Add an ApplicationConnector interface, etc.

mojo/public/cpp/application/application_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_APPLICATION_APPLICATION_IMPL_H_
 #define MOJO_PUBLIC_APPLICATION_APPLICATION_IMPL_H_
 
+#include <memory>
 #include <string>
 #include <vector>
 
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/lib/service_registry.h"
 #include "mojo/public/cpp/system/core.h"
 #include "mojo/public/interfaces/application/application.mojom.h"
+#include "mojo/public/interfaces/application/application_connector.mojom.h"
 #include "mojo/public/interfaces/application/shell.mojom.h"
 
 namespace mojo {
 
 class ApplicationConnection;
 
 // Implements the Application interface, which the shell uses for basic
 // communication with an application (e.g., to connect clients to services
 // provided by an application). Also provides the application access to the
 // Shell, which, e.g., may be used by an application to connect to other
 // services.
 //
 // Typically, you create one or more classes implementing your APIs (e.g.,
 // FooImpl implementing Foo). See bindings/binding.h for more information. Then
 // you implement an mojo::ApplicationDelegate that either is or owns a
 // mojo::InterfaceFactory<Foo> and whose ConfigureIncomingConnection() adds that
 // factory to each connection. Finally, you instantiate your delegate and pass
 // it to an ApplicationRunner, which will create the ApplicationImpl and then
 // run a message (or run) loop.
 class ApplicationImpl : public Application {
  public:
   // Does not take ownership of |delegate|, which must remain valid for the
   // lifetime of ApplicationImpl.
   ApplicationImpl(ApplicationDelegate* delegate,
                   InterfaceRequest<Application> request);
   ~ApplicationImpl() override;
 
+  // Quits the main run loop for this application.
+  // TODO(vtl): This is implemented in application_runner.cc (for example). Its
+  // presence here is pretty dubious.
+  static void Terminate();
+
   // The Mojo shell. This will return a valid pointer after Initialize() has
   // been invoked. It will remain valid until UnbindConnections() is invoked or
   // the ApplicationImpl is destroyed.
   Shell* shell() const { return shell_.get(); }
 
   const std::string& url() const { return url_; }
 
   // Returns any initial configuration arguments, passed by the Shell.
   const std::vector<std::string>& args() const { return args_; }
   bool HasArg(const std::string& arg) const;
 
+  // Creates a new |ApplicationConnector|. The result can be bound to an
+  // |ApplicationConnectorPtr| and used to connect to other applications. (It
+  // returns an |InterfacePtrInfo| instead of an |InterfacePtr| to facilitate
+  // passing it to another thread.)
+  InterfacePtrInfo<ApplicationConnector> CreateApplicationConnector();
+
   // Requests a new connection to an application. Returns a pointer to the
   // connection if the connection is permitted by this application's delegate,
   // or nullptr otherwise. Caller does not take ownership. The pointer remains
   // valid until an error occurs on the connection with the Shell, or until the
   // ApplicationImpl is destroyed, whichever occurs first.
+  // TODO(vtl): Deprecate/remove this.
   ApplicationConnection* ConnectToApplication(const String& application_url);
 
   // Connect to application identified by |application_url| and connect to the
   // service implementation of the interface identified by |Interface|.
+  // TODO(vtl): Deprecate/remove this.
   template <typename Interface>
   void ConnectToService(const std::string& application_url,
                         InterfacePtr<Interface>* ptr) {
     ConnectToApplication(application_url)->ConnectToService(ptr);
   }
 
-  // Application implementation.
-  void Initialize(ShellPtr shell,
-                  Array<String> args,
-                  const mojo::String& url) override;
-
-  // Block until the Application is initialized, if it is not already.
+  // Blocks until the |Application| is initialized (i.e., |Initialize()| is
+  // received), if it is not already.
   void WaitForInitialize();
 
   // Unbinds the Shell and Application connections. Can be used to re-bind the
   // handles to another implementation of ApplicationImpl, for instance when
   // running apptests.
   void UnbindConnections(InterfaceRequest<Application>* application_request,
                          ShellPtr* shell);
 
-  // Quits the main run loop for this application.
-  static void Terminate();
-
- protected:
-  // Application implementation.
+  // |Application| implementation.
+  void Initialize(ShellPtr shell,
+                  Array<String> args,
+                  const mojo::String& url) override;
   void AcceptConnection(const String& requestor_url,
                         InterfaceRequest<ServiceProvider> services,
                         ServiceProviderPtr exposed_services,
                         const String& url) override;
+  void RequestQuit() override;
 
  private:
-  void ClearConnections();
-
-  void OnShellError() {
-    delegate_->Quit();
-    ClearConnections();
-    Terminate();
-  }
-
-  // Application implementation.
-  void RequestQuit() override;
-
-  typedef std::vector<internal::ServiceRegistry*> ServiceRegistryList;
-
+  using ServiceRegistryList =
+      std::vector<std::unique_ptr<internal::ServiceRegistry>>;
   ServiceRegistryList incoming_service_registries_;
   ServiceRegistryList outgoing_service_registries_;
   ApplicationDelegate* delegate_;
   Binding<Application> binding_;
   ShellPtr shell_;
   std::string url_;
   std::vector<std::string> args_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(ApplicationImpl);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_APPLICATION_APPLICATION_IMPL_H_