1/*
2 * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
3 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public License
16 * along with this library; see the file COPYING.LIB. If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 *
20*/
21
22#pragma once
23
24#include <wtf/Forward.h>
25#include <wtf/RefCounted.h>
26
27// This implements a counter tree that is used for finding parents in counters() lookup,
28// and for propagating count changes when nodes are added or removed.
29
30// Parents represent unique counters and their scope, which are created either explicitly
31// by "counter-reset" style rules or implicitly by referring to a counter that is not in scope.
32// Such nodes are tagged as "reset" nodes, although they are not all due to "counter-reset".
33
34// Not that render tree children are often counter tree siblings due to counter scoping rules.
35
36namespace WebCore {
37
38class RenderCounter;
39class RenderElement;
40
41class CounterNode : public RefCounted<CounterNode> {
42public:
43 static Ref<CounterNode> create(RenderElement&, bool isReset, int value);
44 ~CounterNode();
45 bool actsAsReset() const { return m_hasResetType || !m_parent; }
46 bool hasResetType() const { return m_hasResetType; }
47 int value() const { return m_value; }
48 int countInParent() const { return m_countInParent; }
49 RenderElement& owner() const { return m_owner; }
50 void addRenderer(RenderCounter&);
51 void removeRenderer(RenderCounter&);
52
53 // Invalidates the text in the renderers of this counter, if any.
54 void resetRenderers();
55
56 CounterNode* parent() const { return m_parent; }
57 CounterNode* previousSibling() const { return m_previousSibling; }
58 CounterNode* nextSibling() const { return m_nextSibling; }
59 CounterNode* firstChild() const { return m_firstChild; }
60 CounterNode* lastChild() const { return m_lastChild; }
61 CounterNode* lastDescendant() const;
62 CounterNode* previousInPreOrder() const;
63 CounterNode* nextInPreOrder(const CounterNode* stayWithin = nullptr) const;
64 CounterNode* nextInPreOrderAfterChildren(const CounterNode* stayWithin = nullptr) const;
65
66 void insertAfter(CounterNode& newChild, CounterNode* beforeChild, const AtomicString& identifier);
67 // identifier must match the identifier of this counter.
68 void removeChild(CounterNode&);
69
70private:
71 CounterNode(RenderElement&, bool isReset, int value);
72 int computeCountInParent() const;
73 // Invalidates the text in the renderer of this counter, if any,
74 // and in the renderers of all descendants of this counter, if any.
75 void resetThisAndDescendantsRenderers();
76 void recount();
77
78 bool m_hasResetType;
79 int m_value;
80 int m_countInParent;
81 RenderElement& m_owner;
82 RenderCounter* m_rootRenderer { nullptr };
83
84 CounterNode* m_parent { nullptr };
85 CounterNode* m_previousSibling { nullptr };
86 CounterNode* m_nextSibling { nullptr };
87 CounterNode* m_firstChild { nullptr };
88 CounterNode* m_lastChild { nullptr };
89};
90
91} // namespace WebCore
92
93#if ENABLE(TREE_DEBUGGING)
94// Outside the WebCore namespace for ease of invocation from the debugger.
95void showCounterTree(const WebCore::CounterNode*);
96#endif
97