/*
 * NOTE: This copyright does *not* cover user programs that use HQ
 * program services by normal system calls through the application
 * program interfaces provided as part of the Hyperic Plug-in Development
 * Kit or the Hyperic Client Development Kit - this is merely considered
 * normal use of the program, and does *not* fall under the heading of
 * "derived work".
 * 
 * Copyright (C) [2004, 2005, 2006], Hyperic, Inc.
 * This file is part of HQ.
 * 
 * HQ is free software; you can redistribute it and/or modify
 * it under the terms version 2 of the GNU General Public License as
 * published by the Free Software Foundation. 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 General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA.
 */

package org.hyperic.image.chart;

import org.hyperic.util.data.IDisplayDataPoint;
import org.hyperic.util.data.IEventPoint;

/**
 * DataPoint holds a data and label for a single data point in a chart. A
 * collection of DataPoint objects are used to chart a series of data points.
 */
public class DataPoint implements IDisplayDataPoint
{
    private String m_strLabel;
    private double m_dValue;
    private long   m_timestamp;
         
    /**
     * Constructs a DataPoint object with the specified value and an empty
     * label.
     *
     * @param value
     *      A floating point value for the object data point.
     */
    public DataPoint(double value) {
        this(value, null);
    }
    
    /**
     * Constructs a DataPoint object with the specified value and and
     * specified label.
     *
     * @param value
     *      A floating point value for the object's data point.
     * @param timestamp
     *      A timestamp for the object's data point.
     */
    public DataPoint(double value, long timestamp) {
        this.m_dValue    = value;
        this.m_timestamp = timestamp;
    }
    
    /**
     * Constructs a DataPoint object with the specified value and and
     * specified label.
     *
     * @param value
     *      A floating point value for the object's data point.
     * @param label
     *      A String label for the object's data point.
     */
    public DataPoint(double value, String label) {
        this.m_dValue   = value;
        this.m_strLabel = label;
    }

    /**
     * Retrieves the absolute time.
     *
     * @return A long value for the absolute time.
     */
    public long getTimestamp () {
        return this.m_timestamp;
    }
    
    /**
     * Retrieves the label of a chart data point.
     *
     * @return A String label for a chart data point.
     */
    public String getLabel()
    {
        return this.m_strLabel;
    }
    
    /**
     * Sets the label of a chart data point. The label is displayed on the X
     * axis for line and column charts.
     *
     * @param label
     *      A String label for a chart data point.
     */
    public void setLabel(String label)
    {
        if(label == null)
            this.m_strLabel = Chart.EMPTY_STRING;
        else
            this.m_strLabel = label;
    }

    /**
     * Retrieves the value of a chart data point. The data point is charted on
     * the Y axis for line and column charts.
     *
     * @return A floating point value for a chart data point.
     */
    public double getValue()
    {
        return this.m_dValue;
    }
    
    /**
     * Sets the value of a chart data point. The data point is charted on the Y
     * axis for line and column charts.
     *
     * @param value
     *      A floating point value for a chart data point.
     */
    public void setValue(double value)
    {
        this.m_dValue = value;
    }

    public boolean equals(Object obj) {
        if (obj instanceof DataPoint) {
            DataPoint val = (DataPoint) obj;
            return (this.getTimestamp() == val.getTimestamp() &&
                    this.getValue() == val.getValue());
        }

        return false;
    }
}