/*
* Copyright (c) 2006, 2016, 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 netscape.javascript;
import jdk.internal.netscape.javascript.spi.JSObjectProvider;
import java.applet.Applet;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Iterator;
import java.util.ServiceLoader;
/**
* <p>
* Allows Java code to manipulate JavaScript objects.
* </p>
*
* <p>
* When a JavaScript object is passed or returned to Java code, it
* is wrapped in an instance of {@code JSObject}. When a
* {@code JSObject} instance is passed to the JavaScript engine,
* it is unwrapped back to its original JavaScript object. The
* {@code JSObject} class provides a way to invoke JavaScript
* methods and examine JavaScript properties.
* </p>
*
* <p> Any data returned from the JavaScript engine to Java is
* converted to Java data types. Certain data passed to the JavaScript
* engine is converted to JavaScript data types.
* </p>
*
*/
@SuppressWarnings("deprecation")
public abstract class JSObject {
/**
* Constructs a new JSObject. Users should neither call this method nor
* subclass JSObject.
*/
protected JSObject() {
}
/**
* Calls a JavaScript method. Equivalent to
* "this.methodName(args[0], args[1], ...)" in JavaScript.
*
* @param methodName The name of the JavaScript method to be invoked.
* @param args the Java objects passed as arguments to the method.
* @return Result of the method.
* @throws JSException when an error is reported from the browser or
* JavaScript engine.
*/
public abstract Object call(String methodName, Object... args) throws JSException;
/**
* Evaluates a JavaScript expression. The expression is a string of
* JavaScript source code which will be evaluated in the context given by
* "this".
*
* @param s The JavaScript expression.
* @return Result of the JavaScript evaluation.
* @throws JSException when an error is reported from the browser or
* JavaScript engine.
*/
public abstract Object eval(String s) throws JSException;
/**
* Retrieves a named member of a JavaScript object. Equivalent to
* "this.name" in JavaScript.
*
* @param name The name of the JavaScript property to be accessed.
* @return The value of the propery.
* @throws JSException when an error is reported from the browser or
* JavaScript engine.
*/
public abstract Object getMember(String name) throws JSException;
/**
* Sets a named member of a JavaScript object. Equivalent to
* "this.name = value" in JavaScript.
*
* @param name The name of the JavaScript property to be accessed.
* @param value The value of the propery.
* @throws JSException when an error is reported from the browser or
* JavaScript engine.
*/
public abstract void setMember(String name, Object value) throws JSException;
/**
* Removes a named member of a JavaScript object. Equivalent
* to "delete this.name" in JavaScript.
*
* @param name The name of the JavaScript property to be removed.
* @throws JSException when an error is reported from the browser or
* JavaScript engine.
*/
public abstract void removeMember(String name) throws JSException;
/**
* Retrieves an indexed member of a JavaScript object. Equivalent to
* "this[index]" in JavaScript.
*
* @param index The index of the array to be accessed.
* @return The value of the indexed member.
* @throws JSException when an error is reported from the browser or
* JavaScript engine.
*/
public abstract Object getSlot(int index) throws JSException;
/**
* Sets an indexed member of a JavaScript object. Equivalent to
* "this[index] = value" in JavaScript.
*
* @param index The index of the array to be accessed.
* @param value The value to set
* @throws JSException when an error is reported from the browser or
* JavaScript engine.
*/
public abstract void setSlot(int index, Object value) throws JSException;
/**
* Returns a JSObject for the window containing the given applet. This
* method only works when the Java code is running in a browser as an
* applet. The object returned may be used to access the HTML DOM directly.
*
* @param applet The applet.
* @return JSObject representing the window containing the given applet or
* {@code null} if we are not connected to a browser.
* @throws JSException when an error is reported from the browser or
* JavaScript engine or if applet is {@code null}
*
* @deprecated The Applet API is deprecated. See the
* <a href="../../../../../../api/java/applet/package-summary.html">
* java.applet package documentation</a> for further information.
*/
@Deprecated(since = "9")
@SuppressWarnings("exports")
public static JSObject getWindow(Applet applet) throws JSException {
return ProviderLoader.callGetWindow(applet);
}
private static class ProviderLoader {
private static final JSObjectProvider provider;
static {
provider = AccessController.doPrivileged(
new PrivilegedAction<>() {
@Override
public JSObjectProvider run() {
Iterator<JSObjectProvider> providers =
ServiceLoader.loadInstalled(JSObjectProvider.class).iterator();
if (providers.hasNext()) {
return providers.next();
}
return null;
}
}
);
}
private static JSObject callGetWindow(Applet applet) {
if (provider != null) {
return provider.getWindow(applet);
}
return null;
}
}
}