001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2016 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.api;
021
022import java.util.ArrayList;
023import java.util.List;
024
025import com.google.common.base.Joiner;
026
027/**
028 * Represents a full identifier, including dots, with associated
029 * position information.
030 *
031 * <p>
032 * Identifiers such as {@code java.util.HashMap} are spread across
033 * multiple AST nodes in the syntax tree (three IDENT nodes, two DOT nodes).
034 * A FullIdent represents the whole String (excluding any intermediate
035 * whitespace), which is often easier to work with in Checks.
036 * </p>
037 *
038 * @author Oliver Burn
039 * @see TokenTypes#DOT
040 * @see TokenTypes#IDENT
041 **/
042public final class FullIdent {
043    /** The list holding subsequent elements of identifier. **/
044    private final List<String> elements = new ArrayList<>();
045    /** The line number. **/
046    private int lineNo;
047    /** The column number. **/
048    private int columnNo;
049
050    /** Hide default constructor. */
051    private FullIdent() {
052    }
053
054    /**
055     * Creates a new FullIdent starting from the specified node.
056     * @param ast the node to start from
057     * @return a {@code FullIdent} value
058     */
059    public static FullIdent createFullIdent(DetailAST ast) {
060        final FullIdent ident = new FullIdent();
061        extractFullIdent(ident, ast);
062        return ident;
063    }
064
065    /**
066     * Creates a new FullIdent starting from the child of the specified node.
067     * @param ast the parent node from where to start from
068     * @return a {@code FullIdent} value
069     */
070    public static FullIdent createFullIdentBelow(DetailAST ast) {
071        return createFullIdent(ast.getFirstChild());
072    }
073
074    /**
075     * Gets the text.
076     * @return the text
077     */
078    public String getText() {
079        return Joiner.on("").join(elements);
080    }
081
082    /**
083     * Gets the line number.
084     * @return the line number
085     */
086    public int getLineNo() {
087        return lineNo;
088    }
089
090    /**
091     * Gets the column number.
092     * @return the column number
093     */
094    public int getColumnNo() {
095        return columnNo;
096    }
097
098    @Override
099    public String toString() {
100        return getText() + "[" + lineNo + "x" + columnNo + "]";
101    }
102
103    /**
104     * Recursively extract a FullIdent.
105     *
106     * @param full the FullIdent to add to
107     * @param ast the node to recurse from
108     */
109    private static void extractFullIdent(FullIdent full, DetailAST ast) {
110        if (ast != null) {
111            if (ast.getType() == TokenTypes.DOT) {
112                extractFullIdent(full, ast.getFirstChild());
113                full.append(".");
114                extractFullIdent(
115                    full, ast.getFirstChild().getNextSibling());
116            }
117            else {
118                full.append(ast);
119            }
120        }
121    }
122
123    /**
124     * Append the specified text.
125     * @param text the text to append
126     */
127    private void append(String text) {
128        elements.add(text);
129    }
130
131    /**
132     * Append the specified token and also recalibrate the first line and
133     * column.
134     * @param ast the token to append
135     */
136    private void append(DetailAST ast) {
137        elements.add(ast.getText());
138        if (lineNo == 0) {
139            lineNo = ast.getLineNo();
140        }
141        else if (ast.getLineNo() > 0) {
142            lineNo = Math.min(lineNo, ast.getLineNo());
143        }
144        if (columnNo == 0) {
145            columnNo = ast.getColumnNo();
146        }
147        else if (ast.getColumnNo() > 0) {
148            columnNo = Math.min(columnNo, ast.getColumnNo());
149        }
150    }
151}