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

/*
 * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
 * Copyright (C) 2012 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
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#include "core/css/CSSGroupingRule.h"

#include "bindings/core/v8/ExceptionState.h"
#include "core/css/CSSRuleList.h"
#include "core/css/CSSStyleSheet.h"
#include "core/css/parser/CSSParser.h"
#include "core/dom/ExceptionCode.h"
#include "core/frame/UseCounter.h"
#include "wtf/text/StringBuilder.h"

namespace blink {

CSSGroupingRule::CSSGroupingRule(StyleRuleGroup* groupRule,
                                 CSSStyleSheet* parent)
    : CSSRule(parent),
      m_groupRule(groupRule),
      m_childRuleCSSOMWrappers(groupRule->childRules().size()) {}

CSSGroupingRule::~CSSGroupingRule() {}

unsigned CSSGroupingRule::insertRule(const String& ruleString,
                                     unsigned index,
                                     ExceptionState& exceptionState) {
  ASSERT(m_childRuleCSSOMWrappers.size() == m_groupRule->childRules().size());

  if (index > m_groupRule->childRules().size()) {
    exceptionState.throwDOMException(
        IndexSizeError,
        "the index " + String::number(index) +
            " must be less than or equal to the length of the rule list.");
    return 0;
  }

  CSSStyleSheet* styleSheet = parentStyleSheet();
  CSSParserContext context(parserContext(), UseCounter::getFrom(styleSheet));
  StyleRuleBase* newRule = CSSParser::parseRule(
      context, styleSheet ? styleSheet->contents() : nullptr, ruleString);
  if (!newRule) {
    exceptionState.throwDOMException(
        SyntaxError,
        "the rule '" + ruleString + "' is invalid and cannot be parsed.");
    return 0;
  }

  if (newRule->isNamespaceRule()) {
    exceptionState.throwDOMException(
        HierarchyRequestError,
        "'@namespace' rules cannot be inserted inside a group rule.");
    return 0;
  }

  if (newRule->isImportRule()) {
    // FIXME: an HierarchyRequestError should also be thrown for a nested @media
    // rule. They are currently not getting parsed, resulting in a SyntaxError
    // to get raised above.
    exceptionState.throwDOMException(
        HierarchyRequestError,
        "'@import' rules cannot be inserted inside a group rule.");
    return 0;
  }
  CSSStyleSheet::RuleMutationScope mutationScope(this);

  m_groupRule->wrapperInsertRule(index, newRule);

  m_childRuleCSSOMWrappers.insert(index, Member<CSSRule>(nullptr));
  return index;
}

void CSSGroupingRule::deleteRule(unsigned index,
                                 ExceptionState& exceptionState) {
  ASSERT(m_childRuleCSSOMWrappers.size() == m_groupRule->childRules().size());

  if (index >= m_groupRule->childRules().size()) {
    exceptionState.throwDOMException(
        IndexSizeError, "the index " + String::number(index) +
                            " is greated than the length of the rule list.");
    return;
  }

  CSSStyleSheet::RuleMutationScope mutationScope(this);

  m_groupRule->wrapperRemoveRule(index);

  if (m_childRuleCSSOMWrappers[index])
    m_childRuleCSSOMWrappers[index]->setParentRule(0);
  m_childRuleCSSOMWrappers.remove(index);
}

void CSSGroupingRule::appendCSSTextForItems(StringBuilder& result) const {
  unsigned size = length();
  for (unsigned i = 0; i < size; ++i) {
    result.append("  ");
    result.append(item(i)->cssText());
    result.append('\n');
  }
}

unsigned CSSGroupingRule::length() const {
  return m_groupRule->childRules().size();
}

CSSRule* CSSGroupingRule::item(unsigned index) const {
  if (index >= length())
    return nullptr;
  ASSERT(m_childRuleCSSOMWrappers.size() == m_groupRule->childRules().size());
  Member<CSSRule>& rule = m_childRuleCSSOMWrappers[index];
  if (!rule)
    rule = m_groupRule->childRules()[index]->createCSSOMWrapper(
        const_cast<CSSGroupingRule*>(this));
  return rule.get();
}

CSSRuleList* CSSGroupingRule::cssRules() const {
  if (!m_ruleListCSSOMWrapper)
    m_ruleListCSSOMWrapper = LiveCSSRuleList<CSSGroupingRule>::create(
        const_cast<CSSGroupingRule*>(this));
  return m_ruleListCSSOMWrapper.get();
}

void CSSGroupingRule::reattach(StyleRuleBase* rule) {
  ASSERT(rule);
  m_groupRule = static_cast<StyleRuleGroup*>(rule);
  for (unsigned i = 0; i < m_childRuleCSSOMWrappers.size(); ++i) {
    if (m_childRuleCSSOMWrappers[i])
      m_childRuleCSSOMWrappers[i]->reattach(m_groupRule->childRules()[i].get());
  }
}

DEFINE_TRACE(CSSGroupingRule) {
  CSSRule::trace(visitor);
  visitor->trace(m_childRuleCSSOMWrappers);
  visitor->trace(m_groupRule);
  visitor->trace(m_ruleListCSSOMWrapper);
}

}  // namespace blink