content/browser/gamepad/gamepad_platform_data_fetcher_win.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_WIN_H_
#define CONTENT_BROWSER_GAMEPAD_GAMEPAD_PLATFORM_DATA_FETCHER_WIN_H_

#include "build/build_config.h"

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#define DIRECTINPUT_VERSION 0x0800
#include <dinput.h>
#include <stdlib.h>
#include <Unknwn.h>
#include <WinDef.h>
#include <windows.h>
#include <XInput.h>

#include "base/basictypes.h"
#include "base/compiler_specific.h"
#include "base/scoped_native_library.h"
#include "content/browser/gamepad/gamepad_data_fetcher.h"
#include "content/browser/gamepad/gamepad_standard_mappings.h"
#include "third_party/WebKit/public/platform/WebGamepads.h"

namespace content {

class GamepadPlatformDataFetcherWin : public GamepadDataFetcher {
 public:
  GamepadPlatformDataFetcherWin();
  virtual ~GamepadPlatformDataFetcherWin();
  virtual void GetGamepadData(WebKit::WebGamepads* pads,
                              bool devices_changed_hint) OVERRIDE;
 private:
  // XInput-specific implementation for GetGamepadData.
  bool GetXInputGamepadData(WebKit::WebGamepads* pads,
                            bool devices_changed_hint);
  bool GetDirectInputGamepadData(WebKit::WebGamepads* pads,
                                 bool devices_changed_hint);

  // The three function types we use from xinput1_3.dll.
  typedef void (WINAPI *XInputEnableFunc)(BOOL enable);
  typedef DWORD (WINAPI *XInputGetCapabilitiesFunc)(
    DWORD dwUserIndex, DWORD dwFlags, XINPUT_CAPABILITIES* pCapabilities);
  typedef DWORD (WINAPI *XInputGetStateFunc)(
      DWORD dwUserIndex, XINPUT_STATE* pState);

  // Get functions from dynamically loaded xinput1_3.dll. We don't use
  // DELAYLOAD because the import library for Win8 SDK pulls xinput1_4 which
  // isn't redistributable. Returns true if loading was successful. We include
  // xinput1_3.dll with Chrome.
  bool GetXInputDllFunctions();

  // Scan for connected XInput and DirectInput gamepads.
  void EnumerateDevices(WebKit::WebGamepads* pads);
  bool GetXInputPadConnectivity(int i, WebKit::WebGamepad* pad) const;

  void GetXInputPadData(int i, WebKit::WebGamepad* pad);
  void GetDirectInputPadData(int i, WebKit::WebGamepad* pad);

  int FirstAvailableGamepadId() const;
  bool HasXInputGamepad(int index) const;
  bool HasDirectInputGamepad(const GUID &guid) const;

  base::ScopedNativeLibrary xinput_dll_;
  bool xinput_available_;
  bool directinput_available_;

  // Function pointers to XInput functionality, retrieved in
  // |GetXinputDllFunctions|.
  XInputEnableFunc xinput_enable_;
  XInputGetCapabilitiesFunc xinput_get_capabilities_;
  XInputGetStateFunc xinput_get_state_;

  IDirectInput8* directinput_interface_;

  enum PadConnectionStatus {
    DISCONNECTED,
    XINPUT_CONNECTED,
    DIRECTINPUT_CONNECTED
  };

  struct PadState {
    PadConnectionStatus status;
    int xinput_index;  // XInput-only.
    // Fields below are for DirectInput devices only.
    GUID guid;
    IDirectInputDevice8* directinput_gamepad;
    GamepadStandardMappingFunction mapper;
  };
  PadState pad_state_[WebKit::WebGamepads::itemsLengthCap];

  DISALLOW_COPY_AND_ASSIGN(GamepadPlatformDataFetcherWin);
};

}  // namespace content

#endif  // CONTENT_BROWSER_GAMEPAD_GAMEPAD_PLATFORM_DATA_FETCHER_WIN_H_