/*
 * Copyright (c) 2010, 2014, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.javafx.fxml.expression;

import java.util.List;

/**
 * Expression representing a variable value.
 */
public class VariableExpression extends Expression<Object> {
    private KeyPath keyPath;

    public VariableExpression(KeyPath keyPath) {
        if (keyPath == null) {
            throw new NullPointerException();
        }

        this.keyPath = keyPath;
    }

    /**
     * Returns the path to the variable associated with this expression.
     */
    public KeyPath getKeyPath() {
        return keyPath;
    }

    @Override
    public Object evaluate(Object namespace) {
        return get(namespace, keyPath);
    }

    @Override
    public void update(Object namespace, Object value) {
        set(namespace, keyPath, value);
    }

    @Override
    public boolean isDefined(Object namespace) {
        return isDefined(namespace, keyPath);
    }

    @Override
    public boolean isLValue() {
        return true;
    }

    @Override
    protected void getArguments(List<KeyPath> arguments) {
        arguments.add(keyPath);
    }

    @Override
    public String toString() {
        return keyPath.toString();
    }
}
