001// License: GPL. For details, see LICENSE file. 002package org.openstreetmap.josm.gui.mappaint; 003 004import java.util.Objects; 005 006/** 007 * A scale interval of the form "lower < x <= upper" where 0 <= lower < upper. 008 * (upper can be Double.POSITIVE_INFINITY) 009 * immutable class 010 */ 011public class Range { 012 private final double lower; 013 private final double upper; 014 015 /** 016 * The full scale range from zero to infinity 017 */ 018 public static final Range ZERO_TO_INFINITY = new Range(0.0, Double.POSITIVE_INFINITY); 019 020 /** 021 * Constructs a new {@code Range}. 022 * @param lower Lower bound. Must be positive or zero 023 * @param upper Upper bound 024 * @throws IllegalArgumentException if the range is invalid ({@code lower < 0 || lower >= upper}) 025 */ 026 public Range(double lower, double upper) { 027 if (lower < 0 || lower >= upper) 028 throw new IllegalArgumentException("Invalid range: "+lower+'-'+upper); 029 this.lower = lower; 030 this.upper = upper; 031 } 032 033 /** 034 * Check if a number is contained in this range 035 * @param x The number to test 036 * @return <code>true</code> if it is in this range 037 */ 038 public boolean contains(double x) { 039 return lower < x && x <= upper; 040 } 041 042 /** 043 * provides the intersection of 2 overlapping ranges 044 * @param a first range 045 * @param b second range 046 * @return intersection of {@code a} and {@code b} 047 */ 048 public static Range cut(Range a, Range b) { 049 if (b.lower >= a.upper || b.upper <= a.lower) 050 throw new IllegalArgumentException("Ranges do not overlap: "+a+" - "+b); 051 return new Range(Math.max(a.lower, b.lower), Math.min(a.upper, b.upper)); 052 } 053 054 /** 055 * under the premise, that x is within this range, 056 * and not within the other range, it shrinks this range in a way 057 * to exclude the other range, but still contain x. 058 * 059 * x | 060 * 061 * this (------------------------------] 062 * 063 * other (-------] or 064 * (-----------------] 065 * 066 * result (----------------] 067 * @param x value 068 * @param other other range 069 * @return reduced range 070 */ 071 public Range reduceAround(double x, Range other) { 072 if (!contains(x)) 073 throw new IllegalArgumentException(x+" is not inside "+this); 074 if (other.contains(x)) 075 throw new IllegalArgumentException(x+" is inside "+other); 076 077 if (x < other.lower && other.lower < upper) 078 return new Range(lower, other.lower); 079 080 if (this.lower < other.upper && other.upper < x) 081 return new Range(other.upper, this.upper); 082 083 return this; 084 } 085 086 /** 087 * Gets the lower bound 088 * @return The lower, exclusive, bound 089 */ 090 public double getLower() { 091 return lower; 092 } 093 094 /** 095 * Gets the upper bound 096 * @return The upper, inclusive, bound 097 */ 098 public double getUpper() { 099 return upper; 100 } 101 102 @Override 103 public String toString() { 104 return String.format("|s%s-%s", lower, upper); 105 } 106 107 @Override 108 public boolean equals(Object o) { 109 if (this == o) return true; 110 if (o == null || getClass() != o.getClass()) return false; 111 Range range = (Range) o; 112 return Double.compare(range.lower, lower) == 0 && 113 Double.compare(range.upper, upper) == 0; 114 } 115 116 @Override 117 public int hashCode() { 118 return Objects.hash(lower, upper); 119 } 120}