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1   ////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code for adherence to a set of rules.
3   // Copyright (C) 2001-2017 the original author or authors.
4   //
5   // This library is free software; you can redistribute it and/or
6   // modify it under the terms of the GNU Lesser General Public
7   // License as published by the Free Software Foundation; either
8   // version 2.1 of the License, or (at your option) any later version.
9   //
10  // This library is distributed in the hope that it will be useful,
11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  // Lesser General Public License for more details.
14  //
15  // You should have received a copy of the GNU Lesser General Public
16  // License along with this library; if not, write to the Free Software
17  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  ////////////////////////////////////////////////////////////////////////////////
19  
20  package com.puppycrawl.tools.checkstyle.checks.indentation;
21  
22  import com.puppycrawl.tools.checkstyle.api.DetailAST;
23  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
24  
25  /**
26   * Handler for if statements.
27   *
28   * @author jrichard
29   */
30  public class IfHandler extends BlockParentHandler {
31      /**
32       * Construct an instance of this handler with the given indentation check,
33       * abstract syntax tree, and parent handler.
34       *
35       * @param indentCheck   the indentation check
36       * @param ast           the abstract syntax tree
37       * @param parent        the parent handler
38       */
39      public IfHandler(IndentationCheck indentCheck,
40          DetailAST ast, AbstractExpressionHandler parent) {
41          super(indentCheck, "if", ast, parent);
42      }
43  
44      @Override
45      public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
46          final IndentLevel result;
47          if (child instanceof ElseHandler) {
48              result = getIndent();
49          }
50          else {
51              result = super.getSuggestedChildIndent(child);
52          }
53          return result;
54      }
55  
56      @Override
57      protected IndentLevel getIndentImpl() {
58          final IndentLevel result;
59          if (isIfAfterElse()) {
60              result = getParent().getIndent();
61          }
62          else {
63              result = super.getIndentImpl();
64          }
65          return result;
66      }
67  
68      /**
69       * Determines if this 'if' statement is part of an 'else' clause
70       * and on the same line.
71       *
72       * @return true if this 'if' is part of an 'else', false otherwise
73       */
74      private boolean isIfAfterElse() {
75          // check if there is an 'else' and an 'if' on the same line
76          final DetailAST parent = getMainAst().getParent();
77          return parent.getType() == TokenTypes.LITERAL_ELSE
78              && parent.getLineNo() == getMainAst().getLineNo();
79      }
80  
81      @Override
82      protected void checkTopLevelToken() {
83          if (!isIfAfterElse()) {
84              super.checkTopLevelToken();
85          }
86      }
87  
88      /**
89       * Check the indentation of the conditional expression.
90       */
91      private void checkCondExpr() {
92          final DetailAST condAst = getMainAst().findFirstToken(TokenTypes.LPAREN)
93              .getNextSibling();
94          final IndentLevel expected =
95              new IndentLevel(getIndent(), getBasicOffset());
96          checkExpressionSubtree(condAst, expected, false, false);
97      }
98  
99      @Override
100     public void checkIndentation() {
101         super.checkIndentation();
102         checkCondExpr();
103         checkWrappingIndentation(getMainAst(), getIfStatementRightParen(getMainAst()));
104     }
105 
106     /**
107      * Returns right parenthesis of if statement.
108      * @param literalIfAst
109      *          literal-if ast node(TokenTypes.LITERAL_IF)
110      * @return right parenthesis of if statement.
111      */
112     private static DetailAST getIfStatementRightParen(DetailAST literalIfAst) {
113         return literalIfAst.findFirstToken(TokenTypes.RPAREN);
114     }
115 }