1 // Copyright 2014 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 MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_REQUEST_H_ 6 #define MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_REQUEST_H_ 7 8 #include "mojo/public/cpp/bindings/interface_ptr.h" 9 10 namespace mojo { 11 12 // Used in methods that return instances of remote objects. 13 template <typename Interface> 14 class InterfaceRequest { MOJO_MOVE_ONLY_TYPE_FOR_CPP_03(InterfaceRequest,RValue)15 MOJO_MOVE_ONLY_TYPE_FOR_CPP_03(InterfaceRequest, RValue) 16 public: 17 InterfaceRequest() {} 18 InterfaceRequest(RValue other)19 InterfaceRequest(RValue other) { 20 handle_ = other.object->handle_.Pass(); 21 } 22 InterfaceRequest& operator=(RValue other) { 23 handle_ = other.object->handle_.Pass(); 24 return *this; 25 } 26 27 // Returns true if the request has yet to be completed. is_pending()28 bool is_pending() const { return handle_.is_valid(); } 29 Bind(ScopedMessagePipeHandle handle)30 void Bind(ScopedMessagePipeHandle handle) { 31 handle_ = handle.Pass(); 32 } 33 PassMessagePipe()34 ScopedMessagePipeHandle PassMessagePipe() { 35 return handle_.Pass(); 36 } 37 38 private: 39 ScopedMessagePipeHandle handle_; 40 }; 41 42 template <typename Interface> MakeRequest(ScopedMessagePipeHandle handle)43InterfaceRequest<Interface> MakeRequest(ScopedMessagePipeHandle handle) { 44 InterfaceRequest<Interface> request; 45 request.Bind(handle.Pass()); 46 return request.Pass(); 47 } 48 49 // Used to construct a request that synchronously binds an InterfacePtr<..>, 50 // making it immediately usable upon return. The resulting request object may 51 // then be later bound to an InterfaceImpl<..> via BindToRequest. 52 // 53 // Given the following interface: 54 // 55 // interface Foo { 56 // CreateBar(Bar& bar); 57 // } 58 // 59 // The caller of CreateBar would have code similar to the following: 60 // 61 // InterfacePtr<Foo> foo = ...; 62 // InterfacePtr<Bar> bar; 63 // foo->CreateBar(Get(&bar)); 64 // 65 // Upon return from CreateBar, |bar| is ready to have methods called on it. 66 // 67 template <typename Interface> Get(InterfacePtr<Interface> * ptr)68InterfaceRequest<Interface> Get(InterfacePtr<Interface>* ptr) { 69 MessagePipe pipe; 70 ptr->Bind(pipe.handle0.Pass()); 71 return MakeRequest<Interface>(pipe.handle1.Pass()); 72 } 73 74 } // namespace mojo 75 76 #endif // MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_REQUEST_H_ 77