segmentedtimeline.java

java图形利器

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2007, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * -----------------------
 * SegmentedTimeline.java
 * -----------------------
 * (C) Copyright 2003-2007, by Bill Kelemen and Contributors.
 *
 * Original Author:  Bill Kelemen;
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *
 * $Id: SegmentedTimeline.java,v 1.9.2.3 2007/02/02 14:32:42 mungady Exp $
 *
 * Changes
 * -------
 * 23-May-2003 : Version 1 (BK);
 * 15-Aug-2003 : Implemented Cloneable (DG);
 * 01-Jun-2004 : Modified to compile with JDK 1.2.2 (DG);
 * 30-Sep-2004 : Replaced getTime().getTime() with getTimeInMillis() (DG);
 * 04-Nov-2004 : Reverted change of 30-Sep-2004, won't work with JDK 1.3 (DG);
 * 11-Jan-2005 : Removed deprecated code in preparation for 1.0.0 release (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 14-Nov-2006 : Fix in toTimelineValue(long) to avoid stack overflow (DG);
 * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG);
 * 
 */

package org.jfree.chart.axis;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Iterator;
import java.util.List;
import java.util.SimpleTimeZone;
import java.util.TimeZone;

/**
 * A {@link Timeline} that implements a "segmented" timeline with included, 
 * excluded and exception segments.
 * <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.
 * <P>
 * A timeline can be used as parameter to a 
 * {@link org.jfree.chart.axis.DateAxis} to define the values that this axis 
 * supports. This class 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}.
 * <P>
 * In this class, a segment is defined as a unit of time of fixed length. 
 * Examples of segments are: days, hours, minutes, etc. The size of a segment 
 * is defined as the number of milliseconds in the segment. Some useful segment
 * sizes are defined as constants in this class: DAY_SEGMENT_SIZE, 
 * HOUR_SEGMENT_SIZE, FIFTEEN_MINUTE_SEGMENT_SIZE and MINUTE_SEGMENT_SIZE.
 * <P>
 * Segments are group together to form a Segment Group. Each Segment Group will
 * contain a number of Segments included and a number of Segments excluded. This
 * Segment Group structure will repeat for the whole timeline.
 * <P>
 * For example, a working days SegmentedTimeline would be formed by a group of
 * 7 daily segments, where there are 5 included (Monday through Friday) and 2
 * excluded (Saturday and Sunday) segments.
 * <P>
 * Following is a diagram that explains the major attributes that define a 
 * segment.  Each box is one segment and must be of fixed length (ms, second, 
 * hour, day, etc).
 * <p>
 * <pre>
 * start time
 *   |
 *   v
 *   0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 ...
 * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+...
 * |  |  |  |  |  |EE|EE|  |  |  |  |  |EE|EE|  |  |  |  |  |EE|EE|
 * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+...
 *  \____________/ \___/            \_/
 *        \/         |               |
 *     included   excluded        segment
 *     segments   segments         size
 *  \_________  _______/
 *            \/
 *       segment group
 * </pre>
 * Legend:<br>
 * &lt;space&gt; = Included segment<br>
 * EE      = Excluded segments in the base timeline<br>
 * <p>
 * In the example, the following segment attributes are presented:
 * <ul>
 * <li>segment size: the size of each segment in ms.
 * <li>start time: the start of the first segment of the first segment group to
 *     consider.
 * <li>included segments: the number of segments to include in the group.
 * <li>excluded segments: the number of segments to exclude in the group.
 * </ul>
 * <p>
 * Exception Segments are allowed. These exception segments are defined as
 * segments that would have been in the included segments of the Segment Group,
 * but should be excluded for special reasons. In the previous working days
 * SegmentedTimeline example, holidays would be considered exceptions.
 * <P>
 * Additionally the <code>startTime</code>, or start of the first Segment of 
 * the smallest segment group needs to be defined. This startTime could be 
 * relative to January 1, 1970, 00:00:00 GMT or any other date. This creates a 
 * point of reference to start counting Segment Groups. For example, for the 
 * working days SegmentedTimeline, the <code>startTime</code> could be 
 * 00:00:00 GMT of the first Monday after January 1, 1970. In this class, the 
 * constant FIRST_MONDAY_AFTER_1900 refers to a reference point of the first 
 * Monday of the last century.
 * <p>
 * A SegmentedTimeline can include a baseTimeline. This combination of 
 * timelines allows the creation of more complex timelines. For example, in 
 * order to implement a SegmentedTimeline for an intraday stock trading 
 * application, where the trading period is defined as 9:00 AM through 4:00 PM 
 * Monday through Friday, two SegmentedTimelines are used. The first one (the 
 * baseTimeline) would be a working day SegmentedTimeline (daily timeline 
 * Monday through Friday). On top of this baseTimeline, a second one is defined
 * that maps the 9:00 AM to 4:00 PM period. Because the baseTimeline defines a 
 * timeline of Monday through Friday, the resulting (combined) timeline will 
 * expose the period 9:00 AM through 4:00 PM only on Monday through Friday, 
 * and will remove all other intermediate intervals.
 * <P>
 * Two factory methods newMondayThroughFridayTimeline() and
 * newFifteenMinuteTimeline() are provided as examples to create special
 * SegmentedTimelines.
 *
 * @see org.jfree.chart.axis.DateAxis
 */
public class SegmentedTimeline implements Timeline, Cloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 1093779862539903110L;
    
    ////////////////////////////////////////////////////////////////////////////
    // predetermined segments sizes
    ////////////////////////////////////////////////////////////////////////////

    /** Defines a day segment size in ms. */
    public static final long DAY_SEGMENT_SIZE = 24 * 60 * 60 * 1000;

    /** Defines a one hour segment size in ms. */
    public static final long HOUR_SEGMENT_SIZE = 60 * 60 * 1000;

    /** Defines a 15-minute segment size in ms. */
    public static final long FIFTEEN_MINUTE_SEGMENT_SIZE = 15 * 60 * 1000;

    /** Defines a one-minute segment size in ms. */
    public static final long MINUTE_SEGMENT_SIZE = 60 * 1000;

    ////////////////////////////////////////////////////////////////////////////
    // other constants
    ////////////////////////////////////////////////////////////////////////////

    /**
     * Utility constant that defines the startTime as the first monday after 
     * 1/1/1970.  This should be used when creating a SegmentedTimeline for 
     * Monday through Friday. See static block below for calculation of this 
     * constant.
     */
    public static long FIRST_MONDAY_AFTER_1900;

    /**
     * Utility TimeZone object that has no DST and an offset equal to the 
     * default TimeZone. This allows easy arithmetic between days as each one 
     * will have equal size.
     */
    public static TimeZone NO_DST_TIME_ZONE;

    /**
     * This is the default time zone where the application is running. See 
     * getTime() below where we make use of certain transformations between 
     * times in the default time zone and the no-dst time zone used for our 
     * calculations.
     */
    public static TimeZone DEFAULT_TIME_ZONE = TimeZone.getDefault();

    /**
     * This will be a utility calendar that has no DST but is shifted relative 
     * to the default time zone's offset.
     */
    private Calendar workingCalendarNoDST 
        = new GregorianCalendar(NO_DST_TIME_ZONE);

    /**
     * This will be a utility calendar that used the default time zone.
     */
    private Calendar workingCalendar = Calendar.getInstance();

    ////////////////////////////////////////////////////////////////////////////
    // private attributes
    ////////////////////////////////////////////////////////////////////////////

    /** Segment size in ms. */
    private long segmentSize;

    /** Number of consecutive segments to include in a segment group. */
    private int segmentsIncluded;

    /** Number of consecutive segments to exclude in a segment group. */
    private int segmentsExcluded;

    /** Number of segments in a group (segmentsIncluded + segmentsExcluded). */
    private int groupSegmentCount;

    /** 
     * Start of time reference from time zero (1/1/1970). 
     * This is the start of segment #0. 
     */
    private long startTime;

    /** Consecutive ms in segmentsIncluded (segmentsIncluded * segmentSize). */
    private long segmentsIncludedSize;

    /** Consecutive ms in segmentsExcluded (segmentsExcluded * segmentSize). */
    private long segmentsExcludedSize;

    /** ms in a segment group (segmentsIncludedSize + segmentsExcludedSize). */
    private long segmentsGroupSize;

    /**
     * List of exception segments (exceptions segments that would otherwise be
     * included based on the periodic (included, excluded) grouping).
     */
    private List exceptionSegments = new ArrayList();

    /**
     * This base timeline is used to specify exceptions at a higher level. For 
     * example, if we are a intraday timeline and want to exclude holidays, 
     * instead of having to exclude all intraday segments for the holiday, 
     * segments from this base timeline can be excluded. This baseTimeline is 
     * always optional and is only a convenience method.
     * <p>
     * Additionally, all excluded segments from this baseTimeline will be 
     * considered exceptions at this level.
     */
    private SegmentedTimeline baseTimeline;

    /** A flag that controls whether or not to adjust for daylight saving. */
    private boolean adjustForDaylightSaving = false;
    
    ////////////////////////////////////////////////////////////////////////////
    // static block
    ////////////////////////////////////////////////////////////////////////////

    static {
        // make a time zone with no DST for our Calendar calculations
        int offset = TimeZone.getDefault().getRawOffset();
        NO_DST_TIME_ZONE = new SimpleTimeZone(offset, "UTC-" + offset);
        
        // calculate midnight of first monday after 1/1/1900 relative to 
        // current locale
        Calendar cal = new GregorianCalendar(NO_DST_TIME_ZONE);
        cal.set(1900, 0, 1, 0, 0, 0);
        cal.set(Calendar.MILLISECOND, 0);
        while (cal.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY) {
            cal.add(Calendar.DATE, 1);
        }
        // FIRST_MONDAY_AFTER_1900 = cal.getTime().getTime();  
        // preceding code won't work with JDK 1.3
        FIRST_MONDAY_AFTER_1900 = cal.getTime().getTime();
    }

    ////////////////////////////////////////////////////////////////////////////
    // constructors and factory methods
    ////////////////////////////////////////////////////////////////////////////

    /**
     * Constructs a new segmented timeline, optionaly using another segmented
     * timeline as its base. This chaining of SegmentedTimelines allows further
     * segmentation into smaller timelines.
     *
     * If a base
     *
     * @param segmentSize the size of a segment in ms. This time unit will be
     *        used to compute the included and excluded segments of the 
     *        timeline.
     * @param segmentsIncluded Number of consecutive segments to include.
     * @param segmentsExcluded Number of consecutive segments to exclude.
     */
    public SegmentedTimeline(long segmentSize,
                             int segmentsIncluded,
                             int segmentsExcluded) {

        this.segmentSize = segmentSize;
        this.segmentsIncluded = segmentsIncluded;
        this.segmentsExcluded = segmentsExcluded;

        this.groupSegmentCount = this.segmentsIncluded + this.segmentsExcluded;
        this.segmentsIncludedSize = this.segmentsIncluded * this.segmentSize;
        this.segmentsExcludedSize = this.segmentsExcluded * this.segmentSize;
        this.segmentsGroupSize = this.segmentsIncludedSize 
                                 + this.segmentsExcludedSize;

    }

    /**
     * Factory method to create a Monday through Friday SegmentedTimeline.
     * <P>
     * The <code>startTime</code> of the resulting timeline will be midnight 
     * of the first Monday after 1/1/1900.
     *
     * @return A fully initialized SegmentedTimeline.
     */
    public static SegmentedTimeline newMondayThroughFridayTimeline() {
        SegmentedTimeline timeline 
            = new SegmentedTimeline(DAY_SEGMENT_SIZE, 5, 2);
        timeline.setStartTime(FIRST_MONDAY_AFTER_1900);
        return timeline;
    }