WebCore/rendering/CounterNode.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/rendering/CounterNode.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
+ * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+*/
+
+#ifndef CounterNode_h
+#define CounterNode_h
+
+#include <wtf/Noncopyable.h>
+
+// This implements a counter tree that is used for finding parents in counters() lookup,
+// and for propagating count changes when nodes are added or removed.
+
+// Parents represent unique counters and their scope, which are created either explicitly
+// by "counter-reset" style rules or implicitly by referring to a counter that is not in scope.
+// Such nodes are tagged as "reset" nodes, although they are not all due to "counter-reset".
+
+// Not that render tree children are often counter tree siblings due to counter scoping rules.
+
+namespace WebCore {
+
+class AtomicString;
+class RenderObject;
+
+class CounterNode : public Noncopyable {
+public:
+    CounterNode(RenderObject*, bool isReset, int value);
+
+    bool actsAsReset() const { return m_hasResetType || !m_parent; }
+    bool hasResetType() const { return m_hasResetType; }
+    int value() const { return m_value; }
+    int countInParent() const { return m_countInParent; }
+    RenderObject* renderer() const { return m_renderer; }
+
+    CounterNode* parent() const { return m_parent; }
+    CounterNode* previousSibling() const { return m_previousSibling; }
+    CounterNode* nextSibling() const { return m_nextSibling; }
+    CounterNode* firstChild() const { return m_firstChild; }
+    CounterNode* lastChild() const { return m_lastChild; }
+    CounterNode* lastDescendant() const;
+    CounterNode* previousInPreOrder() const;
+    CounterNode* nextInPreOrder(const CounterNode* stayWithin = 0) const;
+    CounterNode* nextInPreOrderAfterChildren(const CounterNode* stayWithin = 0) const;
+
+    void insertAfter(CounterNode* newChild, CounterNode* beforeChild, const AtomicString& identifier);
+
+    // identifier must match the identifier of this counter.
+    void removeChild(CounterNode*, const AtomicString& identifier);
+
+private:
+    int computeCountInParent() const;
+    void recount(const AtomicString& identifier);
+
+    // Invalidates the text in the renderer of this counter, if any.
+    // identifier must match the identifier of this counter.
+    void resetRenderer(const AtomicString& identifier) const;
+
+    // Invalidates the text in the renderer of this counter, if any,
+    // and in the renderers of all descendants of this counter, if any.
+    // identifier must match the identifier of this counter.
+    void resetRenderers(const AtomicString& identifier) const;
+
+    bool m_hasResetType;
+    int m_value;
+    int m_countInParent;
+    RenderObject* m_renderer;
+
+    CounterNode* m_parent;
+    CounterNode* m_previousSibling;
+    CounterNode* m_nextSibling;
+    CounterNode* m_firstChild;
+    CounterNode* m_lastChild;
+};
+
+} // namespace WebCore
+
+#ifndef NDEBUG
+// Outside the WebCore namespace for ease of invocation from gdb.
+void showTree(const WebCore::CounterNode*);
+#endif
+
+#endif // CounterNode_h