001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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.naming;
021
022import com.puppycrawl.tools.checkstyle.api.TokenTypes;
023import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
024
025/**
026 * <p>
027 * Checks that type names conform to a specified pattern.
028 * </p>
029 * <ul>
030 * <li>
031 * Property {@code format} - Specifies valid identifiers. Default value is
032 * {@code "^[A-Z][a-zA-Z0-9]*$"}.
033 * </li>
034 * <li>
035 * Property {@code applyToPublic} - Controls whether to apply the check to public member.
036 * Default value is {@code true}.
037 * </li>
038 * <li>
039 * Property {@code applyToProtected} - Controls whether to apply the check to protected member.
040 * Default value is {@code true}.
041 * </li>
042 * <li>
043 * Property {@code applyToPackage} - Controls whether to apply the check to package-private member.
044 * Default value is {@code true}.
045 * </li>
046 * <li>
047 * Property {@code applyToPrivate} - Controls whether to apply the check to private member.
048 * Default value is {@code true}.
049 * </li>
050 * <li>
051 * Property {@code tokens} - tokens to check Default value is:
052 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CLASS_DEF">
053 * CLASS_DEF</a>,
054 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#INTERFACE_DEF">
055 * INTERFACE_DEF</a>,
056 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_DEF">
057 * ENUM_DEF</a>,
058 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ANNOTATION_DEF">
059 * ANNOTATION_DEF</a>.
060 * </li>
061 * </ul>
062 * <p>
063 * An example of how to configure the check is:
064 * </p>
065 * <pre>
066 * &lt;module name="TypeName"/&gt;
067 * </pre>
068 * <p>
069 * An example of how to configure the check for names that begin with
070 * a lower case letter, followed by letters, digits, and underscores is:
071 * </p>
072 * <pre>
073 * &lt;module name="TypeName"&gt;
074 *   &lt;property name="format" value="^[a-z](_?[a-zA-Z0-9]+)*$"/&gt;
075 * &lt;/module&gt;
076 * </pre>
077 * <p>
078 * The following configuration element ensures that interface names begin with {@code "I_"},
079 * followed by letters and digits:
080 * </p>
081 * <pre>
082 * &lt;module name="TypeName"&gt;
083 *   &lt;property name="format"
084 *     value="^I_[a-zA-Z0-9]*$"/&gt;
085 *   &lt;property name="tokens"
086 *     value="INTERFACE_DEF"/&gt;
087 * &lt;/module&gt;
088 * </pre>
089 *
090 * @since 3.0
091 */
092public class TypeNameCheck
093    extends AbstractAccessControlNameCheck {
094
095    /**
096     * Default pattern for type name.
097     */
098    public static final String DEFAULT_PATTERN = "^[A-Z][a-zA-Z0-9]*$";
099
100    /**
101     * Creates a new {@code TypeNameCheck} instance.
102     */
103    public TypeNameCheck() {
104        super(DEFAULT_PATTERN);
105    }
106
107    @Override
108    public int[] getDefaultTokens() {
109        return getAcceptableTokens();
110    }
111
112    @Override
113    public int[] getAcceptableTokens() {
114        return new int[] {TokenTypes.CLASS_DEF,
115                          TokenTypes.INTERFACE_DEF,
116                          TokenTypes.ENUM_DEF,
117                          TokenTypes.ANNOTATION_DEF,
118        };
119    }
120
121    @Override
122    public int[] getRequiredTokens() {
123        return CommonUtil.EMPTY_INT_ARRAY;
124    }
125
126}