poi/src/main/java/org/apache/poi/hssf/record/RecalcIdRecord.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 java.util.Map;
import java.util.function.Supplier;

import org.apache.poi.util.GenericRecordUtil;
import org.apache.poi.util.LittleEndianOutput;

/**
 * This record contains an ID that marks when a worksheet was last recalculated.
 * It's an optimization Excel uses to determine if it needs to  recalculate the spreadsheet
 * when it's opened. So far, only the two engine ids {@code 0x80 0x38 0x01 0x00} and
 * {@code 0x60 0x69 0x01 0x00} have been seen. A value of {@code 0x00} will cause Excel
 * to recalculate all formulas on the next load.
 *
 * @see <a href="http://chicago.sourceforge.net/devel/docs/excel/biff8.html">Chicago biff8 docs</a>
 */
public final class RecalcIdRecord extends StandardRecord {
    public static final short sid = 0x01C1;
    private final int _reserved0;

    /**
     * An unsigned integer that specifies the recalculation engine identifier
     * of the recalculation engine that performed the last recalculation.
     * If the value is less than the recalculation engine identifier associated with the application,
     * the application will recalculate the results of all formulas on
     * this workbook immediately after loading the file
     */
    private int _engineId;

    public RecalcIdRecord() {
        _reserved0 = 0;
        _engineId = 0;
    }

    public RecalcIdRecord(RecalcIdRecord other) {
        _reserved0 = other._reserved0;
        _engineId = other._engineId;
    }

    public RecalcIdRecord(RecordInputStream in) {
    	in.readUShort(); // field 'rt' should have value 0x01C1, but Excel doesn't care during reading
    	_reserved0 = in.readUShort();
    	_engineId = in.readInt();
    }

    public boolean isNeeded() {
        return true;
    }

    public void setEngineId(int val) {
        _engineId = val;
    }

    public int getEngineId() {
        return _engineId;
    }

    public void serialize(LittleEndianOutput out) {
        out.writeShort(sid); // always write 'rt' field as 0x01C1
        out.writeShort(_reserved0);
        out.writeInt(_engineId);
    }

    protected int getDataSize() {
        return 8;
    }

    public short getSid() {
        return sid;
    }

    @Override
    public RecalcIdRecord copy() {
        return new RecalcIdRecord(this);
    }

    @Override
    public HSSFRecordTypes getGenericRecordType() {
        return HSSFRecordTypes.RECALC_ID;
    }

    @Override
    public Map<String, Supplier<?>> getGenericProperties() {
        return GenericRecordUtil.getGenericProperties(
            "reserved0", () -> _reserved0,
            "engineId", this::getEngineId
        );
    }
}