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 | /** |
| 20 | * InputFilters can be attached to {@link Editable}s to constrain the |
| 21 | * changes that can be made to them. |
| 22 | */ |
| 23 | public interface InputFilter |
| 24 | { |
| 25 | /** |
| 26 | * This method is called when the buffer is going to replace the |
| 27 | * range <code>dstart … dend</code> of <code>dest</code> |
| 28 | * with the new text from the range <code>start … end</code> |
| 29 | * of <code>source</code>. Return the CharSequence that you would |
| 30 | * like to have placed there instead, including an empty string |
| 31 | * if appropriate, or <code>null</code> to accept the original |
| 32 | * replacement. Be careful to not to reject 0-length replacements, |
| 33 | * as this is what happens when you delete text. Also beware that |
| 34 | * you should not attempt to make any changes to <code>dest</code> |
| 35 | * from this method; you may only examine it for context. |
| 36 | * |
| 37 | * Note: If <var>source</var> is an instance of {@link Spanned} or |
| 38 | * {@link Spannable}, the span objects in the <var>source</var> should be |
| 39 | * copied into the filtered result (i.e. the non-null return value). |
| 40 | * {@link TextUtils#copySpansFrom} can be used for convenience. |
| 41 | */ |
| 42 | public CharSequence filter(CharSequence source, int start, int end, |
| 43 | Spanned dest, int dstart, int dend); |
| 44 | |
| 45 | /** |
| 46 | * This filter will capitalize all the lower case letters that are added |
| 47 | * through edits. |
| 48 | */ |
| 49 | public static class AllCaps implements InputFilter { |
| 50 | public CharSequence filter(CharSequence source, int start, int end, |
| 51 | Spanned dest, int dstart, int dend) { |
| 52 | for (int i = start; i < end; i++) { |
| 53 | if (Character.isLowerCase(source.charAt(i))) { |
| 54 | char[] v = new char[end - start]; |
| 55 | TextUtils.getChars(source, start, end, v, 0); |
| 56 | String s = new String(v).toUpperCase(); |
| 57 | |
| 58 | if (source instanceof Spanned) { |
| 59 | SpannableString sp = new SpannableString(s); |
| 60 | TextUtils.copySpansFrom((Spanned) source, |
| 61 | start, end, null, sp, 0); |
| 62 | return sp; |
| 63 | } else { |
| 64 | return s; |
| 65 | } |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | return null; // keep original |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * This filter will constrain edits not to make the length of the text |
| 75 | * greater than the specified length. |
| 76 | */ |
| 77 | public static class LengthFilter implements InputFilter { |
Alan Viverette | 029942f | 2014-08-12 14:55:56 -0700 | [diff] [blame] | 78 | private final int mMax; |
| 79 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 80 | public LengthFilter(int max) { |
| 81 | mMax = max; |
| 82 | } |
| 83 | |
Alan Viverette | 029942f | 2014-08-12 14:55:56 -0700 | [diff] [blame] | 84 | public CharSequence filter(CharSequence source, int start, int end, Spanned dest, |
| 85 | int dstart, int dend) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 86 | int keep = mMax - (dest.length() - (dend - dstart)); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 87 | if (keep <= 0) { |
| 88 | return ""; |
| 89 | } else if (keep >= end - start) { |
| 90 | return null; // keep original |
| 91 | } else { |
Ishibashi Takako | 2f0f442 | 2010-11-04 08:43:33 +0100 | [diff] [blame] | 92 | keep += start; |
| 93 | if (Character.isHighSurrogate(source.charAt(keep - 1))) { |
| 94 | --keep; |
| 95 | if (keep == start) { |
| 96 | return ""; |
| 97 | } |
| 98 | } |
| 99 | return source.subSequence(start, keep); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 100 | } |
| 101 | } |
| 102 | |
Alan Viverette | 029942f | 2014-08-12 14:55:56 -0700 | [diff] [blame] | 103 | /** |
| 104 | * @return the maximum length enforced by this input filter |
| 105 | */ |
| 106 | public int getMax() { |
| 107 | return mMax; |
| 108 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 109 | } |
| 110 | } |