/*
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the "License").  You may not use this file except
 * in compliance with the License.
 *
 * You can obtain a copy of the license at
 * glassfish/bootstrap/legal/CDDLv1.0.txt or
 * https://glassfish.dev.java.net/public/CDDLv1.0.html.
 * See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL
 * HEADER in each file and include the License file at
 * glassfish/bootstrap/legal/CDDLv1.0.txt.  If applicable,
 * add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your
 * own identifying information: Portions Copyright [yyyy]
 * [name of copyright owner]
 *
 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
 *
 * Portions Copyright Apache Software Foundation.
 */ 

package org.apache.taglibs.standard.lang.jstl;

/**
 *
 * <p>The implementation of the and operator
 * 
 * @author Nathan Abramson - Art Technology Group
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: kchung $
 **/

public class AndOperator
  extends BinaryOperator
{
  //-------------------------------------
  // Singleton
  //-------------------------------------

  public static final AndOperator SINGLETON =
    new AndOperator ();

  //-------------------------------------
  /**
   *
   * Constructor
   **/
  public AndOperator ()
  {
  }

  //-------------------------------------
  // Expression methods
  //-------------------------------------
  /**
   *
   * Returns the symbol representing the operator
   **/
  public String getOperatorSymbol ()
  {
    return "and";
  }

  //-------------------------------------
  /**
   *
   * Applies the operator to the given value
   **/
  public Object apply (Object pLeft,
		       Object pRight,
		       Object pContext,
		       Logger pLogger)
    throws ELException
  {
    // Coerce the values to booleans
    boolean left = 
      Coercions.coerceToBoolean (pLeft, pLogger).booleanValue ();
    boolean right = 
      Coercions.coerceToBoolean (pRight, pLogger).booleanValue ();

    return PrimitiveObjects.getBoolean (left && right);
  }

  //-------------------------------------
  /**
   *
   * Returns true if evaluation is necessary given the specified Left
   * value.  The And/OrOperators make use of this
   **/
  public boolean shouldEvaluate (Object pLeft)
  {
    return
      (pLeft instanceof Boolean) &&
      ((Boolean) pLeft).booleanValue () == true;
  }

  //-------------------------------------
  /**
   *
   * Returns true if the operator expects its arguments to be coerced
   * to Booleans.  The And/Or operators set this to true.
   **/
  public boolean shouldCoerceToBoolean ()
  {
    return true;
  }

  //-------------------------------------
}
