1 /*
2 * Copyright (c) 2011-2025 Yegor Bugayenko
3 *
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met: 1) Redistributions of source code must retain the above
9 * copyright notice, this list of conditions and the following
10 * disclaimer. 2) Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following
12 * disclaimer in the documentation and/or other materials provided
13 * with the distribution. 3) Neither the name of the Qulice.com nor
14 * the names of its contributors may be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
20 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
29 * OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31 package com.qulice.checkstyle;
32
33 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
34 import com.puppycrawl.tools.checkstyle.api.FileText;
35 import java.io.File;
36 import org.cactoos.text.Joined;
37
38 /**
39 * Make sure each line indentation is either:
40 * <ul>
41 * <li>the same as previous one or less
42 * <li>bigger than previous by exactly 4
43 * </ul>
44 * All other cases must cause a failure.
45 *
46 * @since 0.3
47 */
48 public final class CascadeIndentationCheck extends AbstractFileSetCheck {
49 /**
50 * Exact indentation increase difference.
51 */
52 private static final int LINE_INDENT_DIFF = 4;
53
54 @Override
55 public void processFiltered(final File file, final FileText lines) {
56 int previous = 0;
57 for (int pos = 0; pos < lines.size(); pos += 1) {
58 final String line = lines.get(pos);
59 final int current = CascadeIndentationCheck.indentation(line);
60 if (CascadeIndentationCheck.inCommentBlock(line)
61 || line.isEmpty()) {
62 continue;
63 }
64 if (current > previous
65 && current != previous
66 + CascadeIndentationCheck.LINE_INDENT_DIFF) {
67 this.log(
68 pos + 1,
69 String.format(
70 new Joined(
71 "",
72 "Indentation (%d) must be same or ",
73 "less than previous line (%d), or ",
74 "bigger by exactly 4"
75 ).toString(),
76 current,
77 previous
78 )
79 );
80 }
81 previous = current;
82 }
83 }
84
85 /**
86 * Checks if the line belongs to a comment block.
87 * @param line Input.
88 * @return True if the line belongs to a comment block.
89 */
90 private static boolean inCommentBlock(final String line) {
91 final String trimmed = line.trim();
92 return !trimmed.isEmpty()
93 && (trimmed.charAt(0) == '*'
94 || trimmed.startsWith("/*")
95 || trimmed.startsWith("*/")
96 );
97 }
98
99 /**
100 * Calculates indentation of a line.
101 * @param line Input line
102 * @return Indentation of the given line.
103 */
104 private static int indentation(final String line) {
105 int result = 0;
106 for (int pos = 0; pos < line.length(); pos += 1) {
107 if (!Character.isWhitespace(line.charAt(pos))) {
108 break;
109 }
110 result += 1;
111 }
112 return result;
113 }
114
115 }