DIAL extension API skeleton.

chrome/browser/extensions/api/dial/dial_api.h

+// Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_H_
+#define CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/extensions/api/api_function.h"
+#include "chrome/browser/extensions/api/dial/dial_device_data.h"
+#include "chrome/browser/extensions/api/dial/dial_registry.h"
+#include "chrome/browser/extensions/event_router.h"
+#include "chrome/browser/profiles/refcounted_profile_keyed_service.h"
+
+namespace extensions {
+
+class DialRegistry;
+
+// Dial API which is a ref-counted ProfileKeyedService that manages the DIAL
+// registry. It takes care of creating the registry on the IO thread and
+// is an observer of the registry. It makes sure devices events are sent out
+// to extension listeners on the right thread.
+class DialAPI : public RefcountedProfileKeyedService,
+                public EventRouter::Observer,
+                public DialRegistry::Observer {
+ public:
+  explicit DialAPI(Profile* profile);
+
+  // The DialRegistry for the API. This must always be used only from the IO
+  // thread.
+  DialRegistry* dial_registry();
+
+  // Called by the DialRegistry on the IO thread so that the DialAPI dispatches
+  // the event to listeners on the UI thread.
+  void SendEventOnUIThread(const DialRegistry::DeviceList& devices);
+
+ private:
+  virtual ~DialAPI();
+
+  // RefcountedProfileKeyedService:
+  virtual void ShutdownOnUIThread() OVERRIDE;
+
+  // EventRouter::Observer:
+  virtual void OnListenerAdded(const EventListenerInfo& details) OVERRIDE;
+  virtual void OnListenerRemoved(const EventListenerInfo& details) OVERRIDE;
+
+  // DialRegistry::Observer:
+  virtual void OnDialDeviceEvent(
+      const DialRegistry::DeviceList& devices) OVERRIDE;
+
+  // Methods to notify the DialRegistry on the correct thread of new/removed
+  // listeners.
+  void NotifyListenerAddedOnIOThread();
+  void NotifyListenerRemovedOnIOThread();
+
+  Profile* profile_;
+
+  // Created lazily on first access on the IO thread.
+  scoped_ptr<DialRegistry> dial_registry_;
+
+  DISALLOW_COPY_AND_ASSIGN(DialAPI);
+};
+
+namespace api {
+
+// DiscoverNow function. This function needs a round-trip from the IO thread
+// because it needs to grab a pointer to the DIAL API in order to get a
+// reference to the DialRegistry while on the IO thread. Then, the result
+// must be returned on the UI thread.
+class DialDiscoverNowFunction : public AsyncApiFunction {
+ public:
+  DialDiscoverNowFunction();
+
+ protected:
+  virtual ~DialDiscoverNowFunction() {}
+
+  // AsyncApiFunction:
+  virtual bool Prepare() OVERRIDE;
+  virtual void Work() OVERRIDE;
+  virtual bool Respond() OVERRIDE;
+
+ private:
+  DECLARE_EXTENSION_FUNCTION_NAME("dial.discoverNow")
+
+  // Pointer to the DIAL API for this profile. We get this on the UI thread.
+  DialAPI* dial_;
+
+  // Result of the discoverNow call to the DIAL registry. This result is
+  // retrieved on the IO thread but the function result is returned on the UI
+  // thread.
+  bool result_;
+};
+
+}  // namespace api
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_H_