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.util;
034
035/**
036 * Utility methods for argument checking.  Throughout Orson Charts, arguments
037 * passed to methods are validated and exceptions thrown for invalid cases
038 * (the idea is to fail fast, which usually helps when tracking down errors
039 * in programming logic).
040 */
041public final class ArgChecks {
042
043    private ArgChecks() {
044        // no need to instantiate this ever
045    }
046 
047    /**
048     * Checks if the specified argument is {@code null} and, if it is,
049     * throws an {@code IllegalArgumentException}.
050     *
051     * @param arg  the argument to check ({@code null} permitted).
052     * @param name  the parameter name ({@code null} not permitted).
053     */
054    public static void nullNotPermitted(Object arg, String name) {
055        if (arg == null) {
056            throw new IllegalArgumentException("Null '" + name + "' argument.");
057        }
058    }
059    
060    /**
061     * Checks if the specified argument is negative and, if it is, throws an
062     * {@code IllegalArgumentException}.
063     * 
064     * @param value  the value.
065     * @param name  the parameter name ({@code null} not permitted).
066     */
067    public static void negativeNotPermitted(double value, String name) {
068        if (value < 0.0) {
069            throw new IllegalArgumentException("Param '" + name 
070                    + "' cannot be negative");
071        }
072    }
073
074    /**
075     * Checks if the specified argument is positive and, if it is NOT, throws an
076     * {@code IllegalArgumentException}.
077     * 
078     * @param value  the value.
079     * @param name  the parameter name ({@code null} not permitted).
080     */
081    public static void positiveRequired(double value, String name) {
082        if (value <= 0.0) {
083            throw new IllegalArgumentException("Param '" + name 
084                    + "' must be positive.");
085        } 
086    }
087    
088    /**
089     * Checks if the specified argument is finite and, if it is NOT, throws an
090     * {@code IllegalArgumentException}.
091     * 
092     * @param value  the value.
093     * @param name  the parameter name ({@code null} not permitted).
094     * 
095     * @since 1.4
096     */
097    public static void finiteRequired(double value, String name) {
098        if (Double.isInfinite(value)) {
099            throw new IllegalArgumentException("Param '" + name 
100                    + "' must be finite.");
101        }
102    }
103
104    /**
105     * Checks if the specified argument is finite and positive and, 
106     * if it is NOT, throws an {@code IllegalArgumentException}.
107     * 
108     * @param value  the value.
109     * @param name  the parameter name ({@code null} not permitted).
110     * 
111     * @since 1.4
112     */
113    public static void finitePositiveRequired(double value, String name) {
114        if (value <= 0.0 || Double.isInfinite(value)) {
115            throw new IllegalArgumentException("Param '" + name 
116                    + "' must be finite and positive.");
117        }
118    }
119
120    /**
121     * Checks that the index is less than the specified {@code arrayLimit}
122     * and throws an {@code IllegalArgumentException} if it is not.
123     * 
124     * @param index  the array index.
125     * @param name  the parameter name (to display in the error message).
126     * @param arrayLimit  the array size.
127     */
128    public static void checkArrayBounds(int index, String name, 
129            int arrayLimit) {
130        if (index >= arrayLimit) {
131            throw new IllegalArgumentException("Requires '" + name
132                    + "' in the range 0 to " + (arrayLimit - 1));
133        }
134    }
135
136}