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/*
* IntegerReusable.java, a mutable Integer for jchart2d.
* Copyright (C) 2004 - 2011 Achim Westermann.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* If you modify or optimize the code in a useful way please let me know.
* [email protected]
*
*/
package info.monitorenter.util.math;
/**
* Mutable {@link java.lang.Integer}.
*
*
* I needed an wrapper of an primitive int to share the same value between
* different instances and to have the changes made to the primitive value take
* effect on all owners of the same instance.
*
*
* What a pity that java.lang.Integer does not allow to change it's internal
* value at runtime. Every time a new Integer has to be constructed.
*
*
*/
public class IntegerMutable {
/**
* The largest value of type int. The constant value of this
* field is 2147483647.
*/
public static final int MAX_VALUE = 0x7fffffff;
/**
* The smallest value of type int. The constant value of this
* field is -2147483648.
*/
public static final int MIN_VALUE = 0x80000000;
/**
* The value of the Integer.
*/
private int m_value;
/**
* Constructs a newly allocated Integer object that represents
* the primitive int argument.
*
* @param value
* the value to be represented by the Integer.
*/
public IntegerMutable(final int value) {
this.m_value = value;
}
/**
* Adds the given value to the internal value.
*
*
* @param i
* the value to add.
*
* @throws ArithmeticException
* if an overflow ({@link Integer#MAX_VALUE}) occurs.
*/
public void add(final int i) throws ArithmeticException {
final int oldval = this.m_value;
this.m_value += i;
if (oldval > this.m_value) {
this.m_value = oldval;
throw new ArithmeticException("Overflow detected. Value saved unchanged.");
}
}
/**
* Adds the given value to the internal value.
*
*
* @param i
* the value to add.
*
* @throws ArithmeticException
* if an overflow ({@link Integer#MAX_VALUE}) occurs.
*/
public void add(final Integer i) throws ArithmeticException {
this.add(i.intValue());
}
/**
* Adds the given value to the internal value.
*
*
* @param i
* the value to add.
*
* @throws ArithmeticException
* if an overflow ({@link Integer#MAX_VALUE}) occurs.
*/
public void add(final IntegerMutable i) throws ArithmeticException {
this.add(i.getValue());
}
/**
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (this.getClass() != obj.getClass()) {
return false;
}
final IntegerMutable other = (IntegerMutable) obj;
if (this.m_value != other.m_value) {
return false;
}
return true;
}
/**
* Returns the value as an int.
*
*
* @return the value as an int.
*/
public int getValue() {
return this.m_value;
}
/**
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + this.m_value;
return result;
}
/**
* Returns the value as an int.
*
*
* @return the value as an int.
*/
public int intValue() {
return this.m_value;
}
/**
* Sets the value.
*
*
* @param value
* the value.
*/
public void setValue(final int value) {
this.m_value = value;
}
/**
* Substracts the given value from the internal value.
*
*
* @param i
* the value to subtract.
*
* @throws ArithmeticException
* if a carry ({@link Integer#MIN_VALUE}) occurs.
*/
public void sub(final int i) throws ArithmeticException {
final int oldval = this.m_value;
this.m_value -= i;
if (oldval < this.m_value) {
this.m_value = oldval;
throw new ArithmeticException("Carry detected. Value saved unchanged.");
}
}
/**
* Substracts the given value from the internal value.
*
*
* @param i
* the value to subtract.
*
* @throws ArithmeticException
* if a carry ({@link Integer#MIN_VALUE}) occurs.
*/
public void sub(final Integer i) throws ArithmeticException {
this.sub(i.intValue());
}
/**
* Substracts the given value from the internal value.
*
*
* @param i
* the value to subtract.
*
* @throws ArithmeticException
* if a carry ({@link Integer#MIN_VALUE}) occurs.
*/
public void sub(final IntegerMutable i) throws ArithmeticException {
this.sub(i.intValue());
}
/**
* Returns a String object representing this Integer's value.
*
*
* The value is converted to signed decimal representation and returned as a
* string, exactly as if the integer value were given as an argument to the
* {@link java.lang.Integer#toString(int)} method.
*
*
*
* @return a string representation of the value of this object in
* base 10.
*/
@Override
public String toString() {
return String.valueOf(this.m_value);
}
}