chromium/third_party/blink/renderer/core/css/css_selector_list.h

/*
 * Copyright (C) 2008 Apple 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. ``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
 * 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.
 */

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_CSS_CSS_SELECTOR_LIST_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_CSS_SELECTOR_LIST_H_

#include "base/types/pass_key.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/css/css_selector.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"

namespace blink {

// This class represents a CSS selector, i.e. a pattern of one or more
// simple selectors. https://www.w3.org/TR/css3-selectors/

// More specifically, a CSS selector is a chain of one or more sequences
// of simple selectors separated by combinators.
//
// For example, "div.c1 > span.c2 + .c3#ident" is represented as a
// CSSSelectorList that owns six CSSSelector instances.
//
// The simple selectors are stored in memory in the following order:
// .c3, #ident, span, .c2, div, .c1
// (See CSSSelector.h for more information.)
//
// First() and Next() can be used to traverse from right to left through
// the chain of sequences: .c3#ident then span.c2 then div.c1
//
// SelectorAt and IndexOfNextSelectorAfter provide an equivalent API:
// size_t index = 0;
// do {
//   const CSSSelector& sequence = selectorList.SelectorAt(index);
//   ...
//   index = IndexOfNextSelectorAfter(index);
// } while (index != kNotFound);
//
// Use CSSSelector::NextSimpleSelector() and
// CSSSelector::IsLastInComplexSelector() to traverse through each sequence of
// simple selectors, from .c3 to #ident; from span to .c2; from div to .c1
//
// StyleRule stores its selectors in an identical memory layout,
// but not as part of a CSSSelectorList (see its class comments).
// It reuses many of the exposed static member functions from CSSSelectorList
// to provide a subset of its API.
class CORE_EXPORT CSSSelectorList : public GarbageCollected<CSSSelectorList> { … };

inline const CSSSelector* CSSSelectorList::Next(const CSSSelector& current) { … }

inline CSSSelector* CSSSelectorList::Next(CSSSelector& current) { … }

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_CSS_CSS_SELECTOR_LIST_H_