1/*
2 * Copyright (C) 2011 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Neither the name of Google Inc. nor the names of its
11 * contributors may be used to endorse or promote products derived from
12 * this software without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
15 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
16 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
17 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
18 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
20 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "config.h"
28#include "core/html/HTMLContentElement.h"
29
30#include "core/HTMLNames.h"
31#include "core/css/SelectorChecker.h"
32#include "core/css/SiblingTraversalStrategies.h"
33#include "core/css/parser/CSSParser.h"
34#include "core/dom/QualifiedName.h"
35#include "core/dom/shadow/ElementShadow.h"
36#include "core/dom/shadow/ShadowRoot.h"
37#include "platform/RuntimeEnabledFeatures.h"
38
39namespace blink {
40
41using namespace HTMLNames;
42
43inline HTMLContentElement::HTMLContentElement(Document& document)
44    : InsertionPoint(contentTag, document)
45    , m_shouldParseSelect(false)
46    , m_isValidSelector(true)
47{
48}
49
50DEFINE_NODE_FACTORY(HTMLContentElement)
51
52HTMLContentElement::~HTMLContentElement()
53{
54}
55
56void HTMLContentElement::parseSelect()
57{
58    ASSERT(m_shouldParseSelect);
59
60    CSSParser parser(CSSParserContext(document(), 0));
61    parser.parseSelector(m_select, m_selectorList);
62    m_shouldParseSelect = false;
63    m_isValidSelector = validateSelect();
64    if (!m_isValidSelector) {
65        CSSSelectorList emptyList;
66        m_selectorList.adopt(emptyList);
67    }
68}
69
70void HTMLContentElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
71{
72    if (name == selectAttr) {
73        if (ShadowRoot* root = containingShadowRoot())
74            root->owner()->willAffectSelector();
75        m_shouldParseSelect = true;
76        m_select = value;
77    } else {
78        InsertionPoint::parseAttribute(name, value);
79    }
80}
81
82static inline bool includesDisallowedPseudoClass(const CSSSelector& selector)
83{
84    if (selector.pseudoType() == CSSSelector::PseudoNot) {
85        const CSSSelector* subSelector = selector.selectorList()->first();
86        return subSelector->match() == CSSSelector::PseudoClass;
87    }
88    return selector.match() == CSSSelector::PseudoClass;
89}
90
91bool HTMLContentElement::validateSelect() const
92{
93    ASSERT(!m_shouldParseSelect);
94
95    if (m_select.isNull() || m_select.isEmpty())
96        return true;
97
98    if (!m_selectorList.isValid())
99        return false;
100
101    bool allowAnyPseudoClasses = RuntimeEnabledFeatures::pseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled() || (containingShadowRoot() && containingShadowRoot()->type() == ShadowRoot::UserAgentShadowRoot);
102
103    for (const CSSSelector* selector = m_selectorList.first(); selector; selector = m_selectorList.next(*selector)) {
104        if (!selector->isCompound())
105            return false;
106        if (allowAnyPseudoClasses)
107            continue;
108        for (const CSSSelector* subSelector = selector; subSelector; subSelector = subSelector->tagHistory()) {
109            if (includesDisallowedPseudoClass(*subSelector))
110                return false;
111        }
112    }
113    return true;
114}
115
116static inline bool checkOneSelector(const CSSSelector& selector, const WillBeHeapVector<RawPtrWillBeMember<Node>, 32>& siblings, int nth)
117{
118    Element* element = toElement(siblings[nth]);
119    SelectorChecker selectorChecker(element->document(), SelectorChecker::CollectingCSSRules);
120    SelectorChecker::SelectorCheckingContext context(selector, element, SelectorChecker::VisitedMatchEnabled);
121    ShadowDOMSiblingTraversalStrategy strategy(siblings, nth);
122    return selectorChecker.match(context, strategy) == SelectorChecker::SelectorMatches;
123}
124
125bool HTMLContentElement::matchSelector(const WillBeHeapVector<RawPtrWillBeMember<Node>, 32>& siblings, int nth) const
126{
127    for (const CSSSelector* selector = selectorList().first(); selector; selector = CSSSelectorList::next(*selector)) {
128        if (checkOneSelector(*selector, siblings, nth))
129            return true;
130    }
131    return false;
132}
133
134}
135