| /* |
| * Copyright 2010 Google Inc. |
| * |
| * 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 com.google.web.bindery.autobean.shared; |
| |
| import java.util.Collection; |
| import java.util.Map; |
| |
| /** |
| * Allows traversal of an AutoBean object graph. |
| */ |
| public class AutoBeanVisitor { |
| /** |
| * A PropertyContext that describes the parameterization of the Collection |
| * being visited. |
| */ |
| public interface CollectionPropertyContext extends PropertyContext { |
| /** |
| * Returns the collection's element type. |
| * |
| * @return a Class object representing the element type |
| */ |
| Class<?> getElementType(); |
| } |
| |
| /** |
| * Reserved for future expansion to avoid API breaks. |
| */ |
| public interface Context { |
| } |
| |
| /** |
| * A PropertyContext that describes the parameterization of the Map being |
| * visited. |
| */ |
| public interface MapPropertyContext extends PropertyContext { |
| /** |
| * Returns the map's key type. |
| * |
| * @return a Class object representing the key type |
| */ |
| Class<?> getKeyType(); |
| |
| /** |
| * Returns the map's value type. |
| * |
| * @return a Class object representing the value type |
| */ |
| Class<?> getValueType(); |
| } |
| |
| /** |
| * The ParameterizationVisitor provides access to more complete type |
| * information than a simple class literal can provide. |
| * <p> |
| * The order of traversal reflects the declared parameterization of the |
| * property. For example, a {@code Map<String, List<Foo>>} would be traversed |
| * via the following sequence: |
| * |
| * <pre> |
| * visitType(Map.class); |
| * visitParameter(); |
| * visitType(String.class); |
| * endVisitType(String.class); |
| * endVisitParameter(); |
| * visitParameter(); |
| * visitType(List.class); |
| * visitParameter(); |
| * visitType(Foo.class); |
| * endVisitType(Foo.class); |
| * endParameter(); |
| * endVisitType(List.class); |
| * endVisitParameter(); |
| * endVisitType(Map.class); |
| * </pre> |
| */ |
| public static class ParameterizationVisitor { |
| /** |
| * Called when finished with a type parameter. |
| */ |
| public void endVisitParameter() { |
| } |
| |
| /** |
| * Called when finished with a type. |
| * |
| * @param type a Class object |
| */ |
| public void endVisitType(Class<?> type) { |
| } |
| |
| /** |
| * Called when visiting a type parameter. |
| * |
| * @return {@code true} if the type parameter should be visited |
| */ |
| public boolean visitParameter() { |
| return true; |
| } |
| |
| /** |
| * Called when visiting a possibly parameterized type. |
| * |
| * @param type a Class object |
| * @return {@code true} if the type should be visited |
| */ |
| public boolean visitType(Class<?> type) { |
| return true; |
| } |
| } |
| |
| /** |
| * Allows properties to be reset. |
| */ |
| public interface PropertyContext { |
| /** |
| * Allows deeper inspection of the declared parameterization of the |
| * property. |
| */ |
| void accept(ParameterizationVisitor visitor); |
| |
| /** |
| * Indicates if the {@link #set} method will succeed. |
| * |
| * @return {@code true} if the property can be set |
| */ |
| boolean canSet(); |
| |
| /** |
| * Returns the expected type of the property. |
| * |
| * @return a Class object representing the property type |
| */ |
| Class<?> getType(); |
| |
| /** |
| * Sets a property value. |
| * |
| * @param value the new value |
| */ |
| void set(Object value); |
| } |
| |
| /** |
| * Called after visiting an {@link AutoBean}. |
| * |
| * @param bean an {@link AutoBean} |
| * @param ctx a Context |
| */ |
| public void endVisit(AutoBean<?> bean, Context ctx) { |
| } |
| |
| /** |
| * Called after visiting a reference property. |
| * |
| * @param propertyName the property name, as a String |
| * @param value the property value |
| * @param ctx a PropertyContext |
| */ |
| public void endVisitCollectionProperty(String propertyName, AutoBean<Collection<?>> value, |
| CollectionPropertyContext ctx) { |
| endVisitReferenceProperty(propertyName, value, ctx); |
| } |
| |
| /** |
| * Called after visiting a reference property. |
| * |
| * @param propertyName the property name, as a String |
| * @param value the property value |
| * @param ctx a PropertyContext |
| */ |
| public void endVisitMapProperty(String propertyName, AutoBean<Map<?, ?>> value, |
| MapPropertyContext ctx) { |
| endVisitReferenceProperty(propertyName, value, ctx); |
| } |
| |
| /** |
| * Called after visiting a reference property. |
| * |
| * @param propertyName the property name, as a String |
| * @param value the property value |
| * @param ctx a PropertyContext |
| */ |
| public void endVisitReferenceProperty(String propertyName, AutoBean<?> value, PropertyContext ctx) { |
| } |
| |
| /** |
| * Called after visiting a value property. |
| * |
| * @param propertyName the property name, as a String |
| * @param value the property value |
| * @param ctx a PropertyContext |
| */ |
| public void endVisitValueProperty(String propertyName, Object value, PropertyContext ctx) { |
| } |
| |
| /** |
| * Called when visiting an {@link AutoBean}. |
| * |
| * @param bean an {@link AutoBean} |
| * @param ctx a Context |
| */ |
| public boolean visit(AutoBean<?> bean, Context ctx) { |
| return true; |
| } |
| |
| /** |
| * Called every time, but {@link #visit(AutoBean, Context)} will be called for |
| * the value only the first time it is encountered. |
| * |
| * @param propertyName the property name, as a String |
| * @param value the property value |
| * @param ctx a PropertyContext |
| */ |
| public boolean visitCollectionProperty(String propertyName, AutoBean<Collection<?>> value, |
| CollectionPropertyContext ctx) { |
| return visitReferenceProperty(propertyName, value, ctx); |
| } |
| |
| /** |
| * Called every time, but {@link #visit(AutoBean, Context)} will be called for |
| * the value only the first time it is encountered. |
| * |
| * @param propertyName the property name, as a String |
| * @param value the property value |
| * @param ctx a PropertyContext |
| */ |
| public boolean visitMapProperty(String propertyName, AutoBean<Map<?, ?>> value, |
| MapPropertyContext ctx) { |
| return visitReferenceProperty(propertyName, value, ctx); |
| } |
| |
| /** |
| * Called every time, but {@link #visit(AutoBean, Context)} will be called for |
| * the value only the first time it is encountered. |
| * |
| * @param propertyName the property name, as a String |
| * @param value the property value |
| * @param ctx a PropertyContext |
| */ |
| public boolean visitReferenceProperty(String propertyName, AutoBean<?> value, PropertyContext ctx) { |
| return true; |
| } |
| |
| /** |
| * TODO: document. |
| * |
| * @param propertyName the property name, as a String |
| * @param value the property value |
| * @param ctx a PropertyContext |
| */ |
| public boolean visitValueProperty(String propertyName, Object value, PropertyContext ctx) { |
| return true; |
| } |
| } |