WebCore/dom/PositionIterator.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/dom/PositionIterator.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2007, 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. 
+ */
+
+#ifndef PositionIterator_h
+#define PositionIterator_h
+
+#include "Node.h"
+#include "Position.h"
+
+namespace WebCore {
+
+// A Position iterator with constant-time
+// increment, decrement, and several predicates on the Position it is at.
+// Conversion to/from Position is O(n) in the offset.
+class PositionIterator {
+public:
+    PositionIterator()
+        : m_anchorNode(0)
+        , m_nodeAfterPositionInAnchor(0)
+        , m_offsetInAnchor(0)
+    {
+    }
+
+    PositionIterator(const Position& pos)
+        : m_anchorNode(pos.anchorNode())
+        , m_nodeAfterPositionInAnchor(m_anchorNode->childNode(pos.deprecatedEditingOffset()))
+        , m_offsetInAnchor(m_nodeAfterPositionInAnchor ? 0 : pos.deprecatedEditingOffset())
+    {
+    }
+    operator Position() const;
+
+    void increment();
+    void decrement();
+
+    Node* node() const { return m_anchorNode; }
+    int offsetInLeafNode() const { return m_offsetInAnchor; }
+
+    bool atStart() const;
+    bool atEnd() const;
+    bool atStartOfNode() const;
+    bool atEndOfNode() const;
+    bool isCandidate() const;
+
+private:
+    Node* m_anchorNode;
+    Node* m_nodeAfterPositionInAnchor; // If this is non-null, m_nodeAfterPositionInAnchor->parentNode() == m_anchorNode;
+    int m_offsetInAnchor;
+};
+
+} // namespace WebCore
+
+#endif // PositionIterator_h