/**
* Copyright (C) 2009-2010 Wilfred Springer
*
* This file is part of Preon.
*
* Preon is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation; either version 2, or (at your option) any later version.
*
* Preon 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 for more details.
*
* You should have received a copy of the GNU General Public License along with
* Preon; see the file COPYING. If not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Linking this library statically or dynamically with other modules is making a
* combined work based on this library. Thus, the terms and conditions of the
* GNU General Public License cover the whole combination.
*
* As a special exception, the copyright holders of this library give you
* permission to link this library with independent modules to produce an
* executable, regardless of the license terms of these independent modules, and
* to copy and distribute the resulting executable under terms of your choice,
* provided that you also meet, for each linked independent module, the terms
* and conditions of the license of that module. An independent module is a
* module which is not derived from or based on this library. If you modify this
* library, you may extend this exception to your version of the library, but
* you are not obligated to do so. If you do not wish to do so, delete this
* exception statement from your version.
*/
package org.codehaus.preon.codec;
import org.codehaus.preon.el.BindingException;
import org.codehaus.preon.el.Expression;
import org.codehaus.preon.el.Expressions;
import org.codehaus.preon.el.InvalidExpressionException;
import org.codehaus.preon.*;
import org.codehaus.preon.annotation.Bound;
import org.codehaus.preon.annotation.BoundList;
import org.codehaus.preon.annotation.BoundObject;
import org.codehaus.preon.annotation.Choices;
import org.codehaus.preon.util.AnnotationWrapper;
import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.util.List;
/**
* A {@link CodecFactory} that will be triggered by {@link Bound} or {@link BoundList} annotations on arrays. Note that
* {@link Codec}s created by this class will always read all data eagerly. (Unlike {@link List}s, you cannot implement
* arrays yourself.)
*
* @author Wilfred Springer (wis)
*/
public class ArrayCodecFactory implements CodecFactory {
/**
* The {@link CodecFactory} that will be used for constructing the {@link Codecs} to construct elements in the
* List.
*/
private CodecFactory factory;
/**
* Constructs a new instance, accepting the {@link CodecFactory} creating the {@link Codec Codecs} that will
* reconstruct elements in the List.
*
* @param delegate The {@link CodecFactory} creating the {@link Codec Codecs} that will reconstruct elements in the
* List.
*/
public ArrayCodecFactory(CodecFactory delegate) {
this.factory = delegate;
}
/*
* (non-Javadoc)
*
* @see
* org.codehaus.preon.CodecFactory#create(java.lang.reflect.AnnotatedElement,
* java.lang.Class, org.codehaus.preon.ResolverContext)
*/
@SuppressWarnings("unchecked")
public <T> Codec<T> create(AnnotatedElement metadata, Class<T> type,
ResolverContext context) {
BoundList settings = null;
if (metadata != null
&& (settings = metadata.getAnnotation(BoundList.class)) != null
&& type.isArray()
&& settings.size() != null
&& settings.size().length() != 0) {
Expression<Integer, Resolver> expr = getSizeExpression(settings,
context);
Codec<Object> elementCodec = null;
if (type.getComponentType().isPrimitive()) {
elementCodec = (Codec<Object>) factory.create(null, type
.getComponentType(), context);
} else {
BoundObject objectSettings = getObjectSettings(settings);
elementCodec = (Codec<Object>) factory.create(
new AnnotationWrapper(objectSettings), type
.getComponentType(), context);
}
return (Codec<T>) new ArrayCodec(expr, elementCodec, type);
} else {
return null;
}
}
private BoundObject getObjectSettings(final BoundList settings) {
return new BoundObject() {
public Class<?> type() {
return settings.type();
}
public Class<?>[] types() {
return settings.types();
}
public Class<? extends Annotation> annotationType() {
return BoundObject.class;
}
public boolean ommitTypePrefix() {
return settings.ommitTypePrefix();
}
public Choices selectFrom() {
return settings.selectFrom();
}
};
}
/**
* Returns the {@link Expression} that will be evaluated to the array's size.
*
* @param listSettings The annotation, holding the expression.
* @return An {@link Expression} instance, representing the expression.
*/
private Expression<Integer, Resolver> getSizeExpression(
BoundList listSettings, ResolverContext context)
throws CodecConstructionException {
try {
return Expressions.createInteger(context, listSettings.size());
} catch (InvalidExpressionException ece) {
throw new CodecConstructionException(ece);
} catch (BindingException be) {
throw new CodecConstructionException(be);
}
}
}