third_party/WebKit/Source/core/css/CSSMarkup.cpp

/*
 * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
 * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc.
 * All rights reserved.
 * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
 * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
 * (http://www.torchmobile.com/)
 * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
 * Copyright (C) 2012 Intel Corporation. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "core/css/CSSMarkup.h"

#include "core/css/parser/CSSParserIdioms.h"
#include "wtf/HexNumber.h"
#include "wtf/text/StringBuffer.h"
#include "wtf/text/StringBuilder.h"

namespace blink {

template <typename CharacterType>
static inline bool isCSSTokenizerIdentifier(const CharacterType* characters,
                                            unsigned length) {
  const CharacterType* end = characters + length;

  // -?
  if (characters != end && characters[0] == '-')
    ++characters;

  // {nmstart}
  if (characters == end || !isNameStartCodePoint(characters[0]))
    return false;
  ++characters;

  // {nmchar}*
  for (; characters != end; ++characters) {
    if (!isNameCodePoint(characters[0]))
      return false;
  }

  return true;
}

// "ident" from the CSS tokenizer, minus backslash-escape sequences
static bool isCSSTokenizerIdentifier(const String& string) {
  unsigned length = string.length();

  if (!length)
    return false;

  if (string.is8Bit())
    return isCSSTokenizerIdentifier(string.characters8(), length);
  return isCSSTokenizerIdentifier(string.characters16(), length);
}

static void serializeCharacter(UChar32 c, StringBuilder& appendTo) {
  appendTo.append('\\');
  appendTo.append(c);
}

static void serializeCharacterAsCodePoint(UChar32 c, StringBuilder& appendTo) {
  appendTo.append('\\');
  appendUnsignedAsHex(c, appendTo, Lowercase);
  appendTo.append(' ');
}

void serializeIdentifier(const String& identifier,
                         StringBuilder& appendTo,
                         bool skipStartChecks) {
  bool isFirst = !skipStartChecks;
  bool isSecond = false;
  bool isFirstCharHyphen = false;
  unsigned index = 0;
  while (index < identifier.length()) {
    UChar32 c = identifier.characterStartingAt(index);
    if (c == 0) {
      // Check for lone surrogate which characterStartingAt does not return.
      c = identifier[index];
    }

    index += U16_LENGTH(c);

    if (c == 0)
      appendTo.append(0xfffd);
    else if (c <= 0x1f || c == 0x7f ||
             (0x30 <= c && c <= 0x39 &&
              (isFirst || (isSecond && isFirstCharHyphen))))
      serializeCharacterAsCodePoint(c, appendTo);
    else if (c == 0x2d && isFirst && index == identifier.length())
      serializeCharacter(c, appendTo);
    else if (0x80 <= c || c == 0x2d || c == 0x5f || (0x30 <= c && c <= 0x39) ||
             (0x41 <= c && c <= 0x5a) || (0x61 <= c && c <= 0x7a))
      appendTo.append(c);
    else
      serializeCharacter(c, appendTo);

    if (isFirst) {
      isFirst = false;
      isSecond = true;
      isFirstCharHyphen = (c == 0x2d);
    } else if (isSecond) {
      isSecond = false;
    }
  }
}

void serializeString(const String& string, StringBuilder& appendTo) {
  appendTo.append('\"');

  unsigned index = 0;
  while (index < string.length()) {
    UChar32 c = string.characterStartingAt(index);
    index += U16_LENGTH(c);

    if (c <= 0x1f || c == 0x7f)
      serializeCharacterAsCodePoint(c, appendTo);
    else if (c == 0x22 || c == 0x5c)
      serializeCharacter(c, appendTo);
    else
      appendTo.append(c);
  }

  appendTo.append('\"');
}

String serializeString(const String& string) {
  StringBuilder builder;
  serializeString(string, builder);
  return builder.toString();
}

String serializeURI(const String& string) {
  return "url(" + serializeString(string) + ")";
}

String serializeFontFamily(const String& string) {
  return isCSSTokenizerIdentifier(string) ? string : serializeString(string);
}

}  // namespace blink