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

   1 // Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_H_
   6 #define CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "chrome/browser/extensions/api/dial/dial_device_data.h"
  11 #include "chrome/browser/extensions/api/dial/dial_registry.h"
  12 #include "components/keyed_service/core/refcounted_keyed_service.h"
  13 #include "extensions/browser/api/async_api_function.h"
  14 #include "extensions/browser/event_router.h"
  15
  16 namespace extensions {
  17
  18 class DialRegistry;
  19
  20 // Dial API which is a ref-counted KeyedService that manages
  21 // the DIAL registry. It takes care of creating the registry on the IO thread
  22 // and is an observer of the registry. It makes sure devices events are sent out
  23 // to extension listeners on the right thread.
  24 //
  25 // TODO(mfoltz): This should probably inherit from BrowserContextKeyedAPI
  26 // instead; ShutdownOnUIThread below is a no-op, which is the whole point of
  27 // RefcountedKeyedService.
  28 class DialAPI : public RefcountedKeyedService,
  29                 public EventRouter::Observer,
  30                 public DialRegistry::Observer {
  31  public:
  32   explicit DialAPI(Profile* profile);
  33
  34   // The DialRegistry for the API. This must always be used only from the IO
  35   // thread.
  36   DialRegistry* dial_registry();
  37
  38   // Called by the DialRegistry on the IO thread so that the DialAPI dispatches
  39   // the event to listeners on the UI thread.
  40   void SendEventOnUIThread(const DialRegistry::DeviceList& devices);
  41   void SendErrorOnUIThread(const DialRegistry::DialErrorCode type);
  42
  43  private:
  44   ~DialAPI() override;
  45
  46   // RefcountedKeyedService:
  47   void ShutdownOnUIThread() override;
  48
  49   // EventRouter::Observer:
  50   void OnListenerAdded(const EventListenerInfo& details) override;
  51   void OnListenerRemoved(const EventListenerInfo& details) override;
  52
  53   // DialRegistry::Observer:
  54   void OnDialDeviceEvent(const DialRegistry::DeviceList& devices) override;
  55   void OnDialError(DialRegistry::DialErrorCode type) override;
  56
  57   // Methods to notify the DialRegistry on the correct thread of new/removed
  58   // listeners.
  59   void NotifyListenerAddedOnIOThread();
  60   void NotifyListenerRemovedOnIOThread();
  61
  62   Profile* profile_;
  63
  64   // Created lazily on first access on the IO thread.
  65   scoped_ptr<DialRegistry> dial_registry_;
  66
  67   DISALLOW_COPY_AND_ASSIGN(DialAPI);
  68 };
  69
  70 namespace api {
  71
  72 // DiscoverNow function. This function needs a round-trip from the IO thread
  73 // because it needs to grab a pointer to the DIAL API in order to get a
  74 // reference to the DialRegistry while on the IO thread. Then, the result
  75 // must be returned on the UI thread.
  76 class DialDiscoverNowFunction : public AsyncApiFunction {
  77  public:
  78   DialDiscoverNowFunction();
  79
  80  protected:
  81   ~DialDiscoverNowFunction() override {}
  82
  83   // AsyncApiFunction:
  84   bool Prepare() override;
  85   void Work() override;
  86   bool Respond() override;
  87
  88  private:
  89   DECLARE_EXTENSION_FUNCTION("dial.discoverNow", DIAL_DISCOVERNOW)
  90
  91   // Pointer to the DIAL API for this profile. We get this on the UI thread.
  92   DialAPI* dial_;
  93
  94   // Result of the discoverNow call to the DIAL registry. This result is
  95   // retrieved on the IO thread but the function result is returned on the UI
  96   // thread.
  97   bool result_;
  98
  99   DISALLOW_COPY_AND_ASSIGN(DialDiscoverNowFunction);
 100 };
 101
 102 }  // namespace api
 103
 104 }  // namespace extensions
 105
 106 #endif  // CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_H_