| /* |
| * Copyright 2011 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.requestfactory.apt; |
| |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import javax.lang.model.element.ElementKind; |
| import javax.lang.model.element.TypeElement; |
| import javax.lang.model.type.DeclaredType; |
| import javax.lang.model.type.PrimitiveType; |
| import javax.lang.model.type.TypeMirror; |
| import javax.lang.model.type.TypeVariable; |
| import javax.lang.model.type.WildcardType; |
| |
| /** |
| * Scans a TypeMirror to determine if it can be transported by RequestFactory. |
| */ |
| class TransportableTypeVisitor extends TypeVisitorBase<Boolean> { |
| |
| /** |
| * AutoBeans supports arbitrary parameterizations, but there's work that needs |
| * to be done on the Request serialization code to support arbitrarily-complex |
| * parameterizations. For the moment, we'll disallow anything other than a |
| * one-level parameterization. |
| */ |
| private boolean allowNestedParameterization = true; |
| |
| @Override |
| public Boolean visitDeclared(DeclaredType t, State state) { |
| if (t.asElement().getKind().equals(ElementKind.ENUM)) { |
| return true; |
| } |
| if (state.types.isAssignable(t, state.entityProxyType) |
| || state.types.isAssignable(t, state.valueProxyType)) { |
| TypeElement proxyElement = (TypeElement) t.asElement(); |
| state.maybeScanProxy(proxyElement); |
| state.requireMapping(proxyElement); |
| return true; |
| } |
| if (state.types.isAssignable(t, state.entityProxyIdType)) { |
| DeclaredType asId = (DeclaredType) State.viewAs(state.entityProxyIdType, t, state); |
| if (asId.getTypeArguments().isEmpty()) { |
| return false; |
| } |
| return asId.getTypeArguments().get(0).accept(this, state); |
| } |
| for (DeclaredType valueType : getValueTypes(state)) { |
| if (state.types.isAssignable(t, valueType)) { |
| return true; |
| } |
| } |
| if (state.types.isAssignable(t, state.findType(List.class)) |
| || state.types.isAssignable(t, state.findType(Set.class))) { |
| if (!allowNestedParameterization) { |
| return false; |
| } |
| allowNestedParameterization = false; |
| DeclaredType asCollection = |
| (DeclaredType) State.viewAs(state.findType(Collection.class), t, state); |
| if (asCollection.getTypeArguments().isEmpty()) { |
| return false; |
| } |
| return t.getTypeArguments().get(0).accept(this, state); |
| } |
| final DeclaredType mapType = state.findType(Map.class); |
| if (state.types.isAssignable(t, mapType)) { |
| if (!allowNestedParameterization) { |
| return false; |
| } |
| allowNestedParameterization = false; |
| DeclaredType asMap = |
| (DeclaredType) State.viewAs(mapType, t, state); |
| if (asMap.getTypeArguments().isEmpty()) { |
| return false; |
| } |
| return t.getTypeArguments().get(0).accept(this, state) |
| && t.getTypeArguments().get(1).accept(this, state); |
| } |
| return false; |
| } |
| |
| @Override |
| public Boolean visitPrimitive(PrimitiveType x, State state) { |
| return true; |
| } |
| |
| @Override |
| public Boolean visitTypeVariable(TypeVariable t, State state) { |
| if (t.equals(t.getUpperBound())) { |
| /* |
| * Weird case seen in Eclipse with self-parameterized type variables such |
| * as <T extends Enum<T>>. |
| * |
| * TODO(bobv): Should intersection types be allowed at all? They don't |
| * seem to make much sense in the most-derived interface types, since the |
| * RF Generator won't know how to implement them. |
| */ |
| return state.types.erasure(t).accept(this, state); |
| } |
| // Allow <T extends FooProxy> |
| return t.getUpperBound().accept(this, state); |
| } |
| |
| @Override |
| public Boolean visitWildcard(WildcardType t, State state) { |
| // Allow List<? extends FooProxy> |
| return state.types.erasure(t).accept(this, state); |
| } |
| |
| @Override |
| protected Boolean defaultAction(TypeMirror arg0, State arg1) { |
| return false; |
| } |
| |
| } |