/*********************************************************************
*
* 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 java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
import jxl.common.Assert;
import jxl.common.Logger;
import jxl.CellFeatures;
import jxl.CellType;
import jxl.DateCell;
import jxl.NumberCell;
import jxl.biff.FormattingRecords;
import jxl.format.CellFormat;
/**
* A date which is stored in the cell
*/
class DateRecord implements DateCell, CellFeaturesAccessor
{
/**
* The logger
*/
private static Logger logger = Logger.getLogger(DateRecord.class);
/**
* The date represented within this cell
*/
private Date date;
/**
* The row number of this cell record
*/
private int row;
/**
* The column number of this cell record
*/
private int column;
/**
* Indicates whether this is a full date, or merely a time
*/
private boolean time;
/**
* The format to use when displaying this cell's contents as a string
*/
private DateFormat format;
/**
* The raw cell format
*/
private CellFormat cellFormat;
/**
* The index to the XF Record
*/
private int xfIndex;
/**
* A handle to the formatting records
*/
private FormattingRecords formattingRecords;
/**
* A handle to the sheet
*/
private SheetImpl sheet;
/**
* The cell features
*/
private CellFeatures features;
/**
* A flag to indicate whether this objects formatting things have
* been initialized
*/
private boolean initialized;
// The default formats used when returning the date as a string
private static final SimpleDateFormat dateFormat =
new SimpleDateFormat("dd MMM yyyy");
private static final SimpleDateFormat timeFormat =
new SimpleDateFormat("HH:mm:ss");
// The number of days between 1 Jan 1900 and 1 March 1900. Excel thinks
// the day before this was 29th Feb 1900, but it was 28th Feb 1900.
// I guess the programmers thought nobody would notice that they
// couldn't be bothered to program this dating anomaly properly
private static final int nonLeapDay = 61;
private static final TimeZone gmtZone = TimeZone.getTimeZone("GMT");
// The number of days between 01 Jan 1900 and 01 Jan 1970 - this gives
// the UTC offset
private static final int utcOffsetDays = 25569;
// The number of days between 01 Jan 1904 and 01 Jan 1970 - this gives
// the UTC offset using the 1904 date system
private static final int utcOffsetDays1904 = 24107;
// The number of milliseconds in a day
private static final long secondsInADay = 24 * 60 * 60;
private static final long msInASecond = 1000;
private static final long msInADay = secondsInADay * msInASecond;
/**
* Constructs this object from the raw data
*
* @param num the numerical representation of this
* @param xfi the java equivalent of the excel date format
* @param fr the formatting records
* @param nf flag indicating whether we are using the 1904 date system
* @param si the sheet
*/
public DateRecord(NumberCell num,
int xfi, FormattingRecords fr,
boolean nf, SheetImpl si)
{
row = num.getRow();
column = num.getColumn();
xfIndex = xfi;
formattingRecords = fr;
sheet = si;
initialized = false;
format = formattingRecords.getDateFormat(xfIndex);
// This value represents the number of days since 01 Jan 1900
double numValue = num.getValue();
if (Math.abs(numValue) < 1)
{
if (format == null)
{
format = timeFormat;
}
time = true;
}
else
{
if (format == null)
{
format = dateFormat;
}
time = false;
}
// Work round a bug in excel. Excel seems to think there is a date
// called the 29th Feb, 1900 - but in actual fact this was not a leap year.
// Therefore for values less than 61 in the 1900 date system,
// add one to the numeric value
if (!nf && !time && numValue < nonLeapDay)
{
numValue += 1;
}
// Get rid of any timezone adjustments - we are not interested
// in automatic adjustments
format.setTimeZone(gmtZone);
// Convert this to the number of days since 01 Jan 1970
int offsetDays = nf ? utcOffsetDays1904 : utcOffsetDays;
double utcDays = numValue - offsetDays;
// Convert this into utc by multiplying by the number of milliseconds
// in a day. Use the round function prior to ms conversion due
// to a rounding feature of Excel (contributed by Jurgen
long utcValue = Math.round(utcDays * secondsInADay) * msInASecond;
date = new Date(utcValue);
}
/**
* Interface method which returns the row number of this cell
*
* @return the zero base row number
*/
public final int getRow()
{
return row;
}
/**
* Interface method which returns the column number of this cell
*
* @return the zero based column number
*/
public final int getColumn()
{
return column;
}
/**
* Gets the date
*
* @return the date
*/
public Date getDate()
{
return date;
}
/**
* Gets the cell contents as a string. This method will use the java
* equivalent of the excel formatting string
*
* @return the label
*/
public String getContents()
{
return format.format(date);
}
/**
* Accessor for the cell type
*
* @return the cell type
*/
public CellType getType()
{
return CellType.DATE;
}
/**
* Indicates whether the date value contained in this cell refers to a date,
* or merely a time
*
* @return TRUE if the value refers to a time
*/
public boolean isTime()
{
return time;
}
/**
* Gets the DateFormat used to format the cell. This will normally be
* the format specified in the excel spreadsheet, but in the event of any
* difficulty parsing this, it will revert to the default date/time format.
*
* @return the DateFormat object used to format the date in the original
* excel cell
*/
public DateFormat getDateFormat()
{
Assert.verify(format != null);
return format;
}
/**
* Gets the CellFormat object for this cell. Used by the WritableWorkbook
* API
*
* @return the CellFormat used for this cell
*/
public CellFormat getCellFormat()
{
if (!initialized)
{
cellFormat = formattingRecords.getXFRecord(xfIndex);
initialized = true;
}
return cellFormat;
}
/**
* Determines whether or not this cell has been hidden
*
* @return TRUE if this cell has been hidden, FALSE otherwise
*/
public boolean isHidden()
{
ColumnInfoRecord cir = sheet.getColumnInfo(column);
if (cir != null && cir.getWidth() == 0)
{
return true;
}
RowRecord rr = sheet.getRowInfo(row);
if (rr != null && (rr.getRowHeight() == 0 || rr.isCollapsed()))
{
return true;
}
return false;
}
/**
* Accessor for the sheet
*
* @return the containing sheet
*/
protected final SheetImpl getSheet()
{
return sheet;
}
/**
* Accessor for the cell features
*
* @return the cell features or NULL if this cell doesn't have any
*/
public CellFeatures getCellFeatures()
{
return features;
}
/**
* Sets the cell features
*
* @param cf the cell features
*/
public void setCellFeatures(CellFeatures cf)
{
features = cf;
}
}