1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2025 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 * <div>
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 * </div>
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 *
54 * <p>
55 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
56 * </p>
57 *
58 * <p>
59 * Violation Message Keys:
60 * </p>
61 * <ul>
62 * <li>
63 * {@code javadoc.missed.html.close}
64 * </li>
65 * <li>
66 * {@code javadoc.parse.rule.error}
67 * </li>
68 * <li>
69 * {@code javadoc.unclosedHtml}
70 * </li>
71 * <li>
72 * {@code javadoc.wrong.singleton.html.tag}
73 * </li>
74 * <li>
75 * {@code tag.continuation.indent}
76 * </li>
77 * </ul>
78 *
79 * @since 6.0
80 *
81 */
82 @StatelessCheck
83 public class JavadocTagContinuationIndentationCheck extends AbstractJavadocCheck {
84
85 /**
86 * A key is pointing to the warning message text in "messages.properties"
87 * file.
88 */
89 public static final String MSG_KEY = "tag.continuation.indent";
90
91 /** Default tag continuation indentation. */
92 private static final int DEFAULT_INDENTATION = 4;
93
94 /**
95 * Specify how many spaces to use for new indentation level.
96 */
97 private int offset = DEFAULT_INDENTATION;
98
99 /**
100 * Setter to specify how many spaces to use for new indentation level.
101 *
102 * @param offset custom value.
103 * @since 6.0
104 */
105 public void setOffset(int offset) {
106 this.offset = offset;
107 }
108
109 @Override
110 public int[] getDefaultJavadocTokens() {
111 return new int[] {JavadocTokenTypes.HTML_TAG, JavadocTokenTypes.DESCRIPTION};
112
113 }
114
115 @Override
116 public int[] getRequiredJavadocTokens() {
117 return getAcceptableJavadocTokens();
118 }
119
120 @Override
121 public void visitJavadocToken(DetailNode ast) {
122 if (isBlockDescription(ast) && !isInlineDescription(ast)) {
123 final List<DetailNode> textNodes = getAllNewlineNodes(ast);
124 for (DetailNode newlineNode : textNodes) {
125 final DetailNode textNode = JavadocUtil.getNextSibling(newlineNode);
126 if (textNode.getType() != JavadocTokenTypes.NEWLINE && isViolation(textNode)) {
127 log(textNode.getLineNumber(), MSG_KEY, offset);
128 }
129 }
130 }
131 }
132
133 /**
134 * Checks if a text node meets the criteria for a violation.
135 * If the text is shorter than {@code offset} characters, then a violation is
136 * detected if the text is not blank or the next node is not a newline.
137 * If the text is longer than {@code offset} characters, then a violation is
138 * detected if any of the first {@code offset} characters are not blank.
139 *
140 * @param textNode the node to check.
141 * @return true if the node has a violation.
142 */
143 private boolean isViolation(DetailNode textNode) {
144 boolean result = false;
145 final String text = textNode.getText();
146 if (text.length() <= offset) {
147 if (CommonUtil.isBlank(text)) {
148 final DetailNode nextNode = JavadocUtil.getNextSibling(textNode);
149 if (nextNode != null && nextNode.getType() != JavadocTokenTypes.NEWLINE) {
150 // text is blank but line hasn't ended yet
151 result = true;
152 }
153 }
154 else {
155 // text is not blank
156 result = true;
157 }
158 }
159 else if (!CommonUtil.isBlank(text.substring(1, offset + 1))) {
160 // first offset number of characters are not blank
161 result = true;
162 }
163 return result;
164 }
165
166 /**
167 * Finds and collects all NEWLINE nodes inside DESCRIPTION node.
168 *
169 * @param descriptionNode DESCRIPTION node.
170 * @return List with NEWLINE nodes.
171 */
172 private static List<DetailNode> getAllNewlineNodes(DetailNode descriptionNode) {
173 final List<DetailNode> textNodes = new ArrayList<>();
174 DetailNode node = JavadocUtil.getFirstChild(descriptionNode);
175 while (JavadocUtil.getNextSibling(node) != null) {
176 if (node.getType() == JavadocTokenTypes.HTML_ELEMENT) {
177 final DetailNode descriptionNodeChild = JavadocUtil.getFirstChild(node);
178 textNodes.addAll(getAllNewlineNodes(descriptionNodeChild));
179 }
180 else if (node.getType() == JavadocTokenTypes.HTML_ELEMENT_START
181 || node.getType() == JavadocTokenTypes.ATTRIBUTE) {
182 textNodes.addAll(getAllNewlineNodes(node));
183 }
184 if (node.getType() == JavadocTokenTypes.LEADING_ASTERISK) {
185 textNodes.add(node);
186 }
187 node = JavadocUtil.getNextSibling(node);
188 }
189 return textNodes;
190 }
191
192 /**
193 * Checks if the given description node is part of a block Javadoc tag.
194 *
195 * @param description the node to check
196 * @return {@code true} if the node is inside a block tag, {@code false} otherwise
197 */
198 private static boolean isBlockDescription(DetailNode description) {
199 boolean isBlock = false;
200 DetailNode currentNode = description;
201 while (currentNode != null) {
202 if (currentNode.getType() == JavadocTokenTypes.JAVADOC_TAG) {
203 isBlock = true;
204 break;
205 }
206 currentNode = currentNode.getParent();
207 }
208 return isBlock;
209 }
210
211 /**
212 * Checks, if description node is a description of in-line tag.
213 *
214 * @param description DESCRIPTION node.
215 * @return true, if description node is a description of in-line tag.
216 */
217 private static boolean isInlineDescription(DetailNode description) {
218 boolean isInline = false;
219 DetailNode currentNode = description;
220 while (currentNode != null) {
221 if (currentNode.getType() == JavadocTokenTypes.JAVADOC_INLINE_TAG) {
222 isInline = true;
223 break;
224 }
225 currentNode = currentNode.getParent();
226 }
227 return isInline;
228 }
229
230 }