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    
015    package org.apache.tapestry5.internal.services;
016    
017    import java.lang.annotation.Annotation;
018    
019    import org.apache.tapestry5.internal.InternalPropertyConduit;
020    import org.apache.tapestry5.ioc.AnnotationProvider;
021    import org.apache.tapestry5.ioc.services.TypeCoercer;
022    
023    /**
024     * A PropertyConduit for a literal value in an expression, such as a number, or "true", "false" or "null".
025     */
026    public class LiteralPropertyConduit extends PropertyConduitDelegate implements InternalPropertyConduit
027    {
028        private final Class propertyType;
029    
030        private final AnnotationProvider annotationProvider;
031    
032        private final String description;
033    
034        private final Object value;
035    
036        public LiteralPropertyConduit(TypeCoercer typeCoercer, Class propertyType, AnnotationProvider annotationProvider,
037                String description, Object value)
038        {
039            super(typeCoercer);
040    
041            this.propertyType = propertyType;
042            this.annotationProvider = annotationProvider;
043            this.description = description;
044    
045            this.value = value;
046        }
047    
048        public Object get(Object instance)
049        {
050            return value;
051        }
052    
053        public void set(Object instance, Object value)
054        {
055            throw new RuntimeException(ServicesMessages.literalConduitNotUpdateable());
056        }
057    
058        public Class getPropertyType()
059        {
060            return propertyType;
061        }
062    
063        public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
064        {
065            return annotationProvider.getAnnotation(annotationClass);
066        }
067    
068        public String getPropertyName()
069        {
070            return null;
071        }
072    
073        @Override
074        public String toString()
075        {
076            return description;
077        }
078    
079    }