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.text.Format; 036 037/** 038 * <p>Provides standard tick sizes and formatting for numerical axes. 039 * Conceptually, the selector maintains a list of standard tick sizes (ordered 040 * by size), and a pointer to the current (selected) tick size. Clients of 041 * the selector will initialise the pointer by calling the 042 * {@link #select(double)} method with a reference value (a guess, based on 043 * context, of the largest usable tick size - for example, one half of the 044 * axis length) then, as required, move the pointer to a smaller or larger 045 * tick size (using the {@link #next()} and {@link #previous()} methods) to 046 * find the most appropriate standard size to use.</p> 047 * 048 * <p>The {@link NumberTickSelector} class provides a standard implementation, 049 * but you can create your own if necessary.</p> 050 */ 051public interface TickSelector { 052 053 /** 054 * Selects and returns a standard tick size that is greater than or equal to 055 * the specified reference value and, ideally, as close to it as possible 056 * (to minimise the number of iterations used by axes to determine the tick 057 * size to use). After a call to this method, the 058 * {@link #getCurrentTickSize()} method should return the selected tick 059 * size (there is a "cursor" that points to this tick size), the 060 * {@link #next()} method should move the pointer to the next (larger) 061 * standard tick size, and the {@link #previous()} method should move the 062 * pointer to the previous (smaller) standard tick size. 063 * 064 * @param reference the reference value (must be positive and finite). 065 * 066 * @return The selected tick size. 067 */ 068 double select(double reference); 069 070 /** 071 * Move the cursor to the next (larger) tick size, if there is one. 072 * Returns {@code true} in the case that the cursor is moved, and 073 * {@code false} where there are a finite number of tick sizes and the 074 * current tick size is the largest available. 075 * 076 * @return A boolean. 077 */ 078 boolean next(); 079 080 /** 081 * Move the cursor to the previous (smaller) tick size, if there is one. 082 * Returns {@code true} in the case that the cursor is moved, and 083 * {@code false} where there are a finite number of tick sizes and the 084 * current tick size is the smallest available. 085 * 086 * @return A boolean. 087 */ 088 boolean previous(); 089 090 /** 091 * Returns the tick size that the cursor is currently referencing. 092 * 093 * @return The tick size. 094 */ 095 double getCurrentTickSize(); 096 097 /** 098 * Returns the tick formatter associated with the tick size that the 099 * cursor is currently referencing. 100 * 101 * @return The formatter. 102 */ 103 Format getCurrentTickLabelFormat(); 104 105}