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 [email protected] (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.dom.safe');
42
goog.require('goog.html.SafeHtml');
43
goog.require('goog.html.uncheckedconversions');
44
goog.require('goog.math.Coordinate');
45
goog.require('goog.math.Size');
46
goog.require('goog.object');
47
goog.require('goog.string');
48
goog.require('goog.string.Unicode');
49
goog.require('goog.userAgent');
50

51

52
/**
53
 * @define {boolean} Whether we know at compile time that the browser is in
54
 * quirks mode.
55
 */
56
goog.define('goog.dom.ASSUME_QUIRKS_MODE', false);
57

58

59
/**
60
 * @define {boolean} Whether we know at compile time that the browser is in
61
 * standards compliance mode.
62
 */
63
goog.define('goog.dom.ASSUME_STANDARDS_MODE', false);
64

65

66
/**
67
 * Whether we know the compatibility mode at compile time.
68
 * @type {boolean}
69
 * @private
70
 */
71
goog.dom.COMPAT_MODE_KNOWN_ =
72
    goog.dom.ASSUME_QUIRKS_MODE || goog.dom.ASSUME_STANDARDS_MODE;
73

74

75
/**
76
 * Gets the DomHelper object for the document where the element resides.
77
 * @param {(Node|Window)=} opt_element If present, gets the DomHelper for this
78
 *     element.
79
 * @return {!goog.dom.DomHelper} The DomHelper.
80
 */
81
goog.dom.getDomHelper = function(opt_element) {
82
  return opt_element ?
83
      new goog.dom.DomHelper(goog.dom.getOwnerDocument(opt_element)) :
84
      (goog.dom.defaultDomHelper_ ||
85
       (goog.dom.defaultDomHelper_ = new goog.dom.DomHelper()));
86
};
87

88

89
/**
90
 * Cached default DOM helper.
91
 * @type {!goog.dom.DomHelper|undefined}
92
 * @private
93
 */
94
goog.dom.defaultDomHelper_;
95

96

97
/**
98
 * Gets the document object being used by the dom library.
99
 * @return {!Document} Document object.
100
 */
101
goog.dom.getDocument = function() {
102
  return document;
103
};
104

105

106
/**
107
 * Gets an element from the current document by element id.
108
 *
109
 * If an Element is passed in, it is returned.
110
 *
111
 * @param {string|Element} element Element ID or a DOM node.
112
 * @return {Element} The element with the given ID, or the node passed in.
113
 */
114
goog.dom.getElement = function(element) {
115
  return goog.dom.getElementHelper_(document, element);
116
};
117

118

119
/**
120
 * Gets an element by id from the given document (if present).
121
 * If an element is given, it is returned.
122
 * @param {!Document} doc
123
 * @param {string|Element} element Element ID or a DOM node.
124
 * @return {Element} The resulting element.
125
 * @private
126
 */
127
goog.dom.getElementHelper_ = function(doc, element) {
128
  return goog.isString(element) ? doc.getElementById(element) : element;
129
};
130

131

132
/**
133
 * Gets an element by id, asserting that the element is found.
134
 *
135
 * This is used when an element is expected to exist, and should fail with
136
 * an assertion error if it does not (if assertions are enabled).
137
 *
138
 * @param {string} id Element ID.
139
 * @return {!Element} The element with the given ID, if it exists.
140
 */
141
goog.dom.getRequiredElement = function(id) {
142
  return goog.dom.getRequiredElementHelper_(document, id);
143
};
144

145

146
/**
147
 * Helper function for getRequiredElementHelper functions, both static and
148
 * on DomHelper.  Asserts the element with the given id exists.
149
 * @param {!Document} doc
150
 * @param {string} id
151
 * @return {!Element} The element with the given ID, if it exists.
152
 * @private
153
 */
154
goog.dom.getRequiredElementHelper_ = function(doc, id) {
155
  // To prevent users passing in Elements as is permitted in getElement().
156
  goog.asserts.assertString(id);
157
  var element = goog.dom.getElementHelper_(doc, id);
158
  element =
159
      goog.asserts.assertElement(element, 'No element found with id: ' + id);
160
  return element;
161
};
162

163

164
/**
165
 * Alias for getElement.
166
 * @param {string|Element} element Element ID or a DOM node.
167
 * @return {Element} The element with the given ID, or the node passed in.
168
 * @deprecated Use {@link goog.dom.getElement} instead.
169
 */
170
goog.dom.$ = goog.dom.getElement;
171

172

173
/**
174
 * Gets elements by tag name.
175
 * @param {!goog.dom.TagName<T>} tagName
176
 * @param {(!Document|!Element)=} opt_parent Parent element or document where to
177
 *     look for elements. Defaults to document.
178
 * @return {!NodeList<R>} List of elements. The members of the list are
179
 *     {!Element} if tagName is not a member of goog.dom.TagName or more
180
 *     specific types if it is (e.g. {!HTMLAnchorElement} for
181
 *     goog.dom.TagName.A).
182
 * @template T
183
 * @template R := cond(isUnknown(T), 'Element', T) =:
184
 */
185
goog.dom.getElementsByTagName = function(tagName, opt_parent) {
186
  var parent = opt_parent || document;
187
  return parent.getElementsByTagName(String(tagName));
188
};
189

190

191
/**
192
 * Looks up elements by both tag and class name, using browser native functions
193
 * ({@code querySelectorAll}, {@code getElementsByTagName} or
194
 * {@code getElementsByClassName}) where possible. This function
195
 * is a useful, if limited, way of collecting a list of DOM elements
196
 * with certain characteristics.  {@code goog.dom.query} offers a
197
 * more powerful and general solution which allows matching on CSS3
198
 * selector expressions, but at increased cost in code size. If all you
199
 * need is particular tags belonging to a single class, this function
200
 * is fast and sleek.
201
 *
202
 * Note that tag names are case sensitive in the SVG namespace, and this
203
 * function converts opt_tag to uppercase for comparisons. For queries in the
204
 * SVG namespace you should use querySelector or querySelectorAll instead.
205
 * https://bugzilla.mozilla.org/show_bug.cgi?id=963870
206
 * https://bugs.webkit.org/show_bug.cgi?id=83438
207
 *
208
 * @see {goog.dom.query}
209
 *
210
 * @param {(string|?goog.dom.TagName<T>)=} opt_tag Element tag name.
211
 * @param {?string=} opt_class Optional class name.
212
 * @param {(Document|Element)=} opt_el Optional element to look in.
213
 * @return {!IArrayLike<R>} Array-like list of elements (only a length property
214
 *     and numerical indices are guaranteed to exist). The members of the array
215
 *     are {!Element} if opt_tag is not a member of goog.dom.TagName or more
216
 *     specific types if it is (e.g. {!HTMLAnchorElement} for
217
 *     goog.dom.TagName.A).
218
 * @template T
219
 * @template R := cond(isUnknown(T), 'Element', T) =:
220
 */
221
goog.dom.getElementsByTagNameAndClass = function(opt_tag, opt_class, opt_el) {
222
  return goog.dom.getElementsByTagNameAndClass_(
223
      document, opt_tag, opt_class, opt_el);
224
};
225

226

227
/**
228
 * Returns a static, array-like list of the elements with the provided
229
 * className.
230
 * @see {goog.dom.query}
231
 * @param {string} className the name of the class to look for.
232
 * @param {(Document|Element)=} opt_el Optional element to look in.
233
 * @return {!IArrayLike<!Element>} The items found with the class name provided.
234
 */
235
goog.dom.getElementsByClass = function(className, opt_el) {
236
  var parent = opt_el || document;
237
  if (goog.dom.canUseQuerySelector_(parent)) {
238
    return parent.querySelectorAll('.' + className);
239
  }
240
  return goog.dom.getElementsByTagNameAndClass_(
241
      document, '*', className, opt_el);
242
};
243

244

245
/**
246
 * Returns the first element with the provided className.
247
 * @see {goog.dom.query}
248
 * @param {string} className the name of the class to look for.
249
 * @param {Element|Document=} opt_el Optional element to look in.
250
 * @return {Element} The first item with the class name provided.
251
 */
252
goog.dom.getElementByClass = function(className, opt_el) {
253
  var parent = opt_el || document;
254
  var retVal = null;
255
  if (parent.getElementsByClassName) {
256
    retVal = parent.getElementsByClassName(className)[0];
257
  } else if (goog.dom.canUseQuerySelector_(parent)) {
258
    retVal = parent.querySelector('.' + className);
259
  } else {
260
    retVal = goog.dom.getElementsByTagNameAndClass_(
261
        document, '*', className, opt_el)[0];
262
  }
263
  return retVal || null;
264
};
265

266

267
/**
268
 * Ensures an element with the given className exists, and then returns the
269
 * first element with the provided className.
270
 * @see {goog.dom.query}
271
 * @param {string} className the name of the class to look for.
272
 * @param {!Element|!Document=} opt_root Optional element or document to look
273
 *     in.
274
 * @return {!Element} The first item with the class name provided.
275
 * @throws {goog.asserts.AssertionError} Thrown if no element is found.
276
 */
277
goog.dom.getRequiredElementByClass = function(className, opt_root) {
278
  var retValue = goog.dom.getElementByClass(className, opt_root);
279
  return goog.asserts.assert(
280
      retValue, 'No element found with className: ' + className);
281
};
282

283

284
/**
285
 * Prefer the standardized (http://www.w3.org/TR/selectors-api/), native and
286
 * fast W3C Selectors API.
287
 * @param {!(Element|Document)} parent The parent document object.
288
 * @return {boolean} whether or not we can use parent.querySelector* APIs.
289
 * @private
290
 */
291
goog.dom.canUseQuerySelector_ = function(parent) {
292
  return !!(parent.querySelectorAll && parent.querySelector);
293
};
294

295

296
/**
297
 * Helper for {@code getElementsByTagNameAndClass}.
298
 * @param {!Document} doc The document to get the elements in.
299
 * @param {(string|?goog.dom.TagName<T>)=} opt_tag Element tag name.
300
 * @param {?string=} opt_class Optional class name.
301
 * @param {(Document|Element)=} opt_el Optional element to look in.
302
 * @return {!IArrayLike<R>} Array-like list of elements (only a length property
303
 *     and numerical indices are guaranteed to exist). The members of the array
304
 *     are {!Element} if opt_tag is not a member of goog.dom.TagName or more
305
 *     specific types if it is (e.g. {!HTMLAnchorElement} for
306
 *     goog.dom.TagName.A).
307
 * @template T
308
 * @template R := cond(isUnknown(T), 'Element', T) =:
309
 * @private
310
 */
311
goog.dom.getElementsByTagNameAndClass_ = function(
312
    doc, opt_tag, opt_class, opt_el) {
313
  var parent = opt_el || doc;
314
  var tagName =
315
      (opt_tag && opt_tag != '*') ? String(opt_tag).toUpperCase() : '';
316

317
  if (goog.dom.canUseQuerySelector_(parent) && (tagName || opt_class)) {
318
    var query = tagName + (opt_class ? '.' + opt_class : '');
319
    return parent.querySelectorAll(query);
320
  }
321

322
  // Use the native getElementsByClassName if available, under the assumption
323
  // that even when the tag name is specified, there will be fewer elements to
324
  // filter through when going by class than by tag name
325
  if (opt_class && parent.getElementsByClassName) {
326
    var els = parent.getElementsByClassName(opt_class);
327

328
    if (tagName) {
329
      var arrayLike = {};
330
      var len = 0;
331

332
      // Filter for specific tags if requested.
333
      for (var i = 0, el; el = els[i]; i++) {
334
        if (tagName == el.nodeName) {
335
          arrayLike[len++] = el;
336
        }
337
      }
338
      arrayLike.length = len;
339

340
      return /** @type {!IArrayLike<!Element>} */ (arrayLike);
341
    } else {
342
      return els;
343
    }
344
  }
345

346
  var els = parent.getElementsByTagName(tagName || '*');
347

348
  if (opt_class) {
349
    var arrayLike = {};
350
    var len = 0;
351
    for (var i = 0, el; el = els[i]; i++) {
352
      var className = el.className;
353
      // Check if className has a split function since SVG className does not.
354
      if (typeof className.split == 'function' &&
355
          goog.array.contains(className.split(/\s+/), opt_class)) {
356
        arrayLike[len++] = el;
357
      }
358
    }
359
    arrayLike.length = len;
360
    return /** @type {!IArrayLike<!Element>} */ (arrayLike);
361
  } else {
362
    return els;
363
  }
364
};
365

366

367
/**
368
 * Alias for {@code getElementsByTagNameAndClass}.
369
 * @param {(string|?goog.dom.TagName<T>)=} opt_tag Element tag name.
370
 * @param {?string=} opt_class Optional class name.
371
 * @param {Element=} opt_el Optional element to look in.
372
 * @return {!IArrayLike<R>} Array-like list of elements (only a length property
373
 *     and numerical indices are guaranteed to exist). The members of the array
374
 *     are {!Element} if opt_tag is not a member of goog.dom.TagName or more
375
 *     specific types if it is (e.g. {!HTMLAnchorElement} for
376
 *     goog.dom.TagName.A).
377
 * @template T
378
 * @template R := cond(isUnknown(T), 'Element', T) =:
379
 * @deprecated Use {@link goog.dom.getElementsByTagNameAndClass} instead.
380
 */
381
goog.dom.$$ = goog.dom.getElementsByTagNameAndClass;
382

383

384
/**
385
 * Sets multiple properties, and sometimes attributes, on an element. Note that
386
 * properties are simply object properties on the element instance, while
387
 * attributes are visible in the DOM. Many properties map to attributes with the
388
 * same names, some with different names, and there are also unmappable cases.
389
 *
390
 * This method sets properties by default (which means that custom attributes
391
 * are not supported). These are the exeptions (some of which is legacy):
392
 * - "style": Even though this is an attribute name, it is translated to a
393
 *   property, "style.cssText". Note that this property sanitizes and formats
394
 *   its value, unlike the attribute.
395
 * - "class": This is an attribute name, it is translated to the "className"
396
 *   property.
397
 * - "for": This is an attribute name, it is translated to the "htmlFor"
398
 *   property.
399
 * - Entries in {@see goog.dom.DIRECT_ATTRIBUTE_MAP_} are set as attributes,
400
 *   this is probably due to browser quirks.
401
 * - "aria-*", "data-*": Always set as attributes, they have no property
402
 *   counterparts.
403
 *
404
 * @param {Element} element DOM node to set properties on.
405
 * @param {Object} properties Hash of property:value pairs.
406
 *     Property values can be strings or goog.string.TypedString values (such as
407
 *     goog.html.SafeUrl).
408
 */
409
goog.dom.setProperties = function(element, properties) {
410
  goog.object.forEach(properties, function(val, key) {
411
    if (val && val.implementsGoogStringTypedString) {
412
      val = val.getTypedStringValue();
413
    }
414
    if (key == 'style') {
415
      element.style.cssText = val;
416
    } else if (key == 'class') {
417
      element.className = val;
418
    } else if (key == 'for') {
419
      element.htmlFor = val;
420
    } else if (goog.dom.DIRECT_ATTRIBUTE_MAP_.hasOwnProperty(key)) {
421
      element.setAttribute(goog.dom.DIRECT_ATTRIBUTE_MAP_[key], val);
422
    } else if (
423
        goog.string.startsWith(key, 'aria-') ||
424
        goog.string.startsWith(key, 'data-')) {
425
      element.setAttribute(key, val);
426
    } else {
427
      element[key] = val;
428
    }
429
  });
430
};
431

432

433
/**
434
 * Map of attributes that should be set using
435
 * element.setAttribute(key, val) instead of element[key] = val.  Used
436
 * by goog.dom.setProperties.
437
 *
438
 * @private {!Object<string, string>}
439
 * @const
440
 */
441
goog.dom.DIRECT_ATTRIBUTE_MAP_ = {
442
  'cellpadding': 'cellPadding',
443
  'cellspacing': 'cellSpacing',
444
  'colspan': 'colSpan',
445
  'frameborder': 'frameBorder',
446
  'height': 'height',
447
  'maxlength': 'maxLength',
448
  'nonce': 'nonce',
449
  'role': 'role',
450
  'rowspan': 'rowSpan',
451
  'type': 'type',
452
  'usemap': 'useMap',
453
  'valign': 'vAlign',
454
  'width': 'width'
455
};
456

457

458
/**
459
 * Gets the dimensions of the viewport.
460
 *
461
 * Gecko Standards mode:
462
 * docEl.clientWidth  Width of viewport excluding scrollbar.
463
 * win.innerWidth     Width of viewport including scrollbar.
464
 * body.clientWidth   Width of body element.
465
 *
466
 * docEl.clientHeight Height of viewport excluding scrollbar.
467
 * win.innerHeight    Height of viewport including scrollbar.
468
 * body.clientHeight  Height of document.
469
 *
470
 * Gecko Backwards compatible mode:
471
 * docEl.clientWidth  Width of viewport excluding scrollbar.
472
 * win.innerWidth     Width of viewport including scrollbar.
473
 * body.clientWidth   Width of viewport excluding scrollbar.
474
 *
475
 * docEl.clientHeight Height of document.
476
 * win.innerHeight    Height of viewport including scrollbar.
477
 * body.clientHeight  Height of viewport excluding scrollbar.
478
 *
479
 * IE6/7 Standards mode:
480
 * docEl.clientWidth  Width of viewport excluding scrollbar.
481
 * win.innerWidth     Undefined.
482
 * body.clientWidth   Width of body element.
483
 *
484
 * docEl.clientHeight Height of viewport excluding scrollbar.
485
 * win.innerHeight    Undefined.
486
 * body.clientHeight  Height of document element.
487
 *
488
 * IE5 + IE6/7 Backwards compatible mode:
489
 * docEl.clientWidth  0.
490
 * win.innerWidth     Undefined.
491
 * body.clientWidth   Width of viewport excluding scrollbar.
492
 *
493
 * docEl.clientHeight 0.
494
 * win.innerHeight    Undefined.
495
 * body.clientHeight  Height of viewport excluding scrollbar.
496
 *
497
 * Opera 9 Standards and backwards compatible mode:
498
 * docEl.clientWidth  Width of viewport excluding scrollbar.
499
 * win.innerWidth     Width of viewport including scrollbar.
500
 * body.clientWidth   Width of viewport excluding scrollbar.
501
 *
502
 * docEl.clientHeight Height of document.
503
 * win.innerHeight    Height of viewport including scrollbar.
504
 * body.clientHeight  Height of viewport excluding scrollbar.
505
 *
506
 * WebKit:
507
 * Safari 2
508
 * docEl.clientHeight Same as scrollHeight.
509
 * docEl.clientWidth  Same as innerWidth.
510
 * win.innerWidth     Width of viewport excluding scrollbar.
511
 * win.innerHeight    Height of the viewport including scrollbar.
512
 * frame.innerHeight  Height of the viewport exluding scrollbar.
513
 *
514
 * Safari 3 (tested in 522)
515
 *
516
 * docEl.clientWidth  Width of viewport excluding scrollbar.
517
 * docEl.clientHeight Height of viewport excluding scrollbar in strict mode.
518
 * body.clientHeight  Height of viewport excluding scrollbar in quirks mode.
519
 *
520
 * @param {Window=} opt_window Optional window element to test.
521
 * @return {!goog.math.Size} Object with values 'width' and 'height'.
522
 */
523
goog.dom.getViewportSize = function(opt_window) {
524
  // TODO(arv): This should not take an argument
525
  return goog.dom.getViewportSize_(opt_window || window);
526
};
527

528

529
/**
530
 * Helper for {@code getViewportSize}.
531
 * @param {Window} win The window to get the view port size for.
532
 * @return {!goog.math.Size} Object with values 'width' and 'height'.
533
 * @private
534
 */
535
goog.dom.getViewportSize_ = function(win) {
536
  var doc = win.document;
537
  var el = goog.dom.isCss1CompatMode_(doc) ? doc.documentElement : doc.body;
538
  return new goog.math.Size(el.clientWidth, el.clientHeight);
539
};
540

541

542
/**
543
 * Calculates the height of the document.
544
 *
545
 * @return {number} The height of the current document.
546
 */
547
goog.dom.getDocumentHeight = function() {
548
  return goog.dom.getDocumentHeight_(window);
549
};
550

551
/**
552
 * Calculates the height of the document of the given window.
553
 *
554
 * @param {!Window} win The window whose document height to retrieve.
555
 * @return {number} The height of the document of the given window.
556
 */
557
goog.dom.getDocumentHeightForWindow = function(win) {
558
  return goog.dom.getDocumentHeight_(win);
559
};
560

561
/**
562
 * Calculates the height of the document of the given window.
563
 *
564
 * Function code copied from the opensocial gadget api:
565
 *   gadgets.window.adjustHeight(opt_height)
566
 *
567
 * @private
568
 * @param {!Window} win The window whose document height to retrieve.
569
 * @return {number} The height of the document of the given window.
570
 */
571
goog.dom.getDocumentHeight_ = function(win) {
572
  // NOTE(eae): This method will return the window size rather than the document
573
  // size in webkit quirks mode.
574
  var doc = win.document;
575
  var height = 0;
576

577
  if (doc) {
578
    // Calculating inner content height is hard and different between
579
    // browsers rendering in Strict vs. Quirks mode.  We use a combination of
580
    // three properties within document.body and document.documentElement:
581
    // - scrollHeight
582
    // - offsetHeight
583
    // - clientHeight
584
    // These values differ significantly between browsers and rendering modes.
585
    // But there are patterns.  It just takes a lot of time and persistence
586
    // to figure out.
587

588
    var body = doc.body;
589
    var docEl = /** @type {!HTMLElement} */ (doc.documentElement);
590
    if (!(docEl && body)) {
591
      return 0;
592
    }
593

594
    // Get the height of the viewport
595
    var vh = goog.dom.getViewportSize_(win).height;
596
    if (goog.dom.isCss1CompatMode_(doc) && docEl.scrollHeight) {
597
      // In Strict mode:
598
      // The inner content height is contained in either:
599
      //    document.documentElement.scrollHeight
600
      //    document.documentElement.offsetHeight
601
      // Based on studying the values output by different browsers,
602
      // use the value that's NOT equal to the viewport height found above.
603
      height =
604
          docEl.scrollHeight != vh ? docEl.scrollHeight : docEl.offsetHeight;
605
    } else {
606
      // In Quirks mode:
607
      // documentElement.clientHeight is equal to documentElement.offsetHeight
608
      // except in IE.  In most browsers, document.documentElement can be used
609
      // to calculate the inner content height.
610
      // However, in other browsers (e.g. IE), document.body must be used
611
      // instead.  How do we know which one to use?
612
      // If document.documentElement.clientHeight does NOT equal
613
      // document.documentElement.offsetHeight, then use document.body.
614
      var sh = docEl.scrollHeight;
615
      var oh = docEl.offsetHeight;
616
      if (docEl.clientHeight != oh) {
617
        sh = body.scrollHeight;
618
        oh = body.offsetHeight;
619
      }
620

621
      // Detect whether the inner content height is bigger or smaller
622
      // than the bounding box (viewport).  If bigger, take the larger
623
      // value.  If smaller, take the smaller value.
624
      if (sh > vh) {
625
        // Content is larger
626
        height = sh > oh ? sh : oh;
627
      } else {
628
        // Content is smaller
629
        height = sh < oh ? sh : oh;
630
      }
631
    }
632
  }
633

634
  return height;
635
};
636

637

638
/**
639
 * Gets the page scroll distance as a coordinate object.
640
 *
641
 * @param {Window=} opt_window Optional window element to test.
642
 * @return {!goog.math.Coordinate} Object with values 'x' and 'y'.
643
 * @deprecated Use {@link goog.dom.getDocumentScroll} instead.
644
 */
645
goog.dom.getPageScroll = function(opt_window) {
646
  var win = opt_window || goog.global || window;
647
  return goog.dom.getDomHelper(win.document).getDocumentScroll();
648
};
649

650

651
/**
652
 * Gets the document scroll distance as a coordinate object.
653
 *
654
 * @return {!goog.math.Coordinate} Object with values 'x' and 'y'.
655
 */
656
goog.dom.getDocumentScroll = function() {
657
  return goog.dom.getDocumentScroll_(document);
658
};
659

660

661
/**
662
 * Helper for {@code getDocumentScroll}.
663
 *
664
 * @param {!Document} doc The document to get the scroll for.
665
 * @return {!goog.math.Coordinate} Object with values 'x' and 'y'.
666
 * @private
667
 */
668
goog.dom.getDocumentScroll_ = function(doc) {
669
  var el = goog.dom.getDocumentScrollElement_(doc);
670
  var win = goog.dom.getWindow_(doc);
671
  if (goog.userAgent.IE && goog.userAgent.isVersionOrHigher('10') &&
672
      win.pageYOffset != el.scrollTop) {
673
    // The keyboard on IE10 touch devices shifts the page using the pageYOffset
674
    // without modifying scrollTop. For this case, we want the body scroll
675
    // offsets.
676
    return new goog.math.Coordinate(el.scrollLeft, el.scrollTop);
677
  }
678
  return new goog.math.Coordinate(
679
      win.pageXOffset || el.scrollLeft, win.pageYOffset || el.scrollTop);
680
};
681

682

683
/**
684
 * Gets the document scroll element.
685
 * @return {!Element} Scrolling element.
686
 */
687
goog.dom.getDocumentScrollElement = function() {
688
  return goog.dom.getDocumentScrollElement_(document);
689
};
690

691

692
/**
693
 * Helper for {@code getDocumentScrollElement}.
694
 * @param {!Document} doc The document to get the scroll element for.
695
 * @return {!Element} Scrolling element.
696
 * @private
697
 */
698
goog.dom.getDocumentScrollElement_ = function(doc) {
699
  // Old WebKit needs body.scrollLeft in both quirks mode and strict mode. We
700
  // also default to the documentElement if the document does not have a body
701
  // (e.g. a SVG document).
702
  // Uses http://dev.w3.org/csswg/cssom-view/#dom-document-scrollingelement to
703
  // avoid trying to guess about browser behavior from the UA string.
704
  if (doc.scrollingElement) {
705
    return doc.scrollingElement;
706
  }
707
  if (!goog.userAgent.WEBKIT && goog.dom.isCss1CompatMode_(doc)) {
708
    return doc.documentElement;
709
  }
710
  return doc.body || doc.documentElement;
711
};
712

713

714
/**
715
 * Gets the window object associated with the given document.
716
 *
717
 * @param {Document=} opt_doc  Document object to get window for.
718
 * @return {!Window} The window associated with the given document.
719
 */
720
goog.dom.getWindow = function(opt_doc) {
721
  // TODO(arv): This should not take an argument.
722
  return opt_doc ? goog.dom.getWindow_(opt_doc) : window;
723
};
724

725

726
/**
727
 * Helper for {@code getWindow}.
728
 *
729
 * @param {!Document} doc  Document object to get window for.
730
 * @return {!Window} The window associated with the given document.
731
 * @private
732
 */
733
goog.dom.getWindow_ = function(doc) {
734
  return /** @type {!Window} */ (doc.parentWindow || doc.defaultView);
735
};
736

737

738
/**
739
 * Returns a dom node with a set of attributes.  This function accepts varargs
740
 * for subsequent nodes to be added.  Subsequent nodes will be added to the
741
 * first node as childNodes.
742
 *
743
 * So:
744
 * <code>createDom(goog.dom.TagName.DIV, null, createDom(goog.dom.TagName.P), createDom(goog.dom.TagName.P));</code>
745
 * would return a div with two child paragraphs
746
 *
747
 * For passing properties, please see {@link goog.dom.setProperties} for more
748
 * information.
749
 *
750
 * @param {string|!goog.dom.TagName<T>} tagName Tag to create.
751
 * @param {(Object|Array<string>|string)=} opt_properties If object, then a map
752
 *     of name-value pairs for properties. If a string, then this is the
753
 *     className of the new element. If an array, the elements will be joined
754
 *     together as the className of the new element.
755
 * @param {...(Object|string|Array|NodeList)} var_args Further DOM nodes or
756
 *     strings for text nodes. If one of the var_args is an array or NodeList,
757
 *     its elements will be added as childNodes instead.
758
 * @return {R} Reference to a DOM node. The return type is {!Element} if tagName
759
 *     is a string or a more specific type if it is a member of
760
 *     goog.dom.TagName (e.g. {!HTMLAnchorElement} for goog.dom.TagName.A).
761
 * @template T
762
 * @template R := cond(isUnknown(T), 'Element', T) =:
763
 */
764
goog.dom.createDom = function(tagName, opt_properties, var_args) {
765
  return goog.dom.createDom_(document, arguments);
766
};
767

768

769
/**
770
 * Helper for {@code createDom}.
771
 * @param {!Document} doc The document to create the DOM in.
772
 * @param {!Arguments} args Argument object passed from the callers. See
773
 *     {@code goog.dom.createDom} for details.
774
 * @return {!Element} Reference to a DOM node.
775
 * @private
776
 */
777
goog.dom.createDom_ = function(doc, args) {
778
  var tagName = String(args[0]);
779
  var attributes = args[1];
780

781
  // Internet Explorer is dumb:
782
  // name: https://msdn.microsoft.com/en-us/library/ms534184(v=vs.85).aspx
783
  // type: https://msdn.microsoft.com/en-us/library/ms534700(v=vs.85).aspx
784
  // Also does not allow setting of 'type' attribute on 'input' or 'button'.
785
  if (!goog.dom.BrowserFeature.CAN_ADD_NAME_OR_TYPE_ATTRIBUTES && attributes &&
786
      (attributes.name || attributes.type)) {
787
    var tagNameArr = ['<', tagName];
788
    if (attributes.name) {
789
      tagNameArr.push(' name="', goog.string.htmlEscape(attributes.name), '"');
790
    }
791
    if (attributes.type) {
792
      tagNameArr.push(' type="', goog.string.htmlEscape(attributes.type), '"');
793

794
      // Clone attributes map to remove 'type' without mutating the input.
795
      var clone = {};
796
      goog.object.extend(clone, attributes);
797

798
      // JSCompiler can't see how goog.object.extend added this property,
799
      // because it was essentially added by reflection.
800
      // So it needs to be quoted.
801
      delete clone['type'];
802

803
      attributes = clone;
804
    }
805
    tagNameArr.push('>');
806
    tagName = tagNameArr.join('');
807
  }
808

809
  var element = doc.createElement(tagName);
810

811
  if (attributes) {
812
    if (goog.isString(attributes)) {
813
      element.className = attributes;
814
    } else if (goog.isArray(attributes)) {
815
      element.className = attributes.join(' ');
816
    } else {
817
      goog.dom.setProperties(element, attributes);
818
    }
819
  }
820

821
  if (args.length > 2) {
822
    goog.dom.append_(doc, element, args, 2);
823
  }
824

825
  return element;
826
};
827

828

829
/**
830
 * Appends a node with text or other nodes.
831
 * @param {!Document} doc The document to create new nodes in.
832
 * @param {!Node} parent The node to append nodes to.
833
 * @param {!Arguments} args The values to add. See {@code goog.dom.append}.
834
 * @param {number} startIndex The index of the array to start from.
835
 * @private
836
 */
837
goog.dom.append_ = function(doc, parent, args, startIndex) {
838
  function childHandler(child) {
839
    // TODO(user): More coercion, ala MochiKit?
840
    if (child) {
841
      parent.appendChild(
842
          goog.isString(child) ? doc.createTextNode(child) : child);
843
    }
844
  }
845

846
  for (var i = startIndex; i < args.length; i++) {
847
    var arg = args[i];
848
    // TODO(attila): Fix isArrayLike to return false for a text node.
849
    if (goog.isArrayLike(arg) && !goog.dom.isNodeLike(arg)) {
850
      // If the argument is a node list, not a real array, use a clone,
851
      // because forEach can't be used to mutate a NodeList.
852
      goog.array.forEach(
853
          goog.dom.isNodeList(arg) ? goog.array.toArray(arg) : arg,
854
          childHandler);
855
    } else {
856
      childHandler(arg);
857
    }
858
  }
859
};
860

861

862
/**
863
 * Alias for {@code createDom}.
864
 * @param {string|!goog.dom.TagName<T>} tagName Tag to create.
865
 * @param {(string|Object)=} opt_properties If object, then a map of name-value
866
 *     pairs for properties. If a string, then this is the className of the new
867
 *     element.
868
 * @param {...(Object|string|Array|NodeList)} var_args Further DOM nodes or
869
 *     strings for text nodes. If one of the var_args is an array, its
870
 *     children will be added as childNodes instead.
871
 * @return {R} Reference to a DOM node. The return type is {!Element} if tagName
872
 *     is a string or a more specific type if it is a member of
873
 *     goog.dom.TagName (e.g. {!HTMLAnchorElement} for goog.dom.TagName.A).
874
 * @template T
875
 * @template R := cond(isUnknown(T), 'Element', T) =:
876
 * @deprecated Use {@link goog.dom.createDom} instead.
877
 */
878
goog.dom.$dom = goog.dom.createDom;
879

880

881
/**
882
 * Creates a new element.
883
 * @param {string|!goog.dom.TagName<T>} name Tag to create.
884
 * @return {R} The new element. The return type is {!Element} if name is
885
 *     a string or a more specific type if it is a member of goog.dom.TagName
886
 *     (e.g. {!HTMLAnchorElement} for goog.dom.TagName.A).
887
 * @template T
888
 * @template R := cond(isUnknown(T), 'Element', T) =:
889
 */
890
goog.dom.createElement = function(name) {
891
  return goog.dom.createElement_(document, name);
892
};
893

894

895
/**
896
 * Creates a new element.
897
 * @param {!Document} doc The document to create the element in.
898
 * @param {string|!goog.dom.TagName<T>} name Tag to create.
899
 * @return {R} The new element. The return type is {!Element} if name is
900
 *     a string or a more specific type if it is a member of goog.dom.TagName
901
 *     (e.g. {!HTMLAnchorElement} for goog.dom.TagName.A).
902
 * @template T
903
 * @template R := cond(isUnknown(T), 'Element', T) =:
904
 * @private
905
 */
906
goog.dom.createElement_ = function(doc, name) {
907
  return doc.createElement(String(name));
908
};
909

910

911
/**
912
 * Creates a new text node.
913
 * @param {number|string} content Content.
914
 * @return {!Text} The new text node.
915
 */
916
goog.dom.createTextNode = function(content) {
917
  return document.createTextNode(String(content));
918
};
919

920

921
/**
922
 * Create a table.
923
 * @param {number} rows The number of rows in the table.  Must be >= 1.
924
 * @param {number} columns The number of columns in the table.  Must be >= 1.
925
 * @param {boolean=} opt_fillWithNbsp If true, fills table entries with
926
 *     {@code goog.string.Unicode.NBSP} characters.
927
 * @return {!Element} The created table.
928
 */
929
goog.dom.createTable = function(rows, columns, opt_fillWithNbsp) {
930
  // TODO(mlourenco): Return HTMLTableElement, also in prototype function.
931
  // Callers need to be updated to e.g. not assign numbers to table.cellSpacing.
932
  return goog.dom.createTable_(document, rows, columns, !!opt_fillWithNbsp);
933
};
934

935

936
/**
937
 * Create a table.
938
 * @param {!Document} doc Document object to use to create the table.
939
 * @param {number} rows The number of rows in the table.  Must be >= 1.
940
 * @param {number} columns The number of columns in the table.  Must be >= 1.
941
 * @param {boolean} fillWithNbsp If true, fills table entries with
942
 *     {@code goog.string.Unicode.NBSP} characters.
943
 * @return {!HTMLTableElement} The created table.
944
 * @private
945
 */
946
goog.dom.createTable_ = function(doc, rows, columns, fillWithNbsp) {
947
  var table = goog.dom.createElement_(doc, goog.dom.TagName.TABLE);
948
  var tbody =
949
      table.appendChild(goog.dom.createElement_(doc, goog.dom.TagName.TBODY));
950
  for (var i = 0; i < rows; i++) {
951
    var tr = goog.dom.createElement_(doc, goog.dom.TagName.TR);
952
    for (var j = 0; j < columns; j++) {
953
      var td = goog.dom.createElement_(doc, goog.dom.TagName.TD);
954
      // IE <= 9 will create a text node if we set text content to the empty
955
      // string, so we avoid doing it unless necessary. This ensures that the
956
      // same DOM tree is returned on all browsers.
957
      if (fillWithNbsp) {
958
        goog.dom.setTextContent(td, goog.string.Unicode.NBSP);
959
      }
960
      tr.appendChild(td);
961
    }
962
    tbody.appendChild(tr);
963
  }
964
  return table;
965
};
966

967

968

969
/**
970
 * Creates a new Node from constant strings of HTML markup.
971
 * @param {...!goog.string.Const} var_args The HTML strings to concatenate then
972
 *     convert into a node.
973
 * @return {!Node}
974
 */
975
goog.dom.constHtmlToNode = function(var_args) {
976
  var stringArray = goog.array.map(arguments, goog.string.Const.unwrap);
977
  var safeHtml =
978
      goog.html.uncheckedconversions
979
          .safeHtmlFromStringKnownToSatisfyTypeContract(
980
              goog.string.Const.from(
981
                  'Constant HTML string, that gets turned into a ' +
982
                  'Node later, so it will be automatically balanced.'),
983
              stringArray.join(''));
984
  return goog.dom.safeHtmlToNode(safeHtml);
985
};
986

987

988
/**
989
 * Converts HTML markup into a node. This is a safe version of
990
 * {@code goog.dom.htmlToDocumentFragment} which is now deleted.
991
 * @param {!goog.html.SafeHtml} html The HTML markup to convert.
992
 * @return {!Node} The resulting node.
993
 */
994
goog.dom.safeHtmlToNode = function(html) {
995
  return goog.dom.safeHtmlToNode_(document, html);
996
};
997

998

999
/**
1000
 * Helper for {@code safeHtmlToNode}.
1001
 * @param {!Document} doc The document.
1002
 * @param {!goog.html.SafeHtml} html The HTML markup to convert.
1003
 * @return {!Node} The resulting node.
1004
 * @private
1005
 */
1006
goog.dom.safeHtmlToNode_ = function(doc, html) {
1007
  var tempDiv = goog.dom.createElement_(doc, goog.dom.TagName.DIV);
1008
  if (goog.dom.BrowserFeature.INNER_HTML_NEEDS_SCOPED_ELEMENT) {
1009
    goog.dom.safe.setInnerHtml(
1010
        tempDiv, goog.html.SafeHtml.concat(goog.html.SafeHtml.BR, html));
1011
    tempDiv.removeChild(tempDiv.firstChild);
1012
  } else {
1013
    goog.dom.safe.setInnerHtml(tempDiv, html);
1014
  }
1015
  return goog.dom.childrenToNode_(doc, tempDiv);
1016
};
1017

1018

1019
/**
1020
 * Helper for {@code safeHtmlToNode_}.
1021
 * @param {!Document} doc The document.
1022
 * @param {!Node} tempDiv The input node.
1023
 * @return {!Node} The resulting node.
1024
 * @private
1025
 */
1026
goog.dom.childrenToNode_ = function(doc, tempDiv) {
1027
  if (tempDiv.childNodes.length == 1) {
1028
    return tempDiv.removeChild(tempDiv.firstChild);
1029
  } else {
1030
    var fragment = doc.createDocumentFragment();
1031
    while (tempDiv.firstChild) {
1032
      fragment.appendChild(tempDiv.firstChild);
1033
    }
1034
    return fragment;
1035
  }
1036
};
1037

1038

1039
/**
1040
 * Returns true if the browser is in "CSS1-compatible" (standards-compliant)
1041
 * mode, false otherwise.
1042
 * @return {boolean} True if in CSS1-compatible mode.
1043
 */
1044
goog.dom.isCss1CompatMode = function() {
1045
  return goog.dom.isCss1CompatMode_(document);
1046
};
1047

1048

1049
/**
1050
 * Returns true if the browser is in "CSS1-compatible" (standards-compliant)
1051
 * mode, false otherwise.
1052
 * @param {!Document} doc The document to check.
1053
 * @return {boolean} True if in CSS1-compatible mode.
1054
 * @private
1055
 */
1056
goog.dom.isCss1CompatMode_ = function(doc) {
1057
  if (goog.dom.COMPAT_MODE_KNOWN_) {
1058
    return goog.dom.ASSUME_STANDARDS_MODE;
1059
  }
1060

1061
  return doc.compatMode == 'CSS1Compat';
1062
};
1063

1064

1065
/**
1066
 * Determines if the given node can contain children, intended to be used for
1067
 * HTML generation.
1068
 *
1069
 * IE natively supports node.canHaveChildren but has inconsistent behavior.
1070
 * Prior to IE8 the base tag allows children and in IE9 all nodes return true
1071
 * for canHaveChildren.
1072
 *
1073
 * In practice all non-IE browsers allow you to add children to any node, but
1074
 * the behavior is inconsistent:
1075
 *
1076
 * <pre>
1077
 *   var a = goog.dom.createElement(goog.dom.TagName.BR);
1078
 *   a.appendChild(document.createTextNode('foo'));
1079
 *   a.appendChild(document.createTextNode('bar'));
1080
 *   console.log(a.childNodes.length);  // 2
1081
 *   console.log(a.innerHTML);  // Chrome: "", IE9: "foobar", FF3.5: "foobar"
1082
 * </pre>
1083
 *
1084
 * For more information, see:
1085
 * http://dev.w3.org/html5/markup/syntax.html#syntax-elements
1086
 *
1087
 * TODO(user): Rename shouldAllowChildren() ?
1088
 *
1089
 * @param {Node} node The node to check.
1090
 * @return {boolean} Whether the node can contain children.
1091
 */
1092
goog.dom.canHaveChildren = function(node) {
1093
  if (node.nodeType != goog.dom.NodeType.ELEMENT) {
1094
    return false;
1095
  }
1096
  switch (/** @type {!Element} */ (node).tagName) {
1097
    case String(goog.dom.TagName.APPLET):
1098
    case String(goog.dom.TagName.AREA):
1099
    case String(goog.dom.TagName.BASE):
1100
    case String(goog.dom.TagName.BR):
1101
    case String(goog.dom.TagName.COL):
1102
    case String(goog.dom.TagName.COMMAND):
1103
    case String(goog.dom.TagName.EMBED):
1104
    case String(goog.dom.TagName.FRAME):
1105
    case String(goog.dom.TagName.HR):
1106
    case String(goog.dom.TagName.IMG):
1107
    case String(goog.dom.TagName.INPUT):
1108
    case String(goog.dom.TagName.IFRAME):
1109
    case String(goog.dom.TagName.ISINDEX):
1110
    case String(goog.dom.TagName.KEYGEN):
1111
    case String(goog.dom.TagName.LINK):
1112
    case String(goog.dom.TagName.NOFRAMES):
1113
    case String(goog.dom.TagName.NOSCRIPT):
1114
    case String(goog.dom.TagName.META):
1115
    case String(goog.dom.TagName.OBJECT):
1116
    case String(goog.dom.TagName.PARAM):
1117
    case String(goog.dom.TagName.SCRIPT):
1118
    case String(goog.dom.TagName.SOURCE):
1119
    case String(goog.dom.TagName.STYLE):
1120
    case String(goog.dom.TagName.TRACK):
1121
    case String(goog.dom.TagName.WBR):
1122
      return false;
1123
  }
1124
  return true;
1125
};
1126

1127

1128
/**
1129
 * Appends a child to a node.
1130
 * @param {Node} parent Parent.
1131
 * @param {Node} child Child.
1132
 */
1133
goog.dom.appendChild = function(parent, child) {
1134
  parent.appendChild(child);
1135
};
1136

1137

1138
/**
1139
 * Appends a node with text or other nodes.
1140
 * @param {!Node} parent The node to append nodes to.
1141
 * @param {...goog.dom.Appendable} var_args The things to append to the node.
1142
 *     If this is a Node it is appended as is.
1143
 *     If this is a string then a text node is appended.
1144
 *     If this is an array like object then fields 0 to length - 1 are appended.
1145
 */
1146
goog.dom.append = function(parent, var_args) {
1147
  goog.dom.append_(goog.dom.getOwnerDocument(parent), parent, arguments, 1);
1148
};
1149

1150

1151
/**
1152
 * Removes all the child nodes on a DOM node.
1153
 * @param {Node} node Node to remove children from.
1154
 */
1155
goog.dom.removeChildren = function(node) {
1156
  // Note: Iterations over live collections can be slow, this is the fastest
1157
  // we could find. The double parenthesis are used to prevent JsCompiler and
1158
  // strict warnings.
1159
  var child;
1160
  while ((child = node.firstChild)) {
1161
    node.removeChild(child);
1162
  }
1163
};
1164

1165

1166
/**
1167
 * Inserts a new node before an existing reference node (i.e. as the previous
1168
 * sibling). If the reference node has no parent, then does nothing.
1169
 * @param {Node} newNode Node to insert.
1170
 * @param {Node} refNode Reference node to insert before.
1171
 */
1172
goog.dom.insertSiblingBefore = function(newNode, refNode) {
1173
  if (refNode.parentNode) {
1174
    refNode.parentNode.insertBefore(newNode, refNode);
1175
  }
1176
};
1177

1178

1179
/**
1180
 * Inserts a new node after an existing reference node (i.e. as the next
1181
 * sibling). If the reference node has no parent, then does nothing.
1182
 * @param {Node} newNode Node to insert.
1183
 * @param {Node} refNode Reference node to insert after.
1184
 */
1185
goog.dom.insertSiblingAfter = function(newNode, refNode) {
1186
  if (refNode.parentNode) {
1187
    refNode.parentNode.insertBefore(newNode, refNode.nextSibling);
1188
  }
1189
};
1190

1191

1192
/**
1193
 * Insert a child at a given index. If index is larger than the number of child
1194
 * nodes that the parent currently has, the node is inserted as the last child
1195
 * node.
1196
 * @param {Element} parent The element into which to insert the child.
1197
 * @param {Node} child The element to insert.
1198
 * @param {number} index The index at which to insert the new child node. Must
1199
 *     not be negative.
1200
 */
1201
goog.dom.insertChildAt = function(parent, child, index) {
1202
  // Note that if the second argument is null, insertBefore
1203
  // will append the child at the end of the list of children.
1204
  parent.insertBefore(child, parent.childNodes[index] || null);
1205
};
1206

1207

1208
/**
1209
 * Removes a node from its parent.
1210
 * @param {Node} node The node to remove.
1211
 * @return {Node} The node removed if removed; else, null.
1212
 */
1213
goog.dom.removeNode = function(node) {
1214
  return node && node.parentNode ? node.parentNode.removeChild(node) : null;
1215
};
1216

1217

1218
/**
1219
 * Replaces a node in the DOM tree. Will do nothing if {@code oldNode} has no
1220
 * parent.
1221
 * @param {Node} newNode Node to insert.
1222
 * @param {Node} oldNode Node to replace.
1223
 */
1224
goog.dom.replaceNode = function(newNode, oldNode) {
1225
  var parent = oldNode.parentNode;
1226
  if (parent) {
1227
    parent.replaceChild(newNode, oldNode);
1228
  }
1229
};
1230

1231

1232
/**
1233
 * Flattens an element. That is, removes it and replace it with its children.
1234
 * Does nothing if the element is not in the document.
1235
 * @param {Element} element The element to flatten.
1236
 * @return {Element|undefined} The original element, detached from the document
1237
 *     tree, sans children; or undefined, if the element was not in the document
1238
 *     to begin with.
1239
 */
1240
goog.dom.flattenElement = function(element) {
1241
  var child, parent = element.parentNode;
1242
  if (parent && parent.nodeType != goog.dom.NodeType.DOCUMENT_FRAGMENT) {
1243
    // Use IE DOM method (supported by Opera too) if available
1244
    if (element.removeNode) {
1245
      return /** @type {Element} */ (element.removeNode(false));
1246
    } else {
1247
      // Move all children of the original node up one level.
1248
      while ((child = element.firstChild)) {
1249
        parent.insertBefore(child, element);
1250
      }
1251

1252
      // Detach the original element.
1253
      return /** @type {Element} */ (goog.dom.removeNode(element));
1254
    }
1255
  }
1256
};
1257

1258

1259
/**
1260
 * Returns an array containing just the element children of the given element.
1261
 * @param {Element} element The element whose element children we want.
1262
 * @return {!(Array<!Element>|NodeList<!Element>)} An array or array-like list
1263
 *     of just the element children of the given element.
1264
 */
1265
goog.dom.getChildren = function(element) {
1266
  // We check if the children attribute is supported for child elements
1267
  // since IE8 misuses the attribute by also including comments.
1268
  if (goog.dom.BrowserFeature.CAN_USE_CHILDREN_ATTRIBUTE &&
1269
      element.children != undefined) {
1270
    return element.children;
1271
  }
1272
  // Fall back to manually filtering the element's child nodes.
1273
  return goog.array.filter(element.childNodes, function(node) {
1274
    return node.nodeType == goog.dom.NodeType.ELEMENT;
1275
  });
1276
};
1277

1278

1279
/**
1280
 * Returns the first child node that is an element.
1281
 * @param {Node} node The node to get the first child element of.
1282
 * @return {Element} The first child node of {@code node} that is an element.
1283
 */
1284
goog.dom.getFirstElementChild = function(node) {
1285
  if (goog.isDef(node.firstElementChild)) {
1286
    return /** @type {!Element} */ (node).firstElementChild;
1287
  }
1288
  return goog.dom.getNextElementNode_(node.firstChild, true);
1289
};
1290

1291

1292
/**
1293
 * Returns the last child node that is an element.
1294
 * @param {Node} node The node to get the last child element of.
1295
 * @return {Element} The last child node of {@code node} that is an element.
1296
 */
1297
goog.dom.getLastElementChild = function(node) {
1298
  if (goog.isDef(node.lastElementChild)) {
1299
    return /** @type {!Element} */ (node).lastElementChild;
1300
  }
1301
  return goog.dom.getNextElementNode_(node.lastChild, false);
1302
};
1303

1304

1305
/**
1306
 * Returns the first next sibling that is an element.
1307
 * @param {Node} node The node to get the next sibling element of.
1308
 * @return {Element} The next sibling of {@code node} that is an element.
1309
 */
1310
goog.dom.getNextElementSibling = function(node) {
1311
  if (goog.isDef(node.nextElementSibling)) {
1312
    return /** @type {!Element} */ (node).nextElementSibling;
1313
  }
1314
  return goog.dom.getNextElementNode_(node.nextSibling, true);
1315
};
1316

1317

1318
/**
1319
 * Returns the first previous sibling that is an element.
1320
 * @param {Node} node The node to get the previous sibling element of.
1321
 * @return {Element} The first previous sibling of {@code node} that is
1322
 *     an element.
1323
 */
1324
goog.dom.getPreviousElementSibling = function(node) {
1325
  if (goog.isDef(node.previousElementSibling)) {
1326
    return /** @type {!Element} */ (node).previousElementSibling;
1327
  }
1328
  return goog.dom.getNextElementNode_(node.previousSibling, false);
1329
};
1330

1331

1332
/**
1333
 * Returns the first node that is an element in the specified direction,
1334
 * starting with {@code node}.
1335
 * @param {Node} node The node to get the next element from.
1336
 * @param {boolean} forward Whether to look forwards or backwards.
1337
 * @return {Element} The first element.
1338
 * @private
1339
 */
1340
goog.dom.getNextElementNode_ = function(node, forward) {
1341
  while (node && node.nodeType != goog.dom.NodeType.ELEMENT) {
1342
    node = forward ? node.nextSibling : node.previousSibling;
1343
  }
1344

1345
  return /** @type {Element} */ (node);
1346
};
1347

1348

1349
/**
1350
 * Returns the next node in source order from the given node.
1351
 * @param {Node} node The node.
1352
 * @return {Node} The next node in the DOM tree, or null if this was the last
1353
 *     node.
1354
 */
1355
goog.dom.getNextNode = function(node) {
1356
  if (!node) {
1357
    return null;
1358
  }
1359

1360
  if (node.firstChild) {
1361
    return node.firstChild;
1362
  }
1363

1364
  while (node && !node.nextSibling) {
1365
    node = node.parentNode;
1366
  }
1367

1368
  return node ? node.nextSibling : null;
1369
};
1370

1371

1372
/**
1373
 * Returns the previous node in source order from the given node.
1374
 * @param {Node} node The node.
1375
 * @return {Node} The previous node in the DOM tree, or null if this was the
1376
 *     first node.
1377
 */
1378
goog.dom.getPreviousNode = function(node) {
1379
  if (!node) {
1380
    return null;
1381
  }
1382

1383
  if (!node.previousSibling) {
1384
    return node.parentNode;
1385
  }
1386

1387
  node = node.previousSibling;
1388
  while (node && node.lastChild) {
1389
    node = node.lastChild;
1390
  }
1391

1392
  return node;
1393
};
1394

1395

1396
/**
1397
 * Whether the object looks like a DOM node.
1398
 * @param {?} obj The object being tested for node likeness.
1399
 * @return {boolean} Whether the object looks like a DOM node.
1400
 */
1401
goog.dom.isNodeLike = function(obj) {
1402
  return goog.isObject(obj) && obj.nodeType > 0;
1403
};
1404

1405

1406
/**
1407
 * Whether the object looks like an Element.
1408
 * @param {?} obj The object being tested for Element likeness.
1409
 * @return {boolean} Whether the object looks like an Element.
1410
 */
1411
goog.dom.isElement = function(obj) {
1412
  return goog.isObject(obj) && obj.nodeType == goog.dom.NodeType.ELEMENT;
1413
};
1414

1415

1416
/**
1417
 * Returns true if the specified value is a Window object. This includes the
1418
 * global window for HTML pages, and iframe windows.
1419
 * @param {?} obj Variable to test.
1420
 * @return {boolean} Whether the variable is a window.
1421
 */
1422
goog.dom.isWindow = function(obj) {
1423
  return goog.isObject(obj) && obj['window'] == obj;
1424
};
1425

1426

1427
/**
1428
 * Returns an element's parent, if it's an Element.
1429
 * @param {Element} element The DOM element.
1430
 * @return {Element} The parent, or null if not an Element.
1431
 */
1432
goog.dom.getParentElement = function(element) {
1433
  var parent;
1434
  if (goog.dom.BrowserFeature.CAN_USE_PARENT_ELEMENT_PROPERTY) {
1435
    var isIe9 = goog.userAgent.IE && goog.userAgent.isVersionOrHigher('9') &&
1436
        !goog.userAgent.isVersionOrHigher('10');
1437
    // SVG elements in IE9 can't use the parentElement property.
1438
    // goog.global['SVGElement'] is not defined in IE9 quirks mode.
1439
    if (!(isIe9 && goog.global['SVGElement'] &&
1440
          element instanceof goog.global['SVGElement'])) {
1441
      parent = element.parentElement;
1442
      if (parent) {
1443
        return parent;
1444
      }
1445
    }
1446
  }
1447
  parent = element.parentNode;
1448
  return goog.dom.isElement(parent) ? /** @type {!Element} */ (parent) : null;
1449
};
1450

1451

1452
/**
1453
 * Whether a node contains another node.
1454
 * @param {?Node|undefined} parent The node that should contain the other node.
1455
 * @param {?Node|undefined} descendant The node to test presence of.
1456
 * @return {boolean} Whether the parent node contains the descendent node.
1457
 */
1458
goog.dom.contains = function(parent, descendant) {
1459
  if (!parent || !descendant) {
1460
    return false;
1461
  }
1462
  // We use browser specific methods for this if available since it is faster
1463
  // that way.
1464

1465
  // IE DOM
1466
  if (parent.contains && descendant.nodeType == goog.dom.NodeType.ELEMENT) {
1467
    return parent == descendant || parent.contains(descendant);
1468
  }
1469

1470
  // W3C DOM Level 3
1471
  if (typeof parent.compareDocumentPosition != 'undefined') {
1472
    return parent == descendant ||
1473
        Boolean(parent.compareDocumentPosition(descendant) & 16);
1474
  }
1475

1476
  // W3C DOM Level 1
1477
  while (descendant && parent != descendant) {
1478
    descendant = descendant.parentNode;
1479
  }
1480
  return descendant == parent;
1481
};
1482

1483

1484
/**
1485
 * Compares the document order of two nodes, returning 0 if they are the same
1486
 * node, a negative number if node1 is before node2, and a positive number if
1487
 * node2 is before node1.  Note that we compare the order the tags appear in the
1488
 * document so in the tree <b><i>text</i></b> the B node is considered to be
1489
 * before the I node.
1490
 *
1491
 * @param {Node} node1 The first node to compare.
1492
 * @param {Node} node2 The second node to compare.
1493
 * @return {number} 0 if the nodes are the same node, a negative number if node1
1494
 *     is before node2, and a positive number if node2 is before node1.
1495
 */
1496
goog.dom.compareNodeOrder = function(node1, node2) {
1497
  // Fall out quickly for equality.
1498
  if (node1 == node2) {
1499
    return 0;
1500
  }
1501

1502
  // Use compareDocumentPosition where available
1503
  if (node1.compareDocumentPosition) {
1504
    // 4 is the bitmask for FOLLOWS.
1505
    return node1.compareDocumentPosition(node2) & 2 ? 1 : -1;
1506
  }
1507

1508
  // Special case for document nodes on IE 7 and 8.
1509
  if (goog.userAgent.IE && !goog.userAgent.isDocumentModeOrHigher(9)) {
1510
    if (node1.nodeType == goog.dom.NodeType.DOCUMENT) {
1511
      return -1;
1512
    }
1513
    if (node2.nodeType == goog.dom.NodeType.DOCUMENT) {
1514
      return 1;
1515
    }
1516
  }
1517

1518
  // Process in IE using sourceIndex - we check to see if the first node has
1519
  // a source index or if its parent has one.
1520
  if ('sourceIndex' in node1 ||
1521
      (node1.parentNode && 'sourceIndex' in node1.parentNode)) {
1522
    var isElement1 = node1.nodeType == goog.dom.NodeType.ELEMENT;
1523
    var isElement2 = node2.nodeType == goog.dom.NodeType.ELEMENT;
1524

1525
    if (isElement1 && isElement2) {
1526
      return node1.sourceIndex - node2.sourceIndex;
1527
    } else {
1528
      var parent1 = node1.parentNode;
1529
      var parent2 = node2.parentNode;
1530

1531
      if (parent1 == parent2) {
1532
        return goog.dom.compareSiblingOrder_(node1, node2);
1533
      }
1534

1535
      if (!isElement1 && goog.dom.contains(parent1, node2)) {
1536
        return -1 * goog.dom.compareParentsDescendantNodeIe_(node1, node2);
1537
      }
1538

1539

1540
      if (!isElement2 && goog.dom.contains(parent2, node1)) {
1541
        return goog.dom.compareParentsDescendantNodeIe_(node2, node1);
1542
      }
1543

1544
      return (isElement1 ? node1.sourceIndex : parent1.sourceIndex) -
1545
          (isElement2 ? node2.sourceIndex : parent2.sourceIndex);
1546
    }
1547
  }
1548

1549
  // For Safari, we compare ranges.
1550
  var doc = goog.dom.getOwnerDocument(node1);
1551

1552
  var range1, range2;
1553
  range1 = doc.createRange();
1554
  range1.selectNode(node1);
1555
  range1.collapse(true);
1556

1557
  range2 = doc.createRange();
1558
  range2.selectNode(node2);
1559
  range2.collapse(true);
1560

1561
  return range1.compareBoundaryPoints(
1562
      goog.global['Range'].START_TO_END, range2);
1563
};
1564

1565

1566
/**
1567
 * Utility function to compare the position of two nodes, when
1568
 * {@code textNode}'s parent is an ancestor of {@code node}.  If this entry
1569
 * condition is not met, this function will attempt to reference a null object.
1570
 * @param {!Node} textNode The textNode to compare.
1571
 * @param {Node} node The node to compare.
1572
 * @return {number} -1 if node is before textNode, +1 otherwise.
1573
 * @private
1574
 */
1575
goog.dom.compareParentsDescendantNodeIe_ = function(textNode, node) {
1576
  var parent = textNode.parentNode;
1577
  if (parent == node) {
1578
    // If textNode is a child of node, then node comes first.
1579
    return -1;
1580
  }
1581
  var sibling = node;
1582
  while (sibling.parentNode != parent) {
1583
    sibling = sibling.parentNode;
1584
  }
1585
  return goog.dom.compareSiblingOrder_(sibling, textNode);
1586
};
1587

1588

1589
/**
1590
 * Utility function to compare the position of two nodes known to be non-equal
1591
 * siblings.
1592
 * @param {Node} node1 The first node to compare.
1593
 * @param {!Node} node2 The second node to compare.
1594
 * @return {number} -1 if node1 is before node2, +1 otherwise.
1595
 * @private
1596
 */
1597
goog.dom.compareSiblingOrder_ = function(node1, node2) {
1598
  var s = node2;
1599
  while ((s = s.previousSibling)) {
1600
    if (s == node1) {
1601
      // We just found node1 before node2.
1602
      return -1;
1603
    }
1604
  }
1605

1606
  // Since we didn't find it, node1 must be after node2.
1607
  return 1;
1608
};
1609

1610

1611
/**
1612
 * Find the deepest common ancestor of the given nodes.
1613
 * @param {...Node} var_args The nodes to find a common ancestor of.
1614
 * @return {Node} The common ancestor of the nodes, or null if there is none.
1615
 *     null will only be returned if two or more of the nodes are from different
1616
 *     documents.
1617
 */
1618
goog.dom.findCommonAncestor = function(var_args) {
1619
  var i, count = arguments.length;
1620
  if (!count) {
1621
    return null;
1622
  } else if (count == 1) {
1623
    return arguments[0];
1624
  }
1625

1626
  var paths = [];
1627
  var minLength = Infinity;
1628
  for (i = 0; i < count; i++) {
1629
    // Compute the list of ancestors.
1630
    var ancestors = [];
1631
    var node = arguments[i];
1632
    while (node) {
1633
      ancestors.unshift(node);
1634
      node = node.parentNode;
1635
    }
1636

1637
    // Save the list for comparison.
1638
    paths.push(ancestors);
1639
    minLength = Math.min(minLength, ancestors.length);
1640
  }
1641
  var output = null;
1642
  for (i = 0; i < minLength; i++) {
1643
    var first = paths[0][i];
1644
    for (var j = 1; j < count; j++) {
1645
      if (first != paths[j][i]) {
1646
        return output;
1647
      }
1648
    }
1649
    output = first;
1650
  }
1651
  return output;
1652
};
1653

1654

1655
/**
1656
 * Returns the owner document for a node.
1657
 * @param {Node|Window} node The node to get the document for.
1658
 * @return {!Document} The document owning the node.
1659
 */
1660
goog.dom.getOwnerDocument = function(node) {
1661
  // TODO(nnaze): Update param signature to be non-nullable.
1662
  goog.asserts.assert(node, 'Node cannot be null or undefined.');
1663
  return /** @type {!Document} */ (
1664
      node.nodeType == goog.dom.NodeType.DOCUMENT ? node : node.ownerDocument ||
1665
              node.document);
1666
};
1667

1668

1669
/**
1670
 * Cross-browser function for getting the document element of a frame or iframe.
1671
 * @param {Element} frame Frame element.
1672
 * @return {!Document} The frame content document.
1673
 */
1674
goog.dom.getFrameContentDocument = function(frame) {
1675
  return frame.contentDocument ||
1676
      /** @type {!HTMLFrameElement} */ (frame).contentWindow.document;
1677
};
1678

1679

1680
/**
1681
 * Cross-browser function for getting the window of a frame or iframe.
1682
 * @param {Element} frame Frame element.
1683
 * @return {Window} The window associated with the given frame, or null if none
1684
 *     exists.
1685
 */
1686
goog.dom.getFrameContentWindow = function(frame) {
1687
  try {
1688
    return frame.contentWindow ||
1689
        (frame.contentDocument ? goog.dom.getWindow(frame.contentDocument) :
1690
                                 null);
1691
  } catch (e) {
1692
    // NOTE(user): In IE8, checking the contentWindow or contentDocument
1693
    // properties will throw a "Unspecified Error" exception if the iframe is
1694
    // not inserted in the DOM. If we get this we can be sure that no window
1695
    // exists, so return null.
1696
  }
1697
  return null;
1698
};
1699

1700

1701
/**
1702
 * Sets the text content of a node, with cross-browser support.
1703
 * @param {Node} node The node to change the text content of.
1704
 * @param {string|number} text The value that should replace the node's content.
1705
 */
1706
goog.dom.setTextContent = function(node, text) {
1707
  goog.asserts.assert(
1708
      node != null,
1709
      'goog.dom.setTextContent expects a non-null value for node');
1710

1711
  if ('textContent' in node) {
1712
    node.textContent = text;
1713
  } else if (node.nodeType == goog.dom.NodeType.TEXT) {
1714
    node.data = text;
1715
  } else if (
1716
      node.firstChild && node.firstChild.nodeType == goog.dom.NodeType.TEXT) {
1717
    // If the first child is a text node we just change its data and remove the
1718
    // rest of the children.
1719
    while (node.lastChild != node.firstChild) {
1720
      node.removeChild(node.lastChild);
1721
    }
1722
    node.firstChild.data = text;
1723
  } else {
1724
    goog.dom.removeChildren(node);
1725
    var doc = goog.dom.getOwnerDocument(node);
1726
    node.appendChild(doc.createTextNode(String(text)));
1727
  }
1728
};
1729

1730

1731
/**
1732
 * Gets the outerHTML of a node, which islike innerHTML, except that it
1733
 * actually contains the HTML of the node itself.
1734
 * @param {Element} element The element to get the HTML of.
1735
 * @return {string} The outerHTML of the given element.
1736
 */
1737
goog.dom.getOuterHtml = function(element) {
1738
  goog.asserts.assert(
1739
      element !== null,
1740
      'goog.dom.getOuterHtml expects a non-null value for element');
1741
  // IE, Opera and WebKit all have outerHTML.
1742
  if ('outerHTML' in element) {
1743
    return element.outerHTML;
1744
  } else {
1745
    var doc = goog.dom.getOwnerDocument(element);
1746
    var div = goog.dom.createElement_(doc, goog.dom.TagName.DIV);
1747
    div.appendChild(element.cloneNode(true));
1748
    return div.innerHTML;
1749
  }
1750
};
1751

1752

1753
/**
1754
 * Finds the first descendant node that matches the filter function, using
1755
 * a depth first search. This function offers the most general purpose way
1756
 * of finding a matching element. You may also wish to consider
1757
 * {@code goog.dom.query} which can express many matching criteria using
1758
 * CSS selector expressions. These expressions often result in a more
1759
 * compact representation of the desired result.
1760
 * @see goog.dom.query
1761
 *
1762
 * @param {Node} root The root of the tree to search.
1763
 * @param {function(Node) : boolean} p The filter function.
1764
 * @return {Node|undefined} The found node or undefined if none is found.
1765
 */
1766
goog.dom.findNode = function(root, p) {
1767
  var rv = [];
1768
  var found = goog.dom.findNodes_(root, p, rv, true);
1769
  return found ? rv[0] : undefined;
1770
};
1771

1772

1773
/**
1774
 * Finds all the descendant nodes that match the filter function, using a
1775
 * a depth first search. This function offers the most general-purpose way
1776
 * of finding a set of matching elements. You may also wish to consider
1777
 * {@code goog.dom.query} which can express many matching criteria using
1778
 * CSS selector expressions. These expressions often result in a more
1779
 * compact representation of the desired result.
1780

1781
 * @param {Node} root The root of the tree to search.
1782
 * @param {function(Node) : boolean} p The filter function.
1783
 * @return {!Array<!Node>} The found nodes or an empty array if none are found.
1784
 */
1785
goog.dom.findNodes = function(root, p) {
1786
  var rv = [];
1787
  goog.dom.findNodes_(root, p, rv, false);
1788
  return rv;
1789
};
1790

1791

1792
/**
1793
 * Finds the first or all the descendant nodes that match the filter function,
1794
 * using a depth first search.
1795
 * @param {Node} root The root of the tree to search.
1796
 * @param {function(Node) : boolean} p The filter function.
1797
 * @param {!Array<!Node>} rv The found nodes are added to this array.
1798
 * @param {boolean} findOne If true we exit after the first found node.
1799
 * @return {boolean} Whether the search is complete or not. True in case findOne
1800
 *     is true and the node is found. False otherwise.
1801
 * @private
1802
 */
1803
goog.dom.findNodes_ = function(root, p, rv, findOne) {
1804
  if (root != null) {
1805
    var child = root.firstChild;
1806
    while (child) {
1807
      if (p(child)) {
1808
        rv.push(child);
1809
        if (findOne) {
1810
          return true;
1811
        }
1812
      }
1813
      if (goog.dom.findNodes_(child, p, rv, findOne)) {
1814
        return true;
1815
      }
1816
      child = child.nextSibling;
1817
    }
1818
  }
1819
  return false;
1820
};
1821

1822

1823
/**
1824
 * Map of tags whose content to ignore when calculating text length.
1825
 * @private {!Object<string, number>}
1826
 * @const
1827
 */
1828
goog.dom.TAGS_TO_IGNORE_ = {
1829
  'SCRIPT': 1,
1830
  'STYLE': 1,
1831
  'HEAD': 1,
1832
  'IFRAME': 1,
1833
  'OBJECT': 1
1834
};
1835

1836

1837
/**
1838
 * Map of tags which have predefined values with regard to whitespace.
1839
 * @private {!Object<string, string>}
1840
 * @const
1841
 */
1842
goog.dom.PREDEFINED_TAG_VALUES_ = {
1843
  'IMG': ' ',
1844
  'BR': '\n'
1845
};
1846

1847

1848
/**
1849
 * Returns true if the element has a tab index that allows it to receive
1850
 * keyboard focus (tabIndex >= 0), false otherwise.  Note that some elements
1851
 * natively support keyboard focus, even if they have no tab index.
1852
 * @param {!Element} element Element to check.
1853
 * @return {boolean} Whether the element has a tab index that allows keyboard
1854
 *     focus.
1855
 */
1856
goog.dom.isFocusableTabIndex = function(element) {
1857
  return goog.dom.hasSpecifiedTabIndex_(element) &&
1858
      goog.dom.isTabIndexFocusable_(element);
1859
};
1860

1861

1862
/**
1863
 * Enables or disables keyboard focus support on the element via its tab index.
1864
 * Only elements for which {@link goog.dom.isFocusableTabIndex} returns true
1865
 * (or elements that natively support keyboard focus, like form elements) can
1866
 * receive keyboard focus.  See http://go/tabindex for more info.
1867
 * @param {Element} element Element whose tab index is to be changed.
1868
 * @param {boolean} enable Whether to set or remove a tab index on the element
1869
 *     that supports keyboard focus.
1870
 */
1871
goog.dom.setFocusableTabIndex = function(element, enable) {
1872
  if (enable) {
1873
    element.tabIndex = 0;
1874
  } else {
1875
    // Set tabIndex to -1 first, then remove it. This is a workaround for
1876
    // Safari (confirmed in version 4 on Windows). When removing the attribute
1877
    // without setting it to -1 first, the element remains keyboard focusable
1878
    // despite not having a tabIndex attribute anymore.
1879
    element.tabIndex = -1;
1880
    element.removeAttribute('tabIndex');  // Must be camelCase!
1881
  }
1882
};
1883

1884

1885
/**
1886
 * Returns true if the element can be focused, i.e. it has a tab index that
1887
 * allows it to receive keyboard focus (tabIndex >= 0), or it is an element
1888
 * that natively supports keyboard focus.
1889
 * @param {!Element} element Element to check.
1890
 * @return {boolean} Whether the element allows keyboard focus.
1891
 */
1892
goog.dom.isFocusable = function(element) {
1893
  var focusable;
1894
  // Some elements can have unspecified tab index and still receive focus.
1895
  if (goog.dom.nativelySupportsFocus_(element)) {
1896
    // Make sure the element is not disabled ...
1897
    focusable = !element.disabled &&
1898
        // ... and if a tab index is specified, it allows focus.
1899
        (!goog.dom.hasSpecifiedTabIndex_(element) ||
1900
         goog.dom.isTabIndexFocusable_(element));
1901
  } else {
1902
    focusable = goog.dom.isFocusableTabIndex(element);
1903
  }
1904

1905
  // IE requires elements to be visible in order to focus them.
1906
  return focusable && goog.userAgent.IE ?
1907
      goog.dom.hasNonZeroBoundingRect_(/** @type {!HTMLElement} */ (element)) :
1908
      focusable;
1909
};
1910

1911

1912
/**
1913
 * Returns true if the element has a specified tab index.
1914
 * @param {!Element} element Element to check.
1915
 * @return {boolean} Whether the element has a specified tab index.
1916
 * @private
1917
 */
1918
goog.dom.hasSpecifiedTabIndex_ = function(element) {
1919
  // IE8 and below don't support hasAttribute(), instead check whether the
1920
  // 'tabindex' attributeNode is specified. Otherwise check hasAttribute().
1921
  if (goog.userAgent.IE && !goog.userAgent.isVersionOrHigher('9')) {
1922
    var attrNode = element.getAttributeNode('tabindex');  // Must be lowercase!
1923
    return goog.isDefAndNotNull(attrNode) && attrNode.specified;
1924
  } else {
1925
    return element.hasAttribute('tabindex');
1926
  }
1927
};
1928

1929

1930
/**
1931
 * Returns true if the element's tab index allows the element to be focused.
1932
 * @param {!Element} element Element to check.
1933
 * @return {boolean} Whether the element's tab index allows focus.
1934
 * @private
1935
 */
1936
goog.dom.isTabIndexFocusable_ = function(element) {
1937
  var index = /** @type {!HTMLElement} */ (element).tabIndex;
1938
  // NOTE: IE9 puts tabIndex in 16-bit int, e.g. -2 is 65534.
1939
  return goog.isNumber(index) && index >= 0 && index < 32768;
1940
};
1941

1942

1943
/**
1944
 * Returns true if the element is focusable even when tabIndex is not set.
1945
 * @param {!Element} element Element to check.
1946
 * @return {boolean} Whether the element natively supports focus.
1947
 * @private
1948
 */
1949
goog.dom.nativelySupportsFocus_ = function(element) {
1950
  return element.tagName == goog.dom.TagName.A ||
1951
      element.tagName == goog.dom.TagName.INPUT ||
1952
      element.tagName == goog.dom.TagName.TEXTAREA ||
1953
      element.tagName == goog.dom.TagName.SELECT ||
1954
      element.tagName == goog.dom.TagName.BUTTON;
1955
};
1956

1957

1958
/**
1959
 * Returns true if the element has a bounding rectangle that would be visible
1960
 * (i.e. its width and height are greater than zero).
1961
 * @param {!HTMLElement} element Element to check.
1962
 * @return {boolean} Whether the element has a non-zero bounding rectangle.
1963
 * @private
1964
 */
1965
goog.dom.hasNonZeroBoundingRect_ = function(element) {
1966
  var rect;
1967
  if (!goog.isFunction(element['getBoundingClientRect']) ||
1968
      // In IE, getBoundingClientRect throws on detached nodes.
1969
      (goog.userAgent.IE && element.parentElement == null)) {
1970
    rect = {'height': element.offsetHeight, 'width': element.offsetWidth};
1971
  } else {
1972
    rect = element.getBoundingClientRect();
1973
  }
1974
  return goog.isDefAndNotNull(rect) && rect.height > 0 && rect.width > 0;
1975
};
1976

1977

1978
/**
1979
 * Returns the text content of the current node, without markup and invisible
1980
 * symbols. New lines are stripped and whitespace is collapsed,
1981
 * such that each character would be visible.
1982
 *
1983
 * In browsers that support it, innerText is used.  Other browsers attempt to
1984
 * simulate it via node traversal.  Line breaks are canonicalized in IE.
1985
 *
1986
 * @param {Node} node The node from which we are getting content.
1987
 * @return {string} The text content.
1988
 */
1989
goog.dom.getTextContent = function(node) {
1990
  var textContent;
1991
  // Note(arv): IE9, Opera, and Safari 3 support innerText but they include
1992
  // text nodes in script tags. So we revert to use a user agent test here.
1993
  if (goog.dom.BrowserFeature.CAN_USE_INNER_TEXT && node !== null &&
1994
      ('innerText' in node)) {
1995
    textContent = goog.string.canonicalizeNewlines(node.innerText);
1996
    // Unfortunately .innerText() returns text with &shy; symbols
1997
    // We need to filter it out and then remove duplicate whitespaces
1998
  } else {
1999
    var buf = [];
2000
    goog.dom.getTextContent_(node, buf, true);
2001
    textContent = buf.join('');
2002
  }
2003

2004
  // Strip &shy; entities. goog.format.insertWordBreaks inserts them in Opera.
2005
  textContent = textContent.replace(/ \xAD /g, ' ').replace(/\xAD/g, '');
2006
  // Strip &#8203; entities. goog.format.insertWordBreaks inserts them in IE8.
2007
  textContent = textContent.replace(/\u200B/g, '');
2008

2009
  // Skip this replacement on old browsers with working innerText, which
2010
  // automatically turns &nbsp; into ' ' and / +/ into ' ' when reading
2011
  // innerText.
2012
  if (!goog.dom.BrowserFeature.CAN_USE_INNER_TEXT) {
2013
    textContent = textContent.replace(/ +/g, ' ');
2014
  }
2015
  if (textContent != ' ') {
2016
    textContent = textContent.replace(/^\s*/, '');
2017
  }
2018

2019
  return textContent;
2020
};
2021

2022

2023
/**
2024
 * Returns the text content of the current node, without markup.
2025
 *
2026
 * Unlike {@code getTextContent} this method does not collapse whitespaces
2027
 * or normalize lines breaks.
2028
 *
2029
 * @param {Node} node The node from which we are getting content.
2030
 * @return {string} The raw text content.
2031
 */
2032
goog.dom.getRawTextContent = function(node) {
2033
  var buf = [];
2034
  goog.dom.getTextContent_(node, buf, false);
2035

2036
  return buf.join('');
2037
};
2038

2039

2040
/**
2041
 * Recursive support function for text content retrieval.
2042
 *
2043
 * @param {Node} node The node from which we are getting content.
2044
 * @param {Array<string>} buf string buffer.
2045
 * @param {boolean} normalizeWhitespace Whether to normalize whitespace.
2046
 * @private
2047
 */
2048
goog.dom.getTextContent_ = function(node, buf, normalizeWhitespace) {
2049
  if (node.nodeName in goog.dom.TAGS_TO_IGNORE_) {
2050
    // ignore certain tags
2051
  } else if (node.nodeType == goog.dom.NodeType.TEXT) {
2052
    if (normalizeWhitespace) {
2053
      buf.push(String(node.nodeValue).replace(/(\r\n|\r|\n)/g, ''));
2054
    } else {
2055
      buf.push(node.nodeValue);
2056
    }
2057
  } else if (node.nodeName in goog.dom.PREDEFINED_TAG_VALUES_) {
2058
    buf.push(goog.dom.PREDEFINED_TAG_VALUES_[node.nodeName]);
2059
  } else {
2060
    var child = node.firstChild;
2061
    while (child) {
2062
      goog.dom.getTextContent_(child, buf, normalizeWhitespace);
2063
      child = child.nextSibling;
2064
    }
2065
  }
2066
};
2067

2068

2069
/**
2070
 * Returns the text length of the text contained in a node, without markup. This
2071
 * is equivalent to the selection length if the node was selected, or the number
2072
 * of cursor movements to traverse the node. Images & BRs take one space.  New
2073
 * lines are ignored.
2074
 *
2075
 * @param {Node} node The node whose text content length is being calculated.
2076
 * @return {number} The length of {@code node}'s text content.
2077
 */
2078
goog.dom.getNodeTextLength = function(node) {
2079
  return goog.dom.getTextContent(node).length;
2080
};
2081

2082

2083
/**
2084
 * Returns the text offset of a node relative to one of its ancestors. The text
2085
 * length is the same as the length calculated by goog.dom.getNodeTextLength.
2086
 *
2087
 * @param {Node} node The node whose offset is being calculated.
2088
 * @param {Node=} opt_offsetParent The node relative to which the offset will
2089
 *     be calculated. Defaults to the node's owner document's body.
2090
 * @return {number} The text offset.
2091
 */
2092
goog.dom.getNodeTextOffset = function(node, opt_offsetParent) {
2093
  var root = opt_offsetParent || goog.dom.getOwnerDocument(node).body;
2094
  var buf = [];
2095
  while (node && node != root) {
2096
    var cur = node;
2097
    while ((cur = cur.previousSibling)) {
2098
      buf.unshift(goog.dom.getTextContent(cur));
2099
    }
2100
    node = node.parentNode;
2101
  }
2102
  // Trim left to deal with FF cases when there might be line breaks and empty
2103
  // nodes at the front of the text
2104
  return goog.string.trimLeft(buf.join('')).replace(/ +/g, ' ').length;
2105
};
2106

2107

2108
/**
2109
 * Returns the node at a given offset in a parent node.  If an object is
2110
 * provided for the optional third parameter, the node and the remainder of the
2111
 * offset will stored as properties of this object.
2112
 * @param {Node} parent The parent node.
2113
 * @param {number} offset The offset into the parent node.
2114
 * @param {Object=} opt_result Object to be used to store the return value. The
2115
 *     return value will be stored in the form {node: Node, remainder: number}
2116
 *     if this object is provided.
2117
 * @return {Node} The node at the given offset.
2118
 */
2119
goog.dom.getNodeAtOffset = function(parent, offset, opt_result) {
2120
  var stack = [parent], pos = 0, cur = null;
2121
  while (stack.length > 0 && pos < offset) {
2122
    cur = stack.pop();
2123
    if (cur.nodeName in goog.dom.TAGS_TO_IGNORE_) {
2124
      // ignore certain tags
2125
    } else if (cur.nodeType == goog.dom.NodeType.TEXT) {
2126
      var text = cur.nodeValue.replace(/(\r\n|\r|\n)/g, '').replace(/ +/g, ' ');
2127
      pos += text.length;
2128
    } else if (cur.nodeName in goog.dom.PREDEFINED_TAG_VALUES_) {
2129
      pos += goog.dom.PREDEFINED_TAG_VALUES_[cur.nodeName].length;
2130
    } else {
2131
      for (var i = cur.childNodes.length - 1; i >= 0; i--) {
2132
        stack.push(cur.childNodes[i]);
2133
      }
2134
    }
2135
  }
2136
  if (goog.isObject(opt_result)) {
2137
    opt_result.remainder = cur ? cur.nodeValue.length + offset - pos - 1 : 0;
2138
    opt_result.node = cur;
2139
  }
2140

2141
  return cur;
2142
};
2143

2144

2145
/**
2146
 * Returns true if the object is a {@code NodeList}.  To qualify as a NodeList,
2147
 * the object must have a numeric length property and an item function (which
2148
 * has type 'string' on IE for some reason).
2149
 * @param {Object} val Object to test.
2150
 * @return {boolean} Whether the object is a NodeList.
2151
 */
2152
goog.dom.isNodeList = function(val) {
2153
  // TODO(attila): Now the isNodeList is part of goog.dom we can use
2154
  // goog.userAgent to make this simpler.
2155
  // A NodeList must have a length property of type 'number' on all platforms.
2156
  if (val && typeof val.length == 'number') {
2157
    // A NodeList is an object everywhere except Safari, where it's a function.
2158
    if (goog.isObject(val)) {
2159
      // A NodeList must have an item function (on non-IE platforms) or an item
2160
      // property of type 'string' (on IE).
2161
      return typeof val.item == 'function' || typeof val.item == 'string';
2162
    } else if (goog.isFunction(val)) {
2163
      // On Safari, a NodeList is a function with an item property that is also
2164
      // a function.
2165
      return typeof val.item == 'function';
2166
    }
2167
  }
2168

2169
  // Not a NodeList.
2170
  return false;
2171
};
2172

2173

2174
/**
2175
 * Walks up the DOM hierarchy returning the first ancestor that has the passed
2176
 * tag name and/or class name. If the passed element matches the specified
2177
 * criteria, the element itself is returned.
2178
 * @param {Node} element The DOM node to start with.
2179
 * @param {?(goog.dom.TagName<T>|string)=} opt_tag The tag name to match (or
2180
 *     null/undefined to match only based on class name).
2181
 * @param {?string=} opt_class The class name to match (or null/undefined to
2182
 *     match only based on tag name).
2183
 * @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2184
 *     dom.
2185
 * @return {?R} The first ancestor that matches the passed criteria, or
2186
 *     null if no match is found. The return type is {?Element} if opt_tag is
2187
 *     not a member of goog.dom.TagName or a more specific type if it is (e.g.
2188
 *     {?HTMLAnchorElement} for goog.dom.TagName.A).
2189
 * @template T
2190
 * @template R := cond(isUnknown(T), 'Element', T) =:
2191
 */
2192
goog.dom.getAncestorByTagNameAndClass = function(
2193
    element, opt_tag, opt_class, opt_maxSearchSteps) {
2194
  if (!opt_tag && !opt_class) {
2195
    return null;
2196
  }
2197
  var tagName = opt_tag ? String(opt_tag).toUpperCase() : null;
2198
  return /** @type {Element} */ (goog.dom.getAncestor(element, function(node) {
2199
    return (!tagName || node.nodeName == tagName) &&
2200
        (!opt_class ||
2201
         goog.isString(node.className) &&
2202
             goog.array.contains(node.className.split(/\s+/), opt_class));
2203
  }, true, opt_maxSearchSteps));
2204
};
2205

2206

2207
/**
2208
 * Walks up the DOM hierarchy returning the first ancestor that has the passed
2209
 * class name. If the passed element matches the specified criteria, the
2210
 * element itself is returned.
2211
 * @param {Node} element The DOM node to start with.
2212
 * @param {string} className The class name to match.
2213
 * @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2214
 *     dom.
2215
 * @return {Element} The first ancestor that matches the passed criteria, or
2216
 *     null if none match.
2217
 */
2218
goog.dom.getAncestorByClass = function(element, className, opt_maxSearchSteps) {
2219
  return goog.dom.getAncestorByTagNameAndClass(
2220
      element, null, className, opt_maxSearchSteps);
2221
};
2222

2223

2224
/**
2225
 * Walks up the DOM hierarchy returning the first ancestor that passes the
2226
 * matcher function.
2227
 * @param {Node} element The DOM node to start with.
2228
 * @param {function(Node) : boolean} matcher A function that returns true if the
2229
 *     passed node matches the desired criteria.
2230
 * @param {boolean=} opt_includeNode If true, the node itself is included in
2231
 *     the search (the first call to the matcher will pass startElement as
2232
 *     the node to test).
2233
 * @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
2234
 *     dom.
2235
 * @return {Node} DOM node that matched the matcher, or null if there was
2236
 *     no match.
2237
 */
2238
goog.dom.getAncestor = function(
2239
    element, matcher, opt_includeNode, opt_maxSearchSteps) {
2240
  if (element && !opt_includeNode) {
2241
    element = element.parentNode;
2242
  }
2243
  var steps = 0;
2244
  while (element &&
2245
         (opt_maxSearchSteps == null || steps <= opt_maxSearchSteps)) {
2246
    goog.asserts.assert(element.name != 'parentNode');
2247
    if (matcher(element)) {
2248
      return element;
2249
    }
2250
    element = element.parentNode;
2251
    steps++;
2252
  }
2253
  // Reached the root of the DOM without a match
2254
  return null;
2255
};
2256

2257

2258
/**
2259
 * Determines the active element in the given document.
2260
 * @param {Document} doc The document to look in.
2261
 * @return {Element} The active element.
2262
 */
2263
goog.dom.getActiveElement = function(doc) {
2264
  try {
2265
    return doc && doc.activeElement;
2266
  } catch (e) {
2267
    // NOTE(nicksantos): Sometimes, evaluating document.activeElement in IE
2268
    // throws an exception. I'm not 100% sure why, but I suspect it chokes
2269
    // on document.activeElement if the activeElement has been recently
2270
    // removed from the DOM by a JS operation.
2271
    //
2272
    // We assume that an exception here simply means
2273
    // "there is no active element."
2274
  }
2275

2276
  return null;
2277
};
2278

2279

2280
/**
2281
 * Gives the current devicePixelRatio.
2282
 *
2283
 * By default, this is the value of window.devicePixelRatio (which should be
2284
 * preferred if present).
2285
 *
2286
 * If window.devicePixelRatio is not present, the ratio is calculated with
2287
 * window.matchMedia, if present. Otherwise, gives 1.0.
2288
 *
2289
 * Some browsers (including Chrome) consider the browser zoom level in the pixel
2290
 * ratio, so the value may change across multiple calls.
2291
 *
2292
 * @return {number} The number of actual pixels per virtual pixel.
2293
 */
2294
goog.dom.getPixelRatio = function() {
2295
  var win = goog.dom.getWindow();
2296
  if (goog.isDef(win.devicePixelRatio)) {
2297
    return win.devicePixelRatio;
2298
  } else if (win.matchMedia) {
2299
    // Should be for IE10 and FF6-17 (this basically clamps to lower)
2300
    // Note that the order of these statements is important
2301
    return goog.dom.matchesPixelRatio_(3) || goog.dom.matchesPixelRatio_(2) ||
2302
           goog.dom.matchesPixelRatio_(1.5) || goog.dom.matchesPixelRatio_(1) ||
2303
           .75;
2304
  }
2305
  return 1;
2306
};
2307

2308

2309
/**
2310
 * Calculates a mediaQuery to check if the current device supports the
2311
 * given actual to virtual pixel ratio.
2312
 * @param {number} pixelRatio The ratio of actual pixels to virtual pixels.
2313
 * @return {number} pixelRatio if applicable, otherwise 0.
2314
 * @private
2315
 */
2316
goog.dom.matchesPixelRatio_ = function(pixelRatio) {
2317
  var win = goog.dom.getWindow();
2318
  /**
2319
   * Due to the 1:96 fixed ratio of CSS in to CSS px, 1dppx is equivalent to
2320
   * 96dpi.
2321
   * @const {number}
2322
   */
2323
  var dpiPerDppx = 96;
2324
  var query =
2325
      // FF16-17
2326
      '(min-resolution: ' + pixelRatio + 'dppx),' +
2327
      // FF6-15
2328
      '(min--moz-device-pixel-ratio: ' + pixelRatio + '),' +
2329
      // IE10 (this works for the two browsers above too but I don't want to
2330
      // trust the 1:96 fixed ratio magic)
2331
      '(min-resolution: ' + (pixelRatio * dpiPerDppx) + 'dpi)';
2332
  return win.matchMedia(query).matches ? pixelRatio : 0;
2333
};
2334

2335

2336
/**
2337
 * Gets '2d' context of a canvas. Shortcut for canvas.getContext('2d') with a
2338
 * type information.
2339
 * @param {!HTMLCanvasElement} canvas
2340
 * @return {!CanvasRenderingContext2D}
2341
 */
2342
goog.dom.getCanvasContext2D = function(canvas) {
2343
  return /** @type {!CanvasRenderingContext2D} */ (canvas.getContext('2d'));
2344
};
2345

2346

2347

2348
/**
2349
 * Create an instance of a DOM helper with a new document object.
2350
 * @param {Document=} opt_document Document object to associate with this
2351
 *     DOM helper.
2352
 * @constructor
2353
 */
2354
goog.dom.DomHelper = function(opt_document) {
2355
  /**
2356
   * Reference to the document object to use
2357
   * @type {!Document}
2358
   * @private
2359
   */
2360
  this.document_ = opt_document || goog.global.document || document;
2361
};
2362

2363

2364
/**
2365
 * Gets the dom helper object for the document where the element resides.
2366
 * @param {Node=} opt_node If present, gets the DomHelper for this node.
2367
 * @return {!goog.dom.DomHelper} The DomHelper.
2368
 */
2369
goog.dom.DomHelper.prototype.getDomHelper = goog.dom.getDomHelper;
2370

2371

2372
/**
2373
 * Sets the document object.
2374
 * @param {!Document} document Document object.
2375
 */
2376
goog.dom.DomHelper.prototype.setDocument = function(document) {
2377
  this.document_ = document;
2378
};
2379

2380

2381
/**
2382
 * Gets the document object being used by the dom library.
2383
 * @return {!Document} Document object.
2384
 */
2385
goog.dom.DomHelper.prototype.getDocument = function() {
2386
  return this.document_;
2387
};
2388

2389

2390
/**
2391
 * Alias for {@code getElementById}. If a DOM node is passed in then we just
2392
 * return that.
2393
 * @param {string|Element} element Element ID or a DOM node.
2394
 * @return {Element} The element with the given ID, or the node passed in.
2395
 */
2396
goog.dom.DomHelper.prototype.getElement = function(element) {
2397
  return goog.dom.getElementHelper_(this.document_, element);
2398
};
2399

2400

2401
/**
2402
 * Gets an element by id, asserting that the element is found.
2403
 *
2404
 * This is used when an element is expected to exist, and should fail with
2405
 * an assertion error if it does not (if assertions are enabled).
2406
 *
2407
 * @param {string} id Element ID.
2408
 * @return {!Element} The element with the given ID, if it exists.
2409
 */
2410
goog.dom.DomHelper.prototype.getRequiredElement = function(id) {
2411
  return goog.dom.getRequiredElementHelper_(this.document_, id);
2412
};
2413

2414

2415
/**
2416
 * Alias for {@code getElement}.
2417
 * @param {string|Element} element Element ID or a DOM node.
2418
 * @return {Element} The element with the given ID, or the node passed in.
2419
 * @deprecated Use {@link goog.dom.DomHelper.prototype.getElement} instead.
2420
 */
2421
goog.dom.DomHelper.prototype.$ = goog.dom.DomHelper.prototype.getElement;
2422

2423

2424
/**
2425
 * Gets elements by tag name.
2426
 * @param {!goog.dom.TagName<T>} tagName
2427
 * @param {(!Document|!Element)=} opt_parent Parent element or document where to
2428
 *     look for elements. Defaults to document of this DomHelper.
2429
 * @return {!NodeList<R>} List of elements. The members of the list are
2430
 *     {!Element} if tagName is not a member of goog.dom.TagName or more
2431
 *     specific types if it is (e.g. {!HTMLAnchorElement} for
2432
 *     goog.dom.TagName.A).
2433
 * @template T
2434
 * @template R := cond(isUnknown(T), 'Element', T) =:
2435
 */
2436
goog.dom.DomHelper.prototype.getElementsByTagName =
2437
    function(tagName, opt_parent) {
2438
  var parent = opt_parent || this.document_;
2439
  return parent.getElementsByTagName(String(tagName));
2440
};
2441

2442

2443
/**
2444
 * Looks up elements by both tag and class name, using browser native functions
2445
 * ({@code querySelectorAll}, {@code getElementsByTagName} or
2446
 * {@code getElementsByClassName}) where possible. The returned array is a live
2447
 * NodeList or a static list depending on the code path taken.
2448
 *
2449
 * @see goog.dom.query
2450
 *
2451
 * @param {(string|?goog.dom.TagName<T>)=} opt_tag Element tag name or * for all
2452
 *     tags.
2453
 * @param {?string=} opt_class Optional class name.
2454
 * @param {(Document|Element)=} opt_el Optional element to look in.
2455
 * @return {!IArrayLike<R>} Array-like list of elements (only a length property
2456
 *     and numerical indices are guaranteed to exist). The members of the array
2457
 *     are {!Element} if opt_tag is not a member of goog.dom.TagName or more
2458
 *     specific types if it is (e.g. {!HTMLAnchorElement} for
2459
 *     goog.dom.TagName.A).
2460
 * @template T
2461
 * @template R := cond(isUnknown(T), 'Element', T) =:
2462
 */
2463
goog.dom.DomHelper.prototype.getElementsByTagNameAndClass = function(
2464
    opt_tag, opt_class, opt_el) {
2465
  return goog.dom.getElementsByTagNameAndClass_(
2466
      this.document_, opt_tag, opt_class, opt_el);
2467
};
2468

2469

2470
/**
2471
 * Returns an array of all the elements with the provided className.
2472
 * @see {goog.dom.query}
2473
 * @param {string} className the name of the class to look for.
2474
 * @param {Element|Document=} opt_el Optional element to look in.
2475
 * @return {!IArrayLike<!Element>} The items found with the class name provided.
2476
 */
2477
goog.dom.DomHelper.prototype.getElementsByClass = function(className, opt_el) {
2478
  var doc = opt_el || this.document_;
2479
  return goog.dom.getElementsByClass(className, doc);
2480
};
2481

2482

2483
/**
2484
 * Returns the first element we find matching the provided class name.
2485
 * @see {goog.dom.query}
2486
 * @param {string} className the name of the class to look for.
2487
 * @param {(Element|Document)=} opt_el Optional element to look in.
2488
 * @return {Element} The first item found with the class name provided.
2489
 */
2490
goog.dom.DomHelper.prototype.getElementByClass = function(className, opt_el) {
2491
  var doc = opt_el || this.document_;
2492
  return goog.dom.getElementByClass(className, doc);
2493
};
2494

2495

2496
/**
2497
 * Ensures an element with the given className exists, and then returns the
2498
 * first element with the provided className.
2499
 * @see {goog.dom.query}
2500
 * @param {string} className the name of the class to look for.
2501
 * @param {(!Element|!Document)=} opt_root Optional element or document to look
2502
 *     in.
2503
 * @return {!Element} The first item found with the class name provided.
2504
 * @throws {goog.asserts.AssertionError} Thrown if no element is found.
2505
 */
2506
goog.dom.DomHelper.prototype.getRequiredElementByClass = function(
2507
    className, opt_root) {
2508
  var root = opt_root || this.document_;
2509
  return goog.dom.getRequiredElementByClass(className, root);
2510
};
2511

2512

2513
/**
2514
 * Alias for {@code getElementsByTagNameAndClass}.
2515
 * @deprecated Use DomHelper getElementsByTagNameAndClass.
2516
 * @see goog.dom.query
2517
 *
2518
 * @param {(string|?goog.dom.TagName<T>)=} opt_tag Element tag name.
2519
 * @param {?string=} opt_class Optional class name.
2520
 * @param {Element=} opt_el Optional element to look in.
2521
 * @return {!IArrayLike<R>} Array-like list of elements (only a length property
2522
 *     and numerical indices are guaranteed to exist). The members of the array
2523
 *     are {!Element} if opt_tag is a string or more specific types if it is
2524
 *     a member of goog.dom.TagName (e.g. {!HTMLAnchorElement} for
2525
 *     goog.dom.TagName.A).
2526
 * @template T
2527
 * @template R := cond(isUnknown(T), 'Element', T) =:
2528
 */
2529
goog.dom.DomHelper.prototype.$$ =
2530
    goog.dom.DomHelper.prototype.getElementsByTagNameAndClass;
2531

2532

2533
/**
2534
 * Sets a number of properties on a node.
2535
 * @param {Element} element DOM node to set properties on.
2536
 * @param {Object} properties Hash of property:value pairs.
2537
 */
2538
goog.dom.DomHelper.prototype.setProperties = goog.dom.setProperties;
2539

2540

2541
/**
2542
 * Gets the dimensions of the viewport.
2543
 * @param {Window=} opt_window Optional window element to test. Defaults to
2544
 *     the window of the Dom Helper.
2545
 * @return {!goog.math.Size} Object with values 'width' and 'height'.
2546
 */
2547
goog.dom.DomHelper.prototype.getViewportSize = function(opt_window) {
2548
  // TODO(arv): This should not take an argument. That breaks the rule of a
2549
  // a DomHelper representing a single frame/window/document.
2550
  return goog.dom.getViewportSize(opt_window || this.getWindow());
2551
};
2552

2553

2554
/**
2555
 * Calculates the height of the document.
2556
 *
2557
 * @return {number} The height of the document.
2558
 */
2559
goog.dom.DomHelper.prototype.getDocumentHeight = function() {
2560
  return goog.dom.getDocumentHeight_(this.getWindow());
2561
};
2562

2563

2564
/**
2565
 * Typedef for use with goog.dom.createDom and goog.dom.append.
2566
 * @typedef {Object|string|Array|NodeList}
2567
 */
2568
goog.dom.Appendable;
2569

2570

2571
/**
2572
 * Returns a dom node with a set of attributes.  This function accepts varargs
2573
 * for subsequent nodes to be added.  Subsequent nodes will be added to the
2574
 * first node as childNodes.
2575
 *
2576
 * So:
2577
 * <code>createDom(goog.dom.TagName.DIV, null, createDom(goog.dom.TagName.P), createDom(goog.dom.TagName.P));</code>
2578
 * would return a div with two child paragraphs
2579
 *
2580
 * An easy way to move all child nodes of an existing element to a new parent
2581
 * element is:
2582
 * <code>createDom(goog.dom.TagName.DIV, null, oldElement.childNodes);</code>
2583
 * which will remove all child nodes from the old element and add them as
2584
 * child nodes of the new DIV.
2585
 *
2586
 * @param {string|!goog.dom.TagName<T>} tagName Tag to create.
2587
 * @param {Object|string=} opt_attributes If object, then a map of name-value
2588
 *     pairs for attributes. If a string, then this is the className of the new
2589
 *     element.
2590
 * @param {...goog.dom.Appendable} var_args Further DOM nodes or
2591
 *     strings for text nodes. If one of the var_args is an array or
2592
 *     NodeList, its elements will be added as childNodes instead.
2593
 * @return {R} Reference to a DOM node. The return type is {!Element} if tagName
2594
 *     is a string or a more specific type if it is a member of
2595
 *     goog.dom.TagName (e.g. {!HTMLAnchorElement} for goog.dom.TagName.A).
2596
 * @template T
2597
 * @template R := cond(isUnknown(T), 'Element', T) =:
2598
 */
2599
goog.dom.DomHelper.prototype.createDom = function(
2600
    tagName, opt_attributes, var_args) {
2601
  return goog.dom.createDom_(this.document_, arguments);
2602
};
2603

2604

2605
/**
2606
 * Alias for {@code createDom}.
2607
 * @param {string|!goog.dom.TagName<T>} tagName Tag to create.
2608
 * @param {(Object|string)=} opt_attributes If object, then a map of name-value
2609
 *     pairs for attributes. If a string, then this is the className of the new
2610
 *     element.
2611
 * @param {...goog.dom.Appendable} var_args Further DOM nodes or strings for
2612
 *     text nodes.  If one of the var_args is an array, its children will be
2613
 *     added as childNodes instead.
2614
 * @return {R} Reference to a DOM node. The return type is {!Element} if tagName
2615
 *     is a string or a more specific type if it is a member of
2616
 *     goog.dom.TagName (e.g. {!HTMLAnchorElement} for goog.dom.TagName.A).
2617
 * @template T
2618
 * @template R := cond(isUnknown(T), 'Element', T) =:
2619
 * @deprecated Use {@link goog.dom.DomHelper.prototype.createDom} instead.
2620
 */
2621
goog.dom.DomHelper.prototype.$dom = goog.dom.DomHelper.prototype.createDom;
2622

2623

2624
/**
2625
 * Creates a new element.
2626
 * @param {string|!goog.dom.TagName<T>} name Tag to create.
2627
 * @return {R} The new element. The return type is {!Element} if name is
2628
 *     a string or a more specific type if it is a member of goog.dom.TagName
2629
 *     (e.g. {!HTMLAnchorElement} for goog.dom.TagName.A).
2630
 * @template T
2631
 * @template R := cond(isUnknown(T), 'Element', T) =:
2632
 */
2633
goog.dom.DomHelper.prototype.createElement = function(name) {
2634
  return goog.dom.createElement_(this.document_, name);
2635
};
2636

2637

2638
/**
2639
 * Creates a new text node.
2640
 * @param {number|string} content Content.
2641
 * @return {!Text} The new text node.
2642
 */
2643
goog.dom.DomHelper.prototype.createTextNode = function(content) {
2644
  return this.document_.createTextNode(String(content));
2645
};
2646

2647

2648
/**
2649
 * Create a table.
2650
 * @param {number} rows The number of rows in the table.  Must be >= 1.
2651
 * @param {number} columns The number of columns in the table.  Must be >= 1.
2652
 * @param {boolean=} opt_fillWithNbsp If true, fills table entries with
2653
 *     {@code goog.string.Unicode.NBSP} characters.
2654
 * @return {!HTMLElement} The created table.
2655
 */
2656
goog.dom.DomHelper.prototype.createTable = function(
2657
    rows, columns, opt_fillWithNbsp) {
2658
  return goog.dom.createTable_(
2659
      this.document_, rows, columns, !!opt_fillWithNbsp);
2660
};
2661

2662

2663
/**
2664
 * Converts an HTML into a node or a document fragment. A single Node is used if
2665
 * {@code html} only generates a single node. If {@code html} generates multiple
2666
 * nodes then these are put inside a {@code DocumentFragment}. This is a safe
2667
 * version of {@code goog.dom.DomHelper#htmlToDocumentFragment} which is now
2668
 * deleted.
2669
 * @param {!goog.html.SafeHtml} html The HTML markup to convert.
2670
 * @return {!Node} The resulting node.
2671
 */
2672
goog.dom.DomHelper.prototype.safeHtmlToNode = function(html) {
2673
  return goog.dom.safeHtmlToNode_(this.document_, html);
2674
};
2675

2676

2677
/**
2678
 * Returns true if the browser is in "CSS1-compatible" (standards-compliant)
2679
 * mode, false otherwise.
2680
 * @return {boolean} True if in CSS1-compatible mode.
2681
 */
2682
goog.dom.DomHelper.prototype.isCss1CompatMode = function() {
2683
  return goog.dom.isCss1CompatMode_(this.document_);
2684
};
2685

2686

2687
/**
2688
 * Gets the window object associated with the document.
2689
 * @return {!Window} The window associated with the given document.
2690
 */
2691
goog.dom.DomHelper.prototype.getWindow = function() {
2692
  return goog.dom.getWindow_(this.document_);
2693
};
2694

2695

2696
/**
2697
 * Gets the document scroll element.
2698
 * @return {!Element} Scrolling element.
2699
 */
2700
goog.dom.DomHelper.prototype.getDocumentScrollElement = function() {
2701
  return goog.dom.getDocumentScrollElement_(this.document_);
2702
};
2703

2704

2705
/**
2706
 * Gets the document scroll distance as a coordinate object.
2707
 * @return {!goog.math.Coordinate} Object with properties 'x' and 'y'.
2708
 */
2709
goog.dom.DomHelper.prototype.getDocumentScroll = function() {
2710
  return goog.dom.getDocumentScroll_(this.document_);
2711
};
2712

2713

2714
/**
2715
 * Determines the active element in the given document.
2716
 * @param {Document=} opt_doc The document to look in.
2717
 * @return {Element} The active element.
2718
 */
2719
goog.dom.DomHelper.prototype.getActiveElement = function(opt_doc) {
2720
  return goog.dom.getActiveElement(opt_doc || this.document_);
2721
};
2722

2723

2724
/**
2725
 * Appends a child to a node.
2726
 * @param {Node} parent Parent.
2727
 * @param {Node} child Child.
2728
 */
2729
goog.dom.DomHelper.prototype.appendChild = goog.dom.appendChild;
2730

2731

2732
/**
2733
 * Appends a node with text or other nodes.
2734
 * @param {!Node} parent The node to append nodes to.
2735
 * @param {...goog.dom.Appendable} var_args The things to append to the node.
2736
 *     If this is a Node it is appended as is.
2737
 *     If this is a string then a text node is appended.
2738
 *     If this is an array like object then fields 0 to length - 1 are appended.
2739
 */
2740
goog.dom.DomHelper.prototype.append = goog.dom.append;
2741

2742

2743
/**
2744
 * Determines if the given node can contain children, intended to be used for
2745
 * HTML generation.
2746
 *
2747
 * @param {Node} node The node to check.
2748
 * @return {boolean} Whether the node can contain children.
2749
 */
2750
goog.dom.DomHelper.prototype.canHaveChildren = goog.dom.canHaveChildren;
2751

2752

2753
/**
2754
 * Removes all the child nodes on a DOM node.
2755
 * @param {Node} node Node to remove children from.
2756
 */
2757
goog.dom.DomHelper.prototype.removeChildren = goog.dom.removeChildren;
2758

2759

2760
/**
2761
 * Inserts a new node before an existing reference node (i.e., as the previous
2762
 * sibling). If the reference node has no parent, then does nothing.
2763
 * @param {Node} newNode Node to insert.
2764
 * @param {Node} refNode Reference node to insert before.
2765
 */
2766
goog.dom.DomHelper.prototype.insertSiblingBefore = goog.dom.insertSiblingBefore;
2767

2768

2769
/**
2770
 * Inserts a new node after an existing reference node (i.e., as the next
2771
 * sibling). If the reference node has no parent, then does nothing.
2772
 * @param {Node} newNode Node to insert.
2773
 * @param {Node} refNode Reference node to insert after.
2774
 */
2775
goog.dom.DomHelper.prototype.insertSiblingAfter = goog.dom.insertSiblingAfter;
2776

2777

2778
/**
2779
 * Insert a child at a given index. If index is larger than the number of child
2780
 * nodes that the parent currently has, the node is inserted as the last child
2781
 * node.
2782
 * @param {Element} parent The element into which to insert the child.
2783
 * @param {Node} child The element to insert.
2784
 * @param {number} index The index at which to insert the new child node. Must
2785
 *     not be negative.
2786
 */
2787
goog.dom.DomHelper.prototype.insertChildAt = goog.dom.insertChildAt;
2788

2789

2790
/**
2791
 * Removes a node from its parent.
2792
 * @param {Node} node The node to remove.
2793
 * @return {Node} The node removed if removed; else, null.
2794
 */
2795
goog.dom.DomHelper.prototype.removeNode = goog.dom.removeNode;
2796

2797

2798
/**
2799
 * Replaces a node in the DOM tree. Will do nothing if {@code oldNode} has no
2800
 * parent.
2801
 * @param {Node} newNode Node to insert.
2802
 * @param {Node} oldNode Node to replace.
2803
 */
2804
goog.dom.DomHelper.prototype.replaceNode = goog.dom.replaceNode;
2805

2806

2807
/**
2808
 * Flattens an element. That is, removes it and replace it with its children.
2809
 * @param {Element} element The element to flatten.
2810
 * @return {Element|undefined} The original element, detached from the document
2811
 *     tree, sans children, or undefined if the element was already not in the
2812
 *     document.
2813
 */
2814
goog.dom.DomHelper.prototype.flattenElement = goog.dom.flattenElement;
2815

2816

2817
/**
2818
 * Returns an array containing just the element children of the given element.
2819
 * @param {Element} element The element whose element children we want.
2820
 * @return {!(Array<!Element>|NodeList<!Element>)} An array or array-like list
2821
 *     of just the element children of the given element.
2822
 */
2823
goog.dom.DomHelper.prototype.getChildren = goog.dom.getChildren;
2824

2825

2826
/**
2827
 * Returns the first child node that is an element.
2828
 * @param {Node} node The node to get the first child element of.
2829
 * @return {Element} The first child node of {@code node} that is an element.
2830
 */
2831
goog.dom.DomHelper.prototype.getFirstElementChild =
2832
    goog.dom.getFirstElementChild;
2833

2834

2835
/**
2836
 * Returns the last child node that is an element.
2837
 * @param {Node} node The node to get the last child element of.
2838
 * @return {Element} The last child node of {@code node} that is an element.
2839
 */
2840
goog.dom.DomHelper.prototype.getLastElementChild = goog.dom.getLastElementChild;
2841

2842

2843
/**
2844
 * Returns the first next sibling that is an element.
2845
 * @param {Node} node The node to get the next sibling element of.
2846
 * @return {Element} The next sibling of {@code node} that is an element.
2847
 */
2848
goog.dom.DomHelper.prototype.getNextElementSibling =
2849
    goog.dom.getNextElementSibling;
2850

2851

2852
/**
2853
 * Returns the first previous sibling that is an element.
2854
 * @param {Node} node The node to get the previous sibling element of.
2855
 * @return {Element} The first previous sibling of {@code node} that is
2856
 *     an element.
2857
 */
2858
goog.dom.DomHelper.prototype.getPreviousElementSibling =
2859
    goog.dom.getPreviousElementSibling;
2860

2861

2862
/**
2863
 * Returns the next node in source order from the given node.
2864
 * @param {Node} node The node.
2865
 * @return {Node} The next node in the DOM tree, or null if this was the last
2866
 *     node.
2867
 */
2868
goog.dom.DomHelper.prototype.getNextNode = goog.dom.getNextNode;
2869

2870

2871
/**
2872
 * Returns the previous node in source order from the given node.
2873
 * @param {Node} node The node.
2874
 * @return {Node} The previous node in the DOM tree, or null if this was the
2875
 *     first node.
2876
 */
2877
goog.dom.DomHelper.prototype.getPreviousNode = goog.dom.getPreviousNode;
2878

2879

2880
/**
2881
 * Whether the object looks like a DOM node.
2882
 * @param {?} obj The object being tested for node likeness.
2883
 * @return {boolean} Whether the object looks like a DOM node.
2884
 */
2885
goog.dom.DomHelper.prototype.isNodeLike = goog.dom.isNodeLike;
2886

2887

2888
/**
2889
 * Whether the object looks like an Element.
2890
 * @param {?} obj The object being tested for Element likeness.
2891
 * @return {boolean} Whether the object looks like an Element.
2892
 */
2893
goog.dom.DomHelper.prototype.isElement = goog.dom.isElement;
2894

2895

2896
/**
2897
 * Returns true if the specified value is a Window object. This includes the
2898
 * global window for HTML pages, and iframe windows.
2899
 * @param {?} obj Variable to test.
2900
 * @return {boolean} Whether the variable is a window.
2901
 */
2902
goog.dom.DomHelper.prototype.isWindow = goog.dom.isWindow;
2903

2904

2905
/**
2906
 * Returns an element's parent, if it's an Element.
2907
 * @param {Element} element The DOM element.
2908
 * @return {Element} The parent, or null if not an Element.
2909
 */
2910
goog.dom.DomHelper.prototype.getParentElement = goog.dom.getParentElement;
2911

2912

2913
/**
2914
 * Whether a node contains another node.
2915
 * @param {Node} parent The node that should contain the other node.
2916
 * @param {Node} descendant The node to test presence of.
2917
 * @return {boolean} Whether the parent node contains the descendent node.
2918
 */
2919
goog.dom.DomHelper.prototype.contains = goog.dom.contains;
2920

2921

2922
/**
2923
 * Compares the document order of two nodes, returning 0 if they are the same
2924
 * node, a negative number if node1 is before node2, and a positive number if
2925
 * node2 is before node1.  Note that we compare the order the tags appear in the
2926
 * document so in the tree <b><i>text</i></b> the B node is considered to be
2927
 * before the I node.
2928
 *
2929
 * @param {Node} node1 The first node to compare.
2930
 * @param {Node} node2 The second node to compare.
2931
 * @return {number} 0 if the nodes are the same node, a negative number if node1
2932
 *     is before node2, and a positive number if node2 is before node1.
2933
 */
2934
goog.dom.DomHelper.prototype.compareNodeOrder = goog.dom.compareNodeOrder;
2935

2936

2937
/**
2938
 * Find the deepest common ancestor of the given nodes.
2939
 * @param {...Node} var_args The nodes to find a common ancestor of.
2940
 * @return {Node} The common ancestor of the nodes, or null if there is none.
2941
 *     null will only be returned if two or more of the nodes are from different
2942
 *     documents.
2943
 */
2944
goog.dom.DomHelper.prototype.findCommonAncestor = goog.dom.findCommonAncestor;
2945

2946

2947
/**
2948
 * Returns the owner document for a node.
2949
 * @param {Node} node The node to get the document for.
2950
 * @return {!Document} The document owning the node.
2951
 */
2952
goog.dom.DomHelper.prototype.getOwnerDocument = goog.dom.getOwnerDocument;
2953

2954

2955
/**
2956
 * Cross browser function for getting the document element of an iframe.
2957
 * @param {Element} iframe Iframe element.
2958
 * @return {!Document} The frame content document.
2959
 */
2960
goog.dom.DomHelper.prototype.getFrameContentDocument =
2961
    goog.dom.getFrameContentDocument;
2962

2963

2964
/**
2965
 * Cross browser function for getting the window of a frame or iframe.
2966
 * @param {Element} frame Frame element.
2967
 * @return {Window} The window associated with the given frame.
2968
 */
2969
goog.dom.DomHelper.prototype.getFrameContentWindow =
2970
    goog.dom.getFrameContentWindow;
2971

2972

2973
/**
2974
 * Sets the text content of a node, with cross-browser support.
2975
 * @param {Node} node The node to change the text content of.
2976
 * @param {string|number} text The value that should replace the node's content.
2977
 */
2978
goog.dom.DomHelper.prototype.setTextContent = goog.dom.setTextContent;
2979

2980

2981
/**
2982
 * Gets the outerHTML of a node, which islike innerHTML, except that it
2983
 * actually contains the HTML of the node itself.
2984
 * @param {Element} element The element to get the HTML of.
2985
 * @return {string} The outerHTML of the given element.
2986
 */
2987
goog.dom.DomHelper.prototype.getOuterHtml = goog.dom.getOuterHtml;
2988

2989

2990
/**
2991
 * Finds the first descendant node that matches the filter function. This does
2992
 * a depth first search.
2993
 * @param {Node} root The root of the tree to search.
2994
 * @param {function(Node) : boolean} p The filter function.
2995
 * @return {Node|undefined} The found node or undefined if none is found.
2996
 */
2997
goog.dom.DomHelper.prototype.findNode = goog.dom.findNode;
2998

2999

3000
/**
3001
 * Finds all the descendant nodes that matches the filter function. This does a
3002
 * depth first search.
3003
 * @param {Node} root The root of the tree to search.
3004
 * @param {function(Node) : boolean} p The filter function.
3005
 * @return {Array<Node>} The found nodes or an empty array if none are found.
3006
 */
3007
goog.dom.DomHelper.prototype.findNodes = goog.dom.findNodes;
3008

3009

3010
/**
3011
 * Returns true if the element has a tab index that allows it to receive
3012
 * keyboard focus (tabIndex >= 0), false otherwise.  Note that some elements
3013
 * natively support keyboard focus, even if they have no tab index.
3014
 * @param {!Element} element Element to check.
3015
 * @return {boolean} Whether the element has a tab index that allows keyboard
3016
 *     focus.
3017
 */
3018
goog.dom.DomHelper.prototype.isFocusableTabIndex = goog.dom.isFocusableTabIndex;
3019

3020

3021
/**
3022
 * Enables or disables keyboard focus support on the element via its tab index.
3023
 * Only elements for which {@link goog.dom.isFocusableTabIndex} returns true
3024
 * (or elements that natively support keyboard focus, like form elements) can
3025
 * receive keyboard focus.  See http://go/tabindex for more info.
3026
 * @param {Element} element Element whose tab index is to be changed.
3027
 * @param {boolean} enable Whether to set or remove a tab index on the element
3028
 *     that supports keyboard focus.
3029
 */
3030
goog.dom.DomHelper.prototype.setFocusableTabIndex =
3031
    goog.dom.setFocusableTabIndex;
3032

3033

3034
/**
3035
 * Returns true if the element can be focused, i.e. it has a tab index that
3036
 * allows it to receive keyboard focus (tabIndex >= 0), or it is an element
3037
 * that natively supports keyboard focus.
3038
 * @param {!Element} element Element to check.
3039
 * @return {boolean} Whether the element allows keyboard focus.
3040
 */
3041
goog.dom.DomHelper.prototype.isFocusable = goog.dom.isFocusable;
3042

3043

3044
/**
3045
 * Returns the text contents of the current node, without markup. New lines are
3046
 * stripped and whitespace is collapsed, such that each character would be
3047
 * visible.
3048
 *
3049
 * In browsers that support it, innerText is used.  Other browsers attempt to
3050
 * simulate it via node traversal.  Line breaks are canonicalized in IE.
3051
 *
3052
 * @param {Node} node The node from which we are getting content.
3053
 * @return {string} The text content.
3054
 */
3055
goog.dom.DomHelper.prototype.getTextContent = goog.dom.getTextContent;
3056

3057

3058
/**
3059
 * Returns the text length of the text contained in a node, without markup. This
3060
 * is equivalent to the selection length if the node was selected, or the number
3061
 * of cursor movements to traverse the node. Images & BRs take one space.  New
3062
 * lines are ignored.
3063
 *
3064
 * @param {Node} node The node whose text content length is being calculated.
3065
 * @return {number} The length of {@code node}'s text content.
3066
 */
3067
goog.dom.DomHelper.prototype.getNodeTextLength = goog.dom.getNodeTextLength;
3068

3069

3070
/**
3071
 * Returns the text offset of a node relative to one of its ancestors. The text
3072
 * length is the same as the length calculated by
3073
 * {@code goog.dom.getNodeTextLength}.
3074
 *
3075
 * @param {Node} node The node whose offset is being calculated.
3076
 * @param {Node=} opt_offsetParent Defaults to the node's owner document's body.
3077
 * @return {number} The text offset.
3078
 */
3079
goog.dom.DomHelper.prototype.getNodeTextOffset = goog.dom.getNodeTextOffset;
3080

3081

3082
/**
3083
 * Returns the node at a given offset in a parent node.  If an object is
3084
 * provided for the optional third parameter, the node and the remainder of the
3085
 * offset will stored as properties of this object.
3086
 * @param {Node} parent The parent node.
3087
 * @param {number} offset The offset into the parent node.
3088
 * @param {Object=} opt_result Object to be used to store the return value. The
3089
 *     return value will be stored in the form {node: Node, remainder: number}
3090
 *     if this object is provided.
3091
 * @return {Node} The node at the given offset.
3092
 */
3093
goog.dom.DomHelper.prototype.getNodeAtOffset = goog.dom.getNodeAtOffset;
3094

3095

3096
/**
3097
 * Returns true if the object is a {@code NodeList}.  To qualify as a NodeList,
3098
 * the object must have a numeric length property and an item function (which
3099
 * has type 'string' on IE for some reason).
3100
 * @param {Object} val Object to test.
3101
 * @return {boolean} Whether the object is a NodeList.
3102
 */
3103
goog.dom.DomHelper.prototype.isNodeList = goog.dom.isNodeList;
3104

3105

3106
/**
3107
 * Walks up the DOM hierarchy returning the first ancestor that has the passed
3108
 * tag name and/or class name. If the passed element matches the specified
3109
 * criteria, the element itself is returned.
3110
 * @param {Node} element The DOM node to start with.
3111
 * @param {?(goog.dom.TagName<T>|string)=} opt_tag The tag name to match (or
3112
 *     null/undefined to match only based on class name).
3113
 * @param {?string=} opt_class The class name to match (or null/undefined to
3114
 *     match only based on tag name).
3115
 * @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
3116
 *     dom.
3117
 * @return {?R} The first ancestor that matches the passed criteria, or
3118
 *     null if no match is found. The return type is {?Element} if opt_tag is
3119
 *     not a member of goog.dom.TagName or a more specific type if it is (e.g.
3120
 *     {?HTMLAnchorElement} for goog.dom.TagName.A).
3121
 * @template T
3122
 * @template R := cond(isUnknown(T), 'Element', T) =:
3123
 */
3124
goog.dom.DomHelper.prototype.getAncestorByTagNameAndClass =
3125
    goog.dom.getAncestorByTagNameAndClass;
3126

3127

3128
/**
3129
 * Walks up the DOM hierarchy returning the first ancestor that has the passed
3130
 * class name. If the passed element matches the specified criteria, the
3131
 * element itself is returned.
3132
 * @param {Node} element The DOM node to start with.
3133
 * @param {string} class The class name to match.
3134
 * @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
3135
 *     dom.
3136
 * @return {Element} The first ancestor that matches the passed criteria, or
3137
 *     null if none match.
3138
 */
3139
goog.dom.DomHelper.prototype.getAncestorByClass = goog.dom.getAncestorByClass;
3140

3141

3142
/**
3143
 * Walks up the DOM hierarchy returning the first ancestor that passes the
3144
 * matcher function.
3145
 * @param {Node} element The DOM node to start with.
3146
 * @param {function(Node) : boolean} matcher A function that returns true if the
3147
 *     passed node matches the desired criteria.
3148
 * @param {boolean=} opt_includeNode If true, the node itself is included in
3149
 *     the search (the first call to the matcher will pass startElement as
3150
 *     the node to test).
3151
 * @param {number=} opt_maxSearchSteps Maximum number of levels to search up the
3152
 *     dom.
3153
 * @return {Node} DOM node that matched the matcher, or null if there was
3154
 *     no match.
3155
 */
3156
goog.dom.DomHelper.prototype.getAncestor = goog.dom.getAncestor;
3157

3158

3159
/**
3160
 * Gets '2d' context of a canvas. Shortcut for canvas.getContext('2d') with a
3161
 * type information.
3162
 * @param {!HTMLCanvasElement} canvas
3163
 * @return {!CanvasRenderingContext2D}
3164
 */
3165
goog.dom.DomHelper.prototype.getCanvasContext2D = goog.dom.getCanvasContext2D;
3166

3167