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47 lines
1.5 KiB
C++
47 lines
1.5 KiB
C++
// Copyright 2014 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef MOJO_PUBLIC_CPP_APPLICATION_LAZY_INTERFACE_PTR_H_
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#define MOJO_PUBLIC_CPP_APPLICATION_LAZY_INTERFACE_PTR_H_
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#include "mojo/public/cpp/application/connect.h"
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#include "mojo/public/interfaces/application/service_provider.mojom.h"
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namespace mojo {
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// An InterfacePtr that will request an implementation from a specified
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// ServiceProvider when it is first accessed with the get() method.
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template <typename Interface>
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class LazyInterfacePtr : public InterfacePtr<Interface> {
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public:
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LazyInterfacePtr() : service_provider_(nullptr) {}
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LazyInterfacePtr(ServiceProvider* service_provider)
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: service_provider_(service_provider) {}
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void set_service_provider(ServiceProvider* service_provider) {
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if (service_provider != service_provider_) {
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InterfacePtr<Interface>::reset();
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}
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service_provider_ = service_provider;
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}
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Interface* get() const {
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if (!InterfacePtr<Interface>::get() && service_provider_) {
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mojo::ConnectToService<Interface>(
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service_provider_, const_cast<LazyInterfacePtr<Interface>*>(this));
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}
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return InterfacePtr<Interface>::get();
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}
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Interface* operator->() const { return get(); }
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Interface& operator*() const { return *get(); }
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private:
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ServiceProvider* service_provider_;
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};
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} // namespace mojo
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#endif // MOJO_PUBLIC_CPP_APPLICATION_LAZY_INTERFACE_PTR_H_
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