org.eclipse.viatra2.gtasm.interpreter/src/org/eclipse/viatra2/gtasm/interpreter/internal/ViatraGTASMInterpreterPlugin.java

/*******************************************************************************
 * Copyright (c) 2004-2008 Peter Pasztor, Akos Horvath, Gergely Varro, Istvan Rath 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:
 *    Peter Pasztor, Akos Horvath, Gergely Varro, Istvan Rath - initial API and implementation
 *******************************************************************************/

package org.eclipse.viatra2.gtasm.interpreter.internal;

import org.eclipse.core.runtime.Plugin;
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.viatra2.gtasm.interpreter.extension.INativeASMRule;
import org.osgi.framework.BundleContext;

public class ViatraGTASMInterpreterPlugin extends Plugin {


	// The plug-in ID
	public static final String PLUGIN_ID = "org.eclipse.viatra2.gtasm.interpreter";
	// Extension points
	public static final String NATIVE_ASM_RULE_EXT_ID = "org.eclipse.viatra2.gtasm.interpreter.nativeasmrule";
	
	// The shared instance
	private static ViatraGTASMInterpreterPlugin plugin;

	/* Native ASM rules*/
	private Map<String,INativeASMRule> nativeASMRules; 
	
	/**
	 * The constructor
	 */
	public ViatraGTASMInterpreterPlugin () {
		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 ViatraGTASMInterpreterPlugin getDefault() {
		return plugin;
	}
	
	
	/** Returns a Map that contains all Native AMS rule implementation attached to the org.eclipse.viatra2.gtasm.interpreter.impl.interpreter
	 * @return
	 */
	public Map<String, INativeASMRule> getNativeAMSRules() {
		if (nativeASMRules == null) {
			nativeASMRules = initNativeASMRules();
		}
		return nativeASMRules;
	}
	
	/**
	 * Returns the native ASM rules registered to the interpreter
	 * @param id
	 *        The id of the registered native AMS rule
	 * @return its implementing object
	 */
	public INativeASMRule getNativeAMSRules(String id) {
		if (nativeASMRules == null || nativeASMRules.size() == 0) {
			nativeASMRules= initNativeASMRules();
		}
		return nativeASMRules.containsKey(id)?nativeASMRules.get(id):null;
	}

	private Map<String, INativeASMRule> initNativeASMRules() {
		IExtensionRegistry reg = Platform.getExtensionRegistry();
		IExtensionPoint poi = reg.getExtensionPoint(NATIVE_ASM_RULE_EXT_ID);
		HashMap<String, INativeASMRule> r = new HashMap<String, INativeASMRule>();
		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 INativeASMRule) {
						String id = ((INativeASMRule)o).getID();
						r.put(id, (INativeASMRule) o);
					}
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		}
		return r;
	}
}