dart_direct_wrappable.h

// Copyright 2016 The Fuchsia 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 LIB_TONIC_DART_DIRECT_WRAPPABLE_H_
#define LIB_TONIC_DART_DIRECT_WRAPPABLE_H_

#include "dart/runtime/include/dart_api.h"
#include "lib/tonic/dart_converter.h"

namespace tonic {
class DartState;
struct DartWrapperInfo;

template <typename T>
struct DartDirectWrappable;

template <>
struct DartDirectWrappable<void*> {
  static Dart_Handle Wrap(DartState* dart_state,
                          void* val,
                          const DartWrapperInfo& info);
  static void* FromDart(Dart_Handle handle);
  static void* FromArguments(Dart_NativeArguments args,
                             int index,
                             Dart_Handle& exception);
};

template <typename T>
struct DartDirectWrappable {
  static Dart_Handle Wrap(DartState* dart_state,
                          T val,
                          const DartWrapperInfo& info) {
    return DartDirectWrappable<void*>::Wrap(dart_state, static_cast<void*>(val),
                                            info);
  }

  static T FromDart(Dart_Handle handle) {
    return static_cast<T>(DartDirectWrappable<void*>::FromDart(handle));
  }

  static T FromArguments(Dart_NativeArguments args,
                         int index,
                         Dart_Handle& exception) {
    return static_cast<T>(
        DartDirectWrappable<void*>::FromArguments(args, index, exception));
  }
};

template <typename T, const DartWrapperInfo& (*GetWrapperInfo)()>
struct DartConverterDirectWrappable {
  static Dart_Handle ToDart(T val) {
    if (!val)
      return Dart_Null();
    return DartDirectWrappable<T>::Wrap(DartState::Current(), val,
                                        GetWrapperInfo());
  }

  static void SetReturnValue(Dart_NativeArguments args, T val) {
    Dart_SetReturnValue(args, ToDart(val));
  }

  static T FromDart(Dart_Handle handle) {
    return DartDirectWrappable<T>::FromDart(handle);
  }

  static T FromArguments(Dart_NativeArguments args,
                         int index,
                         Dart_Handle& exception) {
    return DartDirectWrappable<T>::FromArguments(args, index, exception);
  }
};

#define IMPLEMENT_DIRECT_WRAPPABLE(LibraryName, DartName, ImplType)          \
  static const DartWrapperInfo kDartWrapperInfo_##LibraryName_##DartName = { \
      #LibraryName, #DartName, 0, 0, 0,                                      \
  };                                                                         \
  static const DartWrapperInfo&                                              \
      GetWrapperTypeInfo_##LibraryName_##DartName() {                        \
    return kDartWrapperInfo_##LibraryName_##DartName;                        \
  }                                                                          \
  template <>                                                                \
  struct DartConverter<ImplType>                                             \
      : public DartConverterDirectWrappable<                                 \
            ImplType, GetWrapperTypeInfo_##LibraryName_##DartName> {};

}  // namespace tonic

#endif  // LIB_TONIC_DART_DIRECT_WRAPPABLE_H_