Spec-Zone .ru
спецификации, руководства, описания, API
001/*
002 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.  Oracle designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Oracle in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
022 * or visit www.oracle.com if you need additional information or have any
023 * questions.
024 */
025
026package javafx.scene.control;
027
028/**
029 * Class representing a contiguous range of integral values.
030 */
031public final class IndexRange {
032    private int start;
033    private int end;
034
035    /**
036     * Index range value delimiter.
037     */
038    public static final String VALUE_DELIMITER = ",";
039
040    /**
041     * Creates an instance of IndexRange representing the range between
042     * <code>start</code> and <code>end</code>.
043     * 
044     * @param start The start position of the range.
045     * @param end The end position of the range.
046     */
047    public IndexRange(int start, int end) {
048        if (end < start) {
049            throw new IllegalArgumentException();
050        }
051
052        this.start = start;
053        this.end = end;
054    }
055
056    /**
057     * Creates an instance of IndexRange by copying the values from the
058     * given IndexRange object.
059     * 
060     * @param range The IndexRange instance from which to copy the start and end
061     *      values.
062     */
063    public IndexRange(IndexRange range) {
064        this.start = range.start;
065        this.end = range.end;
066    }
067
068    /**
069     * Returns the start position of the range.
070     */
071    public int getStart() {
072        return start;
073    }
074
075    /**
076     * Returns the end position of the range (exclusive).
077     */
078    public int getEnd() {
079        return end;
080    }
081
082    /**
083     * Returns the length of the range.
084     */
085    public int getLength() {
086        return end - start;
087    }
088
089    /**
090     * Indicates whether some other object is "equal to" this one.
091     * @param object the reference object with which to compare.
092     * @return {@code true} if this object is equal to the {@code object} argument; {@code false} otherwise.
093     */
094    @Override
095    public boolean equals(Object object) {
096        if (object == this) return true;
097        if (object instanceof IndexRange) {
098            IndexRange range = (IndexRange)object;
099            return (start == range.start
100                && end == range.end);
101        }
102
103        return false;
104    }
105
106    /**
107     * Returns a hash code for this {@code Range} object.
108     * @return a hash code for this {@code Range} object.
109     */ 
110    @Override
111    public int hashCode() {
112        return 31 * start + end;
113    }
114
115    /**
116     * Returns a string representation of this {@code Range} object.
117     * @return a string representation of this {@code Range} object.
118     */ 
119    @Override
120    public String toString() {
121        return start + VALUE_DELIMITER + " " + end;
122    }
123
124    /**
125     * Convenience method to create an IndexRange instance that has the smaller
126     * value as the start index, and the larger value as the end index.
127     * 
128     * @param v1 The first value to use in the range.
129     * @param v2 The second value to use in the range.
130     * @return A IndexRange instance where the smaller value is the start, and the
131     *      larger value is the end.
132     */
133    public static IndexRange normalize(int v1, int v2) {
134        return new IndexRange(Math.min(v1, v2), Math.max(v1, v2));
135    }
136
137    /**
138     * Convenience method to parse in a String of the form '2,6', which will
139     * create an IndexRange instance with a start value of 2, and an end value
140     * of 6.
141     * 
142     * @param value The string to be parsed, and converted to an IndexRange.
143     * @return An IndexRange instance representing the start and end values provided
144     *      in the value string.
145     */
146    public static IndexRange valueOf(String value) {
147        if (value == null) {
148            throw new IllegalArgumentException();
149        }
150
151        String[] values = value.split(VALUE_DELIMITER);
152        if (values.length != 2) {
153            throw new IllegalArgumentException();
154        }
155
156        // NOTE As of Java 6, Integer#parseInt() appears to require
157        // trimmed values
158        int start = Integer.parseInt(values[0].trim());
159        int end = Integer.parseInt(values[1].trim());
160
161        return IndexRange.normalize(start, end);
162    }
163}