/*
 * Copyright 2009-2010 Yuichiro Moriguchi
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.morilib.lisp.swing;

import net.morilib.lisp.Cons;
import net.morilib.lisp.ConsIterator;
import net.morilib.lisp.Datum;
import net.morilib.lisp.Environment;
import net.morilib.lisp.LispMessage;
import net.morilib.lisp.Subr;
import net.morilib.lisp.Undef;

/**
 *
 *
 * @author MORIGUCHI, Yuichiro 2011/03/20
 */
public class LayoutFlow extends Subr {

	/* (non-Javadoc)
	 * @see net.morilib.lisp.Subr#eval(net.morilib.lisp.Datum, net.morilib.lisp.Environment, net.morilib.lisp.LispMessage)
	 */
	@Override
	public Datum eval(Datum body, Environment env, LispMessage mesg) {
		if(body instanceof Cons) {
			Cons c = (Cons)body;
			ConsIterator itr;
			LispComposite cmp;

			if(!(c.getCar() instanceof LispComposite)) {
				throw mesg.getError(
						"err.swing.require.composite", c.getCar());
			}

			cmp = (LispComposite)c.getCar();
			itr = new ConsIterator(c.getCdr());
			while(itr.hasNext()) {
				Datum d = itr.next();

				if(d instanceof LispComponent) {
					cmp.getPane().add(
							((LispComponent)d).getComponent());
				} else {
					throw mesg.getError(
							"err.swing.require.component", d);
				}
			}

			if(!itr.getTerminal().isNil()) {
				throw mesg.getError("err.list", body);
			}
			return Undef.UNDEF;
		} else {
			throw mesg.getError("err.argument", body);
		}
	}

}
