SelfAccess.java #2

/*
 * SelfAccess.java 1.0
 *
 * Jun 20, 1997 by micn
 * Sep 29, 1997 by bv
 * Oct 10, 1997 by mich
 *
 * @see openjava.ptree.ParseTree
 * @version 1.0 last updated:  Oct 10, 1997
 * @author  Michiaki Tatsubori
 */
package openjava.ptree;


import openjava.ptree.util.*;
import openjava.mop.*;
import java.io.OutputStream;



/**
 * The class <code>SelfAccess</code> represents an access to
 * <pre>this</pre> object.
 * this or super
 *
 */
public class SelfAccess extends Leaf
    implements Expression
{
    public static final int THIS = 0;
    public static final int SUPER = 1;

    private static SelfAccess _constantSuper = null;
    private static SelfAccess _constantThis = null;

    protected String qualifier = null;

    int id = -1;

    SelfAccess() {
	this( null );
    }

    SelfAccess( String q ) {
	super( ((q == null) ? "" : q + ".") + "this" );
	this.qualifier = q;
	this.id = THIS;
    }

    SelfAccess( int id ) {
	super( id == SUPER ? "super" : "this" );
	this.id = id;
    }

    public String getQualifier() {
	return this.qualifier;
    }

    public int getAccessType() {
	return id;
    }

    public boolean isSuperAccess() {
	return (id == SUPER);
    }

    public static SelfAccess makeSuper() {
	return constantSuper();
    }

    public static SelfAccess makeThis() {
	return constantThis();
    }

    public static SelfAccess makeThis( String  qualifier ) {
	if (qualifier == null || qualifier.equals( "" )) {
	    return constantThis();
	}
	return new SelfAccess( qualifier );
    }

    public static SelfAccess constantSuper() {
	if (_constantSuper == null) {
	    _constantSuper = new SelfAccess( SUPER );
	}
	return _constantSuper;
    }

    public static SelfAccess constantThis() {
	if (_constantThis == null) {
	    _constantThis = new SelfAccess();
	}
	return _constantThis;
    }

    public void accept(ParseTreeVisitor v) throws ParseTreeException {
        v.visit(this);
    }

    public OJClass getType(Environment env) throws Exception
    {
	OJClass current = env.lookupClass(env.currentClassName());
	if (isSuperAccess())  return current.getSuperclass();
	String qualifier = getQualifier();
	if (qualifier == null)	return current;
        return env.lookupClass(env.toQualifiedName(qualifier));
    }

}