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_APPLICATION_LAZY_INTERFACE_PTR_H_
6#define MOJO_PUBLIC_CPP_APPLICATION_LAZY_INTERFACE_PTR_H_
7
8#include <string>
9
10#include "mojo/public/cpp/application/connect.h"
11#include "mojo/public/interfaces/application/service_provider.mojom.h"
12
13namespace mojo {
14
15template<typename Interface>
16class LazyInterfacePtr : public InterfacePtr<Interface> {
17 public:
18  LazyInterfacePtr() : service_provider_(NULL) {}
19
20  LazyInterfacePtr(ServiceProvider* service_provider)
21      : service_provider_(service_provider) {
22  }
23
24  void set_service_provider(ServiceProvider* service_provider) {
25    if (service_provider != service_provider_) {
26      InterfacePtr<Interface>::reset();
27    }
28    service_provider_ = service_provider;
29  }
30
31  Interface* get() const {
32    if (!InterfacePtr<Interface>::get()) {
33      mojo::ConnectToService<Interface>(
34          service_provider_,
35          const_cast<LazyInterfacePtr<Interface>*>(this));
36    }
37    return InterfacePtr<Interface>::get();
38  }
39  Interface* operator->() const { return get(); }
40  Interface& operator*() const { return *get(); }
41
42 private:
43  ServiceProvider* service_provider_;
44};
45
46}  // namespace mojo
47
48#endif  // MOJO_PUBLIC_CPP_APPLICATION_LAZY_INTERFACE_PTR_H_
49