Mercurial > jdk8-mips64-public > nashorn / file revision

 /*

  * Copyright (c) 2010, 2013, 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.api.scripting;

 import java.util.Collection;

 import java.util.Collections;

 import java.util.Set;

 import jdk.nashorn.internal.runtime.JSONListAdapter;

 import jdk.nashorn.internal.runtime.JSType;

 /**

  * This is the base class for nashorn ScriptObjectMirror class.

  *

  * This class can also be subclassed by an arbitrary Java class. Nashorn will

  * treat objects of such classes just like nashorn script objects. Usual nashorn

  * operations like obj[i], obj.foo, obj.func(), delete obj.foo will be glued

  * to appropriate method call of this class.

  *

  * @since 1.8u40

  */

 @jdk.Exported

 public abstract class AbstractJSObject implements JSObject {

     /**

      * Call this object as a JavaScript function. This is equivalent to

      * 'func.apply(thiz, args)' in JavaScript.

      *

      * @param thiz 'this' object to be passed to the function

      * @param args arguments to method

      * @return result of call

      */

     @Override

     public Object call(final Object thiz, final Object... args) {

         throw new UnsupportedOperationException("call");

     }

     /**

      * Call this 'constructor' JavaScript function to create a new object.

      * This is equivalent to 'new func(arg1, arg2...)' in JavaScript.

      *

      * @param args arguments to method

      * @return result of constructor call

      */

     @Override

     public Object newObject(final Object... args) {

         throw new UnsupportedOperationException("newObject");

     }

     /**

      * Evaluate a JavaScript expression.

      *

      * @param s JavaScript expression to evaluate

      * @return evaluation result

      */

     @Override

     public Object eval(final String s) {

         throw new UnsupportedOperationException("eval");

     }

     /**

      * Retrieves a named member of this JavaScript object.

      *

      * @param name of member

      * @return member

      */

     @Override

     public Object getMember(final String name) {

         return null;

     }

     /**

      * Retrieves an indexed member of this JavaScript object.

      *

      * @param index index slot to retrieve

      * @return member

      */

     @Override

     public Object getSlot(final int index) {

         return null;

     }

     /**

      * Does this object have a named member?

      *

      * @param name name of member

      * @return true if this object has a member of the given name

      */

     @Override

     public boolean hasMember(final String name) {

         return false;

     }

     /**

      * Does this object have a indexed property?

      *

      * @param slot index to check

      * @return true if this object has a slot

      */

     @Override

     public boolean hasSlot(final int slot) {

         return false;

     }

     /**

      * Remove a named member from this JavaScript object

      *

      * @param name name of the member

      */

     @Override

     public void removeMember(final String name) {

         //empty

     }

     /**

      * Set a named member in this JavaScript object

      *

      * @param name  name of the member

      * @param value value of the member

      */

     @Override

     public void setMember(final String name, final Object value) {

         //empty

     }

     /**

      * Set an indexed member in this JavaScript object

      *

      * @param index index of the member slot

      * @param value value of the member

      */

     @Override

     public void setSlot(final int index, final Object value) {

         //empty

     }

     // property and value iteration

     /**

      * Returns the set of all property names of this object.

      *

      * @return set of property names

      */

     @Override

     public Set<String> keySet() {

         return Collections.emptySet();

     }

     /**

      * Returns the set of all property values of this object.

      *

      * @return set of property values.

      */

     @Override

     public Collection<Object> values() {

         return Collections.emptySet();

     }

     // JavaScript instanceof check

     /**

      * Checking whether the given object is an instance of 'this' object.

      *

      * @param instance instace to check

      * @return true if the given 'instance' is an instance of this 'function' object

      */

     @Override

     public boolean isInstance(final Object instance) {

         return false;

     }

     /**

      * Checking whether this object is an instance of the given 'clazz' object.

      *

      * @param clazz clazz to check

      * @return true if this object is an instance of the given 'clazz'

      */

     @Override

     public boolean isInstanceOf(final Object clazz) {

         if (clazz instanceof JSObject) {

             return ((JSObject)clazz).isInstance(this);

         }

         return false;

     }

     /**

      * ECMA [[Class]] property

      *

      * @return ECMA [[Class]] property value of this object

      */

     @Override

     public String getClassName() {

         return getClass().getName();

     }

     /**

      * Is this a function object?

      *

      * @return if this mirror wraps a ECMAScript function instance

      */

     @Override

     public boolean isFunction() {

         return false;

     }

     /**

      * Is this a 'use strict' function object?

      *

      * @return true if this mirror represents a ECMAScript 'use strict' function

      */

     @Override

     public boolean isStrictFunction() {

         return false;

     }

     /**

      * Is this an array object?

      *

      * @return if this mirror wraps a ECMAScript array object

      */

     @Override

     public boolean isArray() {

         return false;

     }

     /**

      * Returns this object's numeric value.

      *

      * @return this object's numeric value.

      * @deprecated use {@link #getDefaultValue(Class)} with {@link Number} hint instead.

      */

     @Override @Deprecated

     public double toNumber() {

         return JSType.toNumber(JSType.toPrimitive(this, Number.class));

     }

     /**

      * Implements this object's {@code [[DefaultValue]]} method. The default implementation follows ECMAScript 5.1

      * section 8.6.2 but subclasses are free to provide their own implementations.

      *

      * @param hint the type hint. Should be either {@code null}, {@code Number.class} or {@code String.class}.

      * @return this 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 DefaultValueImpl.getDefaultValue(this, hint);

     }

     /**

      * When passed an {@link AbstractJSObject}, invokes its {@link #getDefaultValue(Class)} method. When passed any

      * other {@link JSObject}, it will obtain its {@code [[DefaultValue]]} method as per ECMAScript 5.1 section

      * 8.6.2.

      *

      * @param jsobj the {@link JSObject} whose {@code [[DefaultValue]]} is obtained.

      * @param hint the type hint. Should be either {@code null}, {@code Number.class} or {@code String.class}.

      * @return this 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 static Object getDefaultValue(final JSObject jsobj, final Class<?> hint) {

         if (jsobj instanceof AbstractJSObject) {

             return ((AbstractJSObject)jsobj).getDefaultValue(hint);

         } else if (jsobj instanceof JSONListAdapter) {

             return ((JSONListAdapter)jsobj).getDefaultValue(hint);

         }

         return DefaultValueImpl.getDefaultValue(jsobj, hint);

     }

 }