    001/* ===========================================================
    002 * Orson Charts : a 3D chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C)opyright 2013-2016, by Object Refinery Limited.  All rights reserved.
    006 *
    007 * http://www.object-refinery.com/orsoncharts/index.html
    008 *
    009 * This program is free software: you can redistribute it and/or modify
    010 * it under the terms of the GNU General Public License as published by
    011 * the Free Software Foundation, either version 3 of the License, or
    012 * (at your option) any later version.
    013 *
    014 * This program is distributed in the hope that it will be useful,
    015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
    016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    017 * GNU General Public License for more details.
    018 *
    019 * You should have received a copy of the GNU General Public License
    020 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    021 *
    022 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    023 * Other names may be trademarks of their respective owners.]
    024 *
    025 * If you do not wish to be bound by the terms of the GPL, an alternative
    026 * commercial license can be purchased.  For details, please see visit the
    027 * Orson Charts home page:
    028 *
    029 * http://www.object-refinery.com/orsoncharts/index.html
    030 *
    031 */
    032
    033package com.orsoncharts.axis;
    034
    035import java.io.Serializable;
    036import java.text.DecimalFormat;
    037import java.text.Format;
    038import com.orsoncharts.util.ArgChecks;
    039
    040/**
    041 * A {@link TickSelector} implementation that selects tick units in multiples
    042 * of 1, 2 and 5.
    043 * <br><br>
    044 * NOTE: This class is serializable, but the serialization format is subject
    045 * to change in future releases and should not be relied upon for persisting
    046 * instances of this class.
    047 */
    048@SuppressWarnings("serial")
    049public class NumberTickSelector implements TickSelector, Serializable {
    050
    051    private int power = 0;
    052
    053    private int factor = 1;
    054
    055    /**
    056     * A flag to track if the units are percentage values, in which case the
    057     * formatter should display less decimal places.
    058     */
    059    private boolean percentage;
    060
    061    /**
    062     * Creates a new instance.
    063     */
    064    public NumberTickSelector() {
    065        this(false);
    066    }
    067
    068    /**
    069     * Creates a new instance, with the option to display the tick values as
    070     * percentages.  The axis follows the normal convention that values in the
    071     * range 0.0 to 1.0 a represented as 0% to 100%.
    072     *
    073     * @param percentage  format the tick values as percentages.
    074     */
    075    public NumberTickSelector(boolean percentage) {
    076        this.power = 0;
    077        this.factor = 1;
    078        this.percentage = percentage;
    079    }
    080
    081    /**
    082     * Selects and returns a standard tick size that is greater than or equal to
    083     * the specified reference value and, ideally, as close to it as possible
    084     * (to minimise the number of iterations used by axes to determine the tick
    085     * size to use).  After a call to this method, the
    086     * {@link #getCurrentTickSize()} method should return the selected tick
    087     * size (there is a "pointer" to this tick size), the {@link #next()}
    088     * method should move the pointer to the next (larger) standard tick size,
    089     * and the {@link #previous()} method should move the pointer to the
    090     * previous (smaller) standard tick size.
    091     *
    092     * @param reference  the reference value (must be positive and finite).
    093     *
    094     * @return The selected tick size.
    095     */
    096    @Override
    097    public double select(double reference) {
    098        ArgChecks.finitePositiveRequired(reference, "reference");
    099        this.power = (int) Math.ceil(Math.log10(reference));
    100        this.factor = 1;
    101        return getCurrentTickSize();
    102    }
    103
    104    /**
    105     * Move the cursor to the next (larger) tick size, if there is one.
    106     * Returns {@code true} in the case that the cursor is moved, and
    107     * {@code false} where there are a finite number of tick sizes and the
    108     * current tick size is the largest available.
    109     */
    110    @Override
    111    public boolean next() {
    112        if (factor == 1) {
    113            factor = 2;
    114            return true;
    115        }
    116        if (factor == 2) {
    117            factor = 5;
    118            return true;
    119        }
    120        if (factor == 5) {
    121            power++;
    122            factor = 1;
    123            return true;
    124        }
    125        throw new IllegalStateException("We should never get here.");
    126    }
    127
    128    /**
    129     * Move the cursor to the previous (smaller) tick size, if there is one.
    130     * Returns {@code true} in the case that the cursor is moved, and
    131     * {@code false} where there are a finite number of tick sizes and the
    132     * current tick size is the smallest available.
    133     */
    134    @Override
    135    public boolean previous() {
    136        if (factor == 1) {
    137            factor = 5;
    138            power--;
    139            return true;
    140        }
    141        if (factor == 2) {
    142            factor = 1;
    143            return true;
    144        }
    145        if (factor == 5) {
    146            factor = 2;
    147            return true;
    148        }
    149        throw new IllegalStateException("We should never get here.");
    150    }
    151
    152    @Override
    153    public double getCurrentTickSize() {
    154        return this.factor * Math.pow(10.0, this.power);
    155    }
    156
    157    private DecimalFormat dfNeg4 = new DecimalFormat("0.0000");
    158    private DecimalFormat dfNeg3 = new DecimalFormat("0.000");
    159    private DecimalFormat dfNeg2 = new DecimalFormat("0.00");
    160    private DecimalFormat dfNeg1 = new DecimalFormat("0.0");
    161    private DecimalFormat df0 = new DecimalFormat("#,##0");
    162    private DecimalFormat dfNeg4P = new DecimalFormat("0.00%");
    163    private DecimalFormat dfNeg3P = new DecimalFormat("0.0%");
    164    private DecimalFormat dfNeg2P = new DecimalFormat("0%");
    165    private DecimalFormat dfNeg1P = new DecimalFormat("0%");
    166    private DecimalFormat df0P = new DecimalFormat("#,##0%");
    167
    168    @Override
    169    public Format getCurrentTickLabelFormat() {
    170        if (power == -4) {
    171            return this.percentage ? dfNeg4P : dfNeg4;
    172        }
    173        if (power == -3) {
    174            return this.percentage ? dfNeg3P : dfNeg3;
    175        }
    176        if (power == -2) {
    177            return this.percentage ? dfNeg2P : dfNeg2;
    178        }
    179        if (power == -1) {
    180            return this.percentage ? dfNeg1P : dfNeg1;
    181        }
    182        if (power >= 0 && power <= 6) {
    183            return this.percentage ? df0P : df0;
    184        }
    185        return this.percentage ? new DecimalFormat("0.0000E0%")
    186                : new DecimalFormat("0.0000E0");
    187    }
    188
    189    /**
    190     * Tests this instance for equality with an arbitrary object.
    191     *
    192     * @param obj  the object ({@code null} permitted).
    193     *
    194     * @return A boolean.
    195     */
    196    @Override
    197    public boolean equals(Object obj) {
    198        if (obj ==  this) {
    199            return true;
    200        }
    201        if (!(obj instanceof NumberTickSelector)) {
    202            return false;
    203        }
    204        NumberTickSelector that = (NumberTickSelector) obj;
    205        if (this.percentage != that.percentage) {
    206            return false;
    207        }
    208        return true;
    209    }
    210
    211}