/*******************************************************************************
* Copyright 2011 Google Inc. All Rights Reserved.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*******************************************************************************/
package com.google.gdt.eclipse.designer.moz.jsni;
import java.lang.ref.WeakReference;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import com.google.gdt.eclipse.designer.moz.jsni.LowLevelMoz32.DispatchMethod32;
import com.google.gdt.eclipse.designer.moz.jsni.LowLevelMoz32.DispatchObject32;
import com.google.gwt.dev.shell.designtime.DispatchIdOracle;
import com.google.gwt.dev.shell.designtime.JavaDispatch;
import com.google.gwt.dev.shell.designtime.JavaDispatchImpl;
import com.google.gwt.dev.shell.designtime.JsValue;
import com.google.gwt.dev.shell.designtime.JsValueGlue;
import com.google.gwt.dev.shell.designtime.MethodAdaptor;
import com.google.gwt.dev.shell.designtime.WrappersCache;
/**
* Wraps an arbitrary Java Object as a Dispatch component. The class was
* motivated by the need to expose Java objects into JavaScript.
*
* An instance of this class with no target is used to globally access all
* static methods or fields.
*/
public class GeckoDispatchAdapter32 implements DispatchObject32/*64*/ {
final WeakReference<DispatchIdOracle> dispIdOracleRef;
final WeakReference<ClassLoader> classLoaderRef;
JavaDispatch javaDispatch;
/**
* This constructor initializes as the static dispatcher, which handles only
* static method calls and field references.
*
* @param cl this class's classLoader
*/
GeckoDispatchAdapter32(ClassLoader cl, DispatchIdOracle ora) {
this.javaDispatch = new JavaDispatchImpl(ora);
this.classLoaderRef = new WeakReference<ClassLoader>(cl);
this.dispIdOracleRef = new WeakReference<DispatchIdOracle>(ora);
}
/**
* This constructor initializes a dispatcher, around a particular instance.
*
* @param cl this class's classLoader
* @param target the object being wrapped as an IDispatch
*/
GeckoDispatchAdapter32(ClassLoader cl, DispatchIdOracle ora, Object target) {
this.javaDispatch = new JavaDispatchImpl(ora, target);
this.classLoaderRef = new WeakReference<ClassLoader>(cl);
this.dispIdOracleRef = new WeakReference<DispatchIdOracle>(ora);
}
/**
* Retrieve a field and store in the passed JsValue. This function is called
* exclusively from native code.
*
* @param name name of the field to retrieve
* @param jsValue a reference to the JsValue object to receive the value of
* the field
*/
public void getField(String member, int /*long*/jsRootedValue) {
JsValueMoz32/*64*/ jsValue = new JsValueMoz32/*64*/(jsRootedValue);
ClassLoader classLoader = classLoaderRef.get();
if (classLoader == null) {
jsValue.setUndefined();
return;
}
DispatchIdOracle dispIdOracle = dispIdOracleRef.get();
if (dispIdOracle == null) {
jsValue.setUndefined();
return;
}
int dispId = getDispId(member);
if (dispId < 0) {
// no field by that name, return undefined
jsValue.setUndefined();
return;
}
if (javaDispatch.isField(dispId)) {
Field field = javaDispatch.getField(dispId);
JsValueGlue.set(jsValue, classLoader, dispIdOracle, field.getType(),
javaDispatch.getFieldValue(dispId));
return;
} else {
MethodAdaptor method = javaDispatch.getMethod(dispId);
AccessibleObject obj = method.getUnderlyingObject();
DispatchMethod32/*64*/ dispMethod = (DispatchMethod32/*64*/)WrappersCache.getWrapperForObject(classLoader, obj);
if (dispMethod == null) {
dispMethod = new MethodDispatch32/*64*/(classLoader, dispIdOracle, method);
WrappersCache.putWrapperForObject(classLoader, obj, dispMethod);
}
jsValue.setWrappedFunction(method.toString(), dispMethod);
}
}
public Object getTarget() {
return javaDispatch.getTarget();
}
public void setField(String member, int /*long*/jsRootedValue) {
ClassLoader classLoader = classLoaderRef.get();
if (classLoader == null) {
throw new RuntimeException("Invalid class loader.");
}
JsValue jsValue = new JsValueMoz32/*64*/(jsRootedValue);
int dispId = getDispId(member);
if (dispId < 0) {
// no field by that name
// TODO: expandos?
throw new RuntimeException("No such field " + member);
}
if (javaDispatch.isMethod(dispId)) {
throw new RuntimeException("Cannot reassign method " + member);
}
Field field = javaDispatch.getField(dispId);
Object val = JsValueGlue.get(jsValue, classLoader, field.getType(),
"setField");
javaDispatch.setFieldValue(dispId, val);
}
private int getDispId(String member) {
if (Character.isDigit(member.charAt(0))) {
return Integer.valueOf(member);
} else {
DispatchIdOracle dispIdOracle = dispIdOracleRef.get();
if (dispIdOracle == null) {
throw new RuntimeException("Invalid dispatch oracle.");
}
return dispIdOracle.getDispId(member);
}
}
}