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+/* $Id: cursor.hpp,v 1.4 2006/11/05 04:42:43 ganzhorn Exp $
+ * This file is part of lfhex.
+ * Copyright (C) 2006 Salem Ganzhorn <eyekode@yahoo.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation version 2.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#ifndef _CURSOR_HPP_
+#define _CURSOR_HPP_
+
+#include <sys/types.h>
+#include <limits.h>
+#include <stdexcept>
+
+#ifdef _LARGEFILE_SOURCE
+#define MAX_OFFSET LONG_LONG_MAX
+#else
+#define MAX_OFFSET LONG_MAX
+#endif
+
+class Cursor {
+public:
+ Cursor( off_t byteOffset = 0,
+ off_t charOffset = 0,
+ off_t low = 0,
+ off_t high = 1,
+ off_t charsPerByte = 2 ); // defaults to hex
+ Cursor( const Cursor& c);
+
+ off_t incrByChar( off_t n );
+ off_t incrByByte( off_t n );
+ off_t decrByChar( off_t n );
+ off_t decrByByte( off_t n );
+
+ off_t byteOffset() const; //returns the current byte offset
+ off_t charOffset() const; //returns the current char offset. (relative)
+ off_t charOffsetAbsolute() const; //returns the current absolute offset.
+
+ bool setRange( off_t low, off_t high );
+ // setCharsPerByte:
+ // sideEffect: sets charOffset to min(_charsPerByte-1,_charOffset)
+ off_t setCharsPerByte( off_t charsPerByte );
+ void setOffset( off_t byteOffset, off_t charOffset );
+
+protected:
+ // performs: dst = src; and clamps the value to [low,high)
+ void assignClamped(off_t& dst,off_t src,off_t low,off_t high);
+
+ enum {
+ OutOfRange = -1,
+ };
+protected:
+ off_t _byteOffset;
+ off_t _charOffset;
+ off_t _low;
+ off_t _high;
+ off_t _charsPerByte;
+};
+
+#endif