////////////////////////////////////////////////////////////////////////////////

 // checkstyle: Checks Java source code for adherence to a set of rules.

 // Copyright (C) 2001-2014  Oliver Burn

 //

 // This library is free software; you can redistribute it and/or

 // modify it under the terms of the GNU Lesser General Public

 // License as published by the Free Software Foundation; either

 // version 2.1 of the License, or (at your option) any later version.

 //

 // This library is distributed in the hope that it will be useful,

 // but WITHOUT ANY WARRANTY; without even the implied warranty of

 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 // Lesser General Public License for more details.

 //

 // You should have received a copy of the GNU Lesser General Public

 // License along with this library; if not, write to the Free Software

 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 ////////////////////////////////////////////////////////////////////////////////

 package com.puppycrawl.tools.checkstyle.checks.indentation;

 import com.puppycrawl.tools.checkstyle.api.DetailAST;

 import com.puppycrawl.tools.checkstyle.api.TokenTypes;

 /**

  * Handler for if statements.

  *

  * @author jrichard

  */

 public class IfHandler extends BlockParentHandler

 {

     /**

      * Construct an instance of this handler with the given indentation check,

      * abstract syntax tree, and parent handler.

      *

      * @param aIndentCheck   the indentation check

      * @param aAst           the abstract syntax tree

      * @param aParent        the parent handler

      */

     public IfHandler(IndentationCheck aIndentCheck,

         DetailAST aAst, ExpressionHandler aParent)

     {

         super(aIndentCheck, "if", aAst, aParent);

     }

     @Override

     public IndentLevel suggestedChildLevel(ExpressionHandler aChild)

     {

         if (aChild instanceof ElseHandler) {

             return getLevel();

         }

         return super.suggestedChildLevel(aChild);

     }

     @Override

     protected IndentLevel getLevelImpl()

     {

         if (isIfAfterElse()) {

             return getParent().getLevel();

         }

         return super.getLevelImpl();

     }

     /**

      * Determines if this 'if' statement is part of an 'else' clause

      * and on the same line.

      *

      * @return true if this 'if' is part of an 'else', false otherwise

      */

     private boolean isIfAfterElse()

     {

         // check if there is an 'else' and an 'if' on the same line

         final DetailAST parent = getMainAst().getParent();

         return (parent.getType() == TokenTypes.LITERAL_ELSE)

             && (parent.getLineNo() == getMainAst().getLineNo());

     }

     @Override

     protected void checkToplevelToken()

     {

         if (isIfAfterElse()) {

             return;

         }

         super.checkToplevelToken();

     }

     /**

      * Check the indentation of the conditional expression.

      */

     private void checkCondExpr()

     {

         final DetailAST condAst = getMainAst().findFirstToken(TokenTypes.LPAREN)

             .getNextSibling();

         final IndentLevel expected =

             new IndentLevel(getLevel(), getBasicOffset());

         checkExpressionSubtree(condAst, expected, false, false);

     }

     @Override

     public void checkIndentation()

     {

         super.checkIndentation();

         checkCondExpr();

     }

 }