a text node.
767	if (goog.isArrayLike(arg) && !goog.dom.isNodeLike(arg)) {
768	// If the argument is a node list, not a real array, use a clone,
769	// because forEach can't be used to mutate a NodeList.
770	goog.array.forEach(goog.dom.isNodeList(arg) ?
771	goog.array.toArray(arg) : arg,
772	childHandler);
773	} else {
774	childHandler(arg);
775	}
776	}
777	};
778
779
780	/**
781	* Alias for {@code createDom}.
782	* @param {string} tagName Tag to create.
783	* @param {(string\|Object)=} opt_attributes If object, then a map of name-value
784	* pairs for attributes. If a string, then this is the className of the new
785	* element.
786	* @param {...(Object\|string\|Array\|NodeList)} var_args Further DOM nodes or
787	* strings for text nodes. If one of the var_args is an array, its
788	* children will be added as childNodes instead.
789	* @return {!Element} Reference to a DOM node.
790	* @deprecated Use {@link goog.dom.createDom} instead.
791	*/
792	goog.dom.$dom = goog.dom.createDom;
793
794
795	/**
796	* Creates a new element.
797	* @param {string} name Tag name.
798	* @return {!Element} The new element.
799	*/
800	goog.dom.createElement = function(name) {
801	return document.createElement(name);
802	};
803
804
805	/**
806	* Creates a new text node.
807	* @param {number\|string} content Content.
808	* @return {!Text} The new text node.
809	*/
810	goog.dom.createTextNode = function(content) {
811	return document.createTextNode(String(content));
812	};
813
814
815	/**
816	* Create a table.
817	* @param {number} rows The number of rows in the table. Must be >= 1.
818	* @param {number} columns The number of columns in the table. Must be >= 1.
819	* @param {boolean=} opt_fillWithNbsp If true, fills table entries with nsbps.
820	* @return {!Element} The created table.
821	*/
822	goog.dom.createTable = function(rows, columns, opt_fillWithNbsp) {
823	return goog.dom.createTable_(document, rows, columns, !!opt_fillWithNbsp);
824	};
825
826
827	/**
828	* Create a table.
829	* @param {!Document} doc Document object to use to create the table.
830	* @param {number} rows The number of rows in the table. Must be >= 1.
831	* @param {number} columns The number of columns in the table. Must be >= 1.
832	* @param {boolean} fillWithNbsp If true, fills table entries with nsbps.
833	* @return {!Element} The created table.
834	* @private
835	*/
836	goog.dom.createTable_ = function(doc, rows, columns, fillWithNbsp) {
837	var rowHtml = ['<tr>'];
838	for (var i = 0; i < columns; i++) {
839	rowHtml.push(fillWithNbsp ? '<td> </td>' : '<td></td>');
840	}
841	rowHtml.push('</tr>');
842	rowHtml = rowHtml.join('');
843	var totalHtml = ['<table>'];
844	for (i = 0; i < rows; i++) {
845	totalHtml.push(rowHtml);
846	}
847	totalHtml.push('</table>');
848
849	var elem = doc.createElement(goog.dom.TagName.DIV);
850	elem.innerHTML = totalHtml.join('');
851	return /** @type {!Element} */ (elem.removeChild(elem.firstChild));
852	};
853
854
855	/**
856	* Converts an HTML string into a document fragment. The string must be
857	* sanitized in order to avoid cross-site scripting. For example
858	* {@code goog.dom.htmlToDocumentFragment('<img src=x onerror=alert(0)>')}
859	* triggers an alert in all browsers, even if the returned document fragment
860	* is thrown away immediately.
861	*
862	* @param {string} htmlString The HTML string to convert.
863	* @return {!Node} The resulting document fragment.
864	*/
865	goog.dom.htmlToDocumentFragment = function(htmlString) {
866	return goog.dom.htmlToDocumentFragment_(document, htmlString);
867	};
868
869
870	/**
871	* Helper for {@code htmlToDocumentFragment}.
872	*
873	* @param {!Document} doc The document.
874	* @param {string} htmlString The HTML string to convert.
875	* @return {!Node} The resulting document fragment.
876	* @private
877	*/
878	goog.dom.htmlToDocumentFragment_ = function(doc, htmlString) {
879	var tempDiv = doc.createElement('div');
880	if (goog.dom.BrowserFeature.INNER_HTML_NEEDS_SCOPED_ELEMENT) {
881	tempDiv.innerHTML = '<br>' + htmlString;
882	tempDiv.removeChild(tempDiv.firstChild);
883	} else {
884	tempDiv.innerHTML = htmlString;
885	}
886	if (tempDiv.childNodes.length == 1) {
887	return /** @type {!Node} */ (tempDiv.removeChild(tempDiv.firstChild));
888	} else {
889	var fragment = doc.createDocumentFragment();
890	while (tempDiv.firstChild) {
891	fragment.appendChild(tempDiv.firstChild);
892	}
893	return fragment;
894	}
895	};
896
897
898	/**
899	* Returns true if the browser is in "CSS1-compatible" (standards-compliant)
900	* mode, false otherwise.
901	* @return {boolean} True if in CSS1-compatible mode.
902	*/
903	goog.dom.isCss1CompatMode = function() {
904	return goog.dom.isCss1CompatMode_(document);
905	};
906
907
908	/**
909	* Returns true if the browser is in "CSS1-compatible" (standards-compliant)
910	* mode, false otherwise.
911	* @param {!Document} doc The document to check.
912	* @return {boolean} True if in CSS1-compatible mode.
913	* @private
914	*/
915	goog.dom.isCss1CompatMode_ = function(doc) {
916	if (goog.dom.COMPAT_MODE_KNOWN_) {
917	return goog.dom.ASSUME_STANDARDS_MODE;
918	}
919
920	return doc.compatMode == 'CSS1Compat';
921	};
922
923
924	/**
925	* Determines if the given node can contain children, intended to be used for
926	* HTML generation.
927	*
928	* IE natively supports node.canHaveChildren but has inconsistent behavior.
929	* Prior to IE8 the base tag allows children and in IE9 all nodes return true
930	* for canHaveChildren.
931	*
932	* In practice all non-IE browsers allow you to add children to any node, but
933	* the behavior is inconsistent:
934	*
935	* <pre>
936	* var a = document.createElement('br');
937	* a.appendChild(document.createTextNode('foo'));
938	* a.appendChild(document.createTextNode('bar'));
939	* console.log(a.childNodes.length); // 2
940	* console.log(a.innerHTML); // Chrome: "", IE9: "foobar", FF3.5: "foobar"
941	* </pre>
942	*
943	* For more information, see:
944	* http://dev.w3.org/html5/markup/syntax.html#syntax-elements
945	*
946	* TODO(user): Rename shouldAllowChildren() ?
947	*
948	* @param {Node} node The node to check.
949	* @return {boolean} Whether the node can contain children.
950	*/
951	goog.dom.canHaveChildren = function(node) {
952	if (node.nodeType != goog.dom.NodeType.ELEMENT) {
953	return false;
954	}
955	switch (node.tagName) {
956	case goog.dom.TagName.APPLET:
957	case goog.dom.TagName.AREA:
958	case goog.dom.TagName.BASE:
959	case goog.dom.TagName.BR:
960	case goog.dom.TagName.COL:
961	case goog.dom.TagName.COMMAND:
962	case goog.dom.TagName.EMBED:
963	case goog.dom.TagName.FRAME:
964	case goog.dom.TagName.HR:
965	case goog.dom.TagName.IMG:
966	case goog.dom.TagName.INPUT:
967	case goog.dom.TagName.IFRAME:
968	case goog.dom.TagName.ISINDEX:
969	case goog.dom.TagName.KEYGEN:
970	case goog.dom.TagName.LINK:
971	case goog.dom.TagName.NOFRAMES:
972	case goog.dom.TagName.NOSCRIPT:
973	case goog.dom.TagName.META:
974	case goog.dom.TagName.OBJECT:
975	case goog.dom.TagName.PARAM:
976	case goog.dom.TagName.SCRIPT:
977	case goog.dom.TagName.SOURCE:
978	case goog.dom.TagName.STYLE:
979	case goog.dom.TagName.TRACK:
980	case goog.dom.TagName.WBR:
981	return false;
982	}
983	return true;
984	};
985
986
987	/**
988	* Appends a child to a node.
989	* @param {Node} parent Parent.
990	* @param {Node} child Child.
991	*/
992	goog.dom.appendChild = function(parent, child) {
993	parent.appendChild(child);
994	};
995
996
997	/**
998	* Appends a node with text or other nodes.
999	* @param {!Node} parent The node to append nodes to.
1000	* @param {...goog.dom.Appendable} var_args The things to append to the node.
1001	* If this is a Node it is appended as is.
1002	* If this is a string then a text node is appended.
1003	* If this is an array like object then fields 0 to length - 1 are appended.
1004	*/
1005	goog.dom.append = function(parent, var_args) {
1006	goog.dom.append_(goog.dom.getOwnerDocument(parent), parent, arguments, 1);
1007	};
1008
1009
1010	/**
1011	* Removes all the child nodes on a DOM node.
1012	* @param {Node} node Node to remove children from.
1013	*/
1014	goog.dom.removeChildren = function(node) {
1015	// Note: Iterations over live collections can be slow, this is the fastest
1016	// we could find. The double parenthesis are used to prevent JsCompiler and
1017	// strict warnings.
1018	var child;
1019	while ((child = node.firstChild)) {
1020	node.removeChild(child);
1021	}
1022	};
1023
1024
1025	/**
1026	* Inserts a new node before an existing reference node (i.e. as the previous
1027	* sibling). If the reference node has no parent, then does nothing.
1028	* @param {Node} newNode Node to insert.
1029	* @param {Node} refNode Reference node to insert before.
1030	*/
1031	goog.dom.insertSiblingBefore = function(newNode, refNode) {
1032	if (refNode.parentNode) {
1033	refNode.parentNode.insertBefore(newNode, refNode);
1034	}
1035	};
1036
1037
1038	/**
1039	* Inserts a new node after an existing reference node (i.e. as the next
1040	* sibling). If the reference node has no parent, then does nothing.
1041	* @param {Node} newNode Node to insert.
1042	* @param {Node} refNode Reference node to insert after.
1043	*/
1044	goog.dom.insertSiblingAfter = function(newNode, refNode) {
1045	if (refNode.parentNode) {
1046	refNode.parentNode.insertBefore(newNode, refNode.nextSibling);
1047	}
1048	};
1049
1050
1051	/**
1052	* Insert a child at a given index. If index is larger than the number of child
1053	* nodes that the parent currently has, the node is inserted as the last child
1054	* node.
1055	* @param {Element} parent The element into which to insert the child.
1056	* @param {Node} child The element to insert.
1057	* @param {number} index The index at which to insert the new child node. Must
1058	* not be negative.
1059	*/
1060	goog.dom.insertChildAt = function(parent, child, index) {
1061	// Note that if the second argument is null, insertBefore
1062	// will append the child at the end of the list of children.
1063	parent.insertBefore(child, parent.childNodes[index] \|\| null);
1064	};
1065
1066
1067	/**
1068	* Removes a node from its parent.
1069	* @param {Node} node The node to remove.
1070	* @return {Node} The node removed if removed; else, null.
1071	*/
1072	goog.dom.removeNode = function(node) {
1073	return node && node.parentNode ? node.parentNode.removeChild(node) : null;
1074	};
1075
1076
1077	/**
1078	* Replaces a node in the DOM tree. Will do nothing if {@code oldNode} has no
1079	* parent.
1080	* @param {Node} newNode Node to insert.
1081	* @param {Node} oldNode Node to replace.
1082	*/
1083	goog.dom.replaceNode = function(newNode, oldNode) {
1084	var parent = oldNode.parentNode;
1085	if (parent) {
1086	parent.replaceChild(newNode, oldNode);
1087	}
1088	};
1089
1090
1091	/**
1092	* Flattens an element. That is, removes it and replace it with its children.
1093	* Does nothing if the element is not in the document.
1094	* @param {Element} element The element to flatten.
1095	* @return {Element\|undefined} The original element, detached from the document
1096	* tree, sans children; or undefined, if the element was not in the document
1097	* to begin with.
1098	*/
1099	goog.dom.flattenElement = function(element) {
1100	var child, parent = element.parentNode;
1101	if (parent && parent.nodeType != goog.dom.NodeType.DOCUMENT_FRAGMENT) {
1102	// Use IE DOM method (supported by Opera too) if available
1103	if (element.removeNode) {
1104	return /** @type {Element} */ (element.removeNode(false));
1105	} else {
1106	// Move all children of the original node up one level.
1107	while ((child = element.firstChild)) {
1108	parent.insertBefore(child, element);
1109	}
1110
1111	// Detach the original element.
1112	return /** @type {Element} */ (goog.dom.removeNode(element));
1113	}
1114	}
1115	};
1116
1117
1118	/**
1119	* Returns an array containing just the element children of the given element.
1120	* @param {Element} element The element whose element children we want.
1121	* @return {!(Array\|NodeList)} An array or array-like list of just the element
1122	* children of the given element.
1123	*/
1124	goog.dom.getChildren = function(element) {
1125	// We check if the children attribute is supported for child elements
1126	// since IE8 misuses the attribute by also including comments.
1127	if (goog.dom.BrowserFeature.CAN_USE_CHILDREN_ATTRIBUTE &&
1128	element.children != undefined) {
1129	return element.children;
1130	}
1131	// Fall back to manually filtering the element's child nodes.
1132	return goog.array.filter(element.childNodes, function(node) {
1133	return node.nodeType == goog.dom.NodeType.ELEMENT;
1134	});
1135	};
1136
1137
1138	/**
1139	* Returns the first child node that is an element.
1140	* @param {Node} node The node to get the first child element of.
1141	* @return {Element} The first child node of {@code node} that is an element.
1142	*/
1143	goog.dom.getFirstElementChild = function(node) {
1144	if (node.firstElementChild != undefined) {
1145	return /** @type {!Element} */(node).firstElementChild;
1146	}
1147	return goog.dom.getNextElementNode_(node.firstChild, true);
1148	};
1149
1150
1151	/**
1152	* Returns the last child node that is an element.
1153	* @param {Node} node The node to get the last child element of.
1154	* @return {Element} The last child node of {@code node} that is an element.
1155	*/
1156	goog.dom.getLastElementChild = function(node) {
1157	if (node.lastElementChild != undefined) {
1158	return /** @type {!Element} */(node).lastElementChild;
1159	}
1160	return goog.dom.getNextElementNode_(node.lastChild, false);
1161	};
1162
1163
1164	/**
1165	* Returns the first next sibling that is an element.
1166	* @param {Node} node The node to get the next sibling element of.
1167	* @return {Element} The next sibling of {@code node} that is an element.
1168	*/
1169	goog.dom.getNextElementSibling = function(node) {
1170	if (node.nextElementSibling != undefined) {
1171	return /** @type {!Element} */(node).nextElementSibling;
1172	}
1173	return goog.dom.getNextElementNode_(node.nextSibling, true);
1174	};
1175
1176
1177	/**
1178	* Returns the first previous sibling that is an element.
1179	* @param {Node} node The node to get the previous sibling element of.
1180	* @return {Element} The first previous sibling of {@code node} that is
1181	* an element.
1182	*/
1183	goog.dom.getPreviousElementSibling = function(node) {
1184	if (node.previousElementSibling != undefined) {
1185	return /** @type {!Element} */(node).previousElementSibling;
1186	}
1187	return goog.dom.getNextElementNode_(node.previousSibling, false);
1188	};
1189
1190
1191	/**
1192	* Returns the first node that is an element in the specified direction,
1193	* starting with {@code node}.
1194	* @param {Node} node The node to get the next element from.
1195	* @param {boolean} forward Whether to look forwards or backwards.
1196	* @return {Element} The first element.
1197	* @private
1198	*/
1199	goog.dom.getNextElementNode_ = function(node, forward) {
1200	while (node && node.nodeType != goog.dom.NodeType.ELEMENT) {
1201	node = forward ? node.nextSibling : node.previousSibling;
1202	}
1203
1204	return /** @type {Element} */ (node);
1205	};
1206
1207
1208	/**
1209	* Returns the next node in source order from the given node.
1210	* @param {Node} node The node.
1211	* @return {Node} The next node in the DOM tree, or null if this was the last
1212	* node.
1213	*/
1214	goog.dom.getNextNode = function(node) {
1215	if (!node) {
1216	return null;
1217	}
1218
1219	if (node.firstChild) {
1220	return node.firstChild;
1221	}
1222
1223	while (node && !node.nextSibling) {
1224	node = node.parentNode;
1225	}
1226
1227	return node ? node.nextSibling : null;
1228	};
1229
1230
1231	/**
1232	* Returns the previous node in source order from the given node.
1233	* @param {Node} node The node.
1234	* @return {Node} The previous node in the DOM tree, or null if this was the
1235	* first node.
1236	*/
1237	goog.dom.getPreviousNode = function(node) {
1238	if (!node) {
1239	return null;
1240	}
1241
1242	if (!node.previousSibling) {
1243	return node.parentNode;
1244	}
1245
1246	node = node.previousSibling;
1247	while (node && node.lastChild) {
1248	node = node.lastChild;
1249	}
1250
1251	return node;
1252	};
1253
1254
1255	/**
1256	* Whether the object looks like a DOM node.
1257	* @param {?} obj The object being tested for node likeness.
1258	* @return {boolean} Whether the object looks like a DOM node.
1259	*/
1260	goog.dom.isNodeLike = function(obj) {
1261	return goog.isObject(obj) && obj.nodeType > 0;
1262	};
1263
1264
1265	/**
1266	* Whether the object looks like an Element.
1267	* @param {?} obj The object being tested for Element likeness.
1268	* @return {boolean} Whether the object looks like an Element.
1269	*/
1270	goog.dom.isElement = function(obj) {
1271	return goog.isObject(obj) && obj.nodeType == goog.dom.NodeType.ELEMENT;
1272	};
1273
1274
1275	/**
1276	* Returns true if the specified value is a Window object. This includes the
1277	* global window for HTML pages, and iframe windows.
1278	* @param {?} obj Variable to test.
1279	* @return {boolean} Whether the variable is a window.
1280	*/
1281	goog.dom.isWindow = function(obj) {
1282	return goog.isObject(obj) && obj['window'] == obj;
1283	};
1284
1285
1286	/**
1287	* Returns an element's parent, if it's an Element.
1288	* @param {Element} element The DOM element.
1289	* @return {Element} The parent, or null if not an Element.
1290	*/
1291	goog.dom.getParentElement = function(element) {
1292	var parent;
1293	if (goog.dom.BrowserFeature.CAN_USE_PARENT_ELEMENT_PROPERTY) {
1294	var isIe9 = goog.userAgent.IE &&
1295	goog.userAgent.isVersionOrHigher('9') &&
1296	!goog.userAgent.isVersionOrHigher('10');
1297	// SVG elements in IE9 can't use the parentElement property.
1298	// goog.global['SVGElement'] is not defined in IE9 quirks mode.
1299	if (!(isIe9 && goog.global['SVGElement'] &&
1300	element instanceof goog.global['SVGElement'])) {
1301	parent = element.parentElement;
1302	if (parent) {
1303	return parent;
1304	}
1305	}
1306	}
1307	parent = element.parentNode;
1308	return goog.dom.isElement(parent) ? /** @type {!Element} */ (parent) : null;
1309	};
1310
1311
1312	/**
1313	* Whether a node contains another node.
1314	* @param {Node} parent The node that should contain the other node.
1315	* @param {Node} descendant The node to test presence of.
1316	* @return {boolean} Whether the parent node contains the descendent node.
1317	*/
1318	goog.dom.contains = function(parent, descendant) {
1319	// We use browser specific methods for this if available since it is faster
1320	// that way.
1321
1322	// IE DOM
1323	if (parent.contains && descendant.nodeType == goog.dom.NodeType.ELEMENT) {
1324	return parent == descendant \|\| parent.contains(descendant);
1325	}
1326
1327	// W3C DOM Level 3
1328	if (typeof parent.compareDocumentPosition != 'undefined') {
1329	return parent == descendant \|\|
1330	Boolean(parent.compareDocumentPosition(descendant) & 16);
1331	}
1332
1333	// W3C DOM Level 1
1334	while (descendant && parent != descendant) {
1335	descendant = descendant.parentNode;
1336	}
1337	return descendant == parent;
1338	};
1339
1340
1341	/**
1342	* Compares the document order of two nodes, returning 0 if they are the same
1343	* node, a negative number if node1 is before node2, and a positive number if
1344	* node2 is before node1. Note that we compare the order the tags appear in the
1345	* document so in the tree <b><i>text</i></b> the B node is considered to be
1346	* before the I node.
1347	*
1348	* @param {Node} node1 The first node to compare.
1349	* @param {Node} node2 The second node to compare.
1350	* @return {number} 0 if the nodes are the same node, a negative number if node1
1351	* is before node2, and a positive number if node2 is before node1.
1352	*/
1353	goog.dom.compareNodeOrder = function(node1, node2) {
1354	// Fall out quickly for equality.
1355	if (node1 == node2) {
1356	return 0;
1357	}
1358
1359	// Use compareDocumentPosition where available
1360	if (node1.compareDocumentPosition) {
1361	// 4 is the bitmask for FOLLOWS.
1362	return node1.compareDocumentPosition(node2) & 2 ? 1 : -1;
1363	}
1364
1365	// Special case for document nodes on IE 7 and 8.
1366	if (goog.userAgent.IE && !goog.userAgent.isDocumentModeOrHigher(9)) {
1367	if (node1.nodeType == goog.dom.NodeType.DOCUMENT) {
1368	return -1;
1369	}
1370	if (node2.nodeType == goog.dom.NodeType.DOCUMENT) {
1371	return 1;
1372	}
1373	}
1374
1375	// Process in IE using sourceIndex - we check to see if the first node has
1376	// a source index or if its parent has one.
1377	if ('sourceIndex' in node1 \|\|
1378	(node1.parentNode && 'sourceIndex' in node1.parentNode)) {
1379	var isElement1 = node1.nodeType == goog.dom.NodeType.ELEMENT;
1380	var isElement2 = node2.nodeType == goog.dom.NodeType.ELEMENT;
1381
1382	if (isElement1 && isElement2) {
1383	return node1.sourceIndex - node2.sourceIndex;
1384	} else {
1385	var parent1 = node1.parentNode;
1386	var parent2 = node2.parentNode;
1387
1388	if (parent1 == parent2) {
1389	return goog.dom.compareSiblingOrder_(node1, node2);
1390	}
1391
1392	if (!isElement1 && goog.dom.contains(parent1, node2)) {
1393	return -1 * goog.dom.compareParentsDescendantNodeIe_(node1, node2);
1394	}
1395
1396
1397	if (!isElement2 && goog.dom.contains(parent2, node1)) {
1398	return goog.dom.compareParentsDescendantNodeIe_(node2, node1);
1399	}
1400
1401	return (isElement1 ? node1.sourceIndex : parent1.sourceIndex) -
1402	(isElement2 ? node2.sourceIndex : parent2.sourceIndex);
1403	}
1404	}
1405
1406	// For Safari, we compare ranges.
1407	var doc = goog.dom.getOwnerDocument(node1);
1408
1409	var range1, range2;
1410	range1 = doc.createRange();
1411	range1.selectNode(node1);
1412	range1.collapse(true);
1413
1414	range2 = doc.createRange();
1415	range2.selectNode(node2);
1416	range2.collapse(true);
1417
1418	return range1.compareBoundaryPoints(goog.global['Range'].START_TO_END,
1419	range2);
1420	};
1421
1422
1423	/**
1424	* Utility function to compare the position of two nodes, when
1425	* {@code textNode}'s parent is an ancestor of {@code node}. If this entry
1426	* condition is not met, this function will attempt to reference a null object.
1427	* @param {!Node} textNode The textNode to compare.
1428	* @param {Node} node The node to compare.
1429	* @return {number} -1 if node is before textNode, +1 otherwise.
1430	* @private
1431	*/
1432	goog.dom.compareParentsDescendantNodeIe_ = function(textNode, node) {
1433	var parent = textNode.parentNode;
1434	if (parent == node) {
1435	// If textNode is a child of node, then node comes first.
1436	return -1;
1437	}
1438	var sibling = node;
1439	while (sibling.parentNode != parent) {
1440	sibling = sibling.parentNode;
1441	}
1442	return goog.dom.compareSiblingOrder_(sibling, textNode);
1443	};
1444
1445
1446	/**
1447	* Utility function to compare the position of two nodes known to be non-equal
1448	* siblings.
1449	* @param {Node} node1 The first node to compare.
1450	* @param {!Node} node2 The second node to compare.
1451	* @return {number} -1 if node1 is before node2, +1 otherwise.
1452	* @private
1453	*/
1454	goog.dom.compareSiblingOrder_ = function(node1, node2) {
1455	var s = node2;
1456	while ((s = s.previousSibling)) {
1457	if (s == node1) {
1458	// We just found node1 before node2.
1459	return -1;
1460	}
1461	}
1462
1463	// Since we didn't find it, node1 must be after node2.
1464	return 1;
1465	};
1466
1467
1468	/**
1469	* Find the deepest common ancestor of the given nodes.
1470	* @param {...Node} var_args The nodes to find a common ancestor of.
1471	* @return {Node} The common ancestor of the nodes, or null if there is none.
1472	* null will only be returned if two or more of the nodes are from different
1473	* documents.
1474	*/
1475	goog.dom.findCommonAncestor = function(var_args) {
1476	var i, count = arguments.length;
1477	if (!count) {
1478	return null;
1479	} else if (count == 1) {
1480	return arguments[0];
1481	}
1482
1483	var paths = [];
1484	var minLength = Infinity;
1485	for (i = 0; i < count; i++) {
1486	// Compute the list of ancestors.
1487	var ancestors = [];
1488	var node = arguments[i];
1489	while (node) {
1490	ancestors.unshift(node);
1491	node = node.parentNode;
1492	}
1493
1494	// Save the list for comparison.
1495	paths.push(ancestors);
1496	minLength = Math.min(minLength, ancestors.length);
1497	}
1498	var output = null;
1499	for (i = 0; i < minLength; i++) {
1500	var first = paths[0][i];
1501	for (var j = 1; j < count; j++) {
1502	if (first != paths[j][i]) {
1503	return output;
1504	}
1505	}
1506	output = first;
1507	}
1508	return output;
1509	};
1510
1511
1512	/**
1513	* Returns the owner document for a node.
1514	* @param {Node\|Window} node The node to get the document for.
1515	* @return {!Document} The document owning the node.
1516	*/
1517	goog.dom.getOwnerDocument = function(node) {
1518	// TODO(nnaze): Update param signature to be non-nullable.
1519	goog.asserts.assert(node, 'Node cannot be null or undefined.');
1520	return /** @type {!Document} */ (
1521	node.nodeType == goog.dom.NodeType.DOCUMENT ? node :
1522	node.ownerDocument \|\| node.document);
1523	};
1524
1525
1526	/**
1527	* Cross-browser function for getting the document element of a frame or iframe.
1528	* @param {Element} frame Frame element.
1529	* @return {!Document} The frame content document.
1530	*/
1531	goog.dom.getFrameContentDocument = function(frame) {
1532	var doc = frame.contentDocument \|\| frame.contentWindow.document;
1533	return doc;
1534	};
1535
1536
1537	/**
1538	* Cross-browser function for getting the window of a frame or iframe.
1539	* @param {Element} frame Frame element.
1540	* @return {Window} The window associated with the given frame.
1541	*/
1542	goog.dom.getFrameContentWindow = function(frame) {
1543	return frame.contentWindow \|\|
1544	goog.dom.getWindow(goog.dom.getFrameContentDocument(frame));
1545	};
1546
1547
1548	/**
1549	* Sets the text content of a node, with cross-browser support.
1550	* @param {Node} node The node to change the text content of.
1551	* @param {string\|number} text The value that should replace the node's content.
1552	*/
1553	goog.dom.setTextContent = function(node, text) {
1554	goog.asserts.assert(node != null,
1555	'goog.dom.setTextContent expects a non-null value for node');
1556
1557	if ('textContent' in node) {
1558	node.textContent = text;
1559	} else if (node.nodeType == goog.dom.NodeType.TEXT) {
1560	node.data = text;
1561	} else if (node.firstChild &&
1562	node.firstChild.nodeType == goog.dom.NodeType.TEXT) {
1563	// If the first child is a text node we just change its data and remove the
1564	// rest of the children.
1565	while (node.lastChild != node.firstChild) {
1566	node.removeChild(node.lastChild);
1567	}
1568	node.firstChild.data = text;
1569	} else {
1570	goog.dom.removeChildren(node);
1571	var doc = goog.dom.getOwnerDocument(node);
1572	node.appendChild(doc.createTextNode(String(text)));
1573	}
1574	};
1575
1576
1577	/**
1578	* Gets the outerHTML of a node, which islike innerHTML, except that it
1579	* actually contains the HTML of the node itself.
1580	* @param {Element} element The element to get the HTML of.
1581	* @return {string} The outerHTML of the given element.
1582	*/
1583	goog.dom.getOuterHtml = function(element) {
1584	// IE, Opera and WebKit all have outerHTML.
1585	if ('outerHTML' in element) {
1586	return element.outerHTML;
1587	} else {
1588	var doc = goog.dom.getOwnerDocument(element);
1589	var div = doc.createElement('div');
1590	div.appendChild(element.cloneNode(true));
1591	return div.innerHTML;
1592	}
1593	};
1594
1595
1596	/**
1597	* Finds the first descendant node that matches the filter function, using
1598	* a depth first search. This function offers the most general purpose way
1599	* of finding a matching element. You may also wish to consider
1600	* {@code goog.dom.query} which can express many matching criteria using
1601	* CSS selector expressions. These expressions often result in a more
1602	* compact representation of the desired result.
1603	* @see goog.dom.query
1604	*
1605	* @param {Node} root The root of the tree to search.
1606	* @param {function(Node) : boolean} p The filter function.
1607	* @return {Node\|undefined} The found node or undefined if none is found.
1608	*/
1609	goog.dom.findNode = function(root, p) {
1610	var rv = [];
1611	var found = goog.dom.findNodes_(root, p, rv, true);
1612	return found ? rv[0] : undefined;
1613	};
1614
1615
1616	/**
1617	* Finds all the descendant nodes that match the filter function, using a
1618	* a depth first search. This function offers the most general-purpose way
1619	* of finding a set of matching elements. You may also wish to consider
1620	* {@code goog.dom.query} which can express many matching criteria using
1621	* CSS selector expressions. These expressions often result in a more
1622	* compact representation of the desired result.
1623
1624	* @param {Node} root The root of the tree to search.
1625	* @param {function(Node) : boolean} p The filter function.
1626	* @return {!Array<!Node>} The found nodes or an empty array if none are found.
1627	*/
1628	goog.dom.findNodes = function(root, p) {
1629	var rv = [];
1630	goog.dom.findNodes_(root, p, rv, false);
1631	return rv;
1632	};
1633
1634
1635	/**
1636	* Finds the first or all the descendant nodes that match the filter function,
1637	* using a depth first search.
1638	* @param {Node} root The root of the tree to search.
1639	* @param {function(Node) : boolean} p The filter function.
1640	* @param {!Array<!Node>} rv The found nodes are added to this array.
1641	* @param {boolean} findOne If true we exit after the first found node.
1642	* @return {boolean} Whether the search is complete or not. True in case findOne
1643	* is true and the node is found. False otherwise.
1644	* @private
1645	*/
1646	goog.dom.findNodes_ = function(root, p, rv, findOne) {
1647	if (root != null) {
1648	var child = root.firstChild;
1649	while (child) {
1650	if (p(child)) {
1651	rv.push(child);
1652	if (findOne) {
1653	return true;
1654	}
1655	}
1656	if (goog.dom.findNodes_(child, p, rv, findOne)) {
1657	return true;
1658	}
1659	child = child.nextSibling;
1660	}
1661	}
1662	return false;
1663	};
1664
1665
1666	/**
1667	* Map of tags whose content to ignore when calculating text length.
1668	* @private {!Object<string, number>}
1669	* @const
1670	*/
1671	goog.dom.TAGS_TO_IGNORE_ = {
1672	'SCRIPT': 1,
1673	'STYLE': 1,
1674	'HEAD': 1,
1675	'IFRAME': 1,
1676	'OBJECT': 1
1677	};
1678
1679
1680	/**
1681	* Map of tags which have predefined values with regard to whitespace.
1682	* @private {!Object<string, string>}
1683	* @const
1684	*/
1685	goog.dom.PREDEFINED_TAG_VALUES_ = {'IMG': ' ', 'BR': '\n'};
1686
1687
1688	/**
1689	* Returns true if the element has a tab index that allows it to receive
1690	* keyboard focus (tabIndex >= 0), false otherwise. Note that some elements
1691	* natively support keyboard focus, even if they have no tab index.
1692	* @param {!Element} element Element to check.
1693	* @return {boolean} Whether the element has a tab index that allows keyboard
1694	* focus.
1695	* @see http://fluidproject.org/blog/2008/01/09/getting-setting-and-removing-tabindex-values-with-javascript/
1696	*/
1697	goog.dom.isFocusableTabIndex = function(element) {
1698	return goog.dom.hasSpecifiedTabIndex_(element) &&
1699	goog.dom.isTabIndexFocusable_(element);
1700	};
1701
1702
1703	/**
1704	* Enables or disables keyboard focus support on the element via its tab index.
1705	* Only elements for which {@link goog.dom.isFocusableTabIndex} returns true
1706	* (or elements that natively support keyboard focus, like form elements) can
1707	* receive keyboard focus. See http://go/tabindex for more info.
1708	* @param {Element} element Element whose tab index is to be changed.
1709	* @param {boolean} enable Whether to set or remove a tab index on the element
1710	* that supports keyboard focus.
1711	*/
1712	goog.dom.setFocusableTabIndex = function(element, enable) {
1713	if (enable) {
1714	element.tabIndex = 0;
1715	} else {
1716	// Set tabIndex to -1 first, then remove it. This is a workaround for
1717	// Safari (confirmed in version 4 on Windows). When removing the attribute
1718	// without setting it to -1 first, the element remains keyboard focusable
1719	// despite not having a tabIndex attribute anymore.
1720	element.tabIndex = -1;
1721	element.removeAttribute('tabIndex'); // Must be camelCase!
1722	}
1723	};
1724
1725
1726	/**
1727	* Returns true if the element can be focused, i.e. it has a tab index that
1728	* allows it to receive keyboard focus (tabIndex >= 0), or it is an element
1729	* that natively supports keyboard focus.
1730	* @param {!Element} element Element to check.
1731	* @return {boolean} Whether the element allows keyboard focus.
1732	*/
1733	goog.dom.isFocusable = function(element) {
1734	var focusable;
1735	// Some elements can have unspecified tab index and still receive focus.
1736	if (goog.dom.nativelySupportsFocus_(element)) {
1737	// Make sure the element is not disabled ...
1738	focusable = !element.disabled &&
1739	// ... and if a tab index is specified, it allows focus.
1740	(!goog.dom.hasSpecifiedTabIndex_(element) \|\|
1741	goog.dom.isTabIndexFocusable_(element));
1742	} else {
1743	focusable = goog.dom.isFocusableTabIndex(element);
1744	}
1745
1746	// IE requires elements to be visible in order to focus them.
1747	return focusable && goog.userAgent.IE ?
1748	goog.dom.hasNonZeroBoundingRect_(element) : focusable;
1749	};
1750
1751
1752	/**
1753	* Returns true if the element has a specified tab index.
1754	* @param {!Element} element Element to check.
1755	* @return {boolean} Whether the element has a specified tab index.
1756	* @private
1757	*/
1758	goog.dom.hasSpecifiedTabIndex_ = function(element) {
1759	// IE returns 0 for an unset tabIndex, so we must use getAttributeNode(),
1760	// which returns an object with a 'specified' property if tabIndex is
1761	// specified. This works on other browsers, too.
1762	var attrNode = element.getAttributeNode('tabindex'); // Must be lowercase!
1763	return goog.isDefAndNotNull(attrNode) && attrNode.specified;
1764	};
1765
1766
1767	/**
1768	* Returns true if the element's tab index allows the element to be focused.
1769	* @param {!Element} element Element to check.
1770	* @return {boolean} Whether the element's tab index allows focus.
1771	* @private
1772	*/
1773	goog.dom.isTabIndexFocusable_ = function(element) {
1774	var index = element.tabIndex;
1775	// NOTE: IE9 puts tabIndex in 16-bit int, e.g. -2 is 65534.
1776	return goog.isNumber(index) && index >= 0 && index < 32768;
1777	};
1778
1779
1780	/**
1781	* Returns true if the element is focusable even when tabIndex is not set.
1782	* @param {!Element} element Element to check.
1783	* @return {boolean} Whether the element natively supports focus.
1784	* @private
1785	*/
1786	goog.dom.nativelySupportsFocus_ = function(element) {
1787	return element.tagName == goog.dom.TagName.A \|\|
1788	element.tagName == goog.dom.TagName.INPUT \|\|
1789	element.tagName == goog.dom.TagName.TEXTAREA \|\|
1790	element.tagName == goog.dom.TagName.SELECT \|\|
1791	element.tagName == goog.dom.TagName.BUTTON;
1792	};
1793
1794
1795	/**
1796	* Returns true if the element has a bounding rectangle that would be visible
1797	* (i.e. its width and height are greater than zero).
1798	* @param {!Element} element Element to check.
1799	* @return {boolean} Whether the element has a non-zero bounding rectangle.
1800	* @private
1801	*/
1802	goog.dom.hasNonZeroBoundingRect_ = function(element) {
1803	var rect = goog.isFunction(element['getBoundingClientRect']) ?
1804	element.getBoundingClientRect() :
1805	{'height': element.offsetHeight, 'width': element.offsetWidth};
1806	return goog.isDefAndNotNull(rect) && rect.height > 0 && rect.width > 0;
1807	};
1808
1809
1810	/**
1811	* Returns the text content of the current node, without markup and invisible
1812	* symbols. New lines are stripped and whitespace is collapsed,
1813	* such that each character would be visible.
1814	*
1815	* In browsers that support it, innerText is used. Other browsers attempt to
1816	* simulate it via node traversal. Line breaks are canonicalized in IE.
1817	*
1818	* @param {Node} node The node from which we are getting content.
1819	* @return {string} The text content.
1820	*/
1821	goog.dom.getTextContent = function(node) {
1822	var textContent;
1823	// Note(arv): IE9, Opera, and Safari 3 support innerText but they include
1824	// text nodes in script tags. So we revert to use a user agent test here.
1825	if (goog.dom.BrowserFeature.CAN_USE_INNER_TEXT && ('innerText' in node)) {
1826	textContent = goog.string.canonicalizeNewlines(node.innerText);
1827	// Unfortunately .innerText() returns text with symbols
1828	// We need to filter it out and then remove duplicate whitespaces
1829	} else {
1830	var buf = [];
1831	goog.dom.getTextContent_(node, buf, true);
1832	textContent = buf.join('');
1833	}
1834
1835	// Strip entities. goog.format.insertWordBreaks inserts them in Opera.
1836	textContent = textContent.replace(/ \xAD /g, ' ').replace(/\xAD/g, '');
1837	// Strip entities. goog.format.insertWordBreaks inserts them in IE8.
1838	textContent = textContent.replace(/\u200B/g, '');
1839
1840	// Skip this replacement on old browsers with working innerText, which
1841	// automatically turns   into ' ' and / +/ into ' ' when reading
1842	// innerText.
1843	if (!goog.dom.BrowserFeature.CAN_USE_INNER_TEXT) {
1844	textContent = textContent.replace(/ +/g, ' ');
1845	}
1846	if (textContent != ' ') {
1847	textContent = textContent.replace(/^\s*/, '');
1848	}
1849
1850	return textContent;
1851	};
1852
1853
1854	/**
1855	* Returns the text content of the current node, without markup.
1856	*
1857	* Unlike {@code getTextContent} this method does not collapse whitespaces
1858	* or normalize lines breaks.
1859	*
1860	* @param {Node} node The node from which we are getting content.
1861	* @return {string} The raw text content.
1862	*/
1863	goog.dom.getRawTextContent = function(node) {
1864	var buf = [];
1865	goog.dom.getTextContent_(node, buf, false);
1866
1867	return buf.join('');
1868	};
1869
1870
1871	/**
1872	* Recursive support function for text content retrieval.
1873	*
1874	* @param {Node} node The node from which we are getting content.
1875	* @param {Array<string>} buf string buffer.
1876	* @param {boolean} normalizeWhitespace Whether to normalize whitespace.
1877	* @private
1878	*/
1879	goog.dom.getTextContent_ = function(node, buf, normalizeWhitespace) {
1880	if (node.nodeName in goog.dom.TAGS_TO_IGNORE_) {
1881	// ignore certain tags
1882	} else if (node.nodeType == goog.dom.NodeType.TEXT) {
1883	if (normalizeWhitespace) {
1884	buf.push(String(node.nodeValue).replace(/(\r\n\|\r\|\n)/g, ''));
1885	} else {
1886	buf.push(node.nodeValue);
1887	}
1888	} else if (node.nodeName in goog.dom.PREDEFINED_TAG_VALUES_) {
1889	buf.push(goog.dom.PREDEFINED_TAG_VALUES_[node.nodeName]);
1890	} else {
1891	var child = node.firstChild;
1892	while (child) {
1893	goog.dom.getTextContent_(child, buf, normalizeWhitespace);
1894	child = child.nextSibling;
1895	}
1896	}
1897	};
1898
1899
1900	/**
1901	* Returns the text length of the text contained in a node, without markup. This
1902	* is equivalent to the selection length if the node was selected, or the number
1903	* of cursor movements to traverse the node. Images & BRs take one space. New
1904	* lines are ignored.
1905	*
1906	* @param {Node} node The node whose text content length is being calculated.
1907	* @return {number} The length of {@code node}'s text content.
1908	*/
1909	goog.dom.getNodeTextLength = function(node) {
1910	return goog.dom.getTextContent(node).length;
1911	};
1912
1913
1914	/**
1915	* Returns the text offset of a node relative to one of its ancestors. The text
1916	* length is the same as the length calculated by goog.dom.getNodeTextLength.
1917	*
1918	* @param {Node} node The node whose offset is being calculated.
1919	* @param {Node=} opt_offsetParent The node relative to which the offset will
1920	* be calculated. Defaults to the node's owner document's body.
1921	* @return {number} The text offset.
1922	*/
1923	goog.dom.getNodeTextOffset = function(node, opt_offsetParent) {
1924	var root = opt_offsetParent \|\| goog.dom.getOwnerDocument(node).body;
1925	var buf = [];
1926	while (node && node != root) {
1927	var cur = node;
1928	while ((cur = cur.previousSibling)) {
1929	buf.unshift(goog.dom.getTextContent(cur));
1930	}
1931	node = node.parentNode;
1932	}
1933	// Trim left to deal with FF cases when there might be line breaks and empty
1934	// nodes at the front of the text
1935	return goog.string.trimLeft(buf.join('')).replace(/ +/g, ' ').length;
1936	};
1937
1938
1939	/**
1940	* Returns the node at a given offset in a parent node. If an object is
1941	* provided for the optional third parameter, the node and the remainder of the
1942	* offset will stored as properties of this object.
1943	* @param {Node} parent The parent node.
1944	* @param {number} offset The offset into the parent node.
1945	* @param {Object=} opt_result Object to be used to store the return value. The
1946	* return value will be stored in the form {node: Node, remainder: number}
1947	* if this object is provided.
1948	* @return {Node} The node at the given offset.
1949	*/
1950	goog.dom.getNodeAtOffset = function(parent, offset, opt_result) {
1951	var stack = [parent], pos = 0, cur = null;
1952	while (stack.length > 0 && pos < offset) {
1953	cur = stack.pop();
1954	if (cur.nodeName in goog.dom.TAGS_TO_IGNORE_) {
1955	// ignore certain tags
1956	} else if (cur.nodeType == goog.dom.NodeType.TEXT) {
1957	var text = cur.nodeValue.replace(/(\r\n\|\r\|\n)/g, '').replace(/ +/g, ' ');
1958	pos += text.length;
1959	} else if (cur.nodeName in goog.dom.PREDEFINED_TAG_VALUES_) {
1960	pos += goog.dom.PREDEFINED_TAG_VALUES_[cur.nodeName].length;
1961	} else {
1962	for (var i = cur.childNodes.length - 1; i >= 0; i--) {
1963	stack.push(cur.childNodes[i]);
1964	}
1965	}
1966	}
1967	if (goog.isObject(opt_result)) {
1968	opt_result.remainder = cur ? cur.nodeValue.length + offset - pos - 1 : 0;
1969	opt_result.node = cur;
1970	}
1971
1972	return cur;
1973	};
1974
1975
1976	/**
1977	* Returns true if the object is a {@code NodeList}. To qualify as a NodeList,
1978	* the object must have a numeric length property and an item function (which
1979	* has type 'string' on IE for some reason).
1980	* @param {Object} val Object to test.
1981	* @return {boolean} Whether the object is a NodeList.
1982	*/
1983	goog.dom.isNodeList = function(val) {
1984	// TODO(attila): Now the isNodeList is part of goog.dom we can use
1985	// goog.userAgent to make this simpler.
1986	// A NodeList must have a length property of type 'number' on all platforms.
1987	if (val && typeof val.length == 'number') {
1988	// A NodeList is an object everywhere except Safari, where it's a function.
1989	if (goog.isObject(val)) {
1990	// A NodeList must have an item function (on non-IE platforms) or an item
1991	// property of type 'string' (on IE).
1992	return typeof val.item == 'function' \|\| typeof val.item == 'string';
1993	} else if (goog.isFunction(val)) {
1994	// On Safari, a NodeList is a function with an item property that is also
1995	// a function.
1996	return typeof val.item == 'function';
1997	}
1998	}
1999
2000	// Not a NodeList.
2001	return false;
2002	};
2003
2004
2005	/**
2006	* Walks up the DOM hierarchy returning the first ancestor that has the passed
2007	* tag name and/or class name. If the passed element matches the specified
2008	* criteria, the element itself is returned.
2009	* @param {Node} element The DOM node to start with.
2010	* @param {?(goog.dom.TagName\|string)=} opt_tag The tag name to match (or
2011	* null/undefined to match only based on class name).
2012	* @param {?string=} opt_class The class name to match (or null/undefined to
2013	* match only based on tag name).
2014	* @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2015	* dom.
2016	* @return {Element} The first ancestor that matches the passed criteria, or
2017	* null if no match is found.
2018	*/
2019	goog.dom.getAncestorByTagNameAndClass = function(element, opt_tag, opt_class,
2020	opt_maxSearchSteps) {
2021	if (!opt_tag && !opt_class) {
2022	return null;
2023	}
2024	var tagName = opt_tag ? opt_tag.toUpperCase() : null;
2025	return /** @type {Element} */ (goog.dom.getAncestor(element,
2026	function(node) {
2027	return (!tagName \|\| node.nodeName == tagName) &&
2028	(!opt_class \|\| goog.isString(node.className) &&
2029	goog.array.contains(node.className.split(/\s+/), opt_class));
2030	}, true, opt_maxSearchSteps));
2031	};
2032
2033
2034	/**
2035	* Walks up the DOM hierarchy returning the first ancestor that has the passed
2036	* class name. If the passed element matches the specified criteria, the
2037	* element itself is returned.
2038	* @param {Node} element The DOM node to start with.
2039	* @param {string} className The class name to match.
2040	* @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2041	* dom.
2042	* @return {Element} The first ancestor that matches the passed criteria, or
2043	* null if none match.
2044	*/
2045	goog.dom.getAncestorByClass = function(element, className, opt_maxSearchSteps) {
2046	return goog.dom.getAncestorByTagNameAndClass(element, null, className,
2047	opt_maxSearchSteps);
2048	};
2049
2050
2051	/**
2052	* Walks up the DOM hierarchy returning the first ancestor that passes the
2053	* matcher function.
2054	* @param {Node} element The DOM node to start with.
2055	* @param {function(Node) : boolean} matcher A function that returns true if the
2056	* passed node matches the desired criteria.
2057	* @param {boolean=} opt_includeNode If true, the node itself is included in
2058	* the search (the first call to the matcher will pass startElement as
2059	* the node to test).
2060	* @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2061	* dom.
2062	* @return {Node} DOM node that matched the matcher, or null if there was
2063	* no match.
2064	*/
2065	goog.dom.getAncestor = function(
2066	element, matcher, opt_includeNode, opt_maxSearchSteps) {
2067	if (!opt_includeNode) {
2068	element = element.parentNode;
2069	}
2070	var ignoreSearchSteps = opt_maxSearchSteps == null;
2071	var steps = 0;
2072	while (element && (ignoreSearchSteps \|\| steps <= opt_maxSearchSteps)) {
2073	if (matcher(element)) {
2074	return element;
2075	}
2076	element = element.parentNode;
2077	steps++;
2078	}
2079	// Reached the root of the DOM without a match
2080	return null;
2081	};
2082
2083
2084	/**
2085	* Determines the active element in the given document.
2086	* @param {Document} doc The document to look in.
2087	* @return {Element} The active element.
2088	*/
2089	goog.dom.getActiveElement = function(doc) {
2090	try {
2091	return doc && doc.activeElement;
2092	} catch (e) {
2093	// NOTE(nicksantos): Sometimes, evaluating document.activeElement in IE
2094	// throws an exception. I'm not 100% sure why, but I suspect it chokes
2095	// on document.activeElement if the activeElement has been recently
2096	// removed from the DOM by a JS operation.
2097	//
2098	// We assume that an exception here simply means
2099	// "there is no active element."
2100	}
2101
2102	return null;
2103	};
2104
2105
2106	/**
2107	* Gives the current devicePixelRatio.
2108	*
2109	* By default, this is the value of window.devicePixelRatio (which should be
2110	* preferred if present).
2111	*
2112	* If window.devicePixelRatio is not present, the ratio is calculated with
2113	* window.matchMedia, if present. Otherwise, gives 1.0.
2114	*
2115	* Some browsers (including Chrome) consider the browser zoom level in the pixel
2116	* ratio, so the value may change across multiple calls.
2117	*
2118	* @return {number} The number of actual pixels per virtual pixel.
2119	*/
2120	goog.dom.getPixelRatio = function() {
2121	var win = goog.dom.getWindow();
2122
2123	// devicePixelRatio does not work on Mobile firefox.
2124	// TODO(user): Enable this check on a known working mobile Gecko version.
2125	// Filed a bug: https://bugzilla.mozilla.org/show_bug.cgi?id=896804
2126	var isFirefoxMobile = goog.userAgent.GECKO && goog.userAgent.MOBILE;
2127
2128	if (goog.isDef(win.devicePixelRatio) && !isFirefoxMobile) {
2129	return win.devicePixelRatio;
2130	} else if (win.matchMedia) {
2131	return goog.dom.matchesPixelRatio_(.75) \|\|
2132	goog.dom.matchesPixelRatio_(1.5) \|\|
2133	goog.dom.matchesPixelRatio_(2) \|\|
2134	goog.dom.matchesPixelRatio_(3) \|\| 1;
2135	}
2136	return 1;
2137	};
2138
2139
2140	/**
2141	* Calculates a mediaQuery to check if the current device supports the
2142	* given actual to virtual pixel ratio.
2143	* @param {number} pixelRatio The ratio of actual pixels to virtual pixels.
2144	* @return {number} pixelRatio if applicable, otherwise 0.
2145	* @private
2146	*/
2147	goog.dom.matchesPixelRatio_ = function(pixelRatio) {
2148	var win = goog.dom.getWindow();
2149	var query = ('(-webkit-min-device-pixel-ratio: ' + pixelRatio + '),' +
2150	'(min--moz-device-pixel-ratio: ' + pixelRatio + '),' +
2151	'(min-resolution: ' + pixelRatio + 'dppx)');
2152	return win.matchMedia(query).matches ? pixelRatio : 0;
2153	};
2154
2155
2156
2157	/**
2158	* Create an instance of a DOM helper with a new document object.
2159	* @param {Document=} opt_document Document object to associate with this
2160	* DOM helper.
2161	* @constructor
2162	*/
2163	goog.dom.DomHelper = function(opt_document) {
2164	/**
2165	* Reference to the document object to use
2166	* @type {!Document}
2167	* @private
2168	*/
2169	this.document_ = opt_document \|\| goog.global.document \|\| document;
2170	};
2171
2172
2173	/**
2174	* Gets the dom helper object for the document where the element resides.
2175	* @param {Node=} opt_node If present, gets the DomHelper for this node.
2176	* @return {!goog.dom.DomHelper} The DomHelper.
2177	*/
2178	goog.dom.DomHelper.prototype.getDomHelper = goog.dom.getDomHelper;
2179
2180
2181	/**
2182	* Sets the document object.
2183	* @param {!Document} document Document object.
2184	*/
2185	goog.dom.DomHelper.prototype.setDocument = function(document) {
2186	this.document_ = document;
2187	};
2188
2189
2190	/**
2191	* Gets the document object being used by the dom library.
2192	* @return {!Document} Document object.
2193	*/
2194	goog.dom.DomHelper.prototype.getDocument = function() {
2195	return this.document_;
2196	};
2197
2198
2199	/**
2200	* Alias for {@code getElementById}. If a DOM node is passed in then we just
2201	* return that.
2202	* @param {string\|Element} element Element ID or a DOM node.
2203	* @return {Element} The element with the given ID, or the node passed in.
2204	*/
2205	goog.dom.DomHelper.prototype.getElement = function(element) {
2206	return goog.dom.getElementHelper_(this.document_, element);
2207	};
2208
2209
2210	/**
2211	* Gets an element by id, asserting that the element is found.
2212	*
2213	* This is used when an element is expected to exist, and should fail with
2214	* an assertion error if it does not (if assertions are enabled).
2215	*
2216	* @param {string} id Element ID.
2217	* @return {!Element} The element with the given ID, if it exists.
2218	*/
2219	goog.dom.DomHelper.prototype.getRequiredElement = function(id) {
2220	return goog.dom.getRequiredElementHelper_(this.document_, id);
2221	};
2222
2223
2224	/**
2225	* Alias for {@code getElement}.
2226	* @param {string\|Element} element Element ID or a DOM node.
2227	* @return {Element} The element with the given ID, or the node passed in.
2228	* @deprecated Use {@link goog.dom.DomHelper.prototype.getElement} instead.
2229	*/
2230	goog.dom.DomHelper.prototype.$ = goog.dom.DomHelper.prototype.getElement;
2231
2232
2233	/**
2234	* Looks up elements by both tag and class name, using browser native functions
2235	* ({@code querySelectorAll}, {@code getElementsByTagName} or
2236	* {@code getElementsByClassName}) where possible. The returned array is a live
2237	* NodeList or a static list depending on the code path taken.
2238	*
2239	* @see goog.dom.query
2240	*
2241	* @param {?string=} opt_tag Element tag name or * for all tags.
2242	* @param {?string=} opt_class Optional class name.
2243	* @param {(Document\|Element)=} opt_el Optional element to look in.
2244	* @return { {length: number} } Array-like list of elements (only a length
2245	* property and numerical indices are guaranteed to exist).
2246	*/
2247	goog.dom.DomHelper.prototype.getElementsByTagNameAndClass = function(opt_tag,
2248	opt_class,
2249	opt_el) {
2250	return goog.dom.getElementsByTagNameAndClass_(this.document_, opt_tag,
2251	opt_class, opt_el);
2252	};
2253
2254
2255	/**
2256	* Returns an array of all the elements with the provided className.
2257	* @see {goog.dom.query}
2258	* @param {string} className the name of the class to look for.
2259	* @param {Element\|Document=} opt_el Optional element to look in.
2260	* @return { {length: number} } The items found with the class name provided.
2261	*/
2262	goog.dom.DomHelper.prototype.getElementsByClass = function(className, opt_el) {
2263	var doc = opt_el \|\| this.document_;
2264	return goog.dom.getElementsByClass(className, doc);
2265	};
2266
2267
2268	/**
2269	* Returns the first element we find matching the provided class name.
2270	* @see {goog.dom.query}
2271	* @param {string} className the name of the class to look for.
2272	* @param {(Element\|Document)=} opt_el Optional element to look in.
2273	* @return {Element} The first item found with the class name provided.
2274	*/
2275	goog.dom.DomHelper.prototype.getElementByClass = function(className, opt_el) {
2276	var doc = opt_el \|\| this.document_;
2277	return goog.dom.getElementByClass(className, doc);
2278	};
2279
2280
2281	/**
2282	* Ensures an element with the given className exists, and then returns the
2283	* first element with the provided className.
2284	* @see {goog.dom.query}
2285	* @param {string} className the name of the class to look for.
2286	* @param {(!Element\|!Document)=} opt_root Optional element or document to look
2287	* in.
2288	* @return {!Element} The first item found with the class name provided.
2289	* @throws {goog.asserts.AssertionError} Thrown if no element is found.
2290	*/
2291	goog.dom.DomHelper.prototype.getRequiredElementByClass = function(className,
2292	opt_root) {
2293	var root = opt_root \|\| this.document_;
2294	return goog.dom.getRequiredElementByClass(className, root);
2295	};
2296
2297
2298	/**
2299	* Alias for {@code getElementsByTagNameAndClass}.
2300	* @deprecated Use DomHelper getElementsByTagNameAndClass.
2301	* @see goog.dom.query
2302	*
2303	* @param {?string=} opt_tag Element tag name.
2304	* @param {?string=} opt_class Optional class name.
2305	* @param {Element=} opt_el Optional element to look in.
2306	* @return { {length: number} } Array-like list of elements (only a length
2307	* property and numerical indices are guaranteed to exist).
2308	*/
2309	goog.dom.DomHelper.prototype.$$ =
2310	goog.dom.DomHelper.prototype.getElementsByTagNameAndClass;
2311
2312
2313	/**
2314	* Sets a number of properties on a node.
2315	* @param {Element} element DOM node to set properties on.
2316	* @param {Object} properties Hash of property:value pairs.
2317	*/
2318	goog.dom.DomHelper.prototype.setProperties = goog.dom.setProperties;
2319
2320
2321	/**
2322	* Gets the dimensions of the viewport.
2323	* @param {Window=} opt_window Optional window element to test. Defaults to
2324	* the window of the Dom Helper.
2325	* @return {!goog.math.Size} Object with values 'width' and 'height'.
2326	*/
2327	goog.dom.DomHelper.prototype.getViewportSize = function(opt_window) {
2328	// TODO(arv): This should not take an argument. That breaks the rule of a
2329	// a DomHelper representing a single frame/window/document.
2330	return goog.dom.getViewportSize(opt_window \|\| this.getWindow());
2331	};
2332
2333
2334	/**
2335	* Calculates the height of the document.
2336	*
2337	* @return {number} The height of the document.
2338	*/
2339	goog.dom.DomHelper.prototype.getDocumentHeight = function() {
2340	return goog.dom.getDocumentHeight_(this.getWindow());
2341	};
2342
2343
2344	/**
2345	* Typedef for use with goog.dom.createDom and goog.dom.append.
2346	* @typedef {Object\|string\|Array\|NodeList}
2347	*/
2348	goog.dom.Appendable;
2349
2350
2351	/**
2352	* Returns a dom node with a set of attributes. This function accepts varargs
2353	* for subsequent nodes to be added. Subsequent nodes will be added to the
2354	* first node as childNodes.
2355	*
2356	* So:
2357	* <code>createDom('div', null, createDom('p'), createDom('p'));</code>
2358	* would return a div with two child paragraphs
2359	*
2360	* An easy way to move all child nodes of an existing element to a new parent
2361	* element is:
2362	* <code>createDom('div', null, oldElement.childNodes);</code>
2363	* which will remove all child nodes from the old element and add them as
2364	* child nodes of the new DIV.
2365	*
2366	* @param {string} tagName Tag to create.
2367	* @param {Object\|string=} opt_attributes If object, then a map of name-value
2368	* pairs for attributes. If a string, then this is the className of the new
2369	* element.
2370	* @param {...goog.dom.Appendable} var_args Further DOM nodes or
2371	* strings for text nodes. If one of the var_args is an array or
2372	* NodeList, its elements will be added as childNodes instead.
2373	* @return {!Element} Reference to a DOM node.
2374	*/
2375	goog.dom.DomHelper.prototype.createDom = function(tagName,
2376	opt_attributes,
2377	var_args) {
2378	return goog.dom.createDom_(this.document_, arguments);
2379	};
2380
2381
2382	/**
2383	* Alias for {@code createDom}.
2384	* @param {string} tagName Tag to create.
2385	* @param {(Object\|string)=} opt_attributes If object, then a map of name-value
2386	* pairs for attributes. If a string, then this is the className of the new
2387	* element.
2388	* @param {...goog.dom.Appendable} var_args Further DOM nodes or strings for
2389	* text nodes. If one of the var_args is an array, its children will be
2390	* added as childNodes instead.
2391	* @return {!Element} Reference to a DOM node.
2392	* @deprecated Use {@link goog.dom.DomHelper.prototype.createDom} instead.
2393	*/
2394	goog.dom.DomHelper.prototype.$dom = goog.dom.DomHelper.prototype.createDom;
2395
2396
2397	/**
2398	* Creates a new element.
2399	* @param {string} name Tag name.
2400	* @return {!Element} The new element.
2401	*/
2402	goog.dom.DomHelper.prototype.createElement = function(name) {
2403	return this.document_.createElement(name);
2404	};
2405
2406
2407	/**
2408	* Creates a new text node.
2409	* @param {number\|string} content Content.
2410	* @return {!Text} The new text node.
2411	*/
2412	goog.dom.DomHelper.prototype.createTextNode = function(content) {
2413	return this.document_.createTextNode(String(content));
2414	};
2415
2416
2417	/**
2418	* Create a table.
2419	* @param {number} rows The number of rows in the table. Must be >= 1.
2420	* @param {number} columns The number of columns in the table. Must be >= 1.
2421	* @param {boolean=} opt_fillWithNbsp If true, fills table entries with nsbps.
2422	* @return {!Element} The created table.
2423	*/
2424	goog.dom.DomHelper.prototype.createTable = function(rows, columns,
2425	opt_fillWithNbsp) {
2426	return goog.dom.createTable_(this.document_, rows, columns,
2427	!!opt_fillWithNbsp);
2428	};
2429
2430
2431	/**
2432	* Converts an HTML string into a node or a document fragment. A single Node
2433	* is used if the {@code htmlString} only generates a single node. If the
2434	* {@code htmlString} generates multiple nodes then these are put inside a
2435	* {@code DocumentFragment}.
2436	*
2437	* @param {string} htmlString The HTML string to convert.
2438	* @return {!Node} The resulting node.
2439	*/
2440	goog.dom.DomHelper.prototype.htmlToDocumentFragment = function(htmlString) {
2441	return goog.dom.htmlToDocumentFragment_(this.document_, htmlString);
2442	};
2443
2444
2445	/**
2446	* Returns true if the browser is in "CSS1-compatible" (standards-compliant)
2447	* mode, false otherwise.
2448	* @return {boolean} True if in CSS1-compatible mode.
2449	*/
2450	goog.dom.DomHelper.prototype.isCss1CompatMode = function() {
2451	return goog.dom.isCss1CompatMode_(this.document_);
2452	};
2453
2454
2455	/**
2456	* Gets the window object associated with the document.
2457	* @return {!Window} The window associated with the given document.
2458	*/
2459	goog.dom.DomHelper.prototype.getWindow = function() {
2460	return goog.dom.getWindow_(this.document_);
2461	};
2462
2463
2464	/**
2465	* Gets the document scroll element.
2466	* @return {!Element} Scrolling element.
2467	*/
2468	goog.dom.DomHelper.prototype.getDocumentScrollElement = function() {
2469	return goog.dom.getDocumentScrollElement_(this.document_);
2470	};
2471
2472
2473	/**
2474	* Gets the document scroll distance as a coordinate object.
2475	* @return {!goog.math.Coordinate} Object with properties 'x' and 'y'.
2476	*/
2477	goog.dom.DomHelper.prototype.getDocumentScroll = function() {
2478	return goog.dom.getDocumentScroll_(this.document_);
2479	};
2480
2481
2482	/**
2483	* Determines the active element in the given document.
2484	* @param {Document=} opt_doc The document to look in.
2485	* @return {Element} The active element.
2486	*/
2487	goog.dom.DomHelper.prototype.getActiveElement = function(opt_doc) {
2488	return goog.dom.getActiveElement(opt_doc \|\| this.document_);
2489	};
2490
2491
2492	/**
2493	* Appends a child to a node.
2494	* @param {Node} parent Parent.
2495	* @param {Node} child Child.
2496	*/
2497	goog.dom.DomHelper.prototype.appendChild = goog.dom.appendChild;
2498
2499
2500	/**
2501	* Appends a node with text or other nodes.
2502	* @param {!Node} parent The node to append nodes to.
2503	* @param {...goog.dom.Appendable} var_args The things to append to the node.
2504	* If this is a Node it is appended as is.
2505	* If this is a string then a text node is appended.
2506	* If this is an array like object then fields 0 to length - 1 are appended.
2507	*/
2508	goog.dom.DomHelper.prototype.append = goog.dom.append;
2509
2510
2511	/**
2512	* Determines if the given node can contain children, intended to be used for
2513	* HTML generation.
2514	*
2515	* @param {Node} node The node to check.
2516	* @return {boolean} Whether the node can contain children.
2517	*/
2518	goog.dom.DomHelper.prototype.canHaveChildren = goog.dom.canHaveChildren;
2519
2520
2521	/**
2522	* Removes all the child nodes on a DOM node.
2523	* @param {Node} node Node to remove children from.
2524	*/
2525	goog.dom.DomHelper.prototype.removeChildren = goog.dom.removeChildren;
2526
2527
2528	/**
2529	* Inserts a new node before an existing reference node (i.e., as the previous
2530	* sibling). If the reference node has no parent, then does nothing.
2531	* @param {Node} newNode Node to insert.
2532	* @param {Node} refNode Reference node to insert before.
2533	*/
2534	goog.dom.DomHelper.prototype.insertSiblingBefore = goog.dom.insertSiblingBefore;
2535
2536
2537	/**
2538	* Inserts a new node after an existing reference node (i.e., as the next
2539	* sibling). If the reference node has no parent, then does nothing.
2540	* @param {Node} newNode Node to insert.
2541	* @param {Node} refNode Reference node to insert after.
2542	*/
2543	goog.dom.DomHelper.prototype.insertSiblingAfter = goog.dom.insertSiblingAfter;
2544
2545
2546	/**
2547	* Insert a child at a given index. If index is larger than the number of child
2548	* nodes that the parent currently has, the node is inserted as the last child
2549	* node.
2550	* @param {Element} parent The element into which to insert the child.
2551	* @param {Node} child The element to insert.
2552	* @param {number} index The index at which to insert the new child node. Must
2553	* not be negative.
2554	*/
2555	goog.dom.DomHelper.prototype.insertChildAt = goog.dom.insertChildAt;
2556
2557
2558	/**
2559	* Removes a node from its parent.
2560	* @param {Node} node The node to remove.
2561	* @return {Node} The node removed if removed; else, null.
2562	*/
2563	goog.dom.DomHelper.prototype.removeNode = goog.dom.removeNode;
2564
2565
2566	/**
2567	* Replaces a node in the DOM tree. Will do nothing if {@code oldNode} has no
2568	* parent.
2569	* @param {Node} newNode Node to insert.
2570	* @param {Node} oldNode Node to replace.
2571	*/
2572	goog.dom.DomHelper.prototype.replaceNode = goog.dom.replaceNode;
2573
2574
2575	/**
2576	* Flattens an element. That is, removes it and replace it with its children.
2577	* @param {Element} element The element to flatten.
2578	* @return {Element\|undefined} The original element, detached from the document
2579	* tree, sans children, or undefined if the element was already not in the
2580	* document.
2581	*/
2582	goog.dom.DomHelper.prototype.flattenElement = goog.dom.flattenElement;
2583
2584
2585	/**
2586	* Returns an array containing just the element children of the given element.
2587	* @param {Element} element The element whose element children we want.
2588	* @return {!(Array\|NodeList)} An array or array-like list of just the element
2589	* children of the given element.
2590	*/
2591	goog.dom.DomHelper.prototype.getChildren = goog.dom.getChildren;
2592
2593
2594	/**
2595	* Returns the first child node that is an element.
2596	* @param {Node} node The node to get the first child element of.
2597	* @return {Element} The first child node of {@code node} that is an element.
2598	*/
2599	goog.dom.DomHelper.prototype.getFirstElementChild =
2600	goog.dom.getFirstElementChild;
2601
2602
2603	/**
2604	* Returns the last child node that is an element.
2605	* @param {Node} node The node to get the last child element of.
2606	* @return {Element} The last child node of {@code node} that is an element.
2607	*/
2608	goog.dom.DomHelper.prototype.getLastElementChild = goog.dom.getLastElementChild;
2609
2610
2611	/**
2612	* Returns the first next sibling that is an element.
2613	* @param {Node} node The node to get the next sibling element of.
2614	* @return {Element} The next sibling of {@code node} that is an element.
2615	*/
2616	goog.dom.DomHelper.prototype.getNextElementSibling =
2617	goog.dom.getNextElementSibling;
2618
2619
2620	/**
2621	* Returns the first previous sibling that is an element.
2622	* @param {Node} node The node to get the previous sibling element of.
2623	* @return {Element} The first previous sibling of {@code node} that is
2624	* an element.
2625	*/
2626	goog.dom.DomHelper.prototype.getPreviousElementSibling =
2627	goog.dom.getPreviousElementSibling;
2628
2629
2630	/**
2631	* Returns the next node in source order from the given node.
2632	* @param {Node} node The node.
2633	* @return {Node} The next node in the DOM tree, or null if this was the last
2634	* node.
2635	*/
2636	goog.dom.DomHelper.prototype.getNextNode = goog.dom.getNextNode;
2637
2638
2639	/**
2640	* Returns the previous node in source order from the given node.
2641	* @param {Node} node The node.
2642	* @return {Node} The previous node in the DOM tree, or null if this was the
2643	* first node.
2644	*/
2645	goog.dom.DomHelper.prototype.getPreviousNode = goog.dom.getPreviousNode;
2646
2647
2648	/**
2649	* Whether the object looks like a DOM node.
2650	* @param {?} obj The object being tested for node likeness.
2651	* @return {boolean} Whether the object looks like a DOM node.
2652	*/
2653	goog.dom.DomHelper.prototype.isNodeLike = goog.dom.isNodeLike;
2654
2655
2656	/**
2657	* Whether the object looks like an Element.
2658	* @param {?} obj The object being tested for Element likeness.
2659	* @return {boolean} Whether the object looks like an Element.
2660	*/
2661	goog.dom.DomHelper.prototype.isElement = goog.dom.isElement;
2662
2663
2664	/**
2665	* Returns true if the specified value is a Window object. This includes the
2666	* global window for HTML pages, and iframe windows.
2667	* @param {?} obj Variable to test.
2668	* @return {boolean} Whether the variable is a window.
2669	*/
2670	goog.dom.DomHelper.prototype.isWindow = goog.dom.isWindow;
2671
2672
2673	/**
2674	* Returns an element's parent, if it's an Element.
2675	* @param {Element} element The DOM element.
2676	* @return {Element} The parent, or null if not an Element.
2677	*/
2678	goog.dom.DomHelper.prototype.getParentElement = goog.dom.getParentElement;
2679
2680
2681	/**
2682	* Whether a node contains another node.
2683	* @param {Node} parent The node that should contain the other node.
2684	* @param {Node} descendant The node to test presence of.
2685	* @return {boolean} Whether the parent node contains the descendent node.
2686	*/
2687	goog.dom.DomHelper.prototype.contains = goog.dom.contains;
2688
2689
2690	/**
2691	* Compares the document order of two nodes, returning 0 if they are the same
2692	* node, a negative number if node1 is before node2, and a positive number if
2693	* node2 is before node1. Note that we compare the order the tags appear in the
2694	* document so in the tree <b><i>text</i></b> the B node is considered to be
2695	* before the I node.
2696	*
2697	* @param {Node} node1 The first node to compare.
2698	* @param {Node} node2 The second node to compare.
2699	* @return {number} 0 if the nodes are the same node, a negative number if node1
2700	* is before node2, and a positive number if node2 is before node1.
2701	*/
2702	goog.dom.DomHelper.prototype.compareNodeOrder = goog.dom.compareNodeOrder;
2703
2704
2705	/**
2706	* Find the deepest common ancestor of the given nodes.
2707	* @param {...Node} var_args The nodes to find a common ancestor of.
2708	* @return {Node} The common ancestor of the nodes, or null if there is none.
2709	* null will only be returned if two or more of the nodes are from different
2710	* documents.
2711	*/
2712	goog.dom.DomHelper.prototype.findCommonAncestor = goog.dom.findCommonAncestor;
2713
2714
2715	/**
2716	* Returns the owner document for a node.
2717	* @param {Node} node The node to get the document for.
2718	* @return {!Document} The document owning the node.
2719	*/
2720	goog.dom.DomHelper.prototype.getOwnerDocument = goog.dom.getOwnerDocument;
2721
2722
2723	/**
2724	* Cross browser function for getting the document element of an iframe.
2725	* @param {Element} iframe Iframe element.
2726	* @return {!Document} The frame content document.
2727	*/
2728	goog.dom.DomHelper.prototype.getFrameContentDocument =
2729	goog.dom.getFrameContentDocument;
2730
2731
2732	/**
2733	* Cross browser function for getting the window of a frame or iframe.
2734	* @param {Element} frame Frame element.
2735	* @return {Window} The window associated with the given frame.
2736	*/
2737	goog.dom.DomHelper.prototype.getFrameContentWindow =
2738	goog.dom.getFrameContentWindow;
2739
2740
2741	/**
2742	* Sets the text content of a node, with cross-browser support.
2743	* @param {Node} node The node to change the text content of.
2744	* @param {string\|number} text The value that should replace the node's content.
2745	*/
2746	goog.dom.DomHelper.prototype.setTextContent = goog.dom.setTextContent;
2747
2748
2749	/**
2750	* Gets the outerHTML of a node, which islike innerHTML, except that it
2751	* actually contains the HTML of the node itself.
2752	* @param {Element} element The element to get the HTML of.
2753	* @return {string} The outerHTML of the given element.
2754	*/
2755	goog.dom.DomHelper.prototype.getOuterHtml = goog.dom.getOuterHtml;
2756
2757
2758	/**
2759	* Finds the first descendant node that matches the filter function. This does
2760	* a depth first search.
2761	* @param {Node} root The root of the tree to search.
2762	* @param {function(Node) : boolean} p The filter function.
2763	* @return {Node\|undefined} The found node or undefined if none is found.
2764	*/
2765	goog.dom.DomHelper.prototype.findNode = goog.dom.findNode;
2766
2767
2768	/**
2769	* Finds all the descendant nodes that matches the filter function. This does a
2770	* depth first search.
2771	* @param {Node} root The root of the tree to search.
2772	* @param {function(Node) : boolean} p The filter function.
2773	* @return {Array<Node>} The found nodes or an empty array if none are found.
2774	*/
2775	goog.dom.DomHelper.prototype.findNodes = goog.dom.findNodes;
2776
2777
2778	/**
2779	* Returns true if the element has a tab index that allows it to receive
2780	* keyboard focus (tabIndex >= 0), false otherwise. Note that some elements
2781	* natively support keyboard focus, even if they have no tab index.
2782	* @param {!Element} element Element to check.
2783	* @return {boolean} Whether the element has a tab index that allows keyboard
2784	* focus.
2785	*/
2786	goog.dom.DomHelper.prototype.isFocusableTabIndex = goog.dom.isFocusableTabIndex;
2787
2788
2789	/**
2790	* Enables or disables keyboard focus support on the element via its tab index.
2791	* Only elements for which {@link goog.dom.isFocusableTabIndex} returns true
2792	* (or elements that natively support keyboard focus, like form elements) can
2793	* receive keyboard focus. See http://go/tabindex for more info.
2794	* @param {Element} element Element whose tab index is to be changed.
2795	* @param {boolean} enable Whether to set or remove a tab index on the element
2796	* that supports keyboard focus.
2797	*/
2798	goog.dom.DomHelper.prototype.setFocusableTabIndex =
2799	goog.dom.setFocusableTabIndex;
2800
2801
2802	/**
2803	* Returns true if the element can be focused, i.e. it has a tab index that
2804	* allows it to receive keyboard focus (tabIndex >= 0), or it is an element
2805	* that natively supports keyboard focus.
2806	* @param {!Element} element Element to check.
2807	* @return {boolean} Whether the element allows keyboard focus.
2808	*/
2809	goog.dom.DomHelper.prototype.isFocusable = goog.dom.isFocusable;
2810
2811
2812	/**
2813	* Returns the text contents of the current node, without markup. New lines are
2814	* stripped and whitespace is collapsed, such that each character would be
2815	* visible.
2816	*
2817	* In browsers that support it, innerText is used. Other browsers attempt to
2818	* simulate it via node traversal. Line breaks are canonicalized in IE.
2819	*
2820	* @param {Node} node The node from which we are getting content.
2821	* @return {string} The text content.
2822	*/
2823	goog.dom.DomHelper.prototype.getTextContent = goog.dom.getTextContent;
2824
2825
2826	/**
2827	* Returns the text length of the text contained in a node, without markup. This
2828	* is equivalent to the selection length if the node was selected, or the number
2829	* of cursor movements to traverse the node. Images & BRs take one space. New
2830	* lines are ignored.
2831	*
2832	* @param {Node} node The node whose text content length is being calculated.
2833	* @return {number} The length of {@code node}'s text content.
2834	*/
2835	goog.dom.DomHelper.prototype.getNodeTextLength = goog.dom.getNodeTextLength;
2836
2837
2838	/**
2839	* Returns the text offset of a node relative to one of its ancestors. The text
2840	* length is the same as the length calculated by
2841	* {@code goog.dom.getNodeTextLength}.
2842	*
2843	* @param {Node} node The node whose offset is being calculated.
2844	* @param {Node=} opt_offsetParent Defaults to the node's owner document's body.
2845	* @return {number} The text offset.
2846	*/
2847	goog.dom.DomHelper.prototype.getNodeTextOffset = goog.dom.getNodeTextOffset;
2848
2849
2850	/**
2851	* Returns the node at a given offset in a parent node. If an object is
2852	* provided for the optional third parameter, the node and the remainder of the
2853	* offset will stored as properties of this object.
2854	* @param {Node} parent The parent node.
2855	* @param {number} offset The offset into the parent node.
2856	* @param {Object=} opt_result Object to be used to store the return value. The
2857	* return value will be stored in the form {node: Node, remainder: number}
2858	* if this object is provided.
2859	* @return {Node} The node at the given offset.
2860	*/
2861	goog.dom.DomHelper.prototype.getNodeAtOffset = goog.dom.getNodeAtOffset;
2862
2863
2864	/**
2865	* Returns true if the object is a {@code NodeList}. To qualify as a NodeList,
2866	* the object must have a numeric length property and an item function (which
2867	* has type 'string' on IE for some reason).
2868	* @param {Object} val Object to test.
2869	* @return {boolean} Whether the object is a NodeList.
2870	*/
2871	goog.dom.DomHelper.prototype.isNodeList = goog.dom.isNodeList;
2872
2873
2874	/**
2875	* Walks up the DOM hierarchy returning the first ancestor that has the passed
2876	* tag name and/or class name. If the passed element matches the specified
2877	* criteria, the element itself is returned.
2878	* @param {Node} element The DOM node to start with.
2879	* @param {?(goog.dom.TagName\|string)=} opt_tag The tag name to match (or
2880	* null/undefined to match only based on class name).
2881	* @param {?string=} opt_class The class name to match (or null/undefined to
2882	* match only based on tag name).
2883	* @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2884	* dom.
2885	* @return {Element} The first ancestor that matches the passed criteria, or
2886	* null if no match is found.
2887	*/
2888	goog.dom.DomHelper.prototype.getAncestorByTagNameAndClass =
2889	goog.dom.getAncestorByTagNameAndClass;
2890
2891
2892	/**
2893	* Walks up the DOM hierarchy returning the first ancestor that has the passed
2894	* class name. If the passed element matches the specified criteria, the
2895	* element itself is returned.
2896	* @param {Node} element The DOM node to start with.
2897	* @param {string} class The class name to match.
2898	* @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2899	* dom.
2900	* @return {Element} The first ancestor that matches the passed criteria, or
2901	* null if none match.
2902	*/
2903	goog.dom.DomHelper.prototype.getAncestorByClass =
2904	goog.dom.getAncestorByClass;
2905
2906
2907	/**
2908	* Walks up the DOM hierarchy returning the first ancestor that passes the
2909	* matcher function.
2910	* @param {Node} element The DOM node to start with.
2911	* @param {function(Node) : boolean} matcher A function that returns true if the
2912	* passed node matches the desired criteria.
2913	* @param {boolean=} opt_includeNode If true, the node itself is included in
2914	* the search (the first call to the matcher will pass startElement as
2915	* the node to test).
2916	* @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2917	* dom.
2918	* @return {Node} DOM node that matched the matcher, or null if there was
2919	* no match.
2920	*/
2921	goog.dom.DomHelper.prototype.getAncestor = goog.dom.getAncestor;