content: /*******************************************************************************
   * Copyright (c) 2000, 2008 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
   *******************************************************************************/
  /*
   * Created on Apr 13, 2004
   * 
   * TODO To change the template for this generated file go to Window -
   * Preferences - Java - Code Generation - Code and Comments
   */
  package org.eclipse.wst.jsdt.internal.ui.search;
  
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.Set;
  
  import org.eclipse.core.resources.IProject;
  import org.eclipse.core.runtime.CoreException;
  import org.eclipse.core.runtime.IConfigurationElement;
  import org.eclipse.core.runtime.IStatus;
  import org.eclipse.core.runtime.Platform;
  import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
  
  public class SearchParticipantsExtensionPoint {
  
  	private Set fActiveParticipants= null;
  	private static SearchParticipantsExtensionPoint fgInstance;
  
  	public boolean hasAnyParticipants() {
  		return Platform.getExtensionRegistry().getConfigurationElementsFor(JavaSearchPage.PARTICIPANT_EXTENSION_POINT).length > 0;
  	}
  
  	private synchronized Set getAllParticipants() {
  		if (fActiveParticipants != null)
  			return fActiveParticipants;
  		IConfigurationElement[] allParticipants= Platform.getExtensionRegistry().getConfigurationElementsFor(JavaSearchPage.PARTICIPANT_EXTENSION_POINT);
  		fActiveParticipants= new HashSet(allParticipants.length);
  		for (int i= 0; i < allParticipants.length; i++) {
  			SearchParticipantDescriptor descriptor= new SearchParticipantDescriptor(allParticipants[i]);
  			IStatus status= descriptor.checkSyntax();
  			if (status.isOK()) {
  				fActiveParticipants.add(descriptor); 
  			} else {
  				JavaScriptPlugin.log(status);
  			}
  		}
  		return fActiveParticipants;
  	}
  
  	private void collectParticipants(Set participants, IProject[] projects) {
  		Iterator activeParticipants= getAllParticipants().iterator();
  		Set seenParticipants= new HashSet();
  		while (activeParticipants.hasNext()) {
  			SearchParticipantDescriptor participant= (SearchParticipantDescriptor) activeParticipants.next();
  			if (participant.isEnabled()) {
  				String id= participant.getID();
  				for (int i= 0; i < projects.length; i++) {
  					if (seenParticipants.contains(id))
  						continue;
  					try {
  						if (projects[i].hasNature(participant.getNature())) {
  							participants.add(new SearchParticipantRecord(participant, participant.create()));
  							seenParticipants.add(id);
  						}
  					} catch (CoreException e) {
  						JavaScriptPlugin.log(e.getStatus());
  						participant.disable();
  					}
  				}
  			}
  		}
  	}
  
  
  
  	public SearchParticipantRecord[] getSearchParticipants(IProject[] concernedProjects) throws CoreException {
  		Set participantSet= new HashSet();
  		collectParticipants(participantSet, concernedProjects);
  		SearchParticipantRecord[] participants= new SearchParticipantRecord[participantSet.size()];
  		return (SearchParticipantRecord[]) participantSet.toArray(participants);
  	}
  
  	public static SearchParticipantsExtensionPoint getInstance() {
  		if (fgInstance == null)
  			fgInstance= new SearchParticipantsExtensionPoint();
  		return fgInstance;
  	}
  	
  	public static void debugSetInstance(SearchParticipantsExtensionPoint instance) {
  		fgInstance= instance;
  	}
  }
  