001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2017 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.indentation;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024
025/**
026 * Handler for method definitions.
027 *
028 * @author jrichard
029 * @author Maikel Steneker
030 */
031public class MethodDefHandler extends BlockParentHandler {
032    /**
033     * Construct an instance of this handler with the given indentation check,
034     * abstract syntax tree, and parent handler.
035     *
036     * @param indentCheck   the indentation check
037     * @param ast           the abstract syntax tree
038     * @param parent        the parent handler
039     */
040    public MethodDefHandler(IndentationCheck indentCheck,
041        DetailAST ast, AbstractExpressionHandler parent) {
042        super(indentCheck, getHandlerName(ast), ast, parent);
043    }
044
045    @Override
046    protected DetailAST getTopLevelAst() {
047        // we check this stuff ourselves below
048        return null;
049    }
050
051    @Override
052    protected void checkModifiers() {
053        final DetailAST modifier = getMainAst().findFirstToken(TokenTypes.MODIFIERS);
054        if (isOnStartOfLine(modifier)
055            && !getIndent().isAcceptable(expandedTabsColumnNo(modifier))) {
056            logError(modifier, "modifier", expandedTabsColumnNo(modifier));
057        }
058    }
059
060    /**
061     * Check the indentation level of the throws clause.
062     */
063    private void checkThrows() {
064        final DetailAST throwsAst = getMainAst().findFirstToken(TokenTypes.LITERAL_THROWS);
065
066        if (throwsAst != null) {
067            checkWrappingIndentation(throwsAst, throwsAst.getNextSibling(), getIndentCheck()
068                    .getThrowsIndent(), getLineStart(getMethodDefLineStart(getMainAst())),
069                    !isOnStartOfLine(throwsAst));
070        }
071    }
072
073    /**
074     * Gets the start line of the method, excluding any annotations. This is required because the
075     * current {@link TokenTypes#METHOD_DEF} may not always be the start as seen in
076     * https://github.com/checkstyle/checkstyle/issues/3145.
077     *
078     * @param mainAst
079     *            The method definition ast.
080     * @return The start column position of the method.
081     */
082    private static int getMethodDefLineStart(DetailAST mainAst) {
083        // get first type position
084        int lineStart = mainAst.findFirstToken(TokenTypes.IDENT).getLineNo();
085
086        // check if there is a type before the indent
087        final DetailAST typeNode = mainAst.findFirstToken(TokenTypes.TYPE);
088        if (typeNode != null) {
089            lineStart = getFirstLine(lineStart, typeNode);
090        }
091
092        // check if there is a modifier before the type
093        for (DetailAST node = mainAst.findFirstToken(TokenTypes.MODIFIERS).getFirstChild();
094                node != null;
095                node = node.getNextSibling()) {
096            // skip annotations as we check them else where as outside the method
097            if (node.getType() == TokenTypes.ANNOTATION) {
098                continue;
099            }
100
101            if (node.getLineNo() < lineStart) {
102                lineStart = node.getLineNo();
103            }
104        }
105
106        return lineStart;
107    }
108
109    @Override
110    public void checkIndentation() {
111        checkModifiers();
112        checkThrows();
113
114        checkWrappingIndentation(getMainAst(), getMethodDefParamRightParen(getMainAst()));
115        // abstract method def -- no body
116        if (getLeftCurly() != null) {
117            super.checkIndentation();
118        }
119    }
120
121    /**
122     * Returns right parenthesis of method definition parameter list.
123     * @param methodDefAst
124     *          method definition ast node(TokenTypes.LITERAL_IF)
125     * @return right parenthesis of method definition parameter list.
126     */
127    private static DetailAST getMethodDefParamRightParen(DetailAST methodDefAst) {
128        return methodDefAst.findFirstToken(TokenTypes.RPAREN);
129    }
130
131    /**
132     * Creates a handler name for this class according to ast type.
133     *
134     * @param ast the abstract syntax tree.
135     * @return handler name for this class.
136     */
137    private static String getHandlerName(DetailAST ast) {
138        final String name;
139
140        if (ast.getType() == TokenTypes.CTOR_DEF) {
141            name = "ctor def";
142        }
143        else if (ast.getType() == TokenTypes.ANNOTATION_FIELD_DEF) {
144            name = "annotation field def";
145        }
146        else {
147            name = "method def";
148        }
149        return name;
150    }
151}