Implement the gamepad API in the IPC proxy

content/browser/gamepad/gamepad_platform_data_fetcher_mac.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 CONTENT_BROWSER_GAMEPAD_GAMEPAD_PLATFORM_DATA_FETCHER_MAC_H_
+#define CONTENT_BROWSER_GAMEPAD_GAMEPAD_PLATFORM_DATA_FETCHER_MAC_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/mac/scoped_cftyperef.h"
+#include "build/build_config.h"
+#include "content/browser/gamepad/gamepad_data_fetcher.h"
+#include "content/browser/gamepad/gamepad_standard_mappings.h"
+#include "content/common/gamepad_hardware_buffer.h"
+
+#include <CoreFoundation/CoreFoundation.h>
+#include <IOKit/hid/IOHIDManager.h>
+
+#if defined(__OBJC__)
+@class NSArray;
+#else
+class NSArray;
+#endif
+
+namespace content {
+
+class GamepadPlatformDataFetcherMac : public GamepadDataFetcher {
+ public:
+  GamepadPlatformDataFetcherMac();
+  virtual ~GamepadPlatformDataFetcherMac();
+  virtual void GetGamepadData(WebKit::WebGamepads* pads,
+                              bool devices_changed_hint) OVERRIDE;
+  virtual void PauseHint(bool paused) OVERRIDE;
+
+ private:
+  bool enabled_;
+  base::mac::ScopedCFTypeRef<IOHIDManagerRef> hid_manager_ref_;
+
+  static GamepadPlatformDataFetcherMac* InstanceFromContext(void* context);
+  static void DeviceAddCallback(void* context,
+                                IOReturn result,
+                                void* sender,
+                                IOHIDDeviceRef ref);
+  static void DeviceRemoveCallback(void* context,
+                                   IOReturn result,
+                                   void* sender,
+                                   IOHIDDeviceRef ref);
+  static void ValueChangedCallback(void* context,
+                                   IOReturn result,
+                                   void* sender,
+                                   IOHIDValueRef ref);
+
+  void DeviceAdd(IOHIDDeviceRef device);
+  void AddButtonsAndAxes(NSArray* elements, size_t slot);
+  void DeviceRemove(IOHIDDeviceRef device);
+  void ValueChanged(IOHIDValueRef value);
+
+  void RegisterForNotifications();
+  void UnregisterFromNotifications();
+
+  WebKit::WebGamepads data_;
+
+  // Side-band data that's not passed to the consumer, but we need to maintain
+  // to update data_.
+  struct AssociatedData {
+    IOHIDDeviceRef device_ref;
+    IOHIDElementRef button_elements[WebKit::WebGamepad::buttonsLengthCap];
+    IOHIDElementRef axis_elements[WebKit::WebGamepad::buttonsLengthCap];
+    CFIndex axis_minimums[WebKit::WebGamepad::axesLengthCap];
+    CFIndex axis_maximums[WebKit::WebGamepad::axesLengthCap];
+    // Function to map from device data to standard layout, if available. May
+    // be null if no mapping is available.
+    GamepadStandardMappingFunction mapper;
+  };
+  AssociatedData associated_[WebKit::WebGamepads::itemsLengthCap];
+
+  DISALLOW_COPY_AND_ASSIGN(GamepadPlatformDataFetcherMac);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_GAMEPAD_GAMEPAD_PLATFORM_DATA_FETCHER_MAC_H_