org.mozilla.javascript.InterfaceAdapter Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of js Show documentation
Show all versions of js Show documentation
Rhino is an open-source implementation of JavaScript written entirely in Java. It is typically embedded into Java applications to provide scripting to end users.
/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Rhino code, released
* May 6, 1999.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1997-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Igor Bukanov
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 or later (the "GPL"), in which
* case the provisions of the GPL are applicable instead of those above. If
* you wish to allow use of your version of this file only under the terms of
* the GPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replacing
* them with the notice and other provisions required by the GPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* ***** END LICENSE BLOCK ***** */
package org.mozilla.javascript;
import java.lang.reflect.Method;
/**
* Adapter to use JS function as implementation of Java interfaces with
* single method or multiple methods with the same signature.
*/
public class InterfaceAdapter
{
private final Object proxyHelper;
/**
* Make glue object implementing interface cl that will
* call the supplied JS function when called.
* Only interfaces were all methods have the same signature is supported.
*
* @return The glue object or null if cl is not interface or
* has methods with different signatures.
*/
static Object create(Context cx, Class cl, Callable function)
{
if (!cl.isInterface()) throw new IllegalArgumentException();
Scriptable topScope = ScriptRuntime.getTopCallScope(cx);
ClassCache cache = ClassCache.get(topScope);
InterfaceAdapter adapter;
adapter = (InterfaceAdapter)cache.getInterfaceAdapter(cl);
ContextFactory cf = cx.getFactory();
if (adapter == null) {
Method[] methods = cl.getMethods();
if (methods.length == 0) {
throw Context.reportRuntimeError2(
"msg.no.empty.interface.conversion",
String.valueOf(function),
cl.getClass().getName());
}
boolean canCallFunction = false;
canCallFunctionChecks: {
Class[] argTypes = methods[0].getParameterTypes();
// check that the rest of methods has the same signature
for (int i = 1; i != methods.length; ++i) {
Class[] types2 = methods[i].getParameterTypes();
if (types2.length != argTypes.length) {
break canCallFunctionChecks;
}
for (int j = 0; j != argTypes.length; ++j) {
if (types2[j] != argTypes[j]) {
break canCallFunctionChecks;
}
}
}
canCallFunction= true;
}
if (!canCallFunction) {
throw Context.reportRuntimeError2(
"msg.no.function.interface.conversion",
String.valueOf(function),
cl.getClass().getName());
}
adapter = new InterfaceAdapter(cf, cl);
cache.cacheInterfaceAdapter(cl, adapter);
}
return VMBridge.instance.newInterfaceProxy(
adapter.proxyHelper, cf, adapter, function, topScope);
}
private InterfaceAdapter(ContextFactory cf, Class cl)
{
this.proxyHelper
= VMBridge.instance.getInterfaceProxyHelper(
cf, new Class[] { cl });
}
public Object invoke(ContextFactory cf,
final Object target,
final Scriptable topScope,
final Method method,
final Object[] args)
{
ContextAction action = new ContextAction() {
public Object run(Context cx)
{
return invokeImpl(cx, target, topScope, method, args);
}
};
return cf.call(action);
}
Object invokeImpl(Context cx,
Object target,
Scriptable topScope,
Method method,
Object[] args)
{
int N = (args == null) ? 0 : args.length;
Callable function = (Callable)target;
Scriptable thisObj = topScope;
Object[] jsargs = new Object[N + 1];
jsargs[N] = method.getName();
if (N != 0) {
WrapFactory wf = cx.getWrapFactory();
for (int i = 0; i != N; ++i) {
jsargs[i] = wf.wrap(cx, topScope, args[i], null);
}
}
Object result = function.call(cx, topScope, thisObj, jsargs);
Class javaResultType = method.getReturnType();
if (javaResultType == Void.TYPE) {
result = null;
} else {
result = Context.jsToJava(result, javaResultType);
}
return result;
}
}