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

 // 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.blocks;

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

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

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

 /**

  * Finds nested blocks.

  *

  * <p>

  * For example this Check flags confusing code like

  * </p>

  * <pre>

  * public void guessTheOutput()

  * {

  *     int whichIsWhich = 0;

  *     {

  *         int whichIsWhich = 2;

  *     }

  *     System.out.println("value = " + whichIsWhich);

  * }

  * </pre>

  *

  * and debugging / refactoring leftovers such as

  *

  * <pre>

  * // if (someOldCondition)

  * {

  *     System.out.println("unconditional");

  * }

  * </pre>

  *

  * <p>

  * A case in a switch statement does not implicitly form a block.

  * Thus to be able to introduce local variables that have case scope

  * it is necessary to open a nested block. This is supported, set

  * the allowInSwitchCase property to true and include all statements

  * of the case in the block.

  * </p>

  *

  * <pre>

  * switch (a)

  * {

  *     case 0:

  *         // Never OK, break outside block

  *         {

  *             x = 1;

  *         }

  *         break;

  *     case 1:

  *         // Never OK, statement outside block

  *         System.out.println("Hello");

  *         {

  *             x = 2;

  *             break;

  *         }

  *     case 1:

  *         // OK if allowInSwitchCase is true

  *         {

  *             System.out.println("Hello");

  *             x = 2;

  *             break;

  *         }

  * }

  * </pre>

  *

  * @author lkuehne

  */

 public class AvoidNestedBlocksCheck extends Check

 {

     /**

      * Whether nested blocks are allowed if they are the

      * only child of a switch case.

      */

     private boolean mAllowInSwitchCase;

     @Override

     public int[] getDefaultTokens()

     {

         return new int[] {TokenTypes.SLIST};

     }

     @Override

     public void visitToken(DetailAST aAST)

     {

         final DetailAST parent = aAST.getParent();

         if (parent.getType() == TokenTypes.SLIST) {

             if (mAllowInSwitchCase

                     && (parent.getParent().getType() == TokenTypes.CASE_GROUP)

                     && (parent.getNumberOfChildren() == 1))

             {

                 return;

             }

             log(aAST.getLineNo(), aAST.getColumnNo(), "block.nested");

         }

     }

     /**

      * Setter for allowInSwitchCase property.

      * @param aAllowInSwitchCase whether nested blocks are allowed

      *                 if they are the only child of a switch case.

      */

     public void setAllowInSwitchCase(boolean aAllowInSwitchCase)

     {

         mAllowInSwitchCase = aAllowInSwitchCase;

     }

 }