The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2007 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.internal.util; |
| 18 | |
Artur Satayev | ed5a6ae | 2019-12-10 17:47:54 +0000 | [diff] [blame] | 19 | import android.compat.annotation.UnsupportedAppUsage; |
Andrei Onea | 1588439 | 2019-03-22 17:28:11 +0000 | [diff] [blame] | 20 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 21 | /** |
| 22 | * {@link CharSequence} utility methods. |
| 23 | */ |
| 24 | public class CharSequences { |
| 25 | |
| 26 | /** |
| 27 | * Adapts {@link CharSequence} to an array of ASCII (7-bits per character) |
| 28 | * bytes. |
| 29 | * |
| 30 | * @param bytes ASCII bytes |
| 31 | */ |
| 32 | public static CharSequence forAsciiBytes(final byte[] bytes) { |
| 33 | return new CharSequence() { |
| 34 | public char charAt(int index) { |
| 35 | return (char) bytes[index]; |
| 36 | } |
| 37 | |
| 38 | public int length() { |
| 39 | return bytes.length; |
| 40 | } |
| 41 | |
| 42 | public CharSequence subSequence(int start, int end) { |
| 43 | return forAsciiBytes(bytes, start, end); |
| 44 | } |
| 45 | |
| 46 | public String toString() { |
| 47 | return new String(bytes); |
| 48 | } |
| 49 | }; |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * Adapts {@link CharSequence} to an array of ASCII (7-bits per character) |
| 54 | * bytes. |
| 55 | * |
| 56 | * @param bytes ASCII bytes |
| 57 | * @param start index, inclusive |
| 58 | * @param end index, exclusive |
| 59 | * |
| 60 | * @throws IndexOutOfBoundsException if start or end are negative, if end |
| 61 | * is greater than length(), or if start is greater than end |
| 62 | */ |
| 63 | public static CharSequence forAsciiBytes(final byte[] bytes, |
| 64 | final int start, final int end) { |
| 65 | validate(start, end, bytes.length); |
| 66 | return new CharSequence() { |
| 67 | public char charAt(int index) { |
| 68 | return (char) bytes[index + start]; |
| 69 | } |
| 70 | |
| 71 | public int length() { |
| 72 | return end - start; |
| 73 | } |
| 74 | |
| 75 | public CharSequence subSequence(int newStart, int newEnd) { |
| 76 | newStart -= start; |
| 77 | newEnd -= start; |
| 78 | validate(newStart, newEnd, length()); |
| 79 | return forAsciiBytes(bytes, newStart, newEnd); |
| 80 | } |
| 81 | |
| 82 | public String toString() { |
| 83 | return new String(bytes, start, length()); |
| 84 | } |
| 85 | }; |
| 86 | } |
| 87 | |
| 88 | static void validate(int start, int end, int length) { |
| 89 | if (start < 0) throw new IndexOutOfBoundsException(); |
| 90 | if (end < 0) throw new IndexOutOfBoundsException(); |
| 91 | if (end > length) throw new IndexOutOfBoundsException(); |
| 92 | if (start > end) throw new IndexOutOfBoundsException(); |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Compares two character sequences for equality. |
| 97 | */ |
Andrei Onea | 1588439 | 2019-03-22 17:28:11 +0000 | [diff] [blame] | 98 | @UnsupportedAppUsage |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 99 | public static boolean equals(CharSequence a, CharSequence b) { |
| 100 | if (a.length() != b.length()) { |
| 101 | return false; |
| 102 | } |
| 103 | |
| 104 | int length = a.length(); |
| 105 | for (int i = 0; i < length; i++) { |
| 106 | if (a.charAt(i) != b.charAt(i)) { |
| 107 | return false; |
| 108 | } |
| 109 | } |
| 110 | return true; |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * Compares two character sequences with API like {@link Comparable#compareTo}. |
| 115 | * |
| 116 | * @param me The CharSequence that receives the compareTo call. |
| 117 | * @param another The other CharSequence. |
| 118 | * @return See {@link Comparable#compareTo}. |
| 119 | */ |
Andrei Onea | 1588439 | 2019-03-22 17:28:11 +0000 | [diff] [blame] | 120 | @UnsupportedAppUsage |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 121 | public static int compareToIgnoreCase(CharSequence me, CharSequence another) { |
| 122 | // Code adapted from String#compareTo |
| 123 | int myLen = me.length(), anotherLen = another.length(); |
| 124 | int myPos = 0, anotherPos = 0, result; |
| 125 | int end = (myLen < anotherLen) ? myLen : anotherLen; |
| 126 | |
| 127 | while (myPos < end) { |
| 128 | if ((result = Character.toLowerCase(me.charAt(myPos++)) |
| 129 | - Character.toLowerCase(another.charAt(anotherPos++))) != 0) { |
| 130 | return result; |
| 131 | } |
| 132 | } |
| 133 | return myLen - anotherLen; |
| 134 | } |
| 135 | } |