org.eclipse.viatra2.gtasm.patternmatcher.impl/src/org/eclipse/viatra2/gtasm/patternmatcher/impl/gtmatcher/extension/VIATRAGTMatcherPlugin.java

/*******************************************************************************
 * Copyright (c) 2004-2008 Akos Horvath, Gergely Varro and Daniel Varro
 * 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:
 *    Akos Horvath, Gergely Varro - initial API and implementation
 *******************************************************************************/

 package org.eclipse.viatra2.gtasm.patternmatcher.impl.gtmatcher.extension;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Plugin;
import org.osgi.framework.BundleContext;

/**
 * The activator class for the GtMatcher. Holds the references for the alternative pattern matcher
 * @author Akos Horvath
 *
 */
public class VIATRAGTMatcherPlugin extends Plugin {
	
	// The plug-in ID
	public static final String PLUGIN_ID = "org.eclipse.viatra2.gtasm.patternmatcher.impl";
	//Extension points
	public static final String PATTERN_MATCHER_EXT_ID = "org.eclipse.viatra2.gtasm.patternmatcher.impl.alternativepatternmatcher";
	
	public static final String INCREMENTAL_PM_FACTORY_ID="org.eclipse.viatra2.gtasm.patternmatcher.incremental.alternativeGTmatcher";
	//  public static final String INCREMENTAL_PARALlEL_PM_FACTORY_ID="org.eclipse.viatra2.gtasm.patternmatcher.incremental.parallel.alternativeGTmatcher";
	//	public static final String LOCAL_PM_FACTORY_ID = "org.eclipse.viatra2.local_search";
	public static final String DEFAULT_ALTERNATIVE_PM_FACTORY_ID = INCREMENTAL_PM_FACTORY_ID;
	
	// The shared instance
	private static VIATRAGTMatcherPlugin  plugin;
	
	/**
	 * The constructor
	 */
	public VIATRAGTMatcherPlugin() {
		plugin = this;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.core.runtime.Plugins#start(org.osgi.framework.BundleContext)
	 */
	public void start(BundleContext context) throws Exception {
		super.start(context);
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.core.runtime.Plugin#stop(org.osgi.framework.BundleContext)
	 */
	public void stop(BundleContext context) throws Exception {
		plugin = null;
		super.stop(context);
	}

	/**
	 * Returns the shared instance
	 *
	 * @return the shared instance
	 */
	public static VIATRAGTMatcherPlugin getDefault() {
		return plugin;
	}
	
	/** PATTERN MATCHER FACTORIES*/ 
	private Map<String,IAlternativePatternMatcherFactory> patternMatcherFactories;
	
	public Map<String,IAlternativePatternMatcherFactory> getPatternMatcherFactories()
	{
		if (patternMatcherFactories==null)
		{
			patternMatcherFactories = initPatternMatcherFactories();
		}
		return patternMatcherFactories;
	}
	
	/** Returns the pattern matcher registered with the input id
	 * @param id The id of the registered patternMatcher plugin id
	 * @return the IAlternativePatternMatcherFactory for the patternMatcher
	 */
	public IAlternativePatternMatcherFactory getPatternMatcherFactory(String id){
		if (patternMatcherFactories==null)
		{
			patternMatcherFactories = initPatternMatcherFactories();
		}
		return patternMatcherFactories.containsKey(id)? patternMatcherFactories.get(id): null;
	}
	
	
	private Map<String,IAlternativePatternMatcherFactory> initPatternMatcherFactories()
	{
		IExtensionRegistry reg = Platform.getExtensionRegistry();
		IExtensionPoint poi = reg.getExtensionPoint(PATTERN_MATCHER_EXT_ID);
		HashMap<String,IAlternativePatternMatcherFactory> r = new HashMap<String,IAlternativePatternMatcherFactory>();
		if (poi==null) return r;
		IExtension[] exts = poi.getExtensions();
		for (int i=0;i<exts.length;i++)
		{
			IConfigurationElement[] el = exts[i].getConfigurationElements();
			for (int j=0;j<el.length;j++)
			{
				try
				{
					Object o = el[j].createExecutableExtension("class");
					if (o instanceof IAlternativePatternMatcherFactory)
						{String id = (String)el[j].getAttribute("id");
						 r.put(id,(IAlternativePatternMatcherFactory)o);
						}
				}
				catch (Exception e)
				{
					e.printStackTrace();
				}
			}
		}								
		return r;
	}
	
	/** Checks if there is a registered pattern matcher on the plugin
	 * @return 
	 */
	public Boolean hasAlternativePatternMatcher(){
		if (patternMatcherFactories==null)
		{
			patternMatcherFactories = initPatternMatcherFactories();
		}
		return patternMatcherFactories.size() > 0;
	}
	

}