Home | History | Annotate | Download | only in mac 
      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 //
     18 // Callback<int(void)> callback = BindBlock(^{return 42;});
     19 //
     20 // Callback<void(const std::string&, const std::string&)> callback =
     21 //     BindBlock(^(const std::string& arg0, const std::string& arg1) {
     22 //         ...
     23 //     });
     24 
     25 namespace base {
     26 
     27 namespace internal {
     28 
     29 // Helper functions to run the block contained in the parameter.
     30 template<typename R>
     31 R RunBlock(base::mac::ScopedBlock<R(^)()> block) {
     32   R(^extracted_block)() = block.get();
     33   return extracted_block();
     34 }
     35 
     36 template<typename R, typename A1>
     37 R RunBlock(base::mac::ScopedBlock<R(^)(A1)> block, A1 a) {
     38   R(^extracted_block)(A1) = block.get();
     39   return extracted_block(a);
     40 }
     41 
     42 template<typename R, typename A1, typename A2>
     43 R RunBlock(base::mac::ScopedBlock<R(^)(A1, A2)> block, A1 a, A2 b) {
     44   R(^extracted_block)(A1, A2) = block.get();
     45   return extracted_block(a, b);
     46 }
     47 
     48 }  // namespace internal
     49 
     50 // Construct a callback with no argument from an objective-C block.
     51 template<typename R>
     52 base::Callback<R(void)> BindBlock(R(^block)()) {
     53   return base::Bind(&base::internal::RunBlock<R>,
     54                     base::mac::ScopedBlock<R(^)()>(Block_copy(block)));
     55 }
     56 
     57 // Construct a callback with one argument from an objective-C block.
     58 template<typename R, typename A1>
     59 base::Callback<R(A1)> BindBlock(R(^block)(A1)) {
     60   return base::Bind(&base::internal::RunBlock<R, A1>,
     61                     base::mac::ScopedBlock<R(^)(A1)>(Block_copy(block)));
     62 }
     63 
     64 // Construct a callback with two arguments from an objective-C block.
     65 template<typename R, typename A1, typename A2>
     66 base::Callback<R(A1, A2)> BindBlock(R(^block)(A1, A2)) {
     67   return base::Bind(&base::internal::RunBlock<R, A1, A2>,
     68                     base::mac::ScopedBlock<R(^)(A1, A2)>(Block_copy(block)));
     69 }
     70 
     71 }  // namespace base
     72 
     73 #endif  // BASE_MAC_BIND_OBJC_BLOCK_H_
     74