content: /*******************************************************************************
   * Copyright (c) 2006, 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.ui.text.java;
  
  import java.util.Comparator;
  
  import org.eclipse.jface.text.contentassist.ICompletionProposal;
  
  /**
   * Abstract base class for sorters contributed to the
   * <code>org.eclipse.wst.jsdt.ui.javaCompletionProposalSorters</code> extension point.
   * <p>
   * Subclasses need to implement {@link #compare(ICompletionProposal, ICompletionProposal)} and may
   * override {@link #beginSorting(ContentAssistInvocationContext) beginSorting} and
   * {@link #endSorting() endSorting}.
   * </p>
   * <p>
   * The orderings imposed by a subclass need not be consistent with equals.
   * </p>
   * 
   *
   * Provisional API: This class/interface is part of an interim API that is still under development and expected to
   * change significantly before reaching stability. It is being made available at this early stage to solicit feedback
   * from pioneering adopters on the understanding that any code that uses this API will almost certainly be broken
   * (repeatedly) as the API evolves. */
  public abstract class AbstractProposalSorter implements Comparator {
  
  	/**
  	 * Creates a new sorter. Note that subclasses must provide a zero-argument constructor to be
  	 * instantiatable via {@link org.eclipse.core.runtime.IConfigurationElement#createExecutableExtension(String)}.
  	 */
  	protected AbstractProposalSorter() {
  	}
  
  	/**
  	 * Called once before sorting.
  	 * <p>
  	 * Clients may override, the default implementation does nothing.
  	 * </p>
  	 * 
  	 * @param context the context of the content assist invocation
  	 */
  	public void beginSorting(ContentAssistInvocationContext context) {
  	}
  
  	/**
  	 * Implements the same contract as {@link Comparator#compare(Object, Object)} but with
  	 * completion proposals as parameters. This method will implement the {@link Comparator}
  	 * interface if this class is ever converted to extend
  	 * <code>Comparator&lt;ICompletionProposal&gt;</code>.
  	 * <p>
  	 * The orderings imposed by an implementation need not be consistent with equals.
  	 * </p>
  	 * 
  	 * @param p1 the first proposal to be compared
  	 * @param p2 the second proposal to be compared
  	 * @return a negative integer, zero, or a positive integer as the first argument is less than,
  	 *         equal to, or greater than the second.
  	 */
  	public abstract int compare(ICompletionProposal p1, ICompletionProposal p2);
  
  	/**
  	 * Called once after sorting.
  	 * <p>
  	 * Clients may override, the default implementation does nothing.
  	 * </p>
  	 */
  	public void endSorting() {
  	}
  
  	/**
  	 * This method delegates to {@link #compare(ICompletionProposal, ICompletionProposal)} and may
  	 * be removed if the class is ever converted to extend
  	 * <code>Comparator&lt;ICompletionProposal&gt;</code>.
  	 * 
  	 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
  	 */
  	public final int compare(Object o1, Object o2) {
  		ICompletionProposal p1= (ICompletionProposal) o1;
  		ICompletionProposal p2= (ICompletionProposal) o2;
  
  		return compare(p1, p2);
  	}
  }
  