trunk/src/java/org/apache/poi/hssf/record/DeltaRecord.java

/* ====================================================================
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   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

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
==================================================================== */

package org.apache.poi.hssf.record;

import org.apache.poi.util.LittleEndianOutput;

/**
 * Title:        Delta Record (0x0010)<p>
 * Description:  controls the accuracy of the calculations<p>
 * REFERENCE:  PG 303 Microsoft Excel 97 Developer's Kit (ISBN: 1-57231-498-2)
 */
public final class DeltaRecord extends StandardRecord implements Cloneable {
    public final static short sid = 0x0010;
    public final static double DEFAULT_VALUE = 0.0010;   // should be .001

    // a double is an IEEE 8-byte float...damn IEEE and their goofy standards an
    // ambiguous numeric identifiers
    private double field_1_max_change;

    public DeltaRecord(double maxChange) {
        field_1_max_change = maxChange;
    }

    public DeltaRecord(RecordInputStream in) {
        field_1_max_change = in.readDouble();
    }

    /**
     * get the maximum change
     * @return maxChange - maximum rounding error
     */
    public double getMaxChange() {
        return field_1_max_change;
    }

    public String toString() {
        StringBuffer buffer = new StringBuffer();

        buffer.append("[DELTA]\n");
        buffer.append("    .maxchange = ").append(getMaxChange()).append("\n");
        buffer.append("[/DELTA]\n");
        return buffer.toString();
    }

    public void serialize(LittleEndianOutput out) {
        out.writeDouble(getMaxChange());
    }

    protected int getDataSize() {
        return 8;
    }

    public short getSid() {
        return sid;
    }

    @Override
    public DeltaRecord clone() {
        // immutable
        return this;
    }
}