/*
 *  JFLAP - Formal Languages and Automata Package
 * 
 * 
 *  Susan H. Rodger
 *  Computer Science Department
 *  Duke University
 *  August 27, 2009

 *  Copyright (c) 2002-2009
 *  All rights reserved.

 *  JFLAP is open source software. Please see the LICENSE for terms.
 *
 */





package gui.environment;

import grammar.Grammar;
import grammar.UnboundGrammar;
import gui.grammar.GrammarInputPane;
import java.io.Serializable;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;

/**
 * The <CODE>GrammarEnvironment</CODE> is an environment for holding a
 * grammar. Owing to certain eccentricities of the way that the grammar is set
 * up as a non-editable object, what is passed into the environment is a <CODE>GrammarInputPane</CODE>
 * which is then used to retrieve the current grammar.
 * 
 * Unlike other environments, the object returned by the <CODE>Grammar</CODE>
 * returned by the <CODE>.getObject</CODE> method will not point to the same
 * object throughout the environment's execution.
 * 
 * @see grammar.Grammar
 * @see gui.grammar.GrammarInputPane
 * 
 * @author Thomas Finley
 */

public class GrammarEnvironment extends Environment {
	/**
	 * Instantiates a new <CODE>GrammarEnvironment</CODE> with the given
	 * <CODE>GrammarInputPane</CODE>.
	 * 
	 * @param input
	 *            the <CODE>GrammarInputPane</CODE>
	 */
	public GrammarEnvironment(GrammarInputPane input) {
		super(null);
		this.input = input;
		input.getTable().getModel().addTableModelListener(
				new TableModelListener() {
					public void tableChanged(TableModelEvent event) {
						setDirty();
					}
				});
	}

	/**
	 * Returns the grammar of this <CODE>GrammarEnvironment</CODE>, which is
	 * retrieved from the <CODE>GrammarInputPane</CODE>'s <CODE>.getGrammar</CODE>
	 * method.
	 * 
	 * @see gui.grammar.GrammarInputPane#getGrammar
	 * @return the <CODE>Grammar</CODE> for this environment
	 */
	public Serializable getObject() {
		return getGrammar(UnboundGrammar.class);
	}

	/**
	 * Returns the context free grammar.
	 * 
	 * @see gui.grammar.GrammarInputPane#getGrammar()
	 * @return the <CODE>ContextFreeGrammar</CODE> for this environment
	 */
	public Grammar getGrammar() {
		return input.getGrammar();
	}

	/**
	 * Returns the grammar of the specified type.
	 * 
	 * @param grammarClass
	 *            specification of the type of grammar which should be returned
	 * @see gui.grammar.GrammarInputPane#getGrammar(Class)
	 * @return the <CODE>Grammar</CODE> for this environment of the specified
	 *         type
	 */
	public Grammar getGrammar(Class grammarClass) {
		return input.getGrammar(grammarClass);
	}

	/** The grammar input pane. */
	private GrammarInputPane input = null;
}