Chiao Cheng | a6b4c79 | 2012-10-31 15:18:29 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2011 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.contacts.common.format; |
| 17 | |
| 18 | import android.database.CharArrayBuffer; |
| 19 | import android.graphics.Typeface; |
| 20 | import android.text.SpannableString; |
| 21 | import android.text.style.StyleSpan; |
| 22 | |
| 23 | import com.google.common.annotations.VisibleForTesting; |
| 24 | |
| 25 | import java.util.Arrays; |
| 26 | |
| 27 | /** |
| 28 | * Assorted utility methods related to text formatting in Contacts. |
| 29 | */ |
| 30 | public class FormatUtils { |
| 31 | |
| 32 | /** |
| 33 | * Finds the earliest point in buffer1 at which the first part of buffer2 matches. For example, |
| 34 | * overlapPoint("abcd", "cdef") == 2. |
| 35 | */ |
| 36 | public static int overlapPoint(CharArrayBuffer buffer1, CharArrayBuffer buffer2) { |
| 37 | if (buffer1 == null || buffer2 == null) { |
| 38 | return -1; |
| 39 | } |
| 40 | return overlapPoint(Arrays.copyOfRange(buffer1.data, 0, buffer1.sizeCopied), |
| 41 | Arrays.copyOfRange(buffer2.data, 0, buffer2.sizeCopied)); |
| 42 | } |
| 43 | |
| 44 | /** |
| 45 | * Finds the earliest point in string1 at which the first part of string2 matches. For example, |
| 46 | * overlapPoint("abcd", "cdef") == 2. |
| 47 | */ |
| 48 | @VisibleForTesting |
| 49 | public static int overlapPoint(String string1, String string2) { |
| 50 | if (string1 == null || string2 == null) { |
| 51 | return -1; |
| 52 | } |
| 53 | return overlapPoint(string1.toCharArray(), string2.toCharArray()); |
| 54 | } |
| 55 | |
| 56 | /** |
| 57 | * Finds the earliest point in array1 at which the first part of array2 matches. For example, |
| 58 | * overlapPoint("abcd", "cdef") == 2. |
| 59 | */ |
| 60 | public static int overlapPoint(char[] array1, char[] array2) { |
| 61 | if (array1 == null || array2 == null) { |
| 62 | return -1; |
| 63 | } |
| 64 | int count1 = array1.length; |
| 65 | int count2 = array2.length; |
| 66 | |
| 67 | // Ignore matching tails of the two arrays. |
| 68 | while (count1 > 0 && count2 > 0 && array1[count1 - 1] == array2[count2 - 1]) { |
| 69 | count1--; |
| 70 | count2--; |
| 71 | } |
| 72 | |
| 73 | int size = count2; |
| 74 | for (int i = 0; i < count1; i++) { |
| 75 | if (i + size > count1) { |
| 76 | size = count1 - i; |
| 77 | } |
| 78 | int j; |
| 79 | for (j = 0; j < size; j++) { |
| 80 | if (array1[i+j] != array2[j]) { |
| 81 | break; |
| 82 | } |
| 83 | } |
| 84 | if (j == size) { |
| 85 | return i; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | return -1; |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Applies the given style to a range of the input CharSequence. |
| 94 | * @param style The style to apply (see the style constants in {@link Typeface}). |
| 95 | * @param input The CharSequence to style. |
| 96 | * @param start Starting index of the range to style (will be clamped to be a minimum of 0). |
| 97 | * @param end Ending index of the range to style (will be clamped to a maximum of the input |
| 98 | * length). |
| 99 | * @param flags Bitmask for configuring behavior of the span. See {@link android.text.Spanned}. |
| 100 | * @return The styled CharSequence. |
| 101 | */ |
| 102 | public static CharSequence applyStyleToSpan(int style, CharSequence input, int start, int end, |
| 103 | int flags) { |
| 104 | // Enforce bounds of the char sequence. |
| 105 | start = Math.max(0, start); |
| 106 | end = Math.min(input.length(), end); |
| 107 | SpannableString text = new SpannableString(input); |
| 108 | text.setSpan(new StyleSpan(style), start, end, flags); |
| 109 | return text; |
| 110 | } |
| 111 | |
| 112 | @VisibleForTesting |
| 113 | public static void copyToCharArrayBuffer(String text, CharArrayBuffer buffer) { |
| 114 | if (text != null) { |
| 115 | char[] data = buffer.data; |
| 116 | if (data == null || data.length < text.length()) { |
| 117 | buffer.data = text.toCharArray(); |
| 118 | } else { |
| 119 | text.getChars(0, text.length(), data, 0); |
| 120 | } |
| 121 | buffer.sizeCopied = text.length(); |
| 122 | } else { |
| 123 | buffer.sizeCopied = 0; |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | /** Returns a String that represents the content of the given {@link CharArrayBuffer}. */ |
| 128 | @VisibleForTesting |
| 129 | public static String charArrayBufferToString(CharArrayBuffer buffer) { |
| 130 | return new String(buffer.data, 0, buffer.sizeCopied); |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * Finds the index of the first word that starts with the given prefix. |
| 135 | * <p> |
| 136 | * If not found, returns -1. |
| 137 | * |
| 138 | * @param text the text in which to search for the prefix |
| 139 | * @param prefix the text to find, in upper case letters |
| 140 | */ |
| 141 | public static int indexOfWordPrefix(CharSequence text, char[] prefix) { |
| 142 | if (prefix == null || text == null) { |
| 143 | return -1; |
| 144 | } |
| 145 | |
| 146 | int textLength = text.length(); |
| 147 | int prefixLength = prefix.length; |
| 148 | |
| 149 | if (prefixLength == 0 || textLength < prefixLength) { |
| 150 | return -1; |
| 151 | } |
| 152 | |
| 153 | int i = 0; |
| 154 | while (i < textLength) { |
| 155 | // Skip non-word characters |
| 156 | while (i < textLength && !Character.isLetterOrDigit(text.charAt(i))) { |
| 157 | i++; |
| 158 | } |
| 159 | |
| 160 | if (i + prefixLength > textLength) { |
| 161 | return -1; |
| 162 | } |
| 163 | |
| 164 | // Compare the prefixes |
| 165 | int j; |
| 166 | for (j = 0; j < prefixLength; j++) { |
| 167 | if (Character.toUpperCase(text.charAt(i + j)) != prefix[j]) { |
| 168 | break; |
| 169 | } |
| 170 | } |
| 171 | if (j == prefixLength) { |
| 172 | return i; |
| 173 | } |
| 174 | |
| 175 | // Skip this word |
| 176 | while (i < textLength && Character.isLetterOrDigit(text.charAt(i))) { |
| 177 | i++; |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | return -1; |
| 182 | } |
| 183 | |
| 184 | } |