1a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard/* 2a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * Copyright (C) 2013 The Android Open Source Project 3a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * 4a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * Licensed under the Apache License, Version 2.0 (the "License"); 5a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * you may not use this file except in compliance with the License. 6a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * You may obtain a copy of the License at 7a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * 8a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * http://www.apache.org/licenses/LICENSE-2.0 9a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * 10a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * Unless required by applicable law or agreed to in writing, software 11a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * distributed under the License is distributed on an "AS IS" BASIS, 12a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * See the License for the specific language governing permissions and 14a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * limitations under the License. 15a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard */ 16a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard 17a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalardpackage android.text; 18a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard 19a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalardpublic class TextUtils { 20a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard private TextUtils() { /* cannot be instantiated */ } 21a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard 22a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard /** 23a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * Returns true if the string is null or 0-length. 24a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * @param str the string to be examined 25a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * @return true if str is null or zero length 26a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard */ 27a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard public static boolean isEmpty(CharSequence str) { 28a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard if (str == null || str.length() == 0) 29a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard return true; 30a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard else 31a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard return false; 32a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 33a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard 34a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard /** 35a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * Returns true if a and b are equal, including if they are both null. 36a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * <p><i>Note: In platform versions 1.1 and earlier, this method only worked well if 37a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * both the arguments were instances of String.</i></p> 38a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * @param a first CharSequence to check 39a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * @param b second CharSequence to check 40a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * @return true if a and b are equal 41a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard */ 42a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard public static boolean equals(CharSequence a, CharSequence b) { 43a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard if (a == b) return true; 44a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard int length; 45a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard if (a != null && b != null && (length = a.length()) == b.length()) { 46a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard if (a instanceof String && b instanceof String) { 47a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard return a.equals(b); 48a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } else { 49a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard for (int i = 0; i < length; i++) { 50a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard if (a.charAt(i) != b.charAt(i)) return false; 51a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 52a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard return true; 53a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 54a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 55a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard return false; 56a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 57a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard 58a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard /** 59a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * Returns list of multiple {@link CharSequence} joined into a single 60a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * {@link CharSequence} separated by localized delimiter such as ", ". 61a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * 62a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * @hide 63a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard */ 64a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard public static CharSequence join(Iterable<CharSequence> list) { 65a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard final CharSequence delimiter = ", "; 66a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard return join(delimiter, list); 67a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 68a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard 69a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard /** 70a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * Returns a string containing the tokens joined by delimiters. 71a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * @param tokens an array objects to be joined. Strings will be formed from 72a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * the objects by calling object.toString(). 73a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard */ 74a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard public static String join(CharSequence delimiter, Object[] tokens) { 75a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard StringBuilder sb = new StringBuilder(); 76a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard boolean firstTime = true; 77a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard for (Object token: tokens) { 78a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard if (firstTime) { 79a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard firstTime = false; 80a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } else { 81a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard sb.append(delimiter); 82a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 83a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard sb.append(token); 84a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 85a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard return sb.toString(); 86a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 87a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard 88a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard /** 89a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * Returns a string containing the tokens joined by delimiters. 90a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * @param tokens an array objects to be joined. Strings will be formed from 91a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard * the objects by calling object.toString(). 92a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard */ 93a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard public static String join(CharSequence delimiter, Iterable tokens) { 94a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard StringBuilder sb = new StringBuilder(); 95a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard boolean firstTime = true; 96a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard for (Object token: tokens) { 97a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard if (firstTime) { 98a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard firstTime = false; 99a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } else { 100a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard sb.append(delimiter); 101a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 102a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard sb.append(token); 103a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 104a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard return sb.toString(); 105a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard } 106a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard 107a245d15da5d295af21ead9a01583c64796a31ad7Jean Chalard} 108