booleanformularecord.java

jxtl API Java中Excel的生成与导入解析参考文档

/*********************************************************************
*
*      Copyright (C) 2002 Andrew Khan
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
***************************************************************************/

package jxl.read.biff;

import common.Assert;

import jxl.BooleanCell;
import jxl.BooleanFormulaCell;
import jxl.CellType;
import jxl.biff.FormattingRecords;
import jxl.biff.FormulaData;
import jxl.biff.WorkbookMethods;
import jxl.biff.formula.ExternalSheet;
import jxl.biff.formula.FormulaException;
import jxl.biff.formula.FormulaParser;

/**
 * A boolean formula's last calculated value
 */
class BooleanFormulaRecord extends CellValue
  implements BooleanCell, FormulaData, BooleanFormulaCell
{
  /**
   * The boolean value of this cell.  If this cell represents an error,
   * this will be false
   */
  private boolean value;

  /**
   * A handle to the class needed to access external sheets
   */
  private ExternalSheet externalSheet;

  /**
   * A handle to the name table
   */
  private WorkbookMethods nameTable;

  /**
   * The formula as an excel string
   */
  private String formulaString;

  /**
   * The raw data
   */
  private byte[] data;

  /**
   * Constructs this object from the raw data
   *
   * @param t the raw data
   * @param fr the formatting records
   * @param si the sheet
   * @param es the sheet
   * @param nt the name table
   */
  public BooleanFormulaRecord(Record t, FormattingRecords fr,
                              ExternalSheet es, WorkbookMethods nt,
                              SheetImpl si)
  {
    super(t, fr, si);
    externalSheet = es;
    nameTable = nt;
    value = false;

    data = getRecord().getData();

    Assert.verify(data[6] != 2);

    value = data[8] == 1 ? true : false;
  }

  /**
   * Interface method which Gets the boolean value stored in this cell.  If
   * this cell contains an error, then returns FALSE.  Always query this cell
   *  type using the accessor method isError() prior to calling this method
   *
   * @return TRUE if this cell contains TRUE, FALSE if it contains FALSE or
   * an error code
   */
  public boolean getValue()
  {
    return value;
  }

  /**
   * Returns the numerical value as a string
   *
   * @return The numerical value of the formula as a string
   */
  public String getContents()
  {
    // return Boolean.toString(value) - only available in 1.4 or later
    return (new Boolean(value)).toString();
  }

  /**
   * Returns the cell type
   *
   * @return The cell type
   */
  public CellType getType()
  {
    return CellType.BOOLEAN_FORMULA;
  }

  /**
   * Gets the raw bytes for the formula.  This will include the
   * parsed tokens array
   *
   * @return the raw record data
   */
  public byte[] getFormulaData() throws FormulaException
  {
    if (!getSheet().getWorkbookBof().isBiff8())
    {
      throw new FormulaException(FormulaException.BIFF8_SUPPORTED);
    }

    // Lop off the standard information
    byte[] d = new byte[data.length - 6];
    System.arraycopy(data, 6, d, 0, data.length - 6);

    return d;
  }

  /**
   * Gets the formula as an excel string
   *
   * @return the formula as an excel string
   * @exception FormulaException
   */
  public String getFormula() throws FormulaException
  {
    if (formulaString == null)
    {
      byte[] tokens = new byte[data.length - 22];
      System.arraycopy(data, 22, tokens, 0, tokens.length);
      FormulaParser fp = new FormulaParser
        (tokens, this, externalSheet, nameTable,
         getSheet().getWorkbook().getSettings());
      fp.parse();
      formulaString = fp.getFormula();
    }

    return formulaString;
  }
}