1 files changed, 104 insertions, 0 deletions
diff --git a/dom/gamepad/GamepadPlatformService.h b/dom/gamepad/GamepadPlatformService.h
new file mode 100644
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+++ b/dom/gamepad/GamepadPlatformService.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_GamepadPlatformService_h_
+#define mozilla_dom_GamepadPlatformService_h_
+
+#include "mozilla/dom/GamepadBinding.h"
+
+#include "mozilla/Mutex.h"
+#include "mozilla/StaticPtr.h"
+
+namespace mozilla {
+namespace dom {
+
+class GamepadEventChannelParent;
+
+// Platform Service for building and transmitting IPDL messages
+// through the HAL sandbox. Used by platform specific
+// Gamepad implementations
+//
+// This class can be accessed by the following 2 threads :
+// 1. Background thread:
+//    This thread takes charge of IPDL communications
+//    between here and DOM side
+//
+// 2. Monitor Thread:
+//    This thread is populated in platform-dependent backends, which
+//    is in charge of processing gamepad hardware events from OS
+class GamepadPlatformService final
+{
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadPlatformService)
+ public:
+  //Get the singleton service
+  static already_AddRefed<GamepadPlatformService> GetParentService();
+
+  // Add a gamepad to the list of known gamepads, and return its index.
+  uint32_t AddGamepad(const char* aID, GamepadMappingType aMapping,
+                      uint32_t aNumButtons, uint32_t aNumAxes);
+  // Remove the gamepad at |aIndex| from the list of known gamepads.
+  void RemoveGamepad(uint32_t aIndex);
+
+  // Update the state of |aButton| for the gamepad at |aIndex| for all
+  // windows that are listening and visible, and fire one of
+  // a gamepadbutton{up,down} event at them as well.
+  // aPressed is used for digital buttons, aValue is for analog buttons.
+  void NewButtonEvent(uint32_t aIndex, uint32_t aButton, bool aPressed,
+                      double aValue);
+  // When only a digital button is available the value will be synthesized.
+  void NewButtonEvent(uint32_t aIndex, uint32_t aButton, bool aPressed);
+
+  // Update the state of |aAxis| for the gamepad at |aIndex| for all
+  // windows that are listening and visible, and fire a gamepadaxismove
+  // event at them as well.
+  void NewAxisMoveEvent(uint32_t aIndex, uint32_t aAxis, double aValue);
+
+  // When shutting down the platform communications for gamepad, also reset the
+  // indexes.
+  void ResetGamepadIndexes();
+
+  //Add IPDL parent instance
+  void AddChannelParent(GamepadEventChannelParent* aParent);
+
+  //Remove IPDL parent instance
+  void RemoveChannelParent(GamepadEventChannelParent* aParent);
+
+  bool HasGamepadListeners();
+
+  void MaybeShutdown();
+
+ private:
+  GamepadPlatformService();
+  ~GamepadPlatformService();
+  template<class T> void NotifyGamepadChange(const T& aInfo);
+
+  // Flush all pending events buffered in mPendingEvents, must be called
+  // with mMutex held
+  void FlushPendingEvents();
+  void Cleanup();
+
+  // mGamepadIndex can only be accessed by monitor thread
+  uint32_t mGamepadIndex;
+
+  // mChannelParents stores all the GamepadEventChannelParent instances
+  // which may be accessed by both background thread and monitor thread
+  // simultaneously, so we have a mutex to prevent race condition
+  nsTArray<RefPtr<GamepadEventChannelParent>> mChannelParents;
+
+  // This mutex protects mChannelParents from race condition
+  // between background and monitor thread
+  Mutex mMutex;
+
+  // In mochitest, it is possible that the test Events is synthesized
+  // before GamepadEventChannel created, we need to buffer all events
+  // until the channel is created if that happens.
+  nsTArray<GamepadChangeEvent> mPendingEvents;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif