poi/src/java/org/apache/poi/hssf/record/RKRecord.java

/* ====================================================================
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   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

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   distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.poi.hssf.record;

import org.apache.poi.hssf.util.RKUtil;
import org.apache.poi.util.LittleEndianOutput;

/**
 * Title:        RK Record (0x027E)<p/>
 * Description:  An internal 32 bit number with the two most significant bits
 *               storing the type.  This is part of a bizarre scheme to save disk
 *               space and memory (gee look at all the other whole records that
 *               are in the file just "cause"..,far better to waste processor
 *               cycles on this then leave on of those "valuable" records out).<p/>
 * We support this in READ-ONLY mode.  HSSF converts these to NUMBER records<p/>
 *
 *
 *
 * REFERENCE:  PG 376 Microsoft Excel 97 Developer's Kit (ISBN: 1-57231-498-2)<P>
 * @author Andrew C. Oliver (acoliver at apache dot org)
 * @author Jason Height (jheight at chariot dot net dot au)
 * @see org.apache.poi.hssf.record.NumberRecord
 */
public final class RKRecord extends CellRecord {
    public final static short sid                      = 0x027E;
    public final static short RK_IEEE_NUMBER           = 0;
    public final static short RK_IEEE_NUMBER_TIMES_100 = 1;
    public final static short RK_INTEGER               = 2;
    public final static short RK_INTEGER_TIMES_100     = 3;
    private int field_4_rk_number;

    private RKRecord() {
    	// fields uninitialised
    }

    public RKRecord(RecordInputStream in) {
        super(in);
        field_4_rk_number = in.readInt();
    }

    /**
     * Extract the value of the number
     * <P>
     * The mechanism for determining the value is dependent on the two
     * low order bits of the raw number. If bit 1 is set, the number
     * is an integer and can be cast directly as a double, otherwise,
     * it's apparently the exponent and mantissa of a double (and the
     * remaining low-order bits of the double's mantissa are 0's).
     * <P>
     * If bit 0 is set, the result of the conversion to a double is
     * divided by 100; otherwise, the value is left alone.
     * <P>
     * [insert picture of Screwy Squirrel in full Napoleonic regalia]
     *
     * @return the value as a proper double (hey, it <B>could</B>
     *         happen)
     */
    public double getRKNumber() {
        return RKUtil.decodeNumber(field_4_rk_number);
    }

    @Override
    protected String getRecordName() {
    	return "RK";
    }

    @Override
    protected void appendValueText(StringBuilder sb) {
    	sb.append("  .value= ").append(getRKNumber());
    }

    @Override
    protected void serializeValue(LittleEndianOutput out) {
    	out.writeInt(field_4_rk_number);
    }

    @Override
    protected int getValueDataSize() {
    	return 4;
    }

    public short getSid() {
        return sid;
    }

    public Object clone() {
      RKRecord rec = new RKRecord();
      copyBaseFields(rec);
      rec.field_4_rk_number = field_4_rk_number;
      return rec;
    }
}