/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program 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.
*
* Copyright (c) 2001 - 2009 Object Refinery Ltd, Pentaho Corporation and Contributors.. All rights reserved.
*/
package org.pentaho.reporting.engine.classic.core.filter;
import java.lang.reflect.Method;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.Format;
import java.util.Locale;
import org.pentaho.reporting.engine.classic.core.Element;
import org.pentaho.reporting.engine.classic.core.function.ExpressionRuntime;
import org.pentaho.reporting.libraries.base.util.ObjectUtilities;
/**
* A filter that parses string values from a data source to a number using the decimal numeric system as base.
* <p/>
* This filter will parse strings using a java.text.DecimalFormat to create the numeric value for the string from the
* datasource. If the datasource does not return a string, the required string is formed by applying String.valueOf
* (Object).
* <p/>
* If the string read from the datasource could not be parsed into a number, the NullValue defined by
* setNullValue(Object) is returned.
*
* @author Thomas Morgner
* @see java.text.NumberFormat
* @see java.lang.Number
*/
public class DecimalFormatParser extends NumberFormatParser
{
/**
* The last locale used to convert numbers.
*/
private Locale lastLocale;
/**
* A flag indicating whether this filter should try to detect locales changes.
*/
private boolean keepState;
/**
* DefaultConstructor, this object is initialized using a DecimalFormat with the default pattern for this locale.
*/
public DecimalFormatParser()
{
setFormatter(new DecimalFormat());
}
/**
* Returns the format for the filter. The DecimalFormatParser has only DecimalFormat objects assigned.
*
* @return the formatter.
*/
public DecimalFormat getDecimalFormat()
{
return (DecimalFormat) getFormatter();
}
/**
* Sets the format for the filter.
*
* @param format the format.
* @throws NullPointerException if the given format is null.
*/
public void setDecimalFormat(final DecimalFormat format)
{
setFormatter(format);
}
/**
* Sets the format for the filter. If the given format is no Decimal format, a ClassCastException is thrown
*
* @param format The format.
* @throws NullPointerException if the given format is null
* @throws ClassCastException if the format is no decimal format
*/
public void setFormatter(final Format format)
{
if (format == null)
{
throw new NullPointerException("The number format given must not be null.");
}
final DecimalFormat dfmt = (DecimalFormat) format;
activateBigDecimalMode(dfmt);
super.setFormatter(dfmt);
}
/**
* Uses reflection to enable the use of BigDecimals in the parsing. This produces better results, but only works on
* JDK 1.4 or higher.
*
* @param format the format object that should be patched.
*/
private void activateBigDecimalMode(final DecimalFormat format)
{
if (ObjectUtilities.isJDK14())
{
try
{
final Method method = DecimalFormat.class.getMethod("setParseBigDecimal", new Class[]{Boolean.TYPE});
method.invoke(format, new Object[]{Boolean.TRUE});
}
catch (Exception e)
{
// ignore it, as it will always fail on JDK 1.4 or lower ..
}
}
}
/**
* Synthesizes a pattern string that represents the current state of this Format object.
*
* @return the pattern string of the format object contained in this filter.
*/
public String getFormatString()
{
return getDecimalFormat().toPattern();
}
/**
* Applies a format string to the internal <code>DecimalFormat</code> instance.
*
* @param format the format string.
*/
public void setFormatString(final String format)
{
getDecimalFormat().applyPattern(format);
}
/**
* Synthesizes a localized pattern string that represents the current state of this Format object.
*
* @return the localized pattern string of the format-object.
*/
public String getLocalizedFormatString()
{
return getDecimalFormat().toLocalizedPattern();
}
/**
* Applies a localised format string to the internal <code>DecimalFormat</code> instance.
*
* @param format the format string.
*/
public void setLocalizedFormatString(final String format)
{
getDecimalFormat().applyLocalizedPattern(format);
}
/**
* Defines, whether the filter should keep its state, if a locale change is detected. This will effectivly disable the
* locale update.
*
* @return true, if the locale should not update the DateSymbols, false otherwise.
*/
public boolean isKeepState()
{
return keepState;
}
/**
* Defines, whether the filter should keep its state, if a locale change is detected. This will effectivly disable the
* locale update.
*
* @param keepState set to true, if the locale should not update the DateSymbols, false otherwise.
*/
public void setKeepState(final boolean keepState)
{
this.keepState = keepState;
}
/**
* Returns the formatted string. The value is read using the data source given and formated using the formatter of
* this object. The formating is guaranteed to completly form the object to an string or to return the defined
* NullValue.
* <p/>
* If format, datasource or object are null, the NullValue is returned.
*
* @param runtime the expression runtime that is used to evaluate formulas and expressions when computing the value of
* this filter.
* @param element
* @return The formatted value.
*/
public Object getValue(final ExpressionRuntime runtime, final Element element)
{
if (keepState == false && runtime != null)
{
final Locale locale = runtime.getResourceBundleFactory().getLocale();
if (locale != null && locale.equals(lastLocale) == false)
{
lastLocale = locale;
getDecimalFormat().setDecimalFormatSymbols(new DecimalFormatSymbols(locale));
}
}
return super.getValue(runtime, element);
}
}