/* ===========================================================

 * JFreeChart : a free chart library for the Java(tm) platform

 * ===========================================================

 *

 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.

 *

 * Project Info:  http://www.jfree.org/jfreechart/index.html

 *

 * 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., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

 * in the United States and other countries.]

 *

 * -------------

 * Timeline.java

 * -------------

 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.

 *

 * Original Author:  Bill Kelemen;

 * Contributor(s):   David Gilbert (for Object Refinery Limited);

 *

 * $Id: Timeline.java,v 1.1 2004/08/31 14:30:24 mungady Exp $

 *

 * Changes

 * -------

 * 23-May-2003 : Version 1 (BK);

 * 09-Sep-2003 : Changed some method and parameter names (DG);

 * 

 */



package org.jfree.chart.axis;



import java.util.Date;



/**

 * An interface that defines the contract for a Timeline.

 * <P>

 * A Timeline will present a series of values to be used for an axis. Each

 * Timeline must provide transformation methods between domain values and

 * timeline values. In theory many transformations are possible. This interface

 * has been implemented completely in {@link org.jfree.chart.axis.SegmentedTimeline}.

 * <P>

 * A timeline can be used as parameter to a {@link org.jfree.chart.axis.DateAxis}

 * to define the values that this axis supports. As an example, the {@link

 * org.jfree.chart.axis.SegmentedTimeline} implements a timeline formed by segments

 * of equal length (ex. days, hours, minutes) where some segments can be included

 * in the timeline and others excluded. Therefore timelines like "working days" or

 * "working hours" can be created where non-working days or non-working hours respectively can

 * be removed from the timeline, and therefore from the axis. This creates a smooth

 * plot with equal separation between all included segments.

 * <P>

 * Because Timelines were created mainly for Date related axis, values are

 * represented as longs instead of doubles. In this case, the domain value is

 * just the number of milliseconds since January 1, 1970, 00:00:00 GMT as defined

 * by the getTime() method of {@link java.util.Date}.

 *

 * @see org.jfree.chart.axis.SegmentedTimeline

 * @see org.jfree.chart.axis.DateAxis

 *

 * @author Bill Kelemen

 */

public interface Timeline {



    /**

     * Translates a millisecond (as defined by java.util.Date) into an index along this timeline.

     *

     * @param millisecond  the millisecond.

     * 

     * @return A timeline value.

     */

    long toTimelineValue(long millisecond);



    /**

     * Translates a date into a value on this timeline.

     *

     * @param date  the date.

     * 

     * @return A timeline value

     */

    long toTimelineValue(Date date);



    /**

     * Translates a value relative to this timeline into a domain value. The domain

     * value obtained by this method is not always the same domain value that

     * could have been supplied to translateDomainValueToTimelineValue(domainValue).

     * This is because the original tranformation may not be complete reversable.

     *

     * @see org.jfree.chart.axis.SegmentedTimeline

     *

     * @param timelineValue  a timeline value.

     * 

     * @return A domain value.

     */

    long toMillisecond(long timelineValue);



    /**

     * Returns <code>true</code> if a value is contained in the timeline values.

     *

     * @param millisecond  the millisecond.

     * 

     * @return <code>true</code> if value is contained in the timeline and <code>false</code> 

     *         otherwise.

     */

    boolean containsDomainValue(long millisecond);



    /**

     * Returns <code>true</code> if a date is contained in the timeline values.

     *

     * @param date  the date to verify.

     * 

     * @return <code>true</code> if value is contained in the timeline and <code>false</code> 

     *         otherwise.

     */

    boolean containsDomainValue(Date date);



    /**

     * Returns <code>true</code> if a range of values are contained in the timeline.

     *

     * @param fromMillisecond  the start of the range to verify.

     * @param toMillisecond  the end of the range to verify.

     * 

     * @return <code>true</code> if the range is contained in the timeline or <code>false</code> 

     *         otherwise

     */

    boolean containsDomainRange(long fromMillisecond, long toMillisecond);



    /**

     * Returns <code>true</code> if a range of dates are contained in the timeline.

     *

     * @param fromDate  the start of the range to verify.

     * @param toDate  the end of the range to verify.

     * 

     * @return <code>true</code> if the range is contained in the timeline or <code>false</code> 

     *         otherwise

     */

    boolean containsDomainRange(Date fromDate, Date toDate);



}

