text: /*
   * Copyright (C) 2010 Google Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1.  Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   * 2.  Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "config.h"
  #include "core/dom/DOMTokenList.h"
  
  #include "bindings/v8/ExceptionState.h"
  #include "core/dom/ExceptionCode.h"
  #include "core/html/parser/HTMLParserIdioms.h"
  #include "wtf/text/StringBuilder.h"
  
  namespace WebCore {
  
  bool DOMTokenList::validateToken(const String& token, ExceptionState& exceptionState)
  {
      if (token.isEmpty()) {
          exceptionState.throwDOMException(SyntaxError, "The token provided must not be empty.");
          return false;
      }
  
      unsigned length = token.length();
      for (unsigned i = 0; i < length; ++i) {
          if (isHTMLSpace<UChar>(token[i])) {
              exceptionState.throwDOMException(InvalidCharacterError, "The token provided ('" + token + "') contains HTML space characters, which are not valid in tokens.");
              return false;
          }
      }
  
      return true;
  }
  
  bool DOMTokenList::validateTokens(const Vector<String>& tokens, ExceptionState& exceptionState)
  {
      for (size_t i = 0; i < tokens.size(); ++i) {
          if (!validateToken(tokens[i], exceptionState))
              return false;
      }
  
      return true;
  }
  
  bool DOMTokenList::contains(const AtomicString& token, ExceptionState& exceptionState) const
  {
      if (!validateToken(token, exceptionState))
          return false;
      return containsInternal(token);
  }
  
  void DOMTokenList::add(const AtomicString& token, ExceptionState& exceptionState)
  {
      Vector<String> tokens;
      tokens.append(token.string());
      add(tokens, exceptionState);
  }
  
  // Optimally, this should take a Vector<AtomicString> const ref in argument but the
  // bindings generator does not handle that.
  void DOMTokenList::add(const Vector<String>& tokens, ExceptionState& exceptionState)
  {
      Vector<String> filteredTokens;
      filteredTokens.reserveCapacity(tokens.size());
      for (size_t i = 0; i < tokens.size(); ++i) {
          if (!validateToken(tokens[i], exceptionState))
              return;
          if (containsInternal(AtomicString(tokens[i])))
              continue;
          if (filteredTokens.contains(tokens[i]))
              continue;
          filteredTokens.append(tokens[i]);
      }
  
      if (filteredTokens.isEmpty())
          return;
  
      setValue(addTokens(value(), filteredTokens));
  }
  
  void DOMTokenList::remove(const AtomicString& token, ExceptionState& exceptionState)
  {
      Vector<String> tokens;
      tokens.append(token.string());
      remove(tokens, exceptionState);
  }
  
  // Optimally, this should take a Vector<AtomicString> const ref in argument but the
  // bindings generator does not handle that.
  void DOMTokenList::remove(const Vector<String>& tokens, ExceptionState& exceptionState)
  {
      if (!validateTokens(tokens, exceptionState))
          return;
  
      // Check using containsInternal first since it is a lot faster than going
      // through the string character by character.
      bool found = false;
      for (size_t i = 0; i < tokens.size(); ++i) {
          if (containsInternal(AtomicString(tokens[i]))) {
              found = true;
              break;
          }
      }
  
      if (found)
          setValue(removeTokens(value(), tokens));
  }
  
  bool DOMTokenList::toggle(const AtomicString& token, ExceptionState& exceptionState)
  {
      if (!validateToken(token, exceptionState))
          return false;
  
      if (containsInternal(token)) {
          removeInternal(token);
          return false;
      }
      addInternal(token);
      return true;
  }
  
  bool DOMTokenList::toggle(const AtomicString& token, bool force, ExceptionState& exceptionState)
  {
      if (!validateToken(token, exceptionState))
          return false;
  
      if (force)
          addInternal(token);
      else
          removeInternal(token);
  
      return force;
  }
  
  void DOMTokenList::addInternal(const AtomicString& token)
  {
      if (!containsInternal(token))
          setValue(addToken(value(), token));
  }
  
  void DOMTokenList::removeInternal(const AtomicString& token)
  {
      // Check using contains first since it uses AtomicString comparisons instead
      // of character by character testing.
      if (!containsInternal(token))
          return;
      setValue(removeToken(value(), token));
  }
  
  AtomicString DOMTokenList::addToken(const AtomicString& input, const AtomicString& token)
  {
      Vector<String> tokens;
      tokens.append(token.string());
      return addTokens(input, tokens);
  }
  
  // This returns an AtomicString because it is always passed as argument to setValue() and setValue()
  // takes an AtomicString in argument.
  AtomicString DOMTokenList::addTokens(const AtomicString& input, const Vector<String>& tokens)
  {
      bool needsSpace = false;
  
      StringBuilder builder;
      if (!input.isEmpty()) {
          builder.append(input);
          needsSpace = !isHTMLSpace<UChar>(input[input.length() - 1]);
      }
  
      for (size_t i = 0; i < tokens.size(); ++i) {
          if (needsSpace)
              builder.append(' ');
          builder.append(tokens[i]);
          needsSpace = true;
      }
  
      return builder.toAtomicString();
  }
  
  AtomicString DOMTokenList::removeToken(const AtomicString& input, const AtomicString& token)
  {
      Vector<String> tokens;
      tokens.append(token.string());
      return removeTokens(input, tokens);
  }
  
  // This returns an AtomicString because it is always passed as argument to setValue() and setValue()
  // takes an AtomicString in argument.
  AtomicString DOMTokenList::removeTokens(const AtomicString& input, const Vector<String>& tokens)
  {
      // Algorithm defined at http://www.whatwg.org/specs/web-apps/current-work/multipage/common-microsyntaxes.html#remove-a-token-from-a-string
      // New spec is at http://dom.spec.whatwg.org/#remove-a-token-from-a-string
  
      unsigned inputLength = input.length();
      StringBuilder output; // 3
      output.reserveCapacity(inputLength);
      unsigned position = 0; // 4
  
      // Step 5
      while (position < inputLength) {
          if (isHTMLSpace<UChar>(input[position])) { // 6
              output.append(input[position++]); // 6.1, 6.2
              continue; // 6.3
          }
  
          // Step 7
          StringBuilder tokenBuilder;
          while (position < inputLength && isNotHTMLSpace<UChar>(input[position]))
              tokenBuilder.append(input[position++]);
  
          // Step 8
          String token = tokenBuilder.toString();
          if (tokens.contains(token)) {
              // Step 8.1
              while (position < inputLength && isHTMLSpace<UChar>(input[position]))
                  ++position;
  
              // Step 8.2
              size_t j = output.length();
              while (j > 0 && isHTMLSpace<UChar>(output[j - 1]))
                  --j;
              output.resize(j);
  
              // Step 8.3
              if (position < inputLength && !output.isEmpty())
                  output.append(' ');
          } else {
              output.append(token); // Step 9
          }
      }
  
      return output.toAtomicString();
  }
  
  } // namespace WebCore
  