The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2006 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 android.text; |
| 18 | |
| 19 | // XXX should this really be in the public API at all? |
| 20 | /** |
| 21 | * An AlteredCharSequence is a CharSequence that is largely mirrored from |
| 22 | * another CharSequence, except that a specified range of characters are |
| 23 | * mirrored from a different char array instead. |
| 24 | */ |
| 25 | public class AlteredCharSequence |
| 26 | implements CharSequence, GetChars |
| 27 | { |
| 28 | /** |
| 29 | * Create an AlteredCharSequence whose text (and possibly spans) |
| 30 | * are mirrored from <code>source</code>, except that the range of |
| 31 | * offsets <code>substart</code> inclusive to <code>subend</code> exclusive |
| 32 | * are mirrored instead from <code>sub</code>, beginning at offset 0. |
| 33 | */ |
| 34 | public static AlteredCharSequence make(CharSequence source, char[] sub, |
| 35 | int substart, int subend) { |
| 36 | if (source instanceof Spanned) |
| 37 | return new AlteredSpanned(source, sub, substart, subend); |
| 38 | else |
| 39 | return new AlteredCharSequence(source, sub, substart, subend); |
| 40 | } |
| 41 | |
| 42 | private AlteredCharSequence(CharSequence source, char[] sub, |
| 43 | int substart, int subend) { |
| 44 | mSource = source; |
| 45 | mChars = sub; |
| 46 | mStart = substart; |
| 47 | mEnd = subend; |
| 48 | } |
| 49 | |
| 50 | /* package */ void update(char[] sub, int substart, int subend) { |
| 51 | mChars = sub; |
| 52 | mStart = substart; |
| 53 | mEnd = subend; |
| 54 | } |
| 55 | |
| 56 | private static class AlteredSpanned |
| 57 | extends AlteredCharSequence |
| 58 | implements Spanned |
| 59 | { |
| 60 | private AlteredSpanned(CharSequence source, char[] sub, |
| 61 | int substart, int subend) { |
| 62 | super(source, sub, substart, subend); |
| 63 | mSpanned = (Spanned) source; |
| 64 | } |
| 65 | |
| 66 | public <T> T[] getSpans(int start, int end, Class<T> kind) { |
| 67 | return mSpanned.getSpans(start, end, kind); |
| 68 | } |
| 69 | |
| 70 | public int getSpanStart(Object span) { |
| 71 | return mSpanned.getSpanStart(span); |
| 72 | } |
| 73 | |
| 74 | public int getSpanEnd(Object span) { |
| 75 | return mSpanned.getSpanEnd(span); |
| 76 | } |
| 77 | |
| 78 | public int getSpanFlags(Object span) { |
| 79 | return mSpanned.getSpanFlags(span); |
| 80 | } |
| 81 | |
| 82 | public int nextSpanTransition(int start, int end, Class kind) { |
| 83 | return mSpanned.nextSpanTransition(start, end, kind); |
| 84 | } |
| 85 | |
| 86 | private Spanned mSpanned; |
| 87 | } |
| 88 | |
| 89 | public char charAt(int off) { |
| 90 | if (off >= mStart && off < mEnd) |
| 91 | return mChars[off - mStart]; |
| 92 | else |
| 93 | return mSource.charAt(off); |
| 94 | } |
| 95 | |
| 96 | public int length() { |
| 97 | return mSource.length(); |
| 98 | } |
| 99 | |
| 100 | public CharSequence subSequence(int start, int end) { |
| 101 | return AlteredCharSequence.make(mSource.subSequence(start, end), |
| 102 | mChars, mStart - start, mEnd - start); |
| 103 | } |
| 104 | |
| 105 | public void getChars(int start, int end, char[] dest, int off) { |
| 106 | TextUtils.getChars(mSource, start, end, dest, off); |
| 107 | |
| 108 | start = Math.max(mStart, start); |
| 109 | end = Math.min(mEnd, end); |
| 110 | |
| 111 | if (start > end) |
| 112 | System.arraycopy(mChars, start - mStart, dest, off, end - start); |
| 113 | } |
| 114 | |
| 115 | public String toString() { |
| 116 | int len = length(); |
| 117 | |
| 118 | char[] ret = new char[len]; |
| 119 | getChars(0, len, ret, 0); |
| 120 | return String.valueOf(ret); |
| 121 | } |
| 122 | |
| 123 | private int mStart; |
| 124 | private int mEnd; |
| 125 | private char[] mChars; |
| 126 | private CharSequence mSource; |
| 127 | } |