content: /*******************************************************************************
   * Copyright (c) 2000, 2007 IBM Corporation and others.
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints2;
  
  import org.eclipse.core.runtime.Assert;
  
  public final class SubTypeConstraint2 implements ITypeConstraint2 {
  
  	private final ConstraintVariable2 fAncestor;
  
  	private final ConstraintVariable2 fDescendant;
  
  	public SubTypeConstraint2(final ConstraintVariable2 descendant, final ConstraintVariable2 ancestor) {
  		Assert.isNotNull(descendant);
  		Assert.isNotNull(ancestor);
  		fDescendant= descendant;
  		fAncestor= ancestor;
  	}
  
  	/*
  	 * @see java.lang.Object#equals(java.lang.Object)
  	 */
  	public final boolean equals(Object other) {
  		// can use object identity on ConstraintVariables, since we have the stored (or to be stored) objects
  		if (other.getClass() != SubTypeConstraint2.class)
  			return false;
  
  		ITypeConstraint2 otherTC= (ITypeConstraint2) other;
  		return fDescendant == otherTC.getLeft() && fAncestor == otherTC.getRight();
  	}
  
  	public final ConstraintVariable2 getLeft() {
  		return fDescendant;
  	}
  
  	public final ConstraintVariable2 getRight() {
  		return fAncestor;
  	}
  
  	/*
  	 * @see java.lang.Object#hashCode()
  	 */
  	public final int hashCode() {
  		return fDescendant.hashCode() ^ 37 * fAncestor.hashCode();
  	}
  
  	/*
  	 * @see java.lang.Object#toString()
  	 */
  	public final String toString() {
  		return fDescendant.toString() + " <= " + fAncestor.toString(); //$NON-NLS-1$ 
  	}
  }
  