src/jdk/nashorn/internal/runtime/JSONListAdapter.java

/*
 * Copyright (c) 2015, 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 jdk.nashorn.internal.runtime;

import java.util.Collection;
import java.util.List;
import java.util.Set;
import jdk.nashorn.api.scripting.AbstractJSObject;
import jdk.nashorn.api.scripting.JSObject;
import jdk.nashorn.api.scripting.ScriptObjectMirror;
import jdk.nashorn.internal.objects.Global;

/**
 * A {@link ListAdapter} that also implements {@link JSObject}. Named {@code JSONListAdapter} as it is used as a
 * {@code JSObject} implementing the {@link List} interface, which is the expected interface to be implemented by
 * JSON-parsed arrays when they are handled in Java. We aren't implementing {@link JSObject} on {@link ListAdapter}
 * directly since that'd have implications for other uses of list adapter (e.g. interferences of JSObject default
 * value calculation vs. List's {@code toString()} etc.)
 */
public final class JSONListAdapter extends ListAdapter implements JSObject {
    /**
     * Creates a new JSON list adapter.
     * @param obj the underlying object being exposed as a list.
     * @param global the home global of the underlying object.
     */
    public JSONListAdapter(final JSObject obj, final Global global) {
        super(obj, global);
    }

    /**
     * Unwraps this adapter into its underlying non-JSObject representative.
     * @param homeGlobal the home global for unwrapping
     * @return either the unwrapped object or this if it should not be unwrapped in the specified global.
     */
    public Object unwrap(final Object homeGlobal) {
        final Object unwrapped = ScriptObjectMirror.unwrap(obj, homeGlobal);
        return unwrapped != obj ? unwrapped : this;
    }

    @Override
    public Object call(final Object thiz, final Object... args) {
        return obj.call(thiz, args);
    }

    @Override
    public Object newObject(final Object... args) {
        return obj.newObject(args);
    }

    @Override
    public Object eval(final String s) {
        return obj.eval(s);
    }

    @Override
    public Object getMember(final String name) {
        return obj.getMember(name);
    }

    @Override
    public Object getSlot(final int index) {
        return obj.getSlot(index);
    }

    @Override
    public boolean hasMember(final String name) {
        return obj.hasMember(name);
    }

    @Override
    public boolean hasSlot(final int slot) {
        return obj.hasSlot(slot);
    }

    @Override
    public void removeMember(final String name) {
        obj.removeMember(name);
    }

    @Override
    public void setMember(final String name, final Object value) {
        obj.setMember(name, value);
    }

    @Override
    public void setSlot(final int index, final Object value) {
        obj.setSlot(index, value);
    }

    @Override
    public Set<String> keySet() {
        return obj.keySet();
    }

    @Override
    public Collection<Object> values() {
        return obj.values();
    }

    @Override
    public boolean isInstance(final Object instance) {
        return obj.isInstance(instance);
    }

    @Override
    public boolean isInstanceOf(final Object clazz) {
        return obj.isInstanceOf(clazz);
    }

    @Override
    public String getClassName() {
        return obj.getClassName();
    }

    @Override
    public boolean isFunction() {
        return obj.isFunction();
    }

    @Override
    public boolean isStrictFunction() {
        return obj.isStrictFunction();
    }

    @Override
    public boolean isArray() {
        return obj.isArray();
    }

    @Override @Deprecated
    public double toNumber() {
        return obj.toNumber();
    }

    /**
     * Implements this object's {@code [[DefaultValue]]} method by returning its wrapped object's {@code [[DefaultValue]]}.
     *
     * @param hint the type hint. Should be either {@code null}, {@code Number.class} or {@code String.class}.
     * @return the wrapped object's default value.
     * @throws UnsupportedOperationException if the conversion can't be performed. The engine will convert this
     * exception into a JavaScript {@code TypeError}.
     */
    public Object getDefaultValue(final Class<?> hint) {
        return AbstractJSObject.getDefaultValue(obj, hint);
    }
}