poi/src/java/org/apache/poi/hssf/record/SharedFormulaRecord.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.
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package org.apache.poi.hssf.record;

import java.util.Map;
import java.util.function.Supplier;

import org.apache.poi.hssf.util.CellRangeAddress8Bit;
import org.apache.poi.ss.SpreadsheetVersion;
import org.apache.poi.ss.formula.Formula;
import org.apache.poi.ss.formula.SharedFormula;
import org.apache.poi.ss.formula.ptg.Ptg;
import org.apache.poi.util.GenericRecordUtil;
import org.apache.poi.util.LittleEndianOutput;

/**
 * Primarily used as an excel optimization so that multiple similar formulas are not
 * written out too many times.  We should recognize this record and serialize as is
 * since this is used when reading templates.
 * <p>
 * Note: the documentation says that the SID is BC where biffviewer reports 4BC.  The hex dump shows
 * that the two byte sid representation to be 'BC 04' that is consistent with the other high byte
 * record types.
 */
public final class SharedFormulaRecord extends SharedValueRecordBase {
    public static final short sid = 0x04BC;

    private int field_5_reserved;
    private Formula field_7_parsed_expr;

    // for testing only
    public SharedFormulaRecord() {
        this(new CellRangeAddress8Bit(0,0,0,0));
    }

    public SharedFormulaRecord(SharedFormulaRecord other) {
        super(other);
        field_5_reserved = other.field_5_reserved;
        field_7_parsed_expr = (other.field_7_parsed_expr == null) ? null : other.field_7_parsed_expr.copy();
    }

    private SharedFormulaRecord(CellRangeAddress8Bit range) {
        super(range);
        field_7_parsed_expr = Formula.create(Ptg.EMPTY_PTG_ARRAY);
    }

    /**
     * @param in the RecordInputstream to read the record from
     */
    public SharedFormulaRecord(RecordInputStream in) {
        super(in);
        field_5_reserved        = in.readShort();
        int field_6_expression_len = in.readShort();
        int nAvailableBytes = in.available();
        field_7_parsed_expr = Formula.read(field_6_expression_len, in, nAvailableBytes);
    }

    protected void serializeExtraData(LittleEndianOutput out) {
        out.writeShort(field_5_reserved);
        field_7_parsed_expr.serialize(out);
    }

    protected int getExtraDataSize() {
        return 2 + field_7_parsed_expr.getEncodedSize();
    }

    public short getSid() {
        return sid;
    }

    /**
     * Convert formula into an array of {@link Ptg} tokens.
     *
     * @param formula The record to break into tokens, cannot be null
     *
     * @return the equivalent {@link Ptg} array that the formula would have, were it not shared.
     */
    public Ptg[] getFormulaTokens(FormulaRecord formula) {
        int formulaRow = formula.getRow();
        int formulaColumn = formula.getColumn();
        //Sanity checks
        if (!isInRange(formulaRow, formulaColumn)) {
            throw new RuntimeException("Shared Formula Conversion: Coding Error");
        }

        SharedFormula sf = new SharedFormula(SpreadsheetVersion.EXCEL97);
        return sf.convertSharedFormulas(field_7_parsed_expr.getTokens(), formulaRow, formulaColumn);
    }

    @Override
    public SharedFormulaRecord copy() {
        return new SharedFormulaRecord(this);
    }
	public boolean isFormulaSame(SharedFormulaRecord other) {
		return field_7_parsed_expr.isSame(other.field_7_parsed_expr);
	}

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

    @Override
    public Map<String, Supplier<?>> getGenericProperties() {
        return GenericRecordUtil.getGenericProperties(
            "range", this::getRange,
            "reserved", () -> field_5_reserved,
            "formula", () -> field_7_parsed_expr
        );
    }
}