net.enilink.composition.asm.processors.BehaviourConstructorGenerator.java Source code

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Here is the source code for net.enilink.composition.asm.processors.BehaviourConstructorGenerator.java

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/*******************************************************************************
 * Copyright (c) 2010 Fraunhofer IWU and others.
 * 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
 *
 * Contributors:
 *     Fraunhofer IWU - initial API and implementation
 *******************************************************************************/
package net.enilink.composition.asm.processors;

import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.Method;
import org.objectweb.asm.tree.FieldNode;
import org.objectweb.asm.tree.MethodNode;
import net.enilink.composition.asm.BehaviourClassNode;
import net.enilink.composition.asm.BehaviourClassProcessor;
import net.enilink.composition.asm.Types;
import net.enilink.composition.asm.util.MethodNodeGenerator;

/**
 * Creates the byte code to implement the constructor of a behaviour class.
 */
public class BehaviourConstructorGenerator implements BehaviourClassProcessor, Opcodes, Types {
    @Override
    @SuppressWarnings("unchecked")
    public void process(BehaviourClassNode classNode) throws Exception {
        FieldNode beanField = new FieldNode(ACC_PRIVATE, "_$bean", OBJECT_TYPE.getDescriptor(), null, null);
        classNode.fields.add(beanField);

        MethodNode constructor = new MethodNode(ACC_PUBLIC, "<init>",
                Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { OBJECT_TYPE }), null, null);

        // call the constructor of the parent class
        MethodNodeGenerator gen = new MethodNodeGenerator(constructor);
        gen.loadThis();
        gen.invokeConstructor(classNode.getParentClass().isInterface() ? OBJECT_TYPE : classNode.getParentType(),
                new Method("<init>", "()V"));
        gen.loadThis();
        gen.loadArg(0);
        gen.putField(classNode.getType(), "_$bean", OBJECT_TYPE);
        gen.returnValue();
        gen.endMethod();

        classNode.methods.add(constructor);
        classNode.getConstructors().add(constructor);
    }

    @Override
    public boolean implementsClass(Class<?> behaviourClass) {
        return false;
    }
}