• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 #ifndef CounterNode_h
23 #define CounterNode_h
24 
25 #include <wtf/Forward.h>
26 #include <wtf/Noncopyable.h>
27 #include <wtf/RefCounted.h>
28 
29 // This implements a counter tree that is used for finding parents in counters() lookup,
30 // and for propagating count changes when nodes are added or removed.
31 
32 // Parents represent unique counters and their scope, which are created either explicitly
33 // by "counter-reset" style rules or implicitly by referring to a counter that is not in scope.
34 // Such nodes are tagged as "reset" nodes, although they are not all due to "counter-reset".
35 
36 // Not that render tree children are often counter tree siblings due to counter scoping rules.
37 
38 namespace WebCore {
39 
40 class RenderObject;
41 class RenderCounter;
42 
43 class CounterNode : public RefCounted<CounterNode> {
44 public:
45     static PassRefPtr<CounterNode> create(RenderObject*, bool isReset, int value);
46     ~CounterNode();
actsAsReset()47     bool actsAsReset() const { return m_hasResetType || !m_parent; }
hasResetType()48     bool hasResetType() const { return m_hasResetType; }
value()49     int value() const { return m_value; }
countInParent()50     int countInParent() const { return m_countInParent; }
owner()51     RenderObject* owner() const { return m_owner; }
52     void addRenderer(RenderCounter*);
53     void removeRenderer(RenderCounter*);
54 
55     // Invalidates the text in the renderers of this counter, if any.
56     void resetRenderers();
57 
parent()58     CounterNode* parent() const { return m_parent; }
previousSibling()59     CounterNode* previousSibling() const { return m_previousSibling; }
nextSibling()60     CounterNode* nextSibling() const { return m_nextSibling; }
firstChild()61     CounterNode* firstChild() const { return m_firstChild; }
lastChild()62     CounterNode* lastChild() const { return m_lastChild; }
63     CounterNode* lastDescendant() const;
64     CounterNode* previousInPreOrder() const;
65     CounterNode* nextInPreOrder(const CounterNode* stayWithin = 0) const;
66     CounterNode* nextInPreOrderAfterChildren(const CounterNode* stayWithin = 0) const;
67 
68     void insertAfter(CounterNode* newChild, CounterNode* beforeChild, const AtomicString& identifier);
69 
70     // identifier must match the identifier of this counter.
71     void removeChild(CounterNode*);
72 
73 private:
74     CounterNode(RenderObject*, bool isReset, int value);
75     int computeCountInParent() const;
76     // Invalidates the text in the renderer of this counter, if any,
77     // and in the renderers of all descendants of this counter, if any.
78     void resetThisAndDescendantsRenderers();
79     void recount();
80 
81     bool m_hasResetType;
82     int m_value;
83     int m_countInParent;
84     RenderObject* m_owner;
85     RenderCounter* m_rootRenderer;
86 
87     CounterNode* m_parent;
88     CounterNode* m_previousSibling;
89     CounterNode* m_nextSibling;
90     CounterNode* m_firstChild;
91     CounterNode* m_lastChild;
92 };
93 
94 } // namespace WebCore
95 
96 #ifndef NDEBUG
97 // Outside the WebCore namespace for ease of invocation from gdb.
98 void showCounterTree(const WebCore::CounterNode*);
99 #endif
100 
101 #endif // CounterNode_h
102