sharedformularecord.java

来自「EXCEL read and write」· Java 代码 · 共 186 行

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package org.apache.poi.hssf.record;

import org.apache.poi.hssf.record.formula.AreaNPtg;
import org.apache.poi.hssf.record.formula.AreaPtg;
import org.apache.poi.hssf.record.formula.Ptg;
import org.apache.poi.hssf.record.formula.RefNPtg;
import org.apache.poi.hssf.record.formula.RefPtg;
import org.apache.poi.util.HexDump;

/**
 * Title:        SHAREDFMLA (0x04BC) SharedFormulaRecord
 * Description:  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.
 * @author Danny Mui at apache dot org
 */
public final class SharedFormulaRecord extends SharedValueRecordBase {
    public final static short   sid = 0x04BC;

    private int field_5_reserved;
    private Ptg[] field_7_parsed_expr;

    public SharedFormulaRecord() {
        field_7_parsed_expr = 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();
        field_7_parsed_expr = Ptg.readTokens(field_6_expression_len, in);
    }
    protected void serializeExtraData(int offset, byte[] data) {
        //Because this record is converted to individual Formula records, this method is not required.
        throw new UnsupportedOperationException("Cannot serialize a SharedFormulaRecord");
    }
    
    protected int getExtraDataSize() {
        //Because this record is converted to individual Formula records, this method is not required.
        throw new UnsupportedOperationException("Cannot get the size for a SharedFormulaRecord");

    }

    /**
     * print a sort of string representation ([SHARED FORMULA RECORD] id = x [/SHARED FORMULA RECORD])
     */

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

        buffer.append("[SHARED FORMULA (").append(HexDump.intToHex(sid)).append("]\n");
        buffer.append("    .range      = ").append(getRange().toString()).append("\n");
        buffer.append("    .reserved    = ").append(HexDump.shortToHex(field_5_reserved)).append("\n");

        for (int k = 0; k < field_7_parsed_expr.length; k++ ) {
           buffer.append("Formula[").append(k).append("]");
           Ptg ptg = field_7_parsed_expr[k];
           buffer.append(ptg.toString()).append(ptg.getRVAType()).append("\n");
        }

        buffer.append("[/SHARED FORMULA]\n");
        return buffer.toString();
    }

    public short getSid() {
        return sid;
    }

    /**
     * Creates a non shared formula from the shared formula
     * counter part
     */
    protected static Ptg[] convertSharedFormulas(Ptg[] ptgs, int formulaRow, int formulaColumn) {
        if(false) {
            /*
             * TODO - (May-2008) Stop converting relative ref Ptgs in shared formula records.
             * If/when POI writes out the workbook, this conversion makes an unnecessary diff in the BIFF records.
             * Disabling this code breaks one existing junit.
             * Some fix-up will be required to make Ptg.toFormulaString(HSSFWorkbook) work properly.
             * That method will need 2 extra params: rowIx and colIx.
             */
            return ptgs;
        }
        Ptg[] newPtgStack = new Ptg[ptgs.length];

        for (int k = 0; k < ptgs.length; k++) {
            Ptg ptg = ptgs[k];
            byte originalOperandClass = -1;
            if (!ptg.isBaseToken()) {
                originalOperandClass = ptg.getPtgClass();
            }
            if (ptg instanceof RefNPtg) {
              RefNPtg refNPtg = (RefNPtg)ptg;
              ptg = new RefPtg(fixupRelativeRow(formulaRow,refNPtg.getRow(),refNPtg.isRowRelative()),
                                     fixupRelativeColumn(formulaColumn,refNPtg.getColumn(),refNPtg.isColRelative()),
                                     refNPtg.isRowRelative(),
                                     refNPtg.isColRelative());
            } else if (ptg instanceof AreaNPtg) {
              AreaNPtg areaNPtg = (AreaNPtg)ptg;
              ptg = new AreaPtg(fixupRelativeRow(formulaRow,areaNPtg.getFirstRow(),areaNPtg.isFirstRowRelative()),
                                fixupRelativeRow(formulaRow,areaNPtg.getLastRow(),areaNPtg.isLastRowRelative()),
                                fixupRelativeColumn(formulaColumn,areaNPtg.getFirstColumn(),areaNPtg.isFirstColRelative()),
                                fixupRelativeColumn(formulaColumn,areaNPtg.getLastColumn(),areaNPtg.isLastColRelative()),
                                areaNPtg.isFirstRowRelative(),
                                areaNPtg.isLastRowRelative(),
                                areaNPtg.isFirstColRelative(),
                                areaNPtg.isLastColRelative());
            } else {
                if (false) {// do we need a ptg clone here?
                    ptg = ptg.copy();
                }
            }
            if (!ptg.isBaseToken()) {
                ptg.setClass(originalOperandClass);
            }

            newPtgStack[k] = ptg;
        }
        return newPtgStack;
    }

    /**
     * Creates a non shared formula from the shared formula
     * counter part
     */
    public void convertSharedFormulaRecord(FormulaRecord formula) {
        int formulaRow = formula.getRow();
        int formulaColumn = formula.getColumn();
        //Sanity checks
        if (!isInRange(formulaRow, formulaColumn)) {
            throw new RuntimeException("Shared Formula Conversion: Coding Error");
        }

        Ptg[] ptgs = convertSharedFormulas(field_7_parsed_expr, formulaRow, formulaColumn);
        formula.setParsedExpression(ptgs);
        //Now its not shared!
        formula.setSharedFormula(false);
    }

    private static int fixupRelativeColumn(int currentcolumn, int column, boolean relative) {
        if(relative) {
            // mask out upper bits to produce 'wrapping' at column 256 ("IV")
            return (column + currentcolumn) & 0x00FF;
        }
        return column;
    }

    private static int fixupRelativeRow(int currentrow, int row, boolean relative) {
        if(relative) {
            // mask out upper bits to produce 'wrapping' at row 65536
            return (row+currentrow) & 0x00FFFF;
        }
        return row;
    }

    public Object clone() {
        //Because this record is converted to individual Formula records, this method is not required.
        throw new UnsupportedOperationException("Cannot clone a SharedFormulaRecord");
    }
}