1 // 2017 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html#License 3 package com.ibm.icu.impl; 4 5 import java.text.CharacterIterator; 6 7 /** 8 * Implement the Java CharacterIterator interface on a CharSequence. 9 * Intended for internal use by ICU only. 10 */ 11 public class CSCharacterIterator implements CharacterIterator { 12 13 private int index; 14 private CharSequence seq; 15 16 17 /** 18 * Constructor. 19 * @param text The CharSequence to iterate over. 20 */ 21 public CSCharacterIterator(CharSequence text) { 22 if (text == null) { 23 throw new NullPointerException(); 24 } 25 seq = text; 26 index = 0; 27 } 28 29 /** @{inheritDoc} */ 30 @Override 31 public char first() { 32 index = 0; 33 return current(); 34 } 35 36 /** @{inheritDoc} */ 37 @Override 38 public char last() { 39 index = seq.length(); 40 return previous(); 41 } 42 43 /** @{inheritDoc} */ 44 @Override 45 public char current() { 46 if (index == seq.length()) { 47 return DONE; 48 } 49 return seq.charAt(index); 50 } 51 52 /** @{inheritDoc} */ 53 @Override 54 public char next() { 55 if (index < seq.length()) { 56 ++index; 57 } 58 return current(); 59 } 60 61 /** @{inheritDoc} */ 62 @Override 63 public char previous() { 64 if (index == 0) { 65 return DONE; 66 } 67 --index; 68 return current(); 69 } 70 71 /** @{inheritDoc} */ 72 @Override 73 public char setIndex(int position) { 74 if (position < 0 || position > seq.length()) { 75 throw new IllegalArgumentException(); 76 } 77 index = position; 78 return current(); 79 } 80 81 /** @{inheritDoc} */ 82 @Override 83 public int getBeginIndex() { 84 return 0; 85 } 86 87 /** @{inheritDoc} */ 88 @Override 89 public int getEndIndex() { 90 return seq.length(); 91 } 92 93 /** @{inheritDoc} */ 94 @Override 95 public int getIndex() { 96 return index; 97 } 98 99 /** @{inheritDoc} */ 100 @Override 101 public Object clone() { 102 CSCharacterIterator copy = new CSCharacterIterator(seq); 103 copy.setIndex(index); 104 return copy; 105 } 106 } 107
