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.naming;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024
025/**
026 * <div>
027 * Checks that class type parameter names conform to a specified pattern.
028 * </div>
029 * <ul>
030 * <li>
031 * Property {@code format} - Sets the pattern to match valid identifiers.
032 * Type is {@code java.util.regex.Pattern}.
033 * Default value is {@code "^[A-Z]$"}.
034 * </li>
035 * </ul>
036 *
037 * <p>
038 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
039 * </p>
040 *
041 * <p>
042 * Violation Message Keys:
043 * </p>
044 * <ul>
045 * <li>
046 * {@code name.invalidPattern}
047 * </li>
048 * </ul>
049 *
050 * @since 5.0
051 */
052public class ClassTypeParameterNameCheck
053    extends AbstractNameCheck {
054
055    /** Creates a new {@code ClassTypeParameterNameCheck} instance. */
056    public ClassTypeParameterNameCheck() {
057        super("^[A-Z]$");
058    }
059
060    @Override
061    public int[] getDefaultTokens() {
062        return getRequiredTokens();
063    }
064
065    @Override
066    public final int[] getAcceptableTokens() {
067        return getRequiredTokens();
068    }
069
070    @Override
071    public int[] getRequiredTokens() {
072        return new int[] {
073            TokenTypes.TYPE_PARAMETER,
074        };
075    }
076
077    @Override
078    protected final boolean mustCheckName(DetailAST ast) {
079        final DetailAST location =
080            ast.getParent().getParent();
081        return location.getType() == TokenTypes.CLASS_DEF;
082    }
083
084}