1/*
2 * Copyright (C) 2012 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
17package com.android.dialer.app.dialpad;
18
19import android.telephony.PhoneNumberUtils;
20import android.text.Spanned;
21import android.text.method.DialerKeyListener;
22
23/**
24 * {@link DialerKeyListener} with Unicode support. Converts any Unicode(e.g. Arabic) characters that
25 * represent digits into digits before filtering the results so that we can support pasted digits
26 * from Unicode languages.
27 */
28public class UnicodeDialerKeyListener extends DialerKeyListener {
29
30  public static final UnicodeDialerKeyListener INSTANCE = new UnicodeDialerKeyListener();
31
32  @Override
33  public CharSequence filter(
34      CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
35    final String converted =
36        PhoneNumberUtils.convertKeypadLettersToDigits(
37            PhoneNumberUtils.replaceUnicodeDigits(source.toString()));
38    // PhoneNumberUtils.replaceUnicodeDigits performs a character for character replacement,
39    // so we can assume that start and end positions should remain unchanged.
40    CharSequence result = super.filter(converted, start, end, dest, dstart, dend);
41    if (result == null) {
42      if (source.equals(converted)) {
43        // There was no conversion or filtering performed. Just return null according to
44        // the behavior of DialerKeyListener.
45        return null;
46      } else {
47        // filter returns null if the charsequence is to be returned unchanged/unfiltered.
48        // But in this case we do want to return a modified character string (even if
49        // none of the characters in the modified string are filtered). So if
50        // result == null we return the unfiltered but converted numeric string instead.
51        return converted.subSequence(start, end);
52      }
53    }
54    return result;
55  }
56}
57