001// Copyright 2008, 2011 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007// http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.internal.services;
016
017import java.lang.annotation.Annotation;
018import java.lang.reflect.Type;
019
020import org.apache.tapestry5.internal.InternalPropertyConduit;
021import org.apache.tapestry5.ioc.AnnotationProvider;
022import org.apache.tapestry5.ioc.services.TypeCoercer;
023
024/**
025 * A PropertyConduit for a literal value in an expression, such as a number, or "true", "false" or "null".
026 */
027public class LiteralPropertyConduit extends PropertyConduitDelegate implements InternalPropertyConduit
028{
029    private final Class propertyType;
030
031    private final AnnotationProvider annotationProvider;
032
033    private final String description;
034
035    private final Object value;
036
037    public LiteralPropertyConduit(TypeCoercer typeCoercer, Class propertyType, AnnotationProvider annotationProvider,
038            String description, Object value)
039    {
040        super(typeCoercer);
041
042        this.propertyType = propertyType;
043        this.annotationProvider = annotationProvider;
044        this.description = description;
045
046        this.value = value;
047    }
048
049    public Object get(Object instance)
050    {
051        return value;
052    }
053
054    public void set(Object instance, Object value)
055    {
056        throw new RuntimeException("Literal values are not updateable.");
057    }
058
059    public Class getPropertyType()
060    {
061        return propertyType;
062    }
063    
064    public Type getPropertyGenericType()
065    {
066        return propertyType;
067    }
068
069    public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
070    {
071        return annotationProvider.getAnnotation(annotationClass);
072    }
073
074    public String getPropertyName()
075    {
076        return null;
077    }
078
079    @Override
080    public String toString()
081    {
082        return description;
083    }
084
085}