// Copyright 2009, 2010, 2011 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
//
// 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 org.apache.tapestry5.ioc.internal.services;
import java.lang.reflect.Method;
import java.util.Map;
import org.apache.tapestry5.ioc.ObjectCreator;
import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
import org.apache.tapestry5.ioc.internal.util.InternalUtils;
import org.apache.tapestry5.ioc.services.Builtin;
import org.apache.tapestry5.ioc.services.PlasticProxyFactory;
import org.apache.tapestry5.ioc.services.ThunkCreator;
import org.apache.tapestry5.plastic.ClassInstantiator;
import org.apache.tapestry5.plastic.InstructionBuilder;
import org.apache.tapestry5.plastic.InstructionBuilderCallback;
import org.apache.tapestry5.plastic.PlasticClass;
import org.apache.tapestry5.plastic.PlasticClassTransformer;
import org.apache.tapestry5.plastic.PlasticField;
import org.apache.tapestry5.plastic.PlasticMethod;
import org.apache.tapestry5.plastic.PlasticUtils;
@SuppressWarnings("all")
public class ThunkCreatorImpl implements ThunkCreator
{
private final Map<Class, ClassInstantiator> interfaceToInstantiator = CollectionFactory.newConcurrentMap();
private final PlasticProxyFactory proxyFactory;
private static final Method CREATE_OBJECT = PlasticUtils.getMethod(ObjectCreator.class, "createObject");
public ThunkCreatorImpl(@Builtin
PlasticProxyFactory proxyFactory)
{
this.proxyFactory = proxyFactory;
}
@Override
public <T> T createThunk(Class<T> proxyType, ObjectCreator objectCreator, String description)
{
assert proxyType != null;
assert objectCreator != null;
assert InternalUtils.isNonBlank(description);
if (!proxyType.isInterface())
throw new IllegalArgumentException(String.format(
"Thunks may only be created for interfaces; %s is a class.",
PlasticUtils.toTypeName(proxyType)));
return getInstantiator(proxyType).with(ObjectCreator.class, objectCreator).with(String.class, description)
.newInstance();
}
private <T> ClassInstantiator<T> getInstantiator(Class<T> interfaceType)
{
ClassInstantiator<T> result = interfaceToInstantiator.get(interfaceType);
if (result == null)
{
result = createInstantiator(interfaceType);
interfaceToInstantiator.put(interfaceType, result);
}
return result;
}
private <T> ClassInstantiator<T> createInstantiator(final Class<T> interfaceType)
{
return proxyFactory.createProxy(interfaceType, new PlasticClassTransformer()
{
@Override
public void transform(PlasticClass plasticClass)
{
final PlasticField objectCreatorField = plasticClass.introduceField(ObjectCreator.class, "creator")
.injectFromInstanceContext();
PlasticMethod delegateMethod = plasticClass.introducePrivateMethod(interfaceType.getName(), "delegate",
null, null);
delegateMethod.changeImplementation(new InstructionBuilderCallback()
{
@Override
public void doBuild(InstructionBuilder builder)
{
builder.loadThis().getField(objectCreatorField);
builder.invoke(CREATE_OBJECT);
builder.checkcast(interfaceType).returnResult();
}
});
for (Method method : interfaceType.getMethods())
{
plasticClass.introduceMethod(method).delegateTo(delegateMethod);
}
if (!plasticClass.isMethodImplemented(PlasticUtils.TO_STRING_DESCRIPTION))
{
final PlasticField descriptionField = plasticClass.introduceField(String.class, "description")
.injectFromInstanceContext();
plasticClass.introduceMethod(PlasticUtils.TO_STRING_DESCRIPTION, new InstructionBuilderCallback()
{
@Override
public void doBuild(InstructionBuilder builder)
{
builder.loadThis().getField(descriptionField).returnResult();
}
});
}
}
});
}
}