| 1 | /* |
| 2 | * Jexer - Java Text User Interface |
| 3 | * |
| 4 | * The MIT License (MIT) |
| 5 | * |
| 6 | * Copyright (C) 2017 Kevin Lamonte |
| 7 | * |
| 8 | * Permission is hereby granted, free of charge, to any person obtaining a |
| 9 | * copy of this software and associated documentation files (the "Software"), |
| 10 | * to deal in the Software without restriction, including without limitation |
| 11 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| 12 | * and/or sell copies of the Software, and to permit persons to whom the |
| 13 | * Software is furnished to do so, subject to the following conditions: |
| 14 | * |
| 15 | * The above copyright notice and this permission notice shall be included in |
| 16 | * all copies or substantial portions of the Software. |
| 17 | * |
| 18 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 19 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 20 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 21 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 22 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 23 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| 24 | * DEALINGS IN THE SOFTWARE. |
| 25 | * |
| 26 | * @author Kevin Lamonte [kevin.lamonte@gmail.com] |
| 27 | * @version 1 |
| 28 | */ |
| 29 | package jexer.bits; |
| 30 | |
| 31 | import java.util.List; |
| 32 | import java.util.LinkedList; |
| 33 | |
| 34 | /** |
| 35 | * StringJustifier contains methods to convert one or more long lines of |
| 36 | * strings into justified text paragraphs. |
| 37 | */ |
| 38 | public final class StringJustifier { |
| 39 | |
| 40 | /** |
| 41 | * Left-justify a string into a list of lines. |
| 42 | * |
| 43 | * @param str the string |
| 44 | * @param n the maximum number of characters in a line |
| 45 | * @return the list of lines |
| 46 | */ |
| 47 | public static List<String> left(final String str, final int n) { |
| 48 | List<String> result = new LinkedList<String>(); |
| 49 | |
| 50 | /* |
| 51 | * General procedure: |
| 52 | * |
| 53 | * 1. Split on '\n' into paragraphs. |
| 54 | * |
| 55 | * 2. Scan each line, noting the position of the last |
| 56 | * beginning-of-a-word. |
| 57 | * |
| 58 | * 3. Chop at the last #2 if the next beginning-of-a-word exceeds |
| 59 | * n. |
| 60 | * |
| 61 | * 4. Return the lines. |
| 62 | */ |
| 63 | |
| 64 | String [] rawLines = str.split("\n"); |
| 65 | for (int i = 0; i < rawLines.length; i++) { |
| 66 | StringBuilder line = new StringBuilder(); |
| 67 | StringBuilder word = new StringBuilder(); |
| 68 | boolean inWord = false; |
| 69 | for (int j = 0; j < rawLines[i].length(); j++) { |
| 70 | char ch = rawLines[i].charAt(j); |
| 71 | if ((ch == ' ') || (ch == '\t')) { |
| 72 | if (inWord == true) { |
| 73 | // We have just transitioned from a word to |
| 74 | // whitespace. See if we have enough space to add |
| 75 | // the word to the line. |
| 76 | if (word.length() + line.length() > n) { |
| 77 | // This word will exceed the line length. Wrap |
| 78 | // at it instead. |
| 79 | result.add(line.toString()); |
| 80 | line = new StringBuilder(); |
| 81 | } |
| 82 | if ((word.toString().startsWith(" ")) |
| 83 | && (line.length() == 0) |
| 84 | ) { |
| 85 | line.append(word.substring(1)); |
| 86 | } else { |
| 87 | line.append(word); |
| 88 | } |
| 89 | word = new StringBuilder(); |
| 90 | word.append(ch); |
| 91 | inWord = false; |
| 92 | } else { |
| 93 | // We are in the whitespace before another word. Do |
| 94 | // nothing. |
| 95 | } |
| 96 | } else { |
| 97 | if (inWord == true) { |
| 98 | // We are appending to a word. |
| 99 | word.append(ch); |
| 100 | } else { |
| 101 | // We have transitioned from whitespace to a word. |
| 102 | word.append(ch); |
| 103 | inWord = true; |
| 104 | } |
| 105 | } |
| 106 | } // for (int j = 0; j < rawLines[i].length(); j++) |
| 107 | |
| 108 | if (word.length() + line.length() > n) { |
| 109 | // This word will exceed the line length. Wrap at it |
| 110 | // instead. |
| 111 | result.add(line.toString()); |
| 112 | line = new StringBuilder(); |
| 113 | } |
| 114 | if ((word.toString().startsWith(" ")) |
| 115 | && (line.length() == 0) |
| 116 | ) { |
| 117 | line.append(word.substring(1)); |
| 118 | } else { |
| 119 | line.append(word); |
| 120 | } |
| 121 | result.add(line.toString()); |
| 122 | } // for (int i = 0; i < rawLines.length; i++) { |
| 123 | |
| 124 | return result; |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * Right-justify a string into a list of lines. |
| 129 | * |
| 130 | * @param str the string |
| 131 | * @param n the maximum number of characters in a line |
| 132 | * @return the list of lines |
| 133 | */ |
| 134 | public static List<String> right(final String str, final int n) { |
| 135 | List<String> result = new LinkedList<String>(); |
| 136 | |
| 137 | /* |
| 138 | * Same as left(), but preceed each line with spaces to make it n |
| 139 | * chars long. |
| 140 | */ |
| 141 | List<String> lines = left(str, n); |
| 142 | for (String line: lines) { |
| 143 | StringBuilder sb = new StringBuilder(); |
| 144 | for (int i = 0; i < n - line.length(); i++) { |
| 145 | sb.append(' '); |
| 146 | } |
| 147 | sb.append(line); |
| 148 | result.add(sb.toString()); |
| 149 | } |
| 150 | |
| 151 | return result; |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * Center a string into a list of lines. |
| 156 | * |
| 157 | * @param str the string |
| 158 | * @param n the maximum number of characters in a line |
| 159 | * @return the list of lines |
| 160 | */ |
| 161 | public static List<String> center(final String str, final int n) { |
| 162 | List<String> result = new LinkedList<String>(); |
| 163 | |
| 164 | /* |
| 165 | * Same as left(), but preceed/succeed each line with spaces to make |
| 166 | * it n chars long. |
| 167 | */ |
| 168 | List<String> lines = left(str, n); |
| 169 | for (String line: lines) { |
| 170 | StringBuilder sb = new StringBuilder(); |
| 171 | int l = (n - line.length()) / 2; |
| 172 | int r = n - line.length() - l; |
| 173 | for (int i = 0; i < l; i++) { |
| 174 | sb.append(' '); |
| 175 | } |
| 176 | sb.append(line); |
| 177 | for (int i = 0; i < r; i++) { |
| 178 | sb.append(' '); |
| 179 | } |
| 180 | result.add(sb.toString()); |
| 181 | } |
| 182 | |
| 183 | return result; |
| 184 | } |
| 185 | |
| 186 | /** |
| 187 | * Fully-justify a string into a list of lines. |
| 188 | * |
| 189 | * @param str the string |
| 190 | * @param n the maximum number of characters in a line |
| 191 | * @return the list of lines |
| 192 | */ |
| 193 | public static List<String> full(final String str, final int n) { |
| 194 | List<String> result = new LinkedList<String>(); |
| 195 | |
| 196 | /* |
| 197 | * Same as left(), but insert spaces between words to make each line |
| 198 | * n chars long. The "algorithm" here is pretty dumb: it performs a |
| 199 | * split on space and then re-inserts multiples of n between words. |
| 200 | */ |
| 201 | List<String> lines = left(str, n); |
| 202 | for (int lineI = 0; lineI < lines.size() - 1; lineI++) { |
| 203 | String line = lines.get(lineI); |
| 204 | String [] words = line.split(" "); |
| 205 | if (words.length > 1) { |
| 206 | int charCount = 0; |
| 207 | for (int i = 0; i < words.length; i++) { |
| 208 | charCount += words[i].length(); |
| 209 | } |
| 210 | int spaceCount = n - charCount; |
| 211 | int q = spaceCount / (words.length - 1); |
| 212 | int r = spaceCount % (words.length - 1); |
| 213 | StringBuilder sb = new StringBuilder(); |
| 214 | for (int i = 0; i < words.length - 1; i++) { |
| 215 | sb.append(words[i]); |
| 216 | for (int j = 0; j < q; j++) { |
| 217 | sb.append(' '); |
| 218 | } |
| 219 | if (r > 0) { |
| 220 | sb.append(' '); |
| 221 | r--; |
| 222 | } |
| 223 | } |
| 224 | for (int j = 0; j < r; j++) { |
| 225 | sb.append(' '); |
| 226 | } |
| 227 | sb.append(words[words.length - 1]); |
| 228 | result.add(sb.toString()); |
| 229 | } else { |
| 230 | result.add(line); |
| 231 | } |
| 232 | } |
| 233 | if (lines.size() > 0) { |
| 234 | result.add(lines.get(lines.size() - 1)); |
| 235 | } |
| 236 | |
| 237 | return result; |
| 238 | } |
| 239 | |
| 240 | } |