001/* ===========================================================
002 * Orson Charts : a 3D chart library for the Java(tm) platform
003 * ===========================================================
004 * 
005 * (C)opyright 2013-2022, by David Gilbert.  All rights reserved.
006 * 
007 * https://github.com/jfree/orson-charts
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 org.jfree.chart3d.axis;
034
035import java.io.Serializable;
036import java.text.DecimalFormat;
037import java.text.Format;
038import org.jfree.chart3d.internal.Args;
039
040/**
041 * A {@link TickSelector} implementation that selects tick units in multiples 
042 * of 1, 2 and 5 and only displays integer values.
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 * @since 1.5
049 */
050@SuppressWarnings("serial")
051public class IntegerTickSelector implements TickSelector, Serializable {
052
053    private int power = 0;
054    
055    private int factor = 1;
056    
057    /**
058     * Creates a new instance.
059     */
060    public IntegerTickSelector() {
061        this.power = 0;
062        this.factor = 1;
063    }
064    
065    /**
066     * Selects and returns a standard tick size that is greater than or equal to 
067     * the specified reference value and, ideally, as close to it as possible 
068     * (to minimise the number of iterations used by axes to determine the tick
069     * size to use).  After a call to this method, the 
070     * {@link #getCurrentTickSize()} method should return the selected tick 
071     * size (there is a "pointer" to this tick size), the {@link #next()} 
072     * method should move the pointer to the next (larger) standard tick size, 
073     * and the {@link #previous()} method should move the pointer to the 
074     * previous (smaller) standard tick size.
075     * 
076     * @param reference  the reference value (must be positive and finite).
077     * 
078     * @return The selected tick size. 
079     */
080    @Override
081    public double select(double reference) {
082        Args.finitePositiveRequired(reference, "reference");
083        this.power = (int) Math.ceil(Math.log10(reference));
084        this.factor = 1;
085        return getCurrentTickSize();
086    }
087
088    /**
089     * Move the cursor to the next (larger) tick size, if there is one.  
090     * Returns {@code true} in the case that the cursor is moved, and 
091     * {@code false} where there are a finite number of tick sizes and the
092     * current tick size is the largest available.
093     */
094    @Override
095    public boolean next() {
096        if (factor == 1) {
097            factor = 2;
098            return true;
099        } 
100        if (factor == 2) {
101            factor = 5;
102            return true;  
103        } 
104        if (factor == 5) {
105            power++;
106            factor = 1;
107            return true;
108        } 
109        throw new IllegalStateException("We should never get here.");
110    }
111
112    /**
113     * Move the cursor to the previous (smaller) tick size, if there is one.  
114     * Returns {@code true} in the case that the cursor is moved, and 
115     * {@code false} where there are a finite number of tick sizes and the
116     * current tick size is the smallest available.
117     */
118    @Override
119    public boolean previous() {
120        if (factor == 1) {
121            if (power == 0) {
122                return false;
123            }
124            factor = 5;
125            power--;
126            return true;
127        } 
128        if (factor == 2) {
129            factor = 1;
130            return true;  
131        } 
132        if (factor == 5) {
133            factor = 2;
134            return true;
135        } 
136        throw new IllegalStateException("We should never get here.");
137    }
138
139    @Override
140    public double getCurrentTickSize() {
141        return this.factor * Math.pow(10.0, this.power);
142    }
143    
144    private final DecimalFormat df0 = new DecimalFormat("#,##0");
145
146    @Override
147    public Format getCurrentTickLabelFormat() {
148        if (power >= 0 && power <= 6) {
149            return df0;
150        }
151        return new DecimalFormat("0.0000E0");
152    }
153    
154    /**
155     * Tests this instance for equality with an arbitrary object.
156     * 
157     * @param obj  the object ({@code null} permitted).
158     * 
159     * @return A boolean. 
160     */
161    @Override
162    public boolean equals(Object obj) {
163        if (obj ==  this) {
164            return true;
165        }
166        if (!(obj instanceof IntegerTickSelector)) {
167            return false;
168        }
169        return true;
170    }
171    
172}