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