Draft: apps APIs in Pepper

ppapi/cpp/dev/struct_wrapper_base_dev.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef PPAPI_CPP_DEV_STRUCT_WRAPPER_BASE_DEV_
+#define PPAPI_CPP_DEV_STRUCT_WRAPPER_BASE_DEV_
+
+#include "ppapi/c/dev/pp_optional_structs_dev.h"
+#include "ppapi/cpp/dev/array_dev.h"
+#include "ppapi/cpp/dev/may_own_ptr_dev.h"
+#include "ppapi/cpp/logging.h"
+#include "ppapi/cpp/var.h"
+
+namespace pp {
+namespace internal {
+
+// The only purpose of this class is for CallbackOutputTraits to determined
+// whether a class is a struct wrapper.
+class StructWrapperIdentifier {
+};
+
+template <class Type, class ArrayType = void>
+class StructWrapperBase : public StructWrapperIdentifier {
+ public:
+  typedef Type CType;
+  typedef ArrayType CArrayType;
+
+  typedef CType* COutputType;
+  typedef const CType* CInputType;
+
+  StructWrapperBase() {
+  }
+
+  // For struct / array members.
+  // It doesn't take ownership of |storage|, therefore |storage| must live
+  // longer than this object.
+  StructWrapperBase(CType* storage, NotOwned) : storage_(storage, NOT_OWNED) {
+  }
+
+  virtual ~StructWrapperBase() {
+  }
+
+  // For input parameters to call PPB_* functions.
+  const CType* ToStruct() const {
+    return storage_.get();
+  }
+
+  // For output parameters to call PPB_* functions. The returned pointer is
+  // still owned by this object. And after it is used, EndRawUpdate() must be
+  // called.
+  CType* StartRawUpdate() {
+    NotifyStartRawUpdate();
+    return storage_.get();
+  }
+
+  void EndRawUpdate() {
+    NotifyEndRawUpdate();
+  }
+
+ protected:
+  virtual void NotifyStartRawUpdate() = 0;
+  virtual void NotifyEndRawUpdate() = 0;
+
+  MayOwnPtr<CType> storage_;
+
+ private:
+  // Disallow copy and assign.
+  StructWrapperBase(const StructWrapperBase<CType, CArrayType>& other);
+  StructWrapperBase<CType, CArrayType>& operator=(
+      const StructWrapperBase<CType, CArrayType>& other);
+};
+
+}  // namespace internal
+}  // namespace pp
+
+#endif  // PPAPI_CPP_DEV_STRUCT_WRAPPER_BASE_DEV_