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.method; 18 19 import android.view.KeyEvent; 20 import android.view.View; 21 import android.text.Editable; 22 import android.text.InputFilter; 23 import android.text.Selection; 24 import android.text.Spannable; 25 import android.text.SpannableStringBuilder; 26 import android.text.Spanned; 27 28 /** 29 * For numeric text entry 30 */ 31 public abstract class NumberKeyListener extends BaseKeyListener 32 implements InputFilter 33 { 34 /** 35 * You can say which characters you can accept. 36 */ 37 protected abstract char[] getAcceptedChars(); 38 39 protected int lookup(KeyEvent event, Spannable content) { 40 return event.getMatch(getAcceptedChars(), getMetaState(content)); 41 } 42 43 public CharSequence filter(CharSequence source, int start, int end, 44 Spanned dest, int dstart, int dend) { 45 char[] accept = getAcceptedChars(); 46 boolean filter = false; 47 48 int i; 49 for (i = start; i < end; i++) { 50 if (!ok(accept, source.charAt(i))) { 51 break; 52 } 53 } 54 55 if (i == end) { 56 // It was all OK. 57 return null; 58 } 59 60 if (end - start == 1) { 61 // It was not OK, and there is only one char, so nothing remains. 62 return ""; 63 } 64 65 SpannableStringBuilder filtered = 66 new SpannableStringBuilder(source, start, end); 67 i -= start; 68 end -= start; 69 70 int len = end - start; 71 // Only count down to i because the chars before that were all OK. 72 for (int j = end - 1; j >= i; j--) { 73 if (!ok(accept, source.charAt(j))) { 74 filtered.delete(j, j + 1); 75 } 76 } 77 78 return filtered; 79 } 80 81 protected static boolean ok(char[] accept, char c) { 82 for (int i = accept.length - 1; i >= 0; i--) { 83 if (accept[i] == c) { 84 return true; 85 } 86 } 87 88 return false; 89 } 90 91 @Override 92 public boolean onKeyDown(View view, Editable content, 93 int keyCode, KeyEvent event) { 94 int selStart, selEnd; 95 96 { 97 int a = Selection.getSelectionStart(content); 98 int b = Selection.getSelectionEnd(content); 99 100 selStart = Math.min(a, b); 101 selEnd = Math.max(a, b); 102 } 103 104 if (selStart < 0 || selEnd < 0) { 105 selStart = selEnd = 0; 106 Selection.setSelection(content, 0); 107 } 108 109 int i = event != null ? lookup(event, content) : 0; 110 int repeatCount = event != null ? event.getRepeatCount() : 0; 111 if (repeatCount == 0) { 112 if (i != 0) { 113 if (selStart != selEnd) { 114 Selection.setSelection(content, selEnd); 115 } 116 117 content.replace(selStart, selEnd, String.valueOf((char) i)); 118 119 adjustMetaAfterKeypress(content); 120 return true; 121 } 122 } else if (i == '0' && repeatCount == 1) { 123 // Pretty hackish, it replaces the 0 with the + 124 125 if (selStart == selEnd && selEnd > 0 && 126 content.charAt(selStart - 1) == '0') { 127 content.replace(selStart - 1, selEnd, String.valueOf('+')); 128 adjustMetaAfterKeypress(content); 129 return true; 130 } 131 } 132 133 adjustMetaAfterKeypress(content); 134 return super.onKeyDown(view, content, keyCode, event); 135 } 136 } 137