1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.checks.javadoc;
21
22 import java.util.ArrayList;
23 import java.util.List;
24
25 import com.puppycrawl.tools.checkstyle.StatelessCheck;
26 import com.puppycrawl.tools.checkstyle.api.DetailNode;
27 import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
28 import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
29 import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
30
31 /**
32 * <p>
33 * Checks the indentation of the continuation lines in block tags. That is whether the continued
34 * description of at clauses should be indented or not. If the text is not properly indented it
35 * throws a violation. A continuation line is when the description starts/spans past the line with
36 * the tag. Default indentation required is at least 4, but this can be changed with the help of
37 * properties below.
38 * </p>
39 * <ul>
40 * <li>
41 * Property {@code offset} - Specify how many spaces to use for new indentation level.
42 * Type is {@code int}.
43 * Default value is {@code 4}.
44 * </li>
45 * <li>
46 * Property {@code violateExecutionOnNonTightHtml} - Control when to print violations
47 * if the Javadoc being examined by this check violates the tight html rules defined at
48 * <a href="https://checkstyle.org/writingjavadocchecks.html#Tight-HTML_rules">Tight-HTML Rules</a>.
49 * Type is {@code boolean}.
50 * Default value is {@code false}.
51 * </li>
52 * </ul>
53 * <p>
54 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
55 * </p>
56 * <p>
57 * Violation Message Keys:
58 * </p>
59 * <ul>
60 * <li>
61 * {@code javadoc.missed.html.close}
62 * </li>
63 * <li>
64 * {@code javadoc.parse.rule.error}
65 * </li>
66 * <li>
67 * {@code javadoc.unclosedHtml}
68 * </li>
69 * <li>
70 * {@code javadoc.wrong.singleton.html.tag}
71 * </li>
72 * <li>
73 * {@code tag.continuation.indent}
74 * </li>
75 * </ul>
76 *
77 * @since 6.0
78 *
79 */
80 @StatelessCheck
81 public class JavadocTagContinuationIndentationCheck extends AbstractJavadocCheck {
82
83 /**
84 * A key is pointing to the warning message text in "messages.properties"
85 * file.
86 */
87 public static final String MSG_KEY = "tag.continuation.indent";
88
89 /** Default tag continuation indentation. */
90 private static final int DEFAULT_INDENTATION = 4;
91
92 /**
93 * Specify how many spaces to use for new indentation level.
94 */
95 private int offset = DEFAULT_INDENTATION;
96
97 /**
98 * Setter to specify how many spaces to use for new indentation level.
99 *
100 * @param offset custom value.
101 * @since 6.0
102 */
103 public void setOffset(int offset) {
104 this.offset = offset;
105 }
106
107 @Override
108 public int[] getDefaultJavadocTokens() {
109 return new int[] {JavadocTokenTypes.DESCRIPTION };
110 }
111
112 @Override
113 public int[] getRequiredJavadocTokens() {
114 return getAcceptableJavadocTokens();
115 }
116
117 @Override
118 public void visitJavadocToken(DetailNode ast) {
119 if (!isInlineDescription(ast)) {
120 final List<DetailNode> textNodes = getAllNewlineNodes(ast);
121 for (DetailNode newlineNode : textNodes) {
122 final DetailNode textNode = JavadocUtil.getNextSibling(newlineNode);
123 if (textNode.getType() == JavadocTokenTypes.TEXT && isViolation(textNode)) {
124 log(textNode.getLineNumber(), MSG_KEY, offset);
125 }
126 }
127 }
128 }
129
130 /**
131 * Checks if a text node meets the criteria for a violation.
132 * If the text is shorter than {@code offset} characters, then a violation is
133 * detected if the text is not blank or the next node is not a newline.
134 * If the text is longer than {@code offset} characters, then a violation is
135 * detected if any of the first {@code offset} characters are not blank.
136 *
137 * @param textNode the node to check.
138 * @return true if the node has a violation.
139 */
140 private boolean isViolation(DetailNode textNode) {
141 boolean result = false;
142 final String text = textNode.getText();
143 if (text.length() <= offset) {
144 if (CommonUtil.isBlank(text)) {
145 final DetailNode nextNode = JavadocUtil.getNextSibling(textNode);
146 if (nextNode != null && nextNode.getType() != JavadocTokenTypes.NEWLINE) {
147 // text is blank but line hasn't ended yet
148 result = true;
149 }
150 }
151 else {
152 // text is not blank
153 result = true;
154 }
155 }
156 else if (!CommonUtil.isBlank(text.substring(1, offset + 1))) {
157 // first offset number of characters are not blank
158 result = true;
159 }
160 return result;
161 }
162
163 /**
164 * Finds and collects all NEWLINE nodes inside DESCRIPTION node.
165 *
166 * @param descriptionNode DESCRIPTION node.
167 * @return List with NEWLINE nodes.
168 */
169 private static List<DetailNode> getAllNewlineNodes(DetailNode descriptionNode) {
170 final List<DetailNode> textNodes = new ArrayList<>();
171 DetailNode node = JavadocUtil.getFirstChild(descriptionNode);
172 while (JavadocUtil.getNextSibling(node) != null) {
173 if (node.getType() == JavadocTokenTypes.HTML_ELEMENT) {
174 final DetailNode descriptionNodeChild = JavadocUtil.getFirstChild(node);
175 textNodes.addAll(getAllNewlineNodes(descriptionNodeChild));
176 }
177 if (node.getType() == JavadocTokenTypes.LEADING_ASTERISK) {
178 textNodes.add(node);
179 }
180 node = JavadocUtil.getNextSibling(node);
181 }
182 return textNodes;
183 }
184
185 /**
186 * Checks, if description node is a description of in-line tag.
187 *
188 * @param description DESCRIPTION node.
189 * @return true, if description node is a description of in-line tag.
190 */
191 private static boolean isInlineDescription(DetailNode description) {
192 boolean isInline = false;
193 DetailNode currentNode = description;
194 while (currentNode != null) {
195 if (currentNode.getType() == JavadocTokenTypes.JAVADOC_INLINE_TAG) {
196 isInline = true;
197 break;
198 }
199 currentNode = currentNode.getParent();
200 }
201 return isInline;
202 }
203
204 }