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;
021
022import java.util.ArrayList;
023import java.util.List;
024import java.util.stream.Collectors;
025
026import com.puppycrawl.tools.checkstyle.api.AuditEvent;
027import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
028import com.puppycrawl.tools.checkstyle.xpath.XpathQueryGenerator;
029
030/**
031 * Catches {@code TreeWalkerAuditEvent} and generates corresponding xpath query.
032 * Stores event and query inside static variables for {@code XpathFileGeneratorAuditListener}.
033 * See issue #102 https://github.com/checkstyle/checkstyle/issues/102
034 */
035public class XpathFileGeneratorAstFilter extends AutomaticBean implements TreeWalkerFilter {
036
037    /** The delimiter between xpath queries. */
038    private static final String DELIMITER = " | \n";
039
040    /** List of the {@code TreeWalkerAuditEvent} objects, which supports xpath suppressions. */
041    private static final List<TreeWalkerAuditEvent> EVENTS = new ArrayList<>();
042
043    /** List of xpath queries for corresponding {@code TreeWalkerAuditEvent} objects. */
044    private static final List<String> QUERIES = new ArrayList<>();
045
046    /** The distance between tab stop position. */
047    private int tabWidth;
048
049    /**
050     * Sets tab width.
051     * @param tabWidth the distance between tab stops
052     */
053    public void setTabWidth(int tabWidth) {
054        this.tabWidth = tabWidth;
055    }
056
057    /**
058     * Returns xpath query corresponding to {@code TreeWalkerAuditEvent} object which points to
059     * the same AST element as specified {@code AuditEvent} object.
060     * @param event the {@code AuditEvent} object.
061     * @return returns corresponding xpath query
062     */
063    public static String findCorrespondingXpathQuery(AuditEvent event) {
064        String result = null;
065        for (int i = 0; i < EVENTS.size(); i++) {
066            final TreeWalkerAuditEvent treeWalkerAuditEvent =
067                    EVENTS.get(i);
068            if (event.getSourceName().equals(treeWalkerAuditEvent.getSourceName())
069                    && event.getLine() == treeWalkerAuditEvent.getLine()
070                    && event.getColumn() == treeWalkerAuditEvent.getColumn()
071                    && event.getFileName().endsWith(treeWalkerAuditEvent.getFileName())) {
072                result = QUERIES.get(i);
073                break;
074            }
075        }
076        return result;
077    }
078
079    @Override
080    protected void finishLocalSetup() {
081        cleanup();
082    }
083
084    /**
085     * Makes {@code EVENTS} and {@code QUERIES} lists empty.
086     */
087    private static void cleanup() {
088        QUERIES.clear();
089        EVENTS.clear();
090    }
091
092    @Override
093    public boolean accept(TreeWalkerAuditEvent event) {
094        if (event.getTokenType() != 0) {
095            final XpathQueryGenerator xpathQueryGenerator =
096                    new XpathQueryGenerator(event, tabWidth);
097            final List<String> xpathQueries = xpathQueryGenerator.generate();
098            if (!xpathQueries.isEmpty()) {
099                final String query = xpathQueries.stream().collect(Collectors.joining(DELIMITER));
100                EVENTS.add(event);
101                QUERIES.add(query);
102            }
103        }
104        return true;
105    }
106}