Home | History | Annotate | Download | only in bindings 
      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 {
     15   MOJO_MOVE_ONLY_TYPE_FOR_CPP_03(InterfaceRequest, RValue)
     16  public:
     17   InterfaceRequest() {}
     18 
     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.
     28   bool is_pending() const { return handle_.is_valid(); }
     29 
     30   void Bind(ScopedMessagePipeHandle handle) {
     31     handle_ = handle.Pass();
     32   }
     33 
     34   ScopedMessagePipeHandle PassMessagePipe() {
     35     return handle_.Pass();
     36   }
     37 
     38  private:
     39   ScopedMessagePipeHandle handle_;
     40 };
     41 
     42 template <typename Interface>
     43 InterfaceRequest<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>
     68 InterfaceRequest<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