Move gson to its own folder

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

diff --git a/gson/com/google/gson/internal/bind/TypeAdapterRuntimeTypeWrapper.java b/gson/com/google/gson/internal/bind/TypeAdapterRuntimeTypeWrapper.java
new file mode 100644 (file)
index 0000000..7e52c27
--- /dev/null
+++ b/gson/com/google/gson/internal/bind/TypeAdapterRuntimeTypeWrapper.java
@@ -0,0 +1,81 @@
+/*\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