1/* GENERATED SOURCE. DO NOT MODIFY. */ 2// © 2016 and later: Unicode, Inc. and others. 3// License & terms of use: http://www.unicode.org/copyright.html#License 4/* 5 ******************************************************************************* 6 * Copyright (C) 1996-2016, International Business Machines Corporation and * 7 * others. All Rights Reserved. * 8 ******************************************************************************* 9 */ 10package android.icu.text; 11 12/** 13 * <code>Replaceable</code> is an interface representing a 14 * string of characters that supports the replacement of a range of 15 * itself with a new string of characters. It is used by APIs that 16 * change a piece of text while retaining metadata. Metadata is data 17 * other than the Unicode characters returned by char32At(). One 18 * example of metadata is style attributes; another is an edit 19 * history, marking each character with an author and revision number. 20 * 21 * <p>An implicit aspect of the <code>Replaceable</code> API is that 22 * during a replace operation, new characters take on the metadata of 23 * the old characters. For example, if the string "the <b>bold</b> 24 * font" has range (4, 8) replaced with "strong", then it becomes "the 25 * <b>strong</b> font". 26 * 27 * <p><code>Replaceable</code> specifies ranges using a start 28 * offset and a limit offset. The range of characters thus specified 29 * includes the characters at offset start..limit-1. That is, the 30 * start offset is inclusive, and the limit offset is exclusive. 31 * 32 * <p><code>Replaceable</code> also includes API to access characters 33 * in the string: <code>length()</code>, <code>charAt()</code>, 34 * <code>char32At()</code>, and <code>extractBetween()</code>. 35 * 36 * <p>For a subclass to support metadata, typical behavior of 37 * <code>replace()</code> is the following: 38 * <ul> 39 * <li>Set the metadata of the new text to the metadata of the first 40 * character replaced</li> 41 * <li>If no characters are replaced, use the metadata of the 42 * previous character</li> 43 * <li>If there is no previous character (i.e. start == 0), use the 44 * following character</li> 45 * <li>If there is no following character (i.e. the replaceable was 46 * empty), use default metadata<br> 47 * <li>If the code point U+FFFF is seen, it should be interpreted as 48 * a special marker having no metadata<li> 49 * </li> 50 * </ul> 51 * If this is not the behavior, the subclass should document any differences. 52 * 53 * <p>Copyright © IBM Corporation 1999. All rights reserved. 54 * 55 * @author Alan Liu 56 */ 57public interface Replaceable { 58 /** 59 * Returns the number of 16-bit code units in the text. 60 * @return number of 16-bit code units in text 61 */ 62 int length(); 63 64 /** 65 * Returns the 16-bit code unit at the given offset into the text. 66 * @param offset an integer between 0 and <code>length()</code>-1 67 * inclusive 68 * @return 16-bit code unit of text at given offset 69 */ 70 char charAt(int offset); 71 72 /** 73 * Returns the 32-bit code point at the given 16-bit offset into 74 * the text. This assumes the text is stored as 16-bit code units 75 * with surrogate pairs intermixed. If the offset of a leading or 76 * trailing code unit of a surrogate pair is given, return the 77 * code point of the surrogate pair. 78 * 79 * <p>Most subclasses can return 80 * <code>android.icu.text.UTF16.charAt(this, offset)</code>. 81 * @param offset an integer between 0 and <code>length()</code>-1 82 * inclusive 83 * @return 32-bit code point of text at given offset 84 */ 85 int char32At(int offset); 86 87 /** 88 * Copies characters from this object into the destination 89 * character array. The first character to be copied is at index 90 * <code>srcStart</code>; the last character to be copied is at 91 * index <code>srcLimit-1</code> (thus the total number of 92 * characters to be copied is <code>srcLimit-srcStart</code>). The 93 * characters are copied into the subarray of <code>dst</code> 94 * starting at index <code>dstStart</code> and ending at index 95 * <code>dstStart + (srcLimit-srcStart) - 1</code>. 96 * 97 * @param srcStart the beginning index to copy, inclusive; <code>0 98 * <= start <= limit</code>. 99 * @param srcLimit the ending index to copy, exclusive; 100 * <code>start <= limit <= length()</code>. 101 * @param dst the destination array. 102 * @param dstStart the start offset in the destination array. 103 */ 104 void getChars(int srcStart, int srcLimit, char dst[], int dstStart); 105 106 /** 107 * Replaces a substring of this object with the given text. 108 * 109 * <p>Subclasses must ensure that if the text between start and 110 * limit is equal to the replacement text, that replace has no 111 * effect. That is, any metadata 112 * should be unaffected. In addition, subclasses are encouraged to 113 * check for initial and trailing identical characters, and make a 114 * smaller replacement if possible. This will preserve as much 115 * metadata as possible. 116 * @param start the beginning index, inclusive; <code>0 <= start 117 * <= limit</code>. 118 * @param limit the ending index, exclusive; <code>start <= limit 119 * <= length()</code>. 120 * @param text the text to replace characters <code>start</code> 121 * to <code>limit - 1</code> 122 */ 123 void replace(int start, int limit, String text); 124 125 /** 126 * Replaces a substring of this object with the given text. 127 * 128 * <p>Subclasses must ensure that if the text between start and 129 * limit is equal to the replacement text, that replace has no 130 * effect. That is, any metadata 131 * should be unaffected. In addition, subclasses are encouraged to 132 * check for initial and trailing identical characters, and make a 133 * smaller replacement if possible. This will preserve as much 134 * metadata as possible. 135 * @param start the beginning index, inclusive; <code>0 <= start 136 * <= limit</code>. 137 * @param limit the ending index, exclusive; <code>start <= limit 138 * <= length()</code>. 139 * @param chars the text to replace characters <code>start</code> 140 * to <code>limit - 1</code> 141 * @param charsStart the beginning index into <code>chars</code>, 142 * inclusive; <code>0 <= start <= limit</code>. 143 * @param charsLen the number of characters of <code>chars</code>. 144 */ 145 void replace(int start, int limit, char[] chars, 146 int charsStart, int charsLen); 147 // Note: We use length rather than limit to conform to StringBuffer 148 // and System.arraycopy. 149 150 /** 151 * Copies a substring of this object, retaining metadata. 152 * This method is used to duplicate or reorder substrings. 153 * The destination index must not overlap the source range. 154 * If <code>hasMetaData()</code> returns false, subclasses 155 * may use the naive implementation: 156 * 157 * <pre> char[] text = new char[limit - start]; 158 * getChars(start, limit, text, 0); 159 * replace(dest, dest, text, 0, limit - start);</pre> 160 * 161 * @param start the beginning index, inclusive; <code>0 <= start <= 162 * limit</code>. 163 * @param limit the ending index, exclusive; <code>start <= limit <= 164 * length()</code>. 165 * @param dest the destination index. The characters from 166 * <code>start..limit-1</code> will be copied to <code>dest</code>. 167 * Implementations of this method may assume that <code>dest <= start || 168 * dest >= limit</code>. 169 */ 170 void copy(int start, int limit, int dest); 171 172 /**R 173 * Returns true if this object contains metadata. If a 174 * Replaceable object has metadata, calls to the Replaceable API 175 * must be made so as to preserve metadata. If it does not, calls 176 * to the Replaceable API may be optimized to improve performance. 177 * @return true if this object contains metadata 178 */ 179 boolean hasMetaData(); 180} 181