DecimalValue.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.binding.tinkerforge.internal.types;

import java.math.BigDecimal;

/**
 * The decimal value uses a BigDecimal internally and thus can be used for integers, longs and
 * floating point numbers alike (inspired by {@link org.openhab.core.library.types.DecimalType}).
 *
 * @author Theo Weiss
 * @since 1.4.0
 */
public class DecimalValue extends Number implements TinkerforgeValue, Comparable<DecimalValue> {
    private static final long serialVersionUID = -165912774170068480L;

    final static public DecimalValue ZERO = new DecimalValue(0);

    protected BigDecimal value;

    public DecimalValue() {
        this.value = BigDecimal.ZERO;
    }

    public DecimalValue(BigDecimal value) {
        this.value = value;
    }

    public DecimalValue(long value) {
        this.value = new BigDecimal(value);
    }

    public DecimalValue(double value) {
        this.value = new BigDecimal(value);
    }

    public DecimalValue(String value) {
        this.value = new BigDecimal(value);
    }

    @Override
    public String toString() {
        return value.toPlainString();
    }

    public static DecimalValue valueOf(String value) {
        return new DecimalValue(value);
    }

    public static DecimalValue valueOf(BigDecimal value) {
        return new DecimalValue(value);
    }

    @Override
    public int intValue() {
        return value.intValue();
    }

    @Override
    public long longValue() {
        return value.longValue();
    }

    @Override
    public float floatValue() {
        return value.floatValue();
    }

    @Override
    public double doubleValue() {
        return value.doubleValue();
    }

    public BigDecimal bigDecimalValue() {
        return value;
    }

    public OnOffValue onOffValue(int scale) {
        BigDecimal scaledvalue = value.setScale(0, BigDecimal.ROUND_UP);
        return scaledvalue.compareTo(BigDecimal.ZERO) == 0 ? OnOffValue.OFF : OnOffValue.ON;
    }

    @Override
    public int compareTo(DecimalValue o) {
        return value.compareTo(o.toBigDecimal());
    }

    /*
     * Compare two values taking a threshold into account.
     * 
     * If the absolute difference between the values is less then threshold 0 is returned elsewhere
     * the values are compared using the compareTo function of BigDecimal.
     */
    public int compareTo(DecimalValue o, BigDecimal threshold) {
        if (o == null) {
            return 1;
        } else if (threshold == null) {
            return value.compareTo(o.toBigDecimal().abs());
        } else if (o != null && threshold != null) {
            BigDecimal difference = value.subtract(o.toBigDecimal()).abs();
            if (difference.compareTo(threshold) < 0) {
                return 0;
            }
            return value.compareTo(o.toBigDecimal().abs());
        }
        return 0;
    }

    private BigDecimal toBigDecimal() {
        return value;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((value == null) ? 0 : value.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        DecimalValue other = (DecimalValue) obj;
        if (value == null) {
            if (other.value != null) {
                return false;
            }
        } else if (!value.equals(other.value)) {
            return false;
        }
        return true;
    }
}