Fix comment
[fanfix.git] / src / jexer / bits / StringUtils.java
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1/*
2 * Jexer - Java Text User Interface
3 *
4 * The MIT License (MIT)
5 *
a69ed767 6 * Copyright (C) 2019 Kevin Lamonte
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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 */
29package jexer.bits;
30
31import java.util.List;
32import java.util.LinkedList;
33
34/**
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35 * StringUtils contains methods to:
36 *
37 * - Convert one or more long lines of strings into justified text
38 * paragraphs.
39 *
40 * - Unescape C0 control codes.
41 *
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051e2913 43public class StringUtils {
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44
45 /**
46 * Left-justify a string into a list of lines.
47 *
48 * @param str the string
49 * @param n the maximum number of characters in a line
50 * @return the list of lines
51 */
52 public static List<String> left(final String str, final int n) {
53 List<String> result = new LinkedList<String>();
54
55 /*
56 * General procedure:
57 *
58 * 1. Split on '\n' into paragraphs.
59 *
60 * 2. Scan each line, noting the position of the last
61 * beginning-of-a-word.
62 *
63 * 3. Chop at the last #2 if the next beginning-of-a-word exceeds
64 * n.
65 *
66 * 4. Return the lines.
67 */
68
69 String [] rawLines = str.split("\n");
70 for (int i = 0; i < rawLines.length; i++) {
71 StringBuilder line = new StringBuilder();
72 StringBuilder word = new StringBuilder();
73 boolean inWord = false;
74 for (int j = 0; j < rawLines[i].length(); j++) {
75 char ch = rawLines[i].charAt(j);
76 if ((ch == ' ') || (ch == '\t')) {
77 if (inWord == true) {
78 // We have just transitioned from a word to
79 // whitespace. See if we have enough space to add
80 // the word to the line.
81 if (word.length() + line.length() > n) {
82 // This word will exceed the line length. Wrap
83 // at it instead.
84 result.add(line.toString());
85 line = new StringBuilder();
86 }
87 if ((word.toString().startsWith(" "))
88 && (line.length() == 0)
89 ) {
90 line.append(word.substring(1));
91 } else {
92 line.append(word);
93 }
94 word = new StringBuilder();
95 word.append(ch);
96 inWord = false;
97 } else {
98 // We are in the whitespace before another word. Do
99 // nothing.
100 }
101 } else {
102 if (inWord == true) {
103 // We are appending to a word.
104 word.append(ch);
105 } else {
106 // We have transitioned from whitespace to a word.
107 word.append(ch);
108 inWord = true;
109 }
110 }
111 } // for (int j = 0; j < rawLines[i].length(); j++)
112
113 if (word.length() + line.length() > n) {
114 // This word will exceed the line length. Wrap at it
115 // instead.
116 result.add(line.toString());
117 line = new StringBuilder();
118 }
119 if ((word.toString().startsWith(" "))
120 && (line.length() == 0)
121 ) {
122 line.append(word.substring(1));
123 } else {
124 line.append(word);
125 }
126 result.add(line.toString());
127 } // for (int i = 0; i < rawLines.length; i++) {
128
129 return result;
130 }
131
132 /**
133 * Right-justify a string into a list of lines.
134 *
135 * @param str the string
136 * @param n the maximum number of characters in a line
137 * @return the list of lines
138 */
139 public static List<String> right(final String str, final int n) {
140 List<String> result = new LinkedList<String>();
141
142 /*
143 * Same as left(), but preceed each line with spaces to make it n
144 * chars long.
145 */
146 List<String> lines = left(str, n);
147 for (String line: lines) {
148 StringBuilder sb = new StringBuilder();
149 for (int i = 0; i < n - line.length(); i++) {
150 sb.append(' ');
151 }
152 sb.append(line);
153 result.add(sb.toString());
154 }
155
156 return result;
157 }
158
159 /**
160 * Center a string into a list of lines.
161 *
162 * @param str the string
163 * @param n the maximum number of characters in a line
164 * @return the list of lines
165 */
166 public static List<String> center(final String str, final int n) {
167 List<String> result = new LinkedList<String>();
168
169 /*
170 * Same as left(), but preceed/succeed each line with spaces to make
171 * it n chars long.
172 */
173 List<String> lines = left(str, n);
174 for (String line: lines) {
175 StringBuilder sb = new StringBuilder();
176 int l = (n - line.length()) / 2;
177 int r = n - line.length() - l;
178 for (int i = 0; i < l; i++) {
179 sb.append(' ');
180 }
181 sb.append(line);
182 for (int i = 0; i < r; i++) {
183 sb.append(' ');
184 }
185 result.add(sb.toString());
186 }
187
188 return result;
189 }
190
191 /**
192 * Fully-justify a string into a list of lines.
193 *
194 * @param str the string
195 * @param n the maximum number of characters in a line
196 * @return the list of lines
197 */
198 public static List<String> full(final String str, final int n) {
199 List<String> result = new LinkedList<String>();
200
201 /*
202 * Same as left(), but insert spaces between words to make each line
203 * n chars long. The "algorithm" here is pretty dumb: it performs a
204 * split on space and then re-inserts multiples of n between words.
205 */
206 List<String> lines = left(str, n);
207 for (int lineI = 0; lineI < lines.size() - 1; lineI++) {
208 String line = lines.get(lineI);
209 String [] words = line.split(" ");
210 if (words.length > 1) {
211 int charCount = 0;
212 for (int i = 0; i < words.length; i++) {
213 charCount += words[i].length();
214 }
215 int spaceCount = n - charCount;
216 int q = spaceCount / (words.length - 1);
217 int r = spaceCount % (words.length - 1);
218 StringBuilder sb = new StringBuilder();
219 for (int i = 0; i < words.length - 1; i++) {
220 sb.append(words[i]);
221 for (int j = 0; j < q; j++) {
222 sb.append(' ');
223 }
224 if (r > 0) {
225 sb.append(' ');
226 r--;
227 }
228 }
229 for (int j = 0; j < r; j++) {
230 sb.append(' ');
231 }
232 sb.append(words[words.length - 1]);
233 result.add(sb.toString());
234 } else {
235 result.add(line);
236 }
237 }
238 if (lines.size() > 0) {
239 result.add(lines.get(lines.size() - 1));
240 }
241
242 return result;
243 }
244
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245 /**
246 * Convert raw strings into escaped strings that be splatted on the
247 * screen.
248 *
249 * @param str the string
250 * @return a string that can be passed into Screen.putStringXY()
251 */
252 public static String unescape(final String str) {
253 StringBuilder sb = new StringBuilder();
254 for (int i = 0; i < str.length(); i++) {
255 char ch = str.charAt(i);
256 if ((ch < 0x20) || (ch == 0x7F)) {
257 switch (ch) {
258 case '\b':
259 sb.append("\\b");
260 continue;
261 case '\f':
262 sb.append("\\f");
263 continue;
264 case '\n':
265 sb.append("\\n");
266 continue;
267 case '\r':
268 sb.append("\\r");
269 continue;
270 case '\t':
271 sb.append("\\t");
272 continue;
273 case 0x7f:
274 sb.append("^?");
275 continue;
276 default:
277 sb.append(' ');
278 continue;
279 }
280 }
281 sb.append(ch);
282 }
283 return sb.toString();
284 }
285
7657ad8c 286}