content/browser/gamepad/gamepad_service.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 CONTENT_BROWSER_GAMEPAD_GAMEPAD_SERVICE_H
   6 #define CONTENT_BROWSER_GAMEPAD_GAMEPAD_SERVICE_H
   7
   8 #include <set>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback_forward.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/memory/shared_memory.h"
  14 #include "base/memory/singleton.h"
  15 #include "base/threading/thread_checker.h"
  16 #include "content/common/content_export.h"
  17
  18 namespace blink {
  19 class WebGamepad;
  20 }
  21
  22 namespace content {
  23
  24 class GamepadConsumer;
  25 class GamepadDataFetcher;
  26 class GamepadProvider;
  27 class GamepadServiceTestConstructor;
  28 class RenderProcessHost;
  29
  30 // Owns the GamepadProvider (the background polling thread) and keeps track of
  31 // the number of consumers currently using the data (and pausing the provider
  32 // when not in use).
  33 class CONTENT_EXPORT GamepadService {
  34  public:
  35   // Returns the GamepadService singleton.
  36   static GamepadService* GetInstance();
  37
  38   // Increments the number of users of the provider. The Provider is running
  39   // when there's > 0 users, and is paused when the count drops to 0.
  40   // consumer is registered to listen for gamepad connections. If this is the
  41   // first time it is added to the set of consumers it will be treated
  42   // specially: it will not be informed about connections before a new user
  43   // gesture is observed at which point it will be notified for every connected
  44   // gamepads.
  45   //
  46   // Must be called on the I/O thread.
  47   void ConsumerBecameActive(GamepadConsumer* consumer);
  48
  49   // Decrements the number of users of the provider. consumer will not be
  50   // informed about connections until it's added back via ConsumerBecameActive.
  51   // Must be matched with a ConsumerBecameActive call.
  52   //
  53   // Must be called on the I/O thread.
  54   void ConsumerBecameInactive(GamepadConsumer* consumer);
  55
  56   // Decrements the number of users of the provider and removes consumer from
  57   // the set of consumers. Should be matched with a a ConsumerBecameActive
  58   // call.
  59   //
  60   // Must be called on the I/O thread.
  61   void RemoveConsumer(GamepadConsumer* consumer);
  62
  63   // Registers the given closure for calling when the user has interacted with
  64   // the device. This callback will only be issued once. Should only be called
  65   // while a consumer is active.
  66   void RegisterForUserGesture(const base::Closure& closure);
  67
  68   // Returns the shared memory handle of the gamepad data duplicated into the
  69   // given process.
  70   base::SharedMemoryHandle GetSharedMemoryHandleForProcess(
  71       base::ProcessHandle handle);
  72
  73   // Stop/join with the background thread in GamepadProvider |provider_|.
  74   void Terminate();
  75
  76   // Called on IO thread when a gamepad is connected.
  77   void OnGamepadConnected(int index, const blink::WebGamepad& pad);
  78
  79   // Called on IO thread when a gamepad is disconnected.
  80   void OnGamepadDisconnected(int index, const blink::WebGamepad& pad);
  81
  82  private:
  83   friend struct DefaultSingletonTraits<GamepadService>;
  84   friend class GamepadServiceTestConstructor;
  85   friend class GamepadServiceTest;
  86
  87   GamepadService();
  88
  89   // Constructor for testing. This specifies the data fetcher to use for a
  90   // provider, bypassing the default platform one.
  91   GamepadService(scoped_ptr<GamepadDataFetcher> fetcher);
  92
  93   virtual ~GamepadService();
  94
  95   static void SetInstance(GamepadService*);
  96
  97   void OnUserGesture();
  98
  99   struct ConsumerInfo {
 100     ConsumerInfo(GamepadConsumer* consumer)
 101         : consumer(consumer),
 102           did_observe_user_gesture(false) {
 103     }
 104
 105     bool operator<(const ConsumerInfo& other) const {
 106       return consumer < other.consumer;
 107     }
 108
 109     GamepadConsumer* consumer;
 110     mutable bool is_active;
 111     mutable bool did_observe_user_gesture;
 112   };
 113
 114   scoped_ptr<GamepadProvider> provider_;
 115
 116   base::ThreadChecker thread_checker_;
 117
 118   typedef std::set<ConsumerInfo> ConsumerSet;
 119   ConsumerSet consumers_;
 120
 121   int num_active_consumers_;
 122
 123   bool gesture_callback_pending_;
 124
 125   DISALLOW_COPY_AND_ASSIGN(GamepadService);
 126 };
 127
 128 }  // namespace content
 129
 130 #endif  // CONTENT_BROWSER_GAMEPAD_GAMEPAD_SERVICE_H_