/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.lang.mutable;

import org.apache.commons.lang.math.NumberUtils;

A mutable double wrapper.
Author:
Apache Software Foundation
See Also:
Double
Since:
2.1
Version:
$Id: MutableDouble.java 905707 2010-02-02 16:59:59Z niallp $/**
 * A mutable <code>double</code> wrapper.
 * 
 * @see Double
 * @since 2.1
 * @author Apache Software Foundation
 * @version $Id: MutableDouble.java 905707 2010-02-02 16:59:59Z niallp $
 */
public class MutableDouble extends Number implements Comparable, Mutable {

    
Required for serialization support.
See Also:
Serializable/**
     * Required for serialization support.
     * 
     * @see java.io.Serializable
     */
    private static final long serialVersionUID = 1587163916L;

    
The mutable value. /** The mutable value. */
    private double value;

    
Constructs a new MutableDouble with the default value of zero.
/**
     * Constructs a new MutableDouble with the default value of zero.
     */
    public MutableDouble() {
        super();
    }

    
Constructs a new MutableDouble with the specified value.
Params:
value –  the initial value to store/**
     * Constructs a new MutableDouble with the specified value.
     * 
     * @param value  the initial value to store
     */
    public MutableDouble(double value) {
        super();
        this.value = value;
    }

    
Constructs a new MutableDouble with the specified value.
Params:
value –  the initial value to store, not null
Throws:
NullPointerException – if the object is null/**
     * Constructs a new MutableDouble with the specified value.
     * 
     * @param value  the initial value to store, not null
     * @throws NullPointerException if the object is null
     */
    public MutableDouble(Number value) {
        super();
        this.value = value.doubleValue();
    }

    
Constructs a new MutableDouble parsing the given string.
Params:
value –  the string to parse, not null
Throws:
NumberFormatException – if the string cannot be parsed into a double
Since:
2.5/**
     * Constructs a new MutableDouble parsing the given string.
     * 
     * @param value  the string to parse, not null
     * @throws NumberFormatException if the string cannot be parsed into a double
     * @since 2.5
     */
    public MutableDouble(String value) throws NumberFormatException {
        super();
        this.value = Double.parseDouble(value);
    }

    //-----------------------------------------------------------------------
    
Gets the value as a Double instance.
Returns:
the value as a Double, never null/**
     * Gets the value as a Double instance.
     * 
     * @return the value as a Double, never null
     */
    public Object getValue() {
        return new Double(this.value);
    }

    
Sets the value.
Params:
value –  the value to set/**
     * Sets the value.
     * 
     * @param value  the value to set
     */
    public void setValue(double value) {
        this.value = value;
    }

    
Sets the value from any Number instance.
Params:
value –  the value to set, not null
Throws:
NullPointerException – if the object is null
ClassCastException – if the type is not a Number/**
     * Sets the value from any Number instance.
     * 
     * @param value  the value to set, not null
     * @throws NullPointerException if the object is null
     * @throws ClassCastException if the type is not a {@link Number}
     */
    public void setValue(Object value) {
        setValue(((Number) value).doubleValue());
    }

    //-----------------------------------------------------------------------
    
Checks whether the double value is the special NaN value.
Returns:
true if NaN/**
     * Checks whether the double value is the special NaN value.
     * 
     * @return true if NaN
     */
    public boolean isNaN() {
        return Double.isNaN(value);
    }

    
Checks whether the double value is infinite.
Returns:
true if infinite/**
     * Checks whether the double value is infinite.
     * 
     * @return true if infinite
     */
    public boolean isInfinite() {
        return Double.isInfinite(value);
    }

    //-----------------------------------------------------------------------
    
Increments the value.
Since:
Commons Lang 2.2/**
     * Increments the value.
     *
     * @since Commons Lang 2.2
     */
    public void increment() {
        value++;
    }

    
Decrements the value.
Since:
Commons Lang 2.2/**
     * Decrements the value.
     *
     * @since Commons Lang 2.2
     */
    public void decrement() {
        value--;
    }

    //-----------------------------------------------------------------------
    
Adds a value to the value of this instance.
Params:
operand –  the value to add
Since:
Commons Lang 2.2/**
     * Adds a value to the value of this instance.
     * 
     * @param operand  the value to add
     * @since Commons Lang 2.2
     */
    public void add(double operand) {
        this.value += operand;
    }

    
Adds a value to the value of this instance.
Params:
operand –  the value to add, not null
Throws:
NullPointerException – if the object is null
Since:
Commons Lang 2.2/**
     * Adds a value to the value of this instance.
     * 
     * @param operand  the value to add, not null
     * @throws NullPointerException if the object is null
     * @since Commons Lang 2.2
     */
    public void add(Number operand) {
        this.value += operand.doubleValue();
    }

    
Subtracts a value from the value of this instance.
Params:
operand –  the value to subtract, not null
Since:
Commons Lang 2.2/**
     * Subtracts a value from the value of this instance.
     * 
     * @param operand  the value to subtract, not null
     * @since Commons Lang 2.2
     */
    public void subtract(double operand) {
        this.value -= operand;
    }

    
Subtracts a value from the value of this instance.
Params:
operand –  the value to subtract, not null
Throws:
NullPointerException – if the object is null
Since:
Commons Lang 2.2/**
     * Subtracts a value from the value of this instance.
     * 
     * @param operand  the value to subtract, not null
     * @throws NullPointerException if the object is null
     * @since Commons Lang 2.2
     */
    public void subtract(Number operand) {
        this.value -= operand.doubleValue();
    }

    //-----------------------------------------------------------------------
    // shortValue and bytValue rely on Number implementation
    
Returns the value of this MutableDouble as an int.
Returns:
the numeric value represented by this object after conversion to type int./**
     * Returns the value of this MutableDouble as an int.
     *
     * @return the numeric value represented by this object after conversion to type int.
     */
    public int intValue() {
        return (int) value;
    }

    
Returns the value of this MutableDouble as a long.
Returns:
the numeric value represented by this object after conversion to type long./**
     * Returns the value of this MutableDouble as a long.
     *
     * @return the numeric value represented by this object after conversion to type long.
     */
    public long longValue() {
        return (long) value;
    }

    
Returns the value of this MutableDouble as a float.
Returns:
the numeric value represented by this object after conversion to type float./**
     * Returns the value of this MutableDouble as a float.
     *
     * @return the numeric value represented by this object after conversion to type float.
     */
    public float floatValue() {
        return (float) value;
    }

    
Returns the value of this MutableDouble as a double.
Returns:
the numeric value represented by this object after conversion to type double./**
     * Returns the value of this MutableDouble as a double.
     *
     * @return the numeric value represented by this object after conversion to type double.
     */
    public double doubleValue() {
        return value;
    }

    //-----------------------------------------------------------------------
    
Gets this mutable as an instance of Double.
Returns:
a Double instance containing the value from this mutable, never null/**
     * Gets this mutable as an instance of Double.
     *
     * @return a Double instance containing the value from this mutable, never null
     */
    public Double toDouble() {
        return new Double(doubleValue());
    }

    //-----------------------------------------------------------------------
    
Compares this object against the specified object. The result is true if and only if the argument
is not null and is a Double object that represents a double that has the identical
bit pattern to the bit pattern of the double represented by this object. For this purpose, two
double values are considered to be the same if and only if the method Double.doubleToLongBits(double)returns the same long value when applied to each. 

Note that in most cases, for two instances of class Double,d1 and d2,
the value of d1.equals(d2) is true if and only if 

  d1.doubleValue() == d2.doubleValue()



also has the value true. However, there are two exceptions:

If d1 and d2 both represent Double.NaN, then the
equals method returns true, even though Double.NaN==Double.NaN has
the value false.
If d1 represents +0.0 while d2 represents -0.0,
or vice versa, the equal test has the value false, even though
+0.0==-0.0 has the value true. This allows hashtables to operate properly.

Params:
obj –  the object to compare with, null returns false
Returns:
true if the objects are the same; false otherwise./**
     * Compares this object against the specified object. The result is <code>true</code> if and only if the argument
     * is not <code>null</code> and is a <code>Double</code> object that represents a double that has the identical
     * bit pattern to the bit pattern of the double represented by this object. For this purpose, two
     * <code>double</code> values are considered to be the same if and only if the method
     * {@link Double#doubleToLongBits(double)}returns the same long value when applied to each.
     * <p>
     * Note that in most cases, for two instances of class <code>Double</code>,<code>d1</code> and <code>d2</code>,
     * the value of <code>d1.equals(d2)</code> is <code>true</code> if and only if <blockquote>
     * 
     * <pre>
     *   d1.doubleValue()&nbsp;== d2.doubleValue()
     * </pre>
     * 
     * </blockquote>
     * <p>
     * also has the value <code>true</code>. However, there are two exceptions:
     * <ul>
     * <li>If <code>d1</code> and <code>d2</code> both represent <code>Double.NaN</code>, then the
     * <code>equals</code> method returns <code>true</code>, even though <code>Double.NaN==Double.NaN</code> has
     * the value <code>false</code>.
     * <li>If <code>d1</code> represents <code>+0.0</code> while <code>d2</code> represents <code>-0.0</code>,
     * or vice versa, the <code>equal</code> test has the value <code>false</code>, even though
     * <code>+0.0==-0.0</code> has the value <code>true</code>. This allows hashtables to operate properly.
     * </ul>
     * 
     * @param obj  the object to compare with, null returns false
     * @return <code>true</code> if the objects are the same; <code>false</code> otherwise.
     */
    public boolean equals(Object obj) {
        return (obj instanceof MutableDouble)
            && (Double.doubleToLongBits(((MutableDouble) obj).value) == Double.doubleToLongBits(value));
    }

    
Returns a suitable hash code for this mutable.
Returns:
a suitable hash code/**
     * Returns a suitable hash code for this mutable.
     * 
     * @return a suitable hash code
     */
    public int hashCode() {
        long bits = Double.doubleToLongBits(value);
        return (int) (bits ^ (bits >>> 32));
    }

    //-----------------------------------------------------------------------
    
Compares this mutable to another in ascending order.
Params:
obj – the other mutable to compare to, not null
Throws:
ClassCastException – if the argument is not a MutableDouble
Returns:
negative if this is less, zero if equal, positive if greater/**
     * Compares this mutable to another in ascending order.
     * 
     * @param obj the other mutable to compare to, not null
     * @return negative if this is less, zero if equal, positive if greater
     * @throws ClassCastException if the argument is not a MutableDouble
     */
    public int compareTo(Object obj) {
        MutableDouble other = (MutableDouble) obj;
        double anotherVal = other.value;
        return NumberUtils.compare(value, anotherVal);
    }

    //-----------------------------------------------------------------------
    
Returns the String value of this mutable.
Returns:
the mutable value as a string/**
     * Returns the String value of this mutable.
     * 
     * @return the mutable value as a string
     */
    public String toString() {
        return String.valueOf(value);
    }

}