001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2018 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;
023
024/**
025 * Handler for lambda expressions.
026 *
027 * @author pietern
028 */
029public class LambdaHandler extends AbstractExpressionHandler {
030
031    /**
032     * Construct an instance of this handler with the given indentation check,
033     * abstract syntax tree, and parent handler.
034     *
035     * @param indentCheck the indentation check
036     * @param ast the abstract syntax tree
037     * @param parent the parent handler
038     */
039    public LambdaHandler(IndentationCheck indentCheck,
040                         DetailAST ast, AbstractExpressionHandler parent) {
041        super(indentCheck, "lambda", ast, parent);
042    }
043
044    @Override
045    public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
046        return getIndent();
047    }
048
049    /**
050     * {@inheritDoc}.
051     * @noinspection MethodWithMultipleReturnPoints
052     */
053    @Override
054    protected IndentLevel getIndentImpl() {
055        if (getParent() instanceof MethodCallHandler) {
056            return getParent().getSuggestedChildIndent(this);
057        }
058
059        DetailAST parent = getMainAst().getParent();
060        if (getParent() instanceof NewHandler) {
061            parent = parent.getParent();
062        }
063
064        // Use the start of the parent's line as the reference indentation level.
065        IndentLevel level = new IndentLevel(getLineStart(parent));
066
067        // If the start of the lambda is the first element on the line;
068        // assume line wrapping with respect to its parent.
069        final DetailAST firstChild = getMainAst().getFirstChild();
070        if (getLineStart(firstChild) == firstChild.getColumnNo()) {
071            level = new IndentLevel(level, getIndentCheck().getLineWrappingIndentation());
072        }
073
074        return level;
075    }
076
077    @Override
078    public void checkIndentation() {
079        // If the argument list is the first element on the line
080        final DetailAST firstChild = getMainAst().getFirstChild();
081        if (getLineStart(firstChild) == firstChild.getColumnNo()) {
082            final IndentLevel level = getIndent();
083            if (!level.isAcceptable(firstChild.getColumnNo())) {
084                logError(firstChild, "arguments", firstChild.getColumnNo(), level);
085            }
086        }
087
088        // If the "->" is the first element on the line, assume line wrapping.
089        if (getLineStart(getMainAst()) == getMainAst().getColumnNo()) {
090            final IndentLevel level =
091                new IndentLevel(getIndent(), getIndentCheck().getLineWrappingIndentation());
092            if (!level.isAcceptable(getMainAst().getColumnNo())) {
093                logError(getMainAst(), "", getMainAst().getColumnNo(), level);
094            }
095        }
096    }
097
098}