chrome/browser/media/router/presentation_session_state_observer.h

   1 // Copyright 2015 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_MEDIA_ROUTER_PRESENTATION_SESSION_STATE_OBSERVER_H_
   6 #define CHROME_BROWSER_MEDIA_ROUTER_PRESENTATION_SESSION_STATE_OBSERVER_H_
   7
   8 #include <vector>
   9
  10 #include "base/gtest_prod_util.h"
  11 #include "chrome/browser/media/router/media_route.h"
  12 #include "chrome/browser/media/router/media_routes_observer.h"
  13 #include "content/public/browser/presentation_service_delegate.h"
  14
  15 namespace media_router {
  16
  17 class MediaRouter;
  18
  19 // MediaRoutesObserver implementation that allows tracking state changes from
  20 // multiple presentation sessions and notifying the client via
  21 // |state_changed_callback|.
  22 // Clients provide the callback on construction, and incrementally add route
  23 // IDs to track by calling |OnPresentationSessionConnected| as they are created,
  24 // which also has the effect of invoking the callback that the session has
  25 // become connected.
  26 // When a presentation is disconnected, the callback will be invoked and it
  27 // will be removed from the tracked set.
  28 // When the routes no longer need to tracked, |Reset| can be called.
  29 class PresentationSessionStateObserver : public MediaRoutesObserver {
  30  public:
  31   PresentationSessionStateObserver(
  32       const content::SessionStateChangedCallback& state_changed_callback,
  33       const MediaRouteIdToPresentationSessionMapping* route_id_to_presentation,
  34       MediaRouter* router);
  35   ~PresentationSessionStateObserver() override;
  36
  37   // Called when a presentation with |route_id| has been created in connected
  38   // state and invoke the callback.
  39   void OnPresentationSessionConnected(const MediaRoute::Id& route_id);
  40
  41   // Clears the set of presentations being tracked.
  42   void Reset();
  43
  44  private:
  45   FRIEND_TEST_ALL_PREFIXES(PresentationSessionStateObserverTest,
  46                            InvokeCallbackWithDisconnected);
  47   FRIEND_TEST_ALL_PREFIXES(PresentationSessionStateObserverTest, Reset);
  48
  49   // MediaRoutesObserver override
  50   void OnRoutesUpdated(const std::vector<MediaRoute>& routes) override;
  51
  52   // Invokes |state_changed_callback_| with PresentationSessionInfo derived from
  53   // |route_id| and |new_state|, if |route_id| is valid.
  54   void InvokeCallback(const MediaRoute::Id& route_id,
  55                       content::PresentationSessionState new_state);
  56
  57   // Route IDs of presentations that are being tracked for state changes.
  58   // It is built by adding entries when a presentation is started,
  59   // and removing entries when the presentation is no longer in subsequent
  60   // route list updates.
  61   std::vector<MediaRoute::Id> tracked_route_ids_;
  62
  63   // Stores previous list of routes observed from MediaRouter.
  64   // It is compared against the new observed list of routes for disconnected
  65   // routes that are in |tracked_route_ids_|.
  66   // TODO(imcheng): A more explicit set of MediaRoutesObserver APIs (e.g.,
  67   // OnRoutesClosed) would be helpful here. (crbug.com/508751)
  68   std::vector<MediaRoute::Id> previous_route_ids_;
  69
  70   // Callback to invoke when state change occurs.
  71   content::SessionStateChangedCallback state_changed_callback_;
  72
  73   // Note that while it is declared const to prevent this class from modifying
  74   // it, its contents can be changed by the PresentationFrame that owns it.
  75   const MediaRouteIdToPresentationSessionMapping* const
  76       route_id_to_presentation_;
  77
  78   DISALLOW_COPY_AND_ASSIGN(PresentationSessionStateObserver);
  79 };
  80
  81 }  // namespace media_router
  82
  83 #endif  // CHROME_BROWSER_MEDIA_ROUTER_PRESENTATION_SESSION_STATE_OBSERVER_H_