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.indentation;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024
025/**
026 * Handler for labels.
027 *
028 */
029public class LabelHandler extends AbstractExpressionHandler {
030
031    /**
032     * The types of expressions that are children of a label.
033     */
034    private static final int[] LABEL_CHILDREN = {
035        TokenTypes.IDENT,
036    };
037
038    /**
039     * Construct an instance of this handler with the given indentation check,
040     * abstract syntax tree, and parent handler.
041     *
042     * @param indentCheck   the indentation check
043     * @param expr          the abstract syntax tree
044     * @param parent        the parent handler
045     */
046    public LabelHandler(IndentationCheck indentCheck,
047        DetailAST expr, AbstractExpressionHandler parent) {
048        super(indentCheck, "label", expr, parent);
049    }
050
051    @Override
052    protected IndentLevel getIndentImpl() {
053        final IndentLevel level = new IndentLevel(super.getIndentImpl(), -getBasicOffset());
054        return IndentLevel.addAcceptable(level, super.getIndentImpl());
055    }
056
057    /**
058     * Check the indentation of the label.
059     */
060    private void checkLabel() {
061        checkChildren(getMainAst(), LABEL_CHILDREN, getIndent(), true, false);
062    }
063
064    @Override
065    public void checkIndentation() {
066        checkLabel();
067        // need to check children (like 'block' parents do)
068        final DetailAST parent = getMainAst().getFirstChild().getNextSibling();
069
070        final IndentLevel expected =
071            new IndentLevel(getIndent(), getBasicOffset());
072
073        checkExpressionSubtree(parent, expected, true, false);
074    }
075
076}