1 /*
2  * Copyright (C) 2015 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 package com.android.messaging.util;
17 
18 import androidx.annotation.Nullable;
19 
20 public class TextUtil {
21     /**
22      * Returns true if the string is empty, null or only whitespace.
23      */
isAllWhitespace(@ullable String string)24     public static boolean isAllWhitespace(@Nullable String string) {
25       if (string == null || string.isEmpty()) {
26         return true;
27       }
28 
29       for (int i = 0; i < string.length(); ++i) {
30         if (!Character.isWhitespace(string.charAt(i))) {
31           return false;
32         }
33       }
34 
35       return true;
36     }
37 
38     /**
39      * Taken from PhoneNumberUtils, where it is only available in API 21+ Replaces all unicode
40      * (e.g. Arabic, Persian) digits with their decimal digit equivalents.
41      *
42      * @param number the number to perform the replacement on.
43      * @return the replaced number.
44      */
replaceUnicodeDigits(String number)45     public static String replaceUnicodeDigits(String number) {
46         StringBuilder normalizedDigits = new StringBuilder(number.length());
47         for (char c : number.toCharArray()) {
48             int digit = Character.digit(c, 10);
49             if (digit != -1) {
50                 normalizedDigits.append(digit);
51             } else {
52                 normalizedDigits.append(c);
53             }
54         }
55         return normalizedDigits.toString();
56     }
57 
58     /**
59      * Appends text to the stringBuilder.
60      * If stringBuilder already has content, separator is prepended to create a separator between
61      * entries.
62      * @param stringBuilder The stringBuilder to add to
63      * @param text The text to append
64      * @param separator The separator to add if there is already text, typically "," or "\n"
65      */
appendWithSeparator(final StringBuilder stringBuilder, final String text, final String separator)66     public static void appendWithSeparator(final StringBuilder stringBuilder, final String text,
67             final String separator) {
68         if (stringBuilder.length() > 0) {
69             stringBuilder.append(separator);
70         }
71         stringBuilder.append(text);
72     }
73 }
74