DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (286cbc3b542b)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * nsIContentSerializer implementation that can be used with an
 * nsIDocumentEncoder to convert an XHTML (not HTML!) DOM to an XHTML
 * string that could be parsed into more or less the original DOM.
 */

#include "nsXHTMLContentSerializer.h"

#include "mozilla/dom/Element.h"
#include "nsIContent.h"
#include "mozilla/dom/Document.h"
#include "nsElementTable.h"
#include "nsNameSpaceManager.h"
#include "nsString.h"
#include "nsUnicharUtils.h"
#include "nsIServiceManager.h"
#include "nsIDocumentEncoder.h"
#include "nsGkAtoms.h"
#include "nsIURI.h"
#include "nsNetUtil.h"
#include "nsEscape.h"
#include "nsCRT.h"
#include "nsContentUtils.h"
#include "nsIScriptElement.h"
#include "nsStubMutationObserver.h"
#include "nsAttrName.h"
#include "nsComputedDOMStyle.h"

using namespace mozilla;
using namespace mozilla::dom;

static const int32_t kLongLineLen = 128;

#define kXMLNS "xmlns"

nsresult NS_NewXHTMLContentSerializer(nsIContentSerializer** aSerializer) {
  RefPtr<nsXHTMLContentSerializer> it = new nsXHTMLContentSerializer();
  it.forget(aSerializer);
  return NS_OK;
}

nsXHTMLContentSerializer::nsXHTMLContentSerializer()
    : mIsHTMLSerializer(false),
      mIsCopying(false),
      mDisableEntityEncoding(0),
      mRewriteEncodingDeclaration(false),
      mIsFirstChildOfOL(false) {}

nsXHTMLContentSerializer::~nsXHTMLContentSerializer() {
  NS_ASSERTION(mOLStateStack.IsEmpty(), "Expected OL State stack to be empty");
}

NS_IMETHODIMP
nsXHTMLContentSerializer::Init(uint32_t aFlags, uint32_t aWrapColumn,
                               const Encoding* aEncoding, bool aIsCopying,
                               bool aRewriteEncodingDeclaration,
                               bool* aNeedsPreformatScanning,
                               nsAString& aOutput) {
  // The previous version of the HTML serializer did implicit wrapping
  // when there is no flags, so we keep wrapping in order to keep
  // compatibility with the existing calling code
  // XXXLJ perhaps should we remove this default settings later ?
  if (aFlags & nsIDocumentEncoder::OutputFormatted) {
    aFlags = aFlags | nsIDocumentEncoder::OutputWrap;
  }

  nsresult rv;
  rv = nsXMLContentSerializer::Init(aFlags, aWrapColumn, aEncoding, aIsCopying,
                                    aRewriteEncodingDeclaration,
                                    aNeedsPreformatScanning, aOutput);
  NS_ENSURE_SUCCESS(rv, rv);

  mRewriteEncodingDeclaration = aRewriteEncodingDeclaration;
  mIsCopying = aIsCopying;
  mIsFirstChildOfOL = false;
  mInBody = 0;
  mDisableEntityEncoding = 0;
  mBodyOnly = (mFlags & nsIDocumentEncoder::OutputBodyOnly) ? true : false;

  return NS_OK;
}

// See if the string has any lines longer than longLineLen:
// if so, we presume formatting is wonky (e.g. the node has been edited)
// and we'd better rewrap the whole text node.
bool nsXHTMLContentSerializer::HasLongLines(const nsString& text,
                                            int32_t& aLastNewlineOffset) {
  uint32_t start = 0;
  uint32_t theLen = text.Length();
  bool rv = false;
  aLastNewlineOffset = kNotFound;
  for (start = 0; start < theLen;) {
    int32_t eol = text.FindChar('\n', start);
    if (eol < 0) {
      eol = text.Length();
    } else {
      aLastNewlineOffset = eol;
    }
    if (int32_t(eol - start) > kLongLineLen) rv = true;
    start = eol + 1;
  }
  return rv;
}

NS_IMETHODIMP
nsXHTMLContentSerializer::AppendText(nsIContent* aText, int32_t aStartOffset,
                                     int32_t aEndOffset) {
  NS_ENSURE_ARG(aText);
  NS_ENSURE_STATE(mOutput);

  nsAutoString data;
  nsresult rv;

  rv = AppendTextData(aText, aStartOffset, aEndOffset, data, true);
  if (NS_FAILED(rv)) return NS_ERROR_FAILURE;

  if (mDoRaw || PreLevel() > 0) {
    NS_ENSURE_TRUE(AppendToStringConvertLF(data, *mOutput),
                   NS_ERROR_OUT_OF_MEMORY);
  } else if (mDoFormat) {
    NS_ENSURE_TRUE(AppendToStringFormatedWrapped(data, *mOutput),
                   NS_ERROR_OUT_OF_MEMORY);
  } else if (mDoWrap) {
    NS_ENSURE_TRUE(AppendToStringWrapped(data, *mOutput),
                   NS_ERROR_OUT_OF_MEMORY);
  } else {
    int32_t lastNewlineOffset = kNotFound;
    if (HasLongLines(data, lastNewlineOffset)) {
      // We have long lines, rewrap
      mDoWrap = true;
      bool result = AppendToStringWrapped(data, *mOutput);
      mDoWrap = false;
      NS_ENSURE_TRUE(result, NS_ERROR_OUT_OF_MEMORY);
    } else {
      NS_ENSURE_TRUE(AppendToStringConvertLF(data, *mOutput),
                     NS_ERROR_OUT_OF_MEMORY);
    }
  }

  return NS_OK;
}

bool nsXHTMLContentSerializer::SerializeAttributes(
    Element* aElement, Element* aOriginalElement, nsAString& aTagPrefix,
    const nsAString& aTagNamespaceURI, nsAtom* aTagName, nsAString& aStr,
    uint32_t aSkipAttr, bool aAddNSAttr) {
  nsresult rv;
  uint32_t index, count;
  nsAutoString prefixStr, uriStr, valueStr;
  nsAutoString xmlnsStr;
  xmlnsStr.AssignLiteral(kXMLNS);

  int32_t contentNamespaceID = aElement->GetNameSpaceID();

  MaybeSerializeIsValue(aElement, aStr);

  // this method is not called by nsHTMLContentSerializer
  // so we don't have to check HTML element, just XHTML

  if (mIsCopying && kNameSpaceID_XHTML == contentNamespaceID) {
    // Need to keep track of OL and LI elements in order to get ordinal number
    // for the LI.
    if (aTagName == nsGkAtoms::ol) {
      // We are copying and current node is an OL;
      // Store its start attribute value in olState->startVal.
      nsAutoString start;
      int32_t startAttrVal = 0;
      aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::start, start);
      if (!start.IsEmpty()) {
        nsresult rv = NS_OK;
        startAttrVal = start.ToInteger(&rv);
        // If OL has "start" attribute, first LI element has to start with that
        // value Therefore subtracting 1 as all the LI elements are incrementing
        // it before using it; In failure of ToInteger(), default StartAttrValue
        // to 0.
        if (NS_SUCCEEDED(rv))
          --startAttrVal;
        else
          startAttrVal = 0;
      }
      olState state(startAttrVal, true);
      mOLStateStack.AppendElement(state);
    } else if (aTagName == nsGkAtoms::li) {
      mIsFirstChildOfOL = IsFirstChildOfOL(aOriginalElement);
      if (mIsFirstChildOfOL) {
        // If OL is parent of this LI, serialize attributes in different manner.
        NS_ENSURE_TRUE(SerializeLIValueAttribute(aElement, aStr), false);
      }
    }
  }

  // If we had to add a new namespace declaration, serialize
  // and push it on the namespace stack
  if (aAddNSAttr) {
    if (aTagPrefix.IsEmpty()) {
      // Serialize default namespace decl
      NS_ENSURE_TRUE(
          SerializeAttr(EmptyString(), xmlnsStr, aTagNamespaceURI, aStr, true),
          false);
    } else {
      // Serialize namespace decl
      NS_ENSURE_TRUE(
          SerializeAttr(xmlnsStr, aTagPrefix, aTagNamespaceURI, aStr, true),
          false);
    }
    PushNameSpaceDecl(aTagPrefix, aTagNamespaceURI, aOriginalElement);
  }

  count = aElement->GetAttrCount();

  // Now serialize each of the attributes
  // XXX Unfortunately we need a namespace manager to get
  // attribute URIs.
  for (index = 0; index < count; index++) {
    if (aSkipAttr == index) {
      continue;
    }

    dom::BorrowedAttrInfo info = aElement->GetAttrInfoAt(index);
    const nsAttrName* name = info.mName;

    int32_t namespaceID = name->NamespaceID();
    nsAtom* attrName = name->LocalName();
    nsAtom* attrPrefix = name->GetPrefix();

    // Filter out any attribute starting with [-|_]moz
    nsDependentAtomString attrNameStr(attrName);
    if (StringBeginsWith(attrNameStr, NS_LITERAL_STRING("_moz")) ||
        StringBeginsWith(attrNameStr, NS_LITERAL_STRING("-moz"))) {
      continue;
    }

    if (attrPrefix) {
      attrPrefix->ToString(prefixStr);
    } else {
      prefixStr.Truncate();
    }

    bool addNSAttr = false;
    if (kNameSpaceID_XMLNS != namespaceID) {
      nsContentUtils::NameSpaceManager()->GetNameSpaceURI(namespaceID, uriStr);
      addNSAttr = ConfirmPrefix(prefixStr, uriStr, aOriginalElement, true);
    }

    info.mValue->ToString(valueStr);

    nsDependentAtomString nameStr(attrName);
    bool isJS = false;

    if (kNameSpaceID_XHTML == contentNamespaceID) {
      if (mIsCopying && mIsFirstChildOfOL && (aTagName == nsGkAtoms::li) &&
          (attrName == nsGkAtoms::value)) {
        // This is handled separately in SerializeLIValueAttribute()
        continue;
      }

      isJS = IsJavaScript(aElement, attrName, namespaceID, valueStr);

      if (namespaceID == kNameSpaceID_None &&
          ((attrName == nsGkAtoms::href) || (attrName == nsGkAtoms::src))) {
        // Make all links absolute when converting only the selection:
        if (mFlags & nsIDocumentEncoder::OutputAbsoluteLinks) {
          // Would be nice to handle OBJECT tags,
          // but that gets more complicated since we have to
          // search the tag list for CODEBASE as well.
          // For now, just leave them relative.
          nsIURI* uri = aElement->GetBaseURI();
          if (uri) {
            nsAutoString absURI;
            rv = NS_MakeAbsoluteURI(absURI, valueStr, uri);
            if (NS_SUCCEEDED(rv)) {
              valueStr = absURI;
            }
          }
        }
      }

      if (mRewriteEncodingDeclaration && aTagName == nsGkAtoms::meta &&
          attrName == nsGkAtoms::content) {
        // If we're serializing a <meta http-equiv="content-type">,
        // use the proper value, rather than what's in the document.
        nsAutoString header;
        aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::httpEquiv, header);
        if (header.LowerCaseEqualsLiteral("content-type")) {
          valueStr = NS_LITERAL_STRING("text/html; charset=") +
                     NS_ConvertASCIItoUTF16(mCharset);
        }
      }

      // Expand shorthand attribute.
      if (namespaceID == kNameSpaceID_None &&
          IsShorthandAttr(attrName, aTagName) && valueStr.IsEmpty()) {
        valueStr = nameStr;
      }
    } else {
      isJS = IsJavaScript(aElement, attrName, namespaceID, valueStr);
    }

    NS_ENSURE_TRUE(SerializeAttr(prefixStr, nameStr, valueStr, aStr, !isJS),
                   false);

    if (addNSAttr) {
      NS_ASSERTION(!prefixStr.IsEmpty(),
                   "Namespaced attributes must have a prefix");
      NS_ENSURE_TRUE(SerializeAttr(xmlnsStr, prefixStr, uriStr, aStr, true),
                     false);
      PushNameSpaceDecl(prefixStr, uriStr, aOriginalElement);
    }
  }

  return true;
}

bool nsXHTMLContentSerializer::AfterElementStart(nsIContent* aContent,
                                                 nsIContent* aOriginalElement,
                                                 nsAString& aStr) {
  if (mRewriteEncodingDeclaration && aContent->IsHTMLElement(nsGkAtoms::head)) {
    // Check if there already are any content-type meta children.
    // If there are, they will be modified to use the correct charset.
    // If there aren't, we'll insert one here.
    bool hasMeta = false;
    for (nsIContent* child = aContent->GetFirstChild(); child;
         child = child->GetNextSibling()) {
      if (child->IsHTMLElement(nsGkAtoms::meta) &&
          child->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::content)) {
        nsAutoString header;
        child->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::httpEquiv,
                                    header);

        if (header.LowerCaseEqualsLiteral("content-type")) {
          hasMeta = true;
          break;
        }
      }
    }

    if (!hasMeta) {
      NS_ENSURE_TRUE(AppendNewLineToString(aStr), false);
      if (mDoFormat) {
        NS_ENSURE_TRUE(AppendIndentation(aStr), false);
      }
      NS_ENSURE_TRUE(
          AppendToString(NS_LITERAL_STRING("<meta http-equiv=\"content-type\""),
                         aStr),
          false);
      NS_ENSURE_TRUE(
          AppendToString(NS_LITERAL_STRING(" content=\"text/html; charset="),
                         aStr),
          false);
      NS_ENSURE_TRUE(AppendToString(NS_ConvertASCIItoUTF16(mCharset), aStr),
                     false);
      if (mIsHTMLSerializer) {
        NS_ENSURE_TRUE(AppendToString(NS_LITERAL_STRING("\">"), aStr), false);
      } else {
        NS_ENSURE_TRUE(AppendToString(NS_LITERAL_STRING("\" />"), aStr), false);
      }
    }
  }

  return true;
}

void nsXHTMLContentSerializer::AfterElementEnd(nsIContent* aContent,
                                               nsAString& aStr) {
  NS_ASSERTION(!mIsHTMLSerializer,
               "nsHTMLContentSerializer shouldn't call this method !");

  // this method is not called by nsHTMLContentSerializer
  // so we don't have to check HTML element, just XHTML
  if (aContent->IsHTMLElement(nsGkAtoms::body)) {
    --mInBody;
  }
}

NS_IMETHODIMP
nsXHTMLContentSerializer::AppendDocumentStart(Document* aDocument) {
  if (!mBodyOnly) {
    return nsXMLContentSerializer::AppendDocumentStart(aDocument);
  }

  return NS_OK;
}

bool nsXHTMLContentSerializer::CheckElementStart(Element* aElement,
                                                 bool& aForceFormat,
                                                 nsAString& aStr,
                                                 nsresult& aResult) {
  aResult = NS_OK;

  // The _moz_dirty attribute is emitted by the editor to
  // indicate that this element should be pretty printed
  // even if we're not in pretty printing mode
  aForceFormat = !(mFlags & nsIDocumentEncoder::OutputIgnoreMozDirty) &&
                 aElement->HasAttr(kNameSpaceID_None, nsGkAtoms::mozdirty);

  if (aElement->IsHTMLElement(nsGkAtoms::br) &&
      (mFlags & nsIDocumentEncoder::OutputNoFormattingInPre) &&
      PreLevel() > 0) {
    aResult = AppendNewLineToString(aStr) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
    return false;
  }

  if (aElement->IsHTMLElement(nsGkAtoms::body)) {
    ++mInBody;
  }

  return true;
}

bool nsXHTMLContentSerializer::CheckElementEnd(Element* aElement,
                                               Element* aOriginalElement,
                                               bool& aForceFormat,
                                               nsAString& aStr) {
  NS_ASSERTION(!mIsHTMLSerializer,
               "nsHTMLContentSerializer shouldn't call this method !");

  aForceFormat = !(mFlags & nsIDocumentEncoder::OutputIgnoreMozDirty) &&
                 aElement->HasAttr(kNameSpaceID_None, nsGkAtoms::mozdirty);

  if (mIsCopying && aElement->IsHTMLElement(nsGkAtoms::ol)) {
    NS_ASSERTION((!mOLStateStack.IsEmpty()), "Cannot have an empty OL Stack");
    /* Though at this point we must always have an state to be deleted as all
       the OL opening tags are supposed to push an olState object to the stack*/
    if (!mOLStateStack.IsEmpty()) {
      mOLStateStack.RemoveLastElement();
    }
  }

  bool dummyFormat;
  return nsXMLContentSerializer::CheckElementEnd(aElement, aOriginalElement,
                                                 dummyFormat, aStr);
}

bool nsXHTMLContentSerializer::AppendAndTranslateEntities(
    const nsAString& aStr, nsAString& aOutputStr) {
  if (mBodyOnly && !mInBody) {
    return true;
  }

  if (mDisableEntityEncoding) {
    return aOutputStr.Append(aStr, fallible);
  }

  return nsXMLContentSerializer::AppendAndTranslateEntities(aStr, aOutputStr);
}

bool nsXHTMLContentSerializer::IsShorthandAttr(const nsAtom* aAttrName,
                                               const nsAtom* aElementName) {
  // checked
  if ((aAttrName == nsGkAtoms::checked) && (aElementName == nsGkAtoms::input)) {
    return true;
  }

  // compact
  if ((aAttrName == nsGkAtoms::compact) &&
      (aElementName == nsGkAtoms::dir || aElementName == nsGkAtoms::dl ||
       aElementName == nsGkAtoms::menu || aElementName == nsGkAtoms::ol ||
       aElementName == nsGkAtoms::ul)) {
    return true;
  }

  // declare
  if ((aAttrName == nsGkAtoms::declare) &&
      (aElementName == nsGkAtoms::object)) {
    return true;
  }

  // defer
  if ((aAttrName == nsGkAtoms::defer) && (aElementName == nsGkAtoms::script)) {
    return true;
  }

  // disabled
  if ((aAttrName == nsGkAtoms::disabled) &&
      (aElementName == nsGkAtoms::button || aElementName == nsGkAtoms::input ||
       aElementName == nsGkAtoms::optgroup ||
       aElementName == nsGkAtoms::option || aElementName == nsGkAtoms::select ||
       aElementName == nsGkAtoms::textarea)) {
    return true;
  }

  // ismap
  if ((aAttrName == nsGkAtoms::ismap) &&
      (aElementName == nsGkAtoms::img || aElementName == nsGkAtoms::input)) {
    return true;
  }

  // multiple
  if ((aAttrName == nsGkAtoms::multiple) &&
      (aElementName == nsGkAtoms::select)) {
    return true;
  }

  // noresize
  if ((aAttrName == nsGkAtoms::noresize) &&
      (aElementName == nsGkAtoms::frame)) {
    return true;
  }

  // noshade
  if ((aAttrName == nsGkAtoms::noshade) && (aElementName == nsGkAtoms::hr)) {
    return true;
  }

  // nowrap
  if ((aAttrName == nsGkAtoms::nowrap) &&
      (aElementName == nsGkAtoms::td || aElementName == nsGkAtoms::th)) {
    return true;
  }

  // readonly
  if ((aAttrName == nsGkAtoms::readonly) &&
      (aElementName == nsGkAtoms::input ||
       aElementName == nsGkAtoms::textarea)) {
    return true;
  }

  // selected
  if ((aAttrName == nsGkAtoms::selected) &&
      (aElementName == nsGkAtoms::option)) {
    return true;
  }

  // autoplay and controls
  if ((aElementName == nsGkAtoms::video || aElementName == nsGkAtoms::audio) &&
      (aAttrName == nsGkAtoms::autoplay || aAttrName == nsGkAtoms::muted ||
       aAttrName == nsGkAtoms::controls)) {
    return true;
  }

  return false;
}

bool nsXHTMLContentSerializer::LineBreakBeforeOpen(int32_t aNamespaceID,
                                                   nsAtom* aName) {
  if (aNamespaceID != kNameSpaceID_XHTML) {
    return mAddSpace;
  }

  if (aName == nsGkAtoms::title || aName == nsGkAtoms::meta ||
      aName == nsGkAtoms::link || aName == nsGkAtoms::style ||
      aName == nsGkAtoms::select || aName == nsGkAtoms::option ||
      aName == nsGkAtoms::script || aName == nsGkAtoms::html) {
    return true;
  }

  return nsHTMLElement::IsBlock(nsHTMLTags::CaseSensitiveAtomTagToId(aName));
}

bool nsXHTMLContentSerializer::LineBreakAfterOpen(int32_t aNamespaceID,
                                                  nsAtom* aName) {
  if (aNamespaceID != kNameSpaceID_XHTML) {
    return false;
  }

  if ((aName == nsGkAtoms::html) || (aName == nsGkAtoms::head) ||
      (aName == nsGkAtoms::body) || (aName == nsGkAtoms::ul) ||
      (aName == nsGkAtoms::ol) || (aName == nsGkAtoms::dl) ||
      (aName == nsGkAtoms::table) || (aName == nsGkAtoms::tbody) ||
      (aName == nsGkAtoms::tr) || (aName == nsGkAtoms::br) ||
      (aName == nsGkAtoms::meta) || (aName == nsGkAtoms::link) ||
      (aName == nsGkAtoms::script) || (aName == nsGkAtoms::select) ||
      (aName == nsGkAtoms::map) || (aName == nsGkAtoms::area) ||
      (aName == nsGkAtoms::style)) {
    return true;
  }

  return false;
}

bool nsXHTMLContentSerializer::LineBreakBeforeClose(int32_t aNamespaceID,
                                                    nsAtom* aName) {
  if (aNamespaceID != kNameSpaceID_XHTML) {
    return false;
  }

  if ((aName == nsGkAtoms::html) || (aName == nsGkAtoms::head) ||
      (aName == nsGkAtoms::body) || (aName == nsGkAtoms::ul) ||
      (aName == nsGkAtoms::ol) || (aName == nsGkAtoms::dl) ||
      (aName == nsGkAtoms::select) || (aName == nsGkAtoms::table) ||
      (aName == nsGkAtoms::tbody)) {
    return true;
  }
  return false;
}

bool nsXHTMLContentSerializer::LineBreakAfterClose(int32_t aNamespaceID,
                                                   nsAtom* aName) {
  if (aNamespaceID != kNameSpaceID_XHTML) {
    return false;
  }

  if ((aName == nsGkAtoms::html) || (aName == nsGkAtoms::head) ||
      (aName == nsGkAtoms::body) || (aName == nsGkAtoms::tr) ||
      (aName == nsGkAtoms::th) || (aName == nsGkAtoms::td) ||
      (aName == nsGkAtoms::title) || (aName == nsGkAtoms::dt) ||
      (aName == nsGkAtoms::dd) || (aName == nsGkAtoms::select) ||
      (aName == nsGkAtoms::option) || (aName == nsGkAtoms::map)) {
    return true;
  }

  return nsHTMLElement::IsBlock(nsHTMLTags::CaseSensitiveAtomTagToId(aName));
}

void nsXHTMLContentSerializer::MaybeEnterInPreContent(nsIContent* aNode) {
  if (!ShouldMaintainPreLevel() || !aNode->IsHTMLElement()) {
    return;
  }

  if (IsElementPreformatted(aNode) ||
      aNode->IsAnyOfHTMLElements(nsGkAtoms::script, nsGkAtoms::style,
                                 nsGkAtoms::noscript, nsGkAtoms::noframes)) {
    PreLevel()++;
  }
}

void nsXHTMLContentSerializer::MaybeLeaveFromPreContent(nsIContent* aNode) {
  if (!ShouldMaintainPreLevel() || !aNode->IsHTMLElement()) {
    return;
  }

  if (IsElementPreformatted(aNode) ||
      aNode->IsAnyOfHTMLElements(nsGkAtoms::script, nsGkAtoms::style,
                                 nsGkAtoms::noscript, nsGkAtoms::noframes)) {
    --PreLevel();
  }
}

bool nsXHTMLContentSerializer::IsElementPreformatted(nsIContent* aNode) {
  MOZ_ASSERT(ShouldMaintainPreLevel(),
             "We should not be calling this needlessly");

  if (!aNode->IsElement()) {
    return false;
  }
  RefPtr<ComputedStyle> computedStyle =
      nsComputedDOMStyle::GetComputedStyleNoFlush(aNode->AsElement(), nullptr);
  if (computedStyle) {
    const nsStyleText* textStyle = computedStyle->StyleText();
    return textStyle->WhiteSpaceOrNewlineIsSignificant();
  }
  return false;
}

bool nsXHTMLContentSerializer::SerializeLIValueAttribute(nsIContent* aElement,
                                                         nsAString& aStr) {
  // We are copying and we are at the "first" LI node of OL in selected range.
  // It may not be the first LI child of OL but it's first in the selected
  // range. Note that we get into this condition only once per a OL.
  bool found = false;
  nsAutoString valueStr;

  olState state(0, false);

  if (!mOLStateStack.IsEmpty()) {
    state = mOLStateStack[mOLStateStack.Length() - 1];
    // isFirstListItem should be true only before the serialization of the
    // first item in the list.
    state.isFirstListItem = false;
    mOLStateStack[mOLStateStack.Length() - 1] = state;
  }

  int32_t startVal = state.startVal;
  int32_t offset = 0;

  // Traverse previous siblings until we find one with "value" attribute.
  // offset keeps track of how many previous siblings we had to traverse.
  nsIContent* currNode = aElement;
  while (currNode && !found) {
    if (currNode->IsHTMLElement(nsGkAtoms::li)) {
      currNode->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::value,
                                     valueStr);
      if (valueStr.IsEmpty()) {
        offset++;
      } else {
        found = true;
        nsresult rv = NS_OK;
        startVal = valueStr.ToInteger(&rv);
      }
    }
    currNode = currNode->GetPreviousSibling();
  }
  // If LI was not having "value", Set the "value" attribute for it.
  // Note that We are at the first LI in the selected range of OL.
  if (offset == 0 && found) {
    // offset = 0 => LI itself has the value attribute and we did not need to
    // traverse back. Just serialize value attribute like other tags.
    NS_ENSURE_TRUE(SerializeAttr(EmptyString(), NS_LITERAL_STRING("value"),
                                 valueStr, aStr, false),
                   false);
  } else if (offset == 1 && !found) {
    /*(offset = 1 && !found) means either LI is the first child node of OL
    and LI is not having "value" attribute.
    In that case we would not like to set "value" attribute to reduce the
    changes.
    */
    // do nothing...
  } else if (offset > 0) {
    // Set value attribute.
    nsAutoString valueStr;

    // As serializer needs to use this valueAttr we are creating here,
    valueStr.AppendInt(startVal + offset);
    NS_ENSURE_TRUE(SerializeAttr(EmptyString(), NS_LITERAL_STRING("value"),
                                 valueStr, aStr, false),
                   false);
  }

  return true;
}

bool nsXHTMLContentSerializer::IsFirstChildOfOL(nsIContent* aElement) {
  nsIContent* parent = aElement->GetParent();
  if (parent && parent->NodeName().LowerCaseEqualsLiteral("ol")) {
    if (!mOLStateStack.IsEmpty()) {
      olState state = mOLStateStack[mOLStateStack.Length() - 1];
      if (state.isFirstListItem) return true;
    }
  }

  return false;
}

bool nsXHTMLContentSerializer::HasNoChildren(nsIContent* aContent) {
  for (nsIContent* child = aContent->GetFirstChild(); child;
       child = child->GetNextSibling()) {
    if (!child->IsText()) return false;

    if (child->TextLength()) return false;
  }

  return true;
}