Add event basic tab. work in progress

[unical.git] / gson / com / google / gson / internal / bind / TypeAdapterRuntimeTypeWrapper.java

/*\r
 * Copyright (C) 2011 Google Inc.\r
 *\r
 * Licensed under the Apache License, Version 2.0 (the "License");\r
 * you may not use this file except in compliance with the License.\r
 * You may obtain a copy of the License at\r
 *\r
 *      http://www.apache.org/licenses/LICENSE-2.0\r
 *\r
 * Unless required by applicable law or agreed to in writing, software\r
 * distributed under the License is distributed on an "AS IS" BASIS,\r
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
 * See the License for the specific language governing permissions and\r
 * limitations under the License.\r
 */\r
package com.google.gson.internal.bind;\r
\r
import com.google.gson.Gson;\r
import com.google.gson.TypeAdapter;\r
import com.google.gson.reflect.TypeToken;\r
import com.google.gson.stream.JsonReader;\r
import com.google.gson.stream.JsonWriter;\r
import java.io.IOException;\r
import java.lang.reflect.Type;\r
import java.lang.reflect.TypeVariable;\r
\r
final class TypeAdapterRuntimeTypeWrapper<T> extends TypeAdapter<T> {\r
  private final Gson context;\r
  private final TypeAdapter<T> delegate;\r
  private final Type type;\r
\r
  TypeAdapterRuntimeTypeWrapper(Gson context, TypeAdapter<T> delegate, Type type) {\r
    this.context = context;\r
    this.delegate = delegate;\r
    this.type = type;\r
  }\r
\r
  @Override\r
  public T read(JsonReader in) throws IOException {\r
    return delegate.read(in);\r
  }\r
\r
  @SuppressWarnings({"rawtypes", "unchecked"})\r
  @Override\r
  public void write(JsonWriter out, T value) throws IOException {\r
    // Order of preference for choosing type adapters\r
    // First preference: a type adapter registered for the runtime type\r
    // Second preference: a type adapter registered for the declared type\r
    // Third preference: reflective type adapter for the runtime type (if it is a sub class of the declared type)\r
    // Fourth preference: reflective type adapter for the declared type\r
\r
    TypeAdapter chosen = delegate;\r
    Type runtimeType = getRuntimeTypeIfMoreSpecific(type, value);\r
    if (runtimeType != type) {\r
      TypeAdapter runtimeTypeAdapter = context.getAdapter(TypeToken.get(runtimeType));\r
      if (!(runtimeTypeAdapter instanceof ReflectiveTypeAdapterFactory.Adapter)) {\r
        // The user registered a type adapter for the runtime type, so we will use that\r
        chosen = runtimeTypeAdapter;\r
      } else if (!(delegate instanceof ReflectiveTypeAdapterFactory.Adapter)) {\r
        // The user registered a type adapter for Base class, so we prefer it over the\r
        // reflective type adapter for the runtime type\r
        chosen = delegate;\r
      } else {\r
        // Use the type adapter for runtime type\r
        chosen = runtimeTypeAdapter;\r
      }\r
    }\r
    chosen.write(out, value);\r
  }\r
\r
  /**\r
   * Finds a compatible runtime type if it is more specific\r
   */\r
  private Type getRuntimeTypeIfMoreSpecific(Type type, Object value) {\r
    if (value != null\r
        && (type == Object.class || type instanceof TypeVariable<?> || type instanceof Class<?>)) {\r
      type = value.getClass();\r
    }\r
    return type;\r
  }\r
}\r