1    /* ====================================================================
2     * The Apache Software License, Version 1.1
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4     * Copyright (c) 2002 The Apache Software Foundation.  All rights
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12    *    notice, this list of conditions and the following disclaimer.
13    *
14    * 2. Redistributions in binary form must reproduce the above copyright
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53    */
54   
55   package org.apache.poi.hssf.util;
56   
57   /**
58    * Utility class for helping convert RK numbers.
59    *
60    * @author Andrew C. Oliver (acoliver at apache dot org)
61    * @author Glen Stampoultzis (glens at apache.org)
62    * @author Rolf-J�rgen Moll
63    *
64    * @see org.apache.poi.hssf.record.MulRKRecord
65    * @see org.apache.poi.hssf.record.RKRecord
66    */
67   public class RKUtil
68   {
69       private RKUtil()
70       {
71       }
72   
73       /**
74        * Do the dirty work of decoding; made a private static method to
75        * facilitate testing the algorithm
76        */
77   
78       public static double decodeNumber(int number)
79       {
80           long raw_number = number;
81   
82           // mask off the two low-order bits, 'cause they're not part of
83           // the number
84           raw_number = raw_number >> 2;
85           double rvalue = 0;
86   
87           if ((number & 0x02) == 0x02)
88           {
89               // ok, it's just a plain ol' int; we can handle this
90               // trivially by casting
91               rvalue = ( double ) (raw_number);
92           }
93           else
94           {
95   
96               // also trivial, but not as obvious ... left shift the
97               // bits high and use that clever static method in Double
98               // to convert the resulting bit image to a double
99               rvalue = Double.longBitsToDouble(raw_number << 34);
100          }
101          if ((number & 0x01) == 0x01)
102          {
103  
104              // low-order bit says divide by 100, and so we do. Why?
105              // 'cause that's what the algorithm says. Can't fight city
106              // hall, especially if it's the city of Redmond
107              rvalue /= 100;
108          }
109  
110          return rvalue;
111      }
112  
113  }
114