/*
 * 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 - 2013 Object Refinery Ltd, Pentaho Corporation and Contributors..  All rights reserved.
 */

package org.pentaho.reporting.engine.classic.core.filter;

import java.text.Format;
import java.text.NumberFormat;

/**
 * A filter that parses the numeric value from a data source string into a number representation.
 * <p/>
 * This filter will parse the string obtained from the datasource into a java.lang.Number objects using a
 * java.text.NumericFormat.
 * <p/>
 * If the object read from the datasource is no number, the NullValue defined by setNullValue(Object) is returned.
 *
 * @author Thomas Morgner
 * @see java.text.NumberFormat
 */
public class NumberFormatParser extends FormatParser {
  /**
   * Default constructor.
   * <P>
   * Uses a general number format for the current locale.
   */
  public NumberFormatParser() {
    setNumberFormat( NumberFormat.getInstance() );
  }

  /**
   * Sets the number format.
   *
   * @param nf
   *          The number format.
   */
  public void setNumberFormat( final NumberFormat nf ) {
    super.setFormatter( nf );
  }

  /**
   * Returns the number format.
   *
   * @return The number format.
   */
  public NumberFormat getNumberFormat() {
    return (NumberFormat) getFormatter();
  }

  /**
   * Sets the formatter.
   *
   * @param f
   *          The format.
   */
  public void setFormatter( final Format f ) {
    final NumberFormat fm = (NumberFormat) f;
    super.setFormatter( fm );
  }

  /**
   * Turns grouping on or off for the current number format.
   *
   * @param newValue
   *          The new value of the grouping flag.
   */
  public void setGroupingUsed( final boolean newValue ) {
    getNumberFormat().setGroupingUsed( newValue );
  }

  /**
   * Returns the value of the grouping flag for the current number format.
   *
   * @return The grouping flag.
   */
  public boolean isGroupingUsed() {
    return getNumberFormat().isGroupingUsed();
  }

  /**
   * Sets the maximum number of fraction digits for the current number format.
   *
   * @param newValue
   *          The number of digits.
   */
  public void setMaximumFractionDigits( final int newValue ) {
    getNumberFormat().setMaximumFractionDigits( newValue );
  }

  /**
   * Returns the maximum number of fraction digits.
   *
   * @return The digits.
   */
  public int getMaximumFractionDigits() {
    return getNumberFormat().getMaximumFractionDigits();
  }

  /**
   * Sets the maximum number of digits in the integer part of the current number format.
   *
   * @param newValue
   *          The number of digits.
   */
  public void setMaximumIntegerDigits( final int newValue ) {
    getNumberFormat().setMaximumFractionDigits( newValue );
  }

  /**
   * Returns the maximum number of integer digits.
   *
   * @return The digits.
   */
  public int getMaximumIntegerDigits() {
    return getNumberFormat().getMaximumFractionDigits();
  }

  /**
   * Sets the minimum number of fraction digits for the current number format.
   *
   * @param newValue
   *          The number of digits.
   */
  public void setMinimumFractionDigits( final int newValue ) {
    getNumberFormat().setMaximumFractionDigits( newValue );
  }

  /**
   * Returns the minimum number of fraction digits.
   *
   * @return The digits.
   */
  public int getMinimumFractionDigits() {
    return getNumberFormat().getMaximumFractionDigits();
  }

  /**
   * Sets the minimum number of digits in the integer part of the current number format.
   *
   * @param newValue
   *          The number of digits.
   */
  public void setMinimumIntegerDigits( final int newValue ) {
    getNumberFormat().setMaximumFractionDigits( newValue );
  }

  /**
   * Returns the minimum number of integer digits.
   *
   * @return The digits.
   */
  public int getMinimumIntegerDigits() {
    return getNumberFormat().getMaximumFractionDigits();
  }

  /**
   * Checks whether the given value is already a valid result. IF the datasource already returned a valid value, and no
   * parsing is required, a parser can skip the parsing process by returning true in this function.
   *
   * @param o
   *          the value to parse.
   * @return true, if the given object is already an instance of number.
   */
  protected boolean isValidOutput( final Object o ) {
    return o instanceof Number;
  }
}