1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef BASE_MAC_BIND_OBJC_BLOCK_H_
6#define BASE_MAC_BIND_OBJC_BLOCK_H_
7
8#include <Block.h>
9
10#include "base/bind.h"
11#include "base/callback_forward.h"
12#include "base/mac/scoped_block.h"
13
14// BindBlock builds a callback from an Objective-C block. Example usages:
15//
16// Closure closure = BindBlock(^{DoSomething();});
17// Callback<int(void)> callback = BindBlock(^{return 42;});
18
19namespace base {
20
21namespace internal {
22
23// Helper functions to run the block contained in the parameter.
24template<typename R>
25R RunBlock(base::mac::ScopedBlock<R(^)()> block) {
26  R(^extracted_block)() = block.get();
27  return extracted_block();
28}
29
30template<typename R, typename A1>
31R RunBlock(base::mac::ScopedBlock<R(^)(A1)> block, A1 a) {
32  R(^extracted_block)(A1) = block.get();
33  return extracted_block(a);
34}
35
36}  // namespace internal
37
38// Construct a callback with no argument from an objective-C block.
39template<typename R>
40base::Callback<R(void)> BindBlock(R(^block)()) {
41  return base::Bind(&base::internal::RunBlock<R>,
42                    base::mac::ScopedBlock<R(^)()>(Block_copy(block)));
43}
44
45// Construct a callback with one argument from an objective-C block.
46template<typename R, typename A1>
47base::Callback<R(A1)> BindBlock(R(^block)(A1)) {
48  return base::Bind(&base::internal::RunBlock<R, A1>,
49                    base::mac::ScopedBlock<R(^)(A1)>(Block_copy(block)));
50}
51
52}  // namespace base
53
54#endif  // BASE_MAC_BIND_OBJC_BLOCK_H_
55