001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2024 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.javadoc;
021
022import java.util.ArrayList;
023import java.util.List;
024
025import com.puppycrawl.tools.checkstyle.StatelessCheck;
026import com.puppycrawl.tools.checkstyle.api.DetailNode;
027import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
028import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
029import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
030
031/**
032 * <p>
033 * Checks the indentation of the continuation lines in block tags. That is whether the continued
034 * description of at clauses should be indented or not. If the text is not properly indented it
035 * throws a violation. A continuation line is when the description starts/spans past the line with
036 * the tag. Default indentation required is at least 4, but this can be changed with the help of
037 * properties below.
038 * </p>
039 * <ul>
040 * <li>
041 * Property {@code offset} - Specify how many spaces to use for new indentation level.
042 * Type is {@code int}.
043 * Default value is {@code 4}.
044 * </li>
045 * <li>
046 * Property {@code violateExecutionOnNonTightHtml} - Control when to print violations
047 * if the Javadoc being examined by this check violates the tight html rules defined at
048 * <a href="https://checkstyle.org/writingjavadocchecks.html#Tight-HTML_rules">Tight-HTML Rules</a>.
049 * Type is {@code boolean}.
050 * Default value is {@code false}.
051 * </li>
052 * </ul>
053 * <p>
054 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
055 * </p>
056 * <p>
057 * Violation Message Keys:
058 * </p>
059 * <ul>
060 * <li>
061 * {@code javadoc.missed.html.close}
062 * </li>
063 * <li>
064 * {@code javadoc.parse.rule.error}
065 * </li>
066 * <li>
067 * {@code javadoc.unclosedHtml}
068 * </li>
069 * <li>
070 * {@code javadoc.wrong.singleton.html.tag}
071 * </li>
072 * <li>
073 * {@code tag.continuation.indent}
074 * </li>
075 * </ul>
076 *
077 * @since 6.0
078 *
079 */
080@StatelessCheck
081public class JavadocTagContinuationIndentationCheck extends AbstractJavadocCheck {
082
083    /**
084     * A key is pointing to the warning message text in "messages.properties"
085     * file.
086     */
087    public static final String MSG_KEY = "tag.continuation.indent";
088
089    /** Default tag continuation indentation. */
090    private static final int DEFAULT_INDENTATION = 4;
091
092    /**
093     * Specify how many spaces to use for new indentation level.
094     */
095    private int offset = DEFAULT_INDENTATION;
096
097    /**
098     * Setter to specify how many spaces to use for new indentation level.
099     *
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}