widget/windows/KeyboardLayout.cpp
author Masayuki Nakano <masayuki@d-toybox.com>
Tue, 31 Jan 2017 23:23:06 +0900
changeset 375796 3c3be02271337ec3d23c4515f2aa7041c8ee4c09
parent 373883 0673be23886e7eadfa5d815394357db365b86f70
child 375928 d4910d723a36c7e49c0a40f0015603aa4c02b8dd
permissions -rw-r--r--
Bug 1335306 Append active keyboard layout information into crash report when NativeKey crashes due to detecting impossible case caused by 3rd party's keyboard layout or utils r=m_kato a=jcristau When NativeKey crashes by itself, it means that we detect an impossible situation in usual environment. In such case, active 3rd party's keyboard layout or something other utility may hook API and returns odd result to us. For investigating the cause and deciding what we should do in such cases, we should collect active keyboard layout name via crash reports. MozReview-Commit-ID: HYRj24GwDHZ

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */

#include "mozilla/Logging.h"

#include "mozilla/ArrayUtils.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/MiscEvents.h"
#include "mozilla/TextEvents.h"
#include "mozilla/WindowsVersion.h"

#include "nsAlgorithm.h"
#ifdef MOZ_CRASHREPORTER
#include "nsExceptionHandler.h"
#endif
#include "nsGkAtoms.h"
#include "nsIDOMKeyEvent.h"
#include "nsIIdleServiceInternal.h"
#include "nsIWindowsRegKey.h"
#include "nsMemory.h"
#include "nsPrintfCString.h"
#include "nsQuickSort.h"
#include "nsServiceManagerUtils.h"
#include "nsToolkit.h"
#include "nsUnicharUtils.h"
#include "nsWindowDbg.h"

#include "KeyboardLayout.h"
#include "WidgetUtils.h"
#include "WinUtils.h"

#include "npapi.h"

#include <windows.h>
#include <winuser.h>
#include <algorithm>

#ifndef WINABLEAPI
#include <winable.h>
#endif

// In WinUser.h, MAPVK_VK_TO_VSC_EX is defined only when WINVER >= 0x0600
#ifndef MAPVK_VK_TO_VSC_EX
#define MAPVK_VK_TO_VSC_EX (4)
#endif

namespace mozilla {
namespace widget {

static const char* kVirtualKeyName[] = {
  "NULL", "VK_LBUTTON", "VK_RBUTTON", "VK_CANCEL",
  "VK_MBUTTON", "VK_XBUTTON1", "VK_XBUTTON2", "0x07",
  "VK_BACK", "VK_TAB", "0x0A", "0x0B",
  "VK_CLEAR", "VK_RETURN", "0x0E", "0x0F",

  "VK_SHIFT", "VK_CONTROL", "VK_MENU", "VK_PAUSE",
  "VK_CAPITAL", "VK_KANA, VK_HANGUL", "0x16", "VK_JUNJA",
  "VK_FINAL", "VK_HANJA, VK_KANJI", "0x1A", "VK_ESCAPE",
  "VK_CONVERT", "VK_NONCONVERT", "VK_ACCEPT", "VK_MODECHANGE",

  "VK_SPACE", "VK_PRIOR", "VK_NEXT", "VK_END",
  "VK_HOME", "VK_LEFT", "VK_UP", "VK_RIGHT",
  "VK_DOWN", "VK_SELECT", "VK_PRINT", "VK_EXECUTE",
  "VK_SNAPSHOT", "VK_INSERT", "VK_DELETE", "VK_HELP",

  "VK_0", "VK_1", "VK_2", "VK_3",
  "VK_4", "VK_5", "VK_6", "VK_7",
  "VK_8", "VK_9", "0x3A", "0x3B",
  "0x3C", "0x3D", "0x3E", "0x3F",

  "0x40", "VK_A", "VK_B", "VK_C",
  "VK_D", "VK_E", "VK_F", "VK_G",
  "VK_H", "VK_I", "VK_J", "VK_K",
  "VK_L", "VK_M", "VK_N", "VK_O",

  "VK_P", "VK_Q", "VK_R", "VK_S",
  "VK_T", "VK_U", "VK_V", "VK_W",
  "VK_X", "VK_Y", "VK_Z", "VK_LWIN",
  "VK_RWIN", "VK_APPS", "0x5E", "VK_SLEEP",

  "VK_NUMPAD0", "VK_NUMPAD1", "VK_NUMPAD2", "VK_NUMPAD3",
  "VK_NUMPAD4", "VK_NUMPAD5", "VK_NUMPAD6", "VK_NUMPAD7",
  "VK_NUMPAD8", "VK_NUMPAD9", "VK_MULTIPLY", "VK_ADD",
  "VK_SEPARATOR", "VK_SUBTRACT", "VK_DECIMAL", "VK_DIVIDE",

  "VK_F1", "VK_F2", "VK_F3", "VK_F4",
  "VK_F5", "VK_F6", "VK_F7", "VK_F8",
  "VK_F9", "VK_F10", "VK_F11", "VK_F12",
  "VK_F13", "VK_F14", "VK_F15", "VK_F16",

  "VK_F17", "VK_F18", "VK_F19", "VK_F20",
  "VK_F21", "VK_F22", "VK_F23", "VK_F24",
  "0x88", "0x89", "0x8A", "0x8B",
  "0x8C", "0x8D", "0x8E", "0x8F",

  "VK_NUMLOCK", "VK_SCROLL", "VK_OEM_NEC_EQUAL, VK_OEM_FJ_JISHO",
    "VK_OEM_FJ_MASSHOU",
  "VK_OEM_FJ_TOUROKU", "VK_OEM_FJ_LOYA", "VK_OEM_FJ_ROYA", "0x97",
  "0x98", "0x99", "0x9A", "0x9B",
  "0x9C", "0x9D", "0x9E", "0x9F",

  "VK_LSHIFT", "VK_RSHIFT", "VK_LCONTROL", "VK_RCONTROL",
  "VK_LMENU", "VK_RMENU", "VK_BROWSER_BACK", "VK_BROWSER_FORWARD",
  "VK_BROWSER_REFRESH", "VK_BROWSER_STOP", "VK_BROWSER_SEARCH",
    "VK_BROWSER_FAVORITES",
  "VK_BROWSER_HOME", "VK_VOLUME_MUTE", "VK_VOLUME_DOWN", "VK_VOLUME_UP",

  "VK_MEDIA_NEXT_TRACK", "VK_MEDIA_PREV_TRACK", "VK_MEDIA_STOP",
    "VK_MEDIA_PLAY_PAUSE",
  "VK_LAUNCH_MAIL", "VK_LAUNCH_MEDIA_SELECT", "VK_LAUNCH_APP1",
    "VK_LAUNCH_APP2",
  "0xB8", "0xB9", "VK_OEM_1", "VK_OEM_PLUS",
  "VK_OEM_COMMA", "VK_OEM_MINUS", "VK_OEM_PERIOD", "VK_OEM_2",

  "VK_OEM_3", "VK_ABNT_C1", "VK_ABNT_C2", "0xC3",
  "0xC4", "0xC5", "0xC6", "0xC7",
  "0xC8", "0xC9", "0xCA", "0xCB",
  "0xCC", "0xCD", "0xCE", "0xCF",

  "0xD0", "0xD1", "0xD2", "0xD3",
  "0xD4", "0xD5", "0xD6", "0xD7",
  "0xD8", "0xD9", "0xDA", "VK_OEM_4",
  "VK_OEM_5", "VK_OEM_6", "VK_OEM_7", "VK_OEM_8",

  "0xE0", "VK_OEM_AX", "VK_OEM_102", "VK_ICO_HELP",
  "VK_ICO_00", "VK_PROCESSKEY", "VK_ICO_CLEAR", "VK_PACKET",
  "0xE8", "VK_OEM_RESET", "VK_OEM_JUMP", "VK_OEM_PA1",
  "VK_OEM_PA2", "VK_OEM_PA3", "VK_OEM_WSCTRL", "VK_OEM_CUSEL",

  "VK_OEM_ATTN", "VK_OEM_FINISH", "VK_OEM_COPY", "VK_OEM_AUTO",
  "VK_OEM_ENLW", "VK_OEM_BACKTAB", "VK_ATTN", "VK_CRSEL",
  "VK_EXSEL", "VK_EREOF", "VK_PLAY", "VK_ZOOM",
  "VK_NONAME", "VK_PA1", "VK_OEM_CLEAR", "0xFF"
};

static_assert(sizeof(kVirtualKeyName) / sizeof(const char*) == 0x100,
  "The virtual key name must be defined just 256 keys");

static const char*
GetBoolName(bool aBool)
{
  return aBool ? "true" : "false";
}

static const nsCString
GetCharacterCodeName(WPARAM aCharCode)
{
  switch (aCharCode) {
    case 0x0000:
      return NS_LITERAL_CSTRING("NULL (0x0000)");
    case 0x0008:
      return NS_LITERAL_CSTRING("BACKSPACE (0x0008)");
    case 0x0009:
      return NS_LITERAL_CSTRING("CHARACTER TABULATION (0x0009)");
    case 0x000A:
      return NS_LITERAL_CSTRING("LINE FEED (0x000A)");
    case 0x000B:
      return NS_LITERAL_CSTRING("LINE TABULATION (0x000B)");
    case 0x000C:
      return NS_LITERAL_CSTRING("FORM FEED (0x000C)");
    case 0x000D:
      return NS_LITERAL_CSTRING("CARRIAGE RETURN (0x000D)");
    case 0x0018:
      return NS_LITERAL_CSTRING("CANCEL (0x0018)");
    case 0x001B:
      return NS_LITERAL_CSTRING("ESCAPE (0x001B)");
    case 0x0020:
      return NS_LITERAL_CSTRING("SPACE (0x0020)");
    case 0x007F:
      return NS_LITERAL_CSTRING("DELETE (0x007F)");
    case 0x00A0:
      return NS_LITERAL_CSTRING("NO-BREAK SPACE (0x00A0)");
    case 0x00AD:
      return NS_LITERAL_CSTRING("SOFT HYPHEN (0x00AD)");
    case 0x2000:
      return NS_LITERAL_CSTRING("EN QUAD (0x2000)");
    case 0x2001:
      return NS_LITERAL_CSTRING("EM QUAD (0x2001)");
    case 0x2002:
      return NS_LITERAL_CSTRING("EN SPACE (0x2002)");
    case 0x2003:
      return NS_LITERAL_CSTRING("EM SPACE (0x2003)");
    case 0x2004:
      return NS_LITERAL_CSTRING("THREE-PER-EM SPACE (0x2004)");
    case 0x2005:
      return NS_LITERAL_CSTRING("FOUR-PER-EM SPACE (0x2005)");
    case 0x2006:
      return NS_LITERAL_CSTRING("SIX-PER-EM SPACE (0x2006)");
    case 0x2007:
      return NS_LITERAL_CSTRING("FIGURE SPACE (0x2007)");
    case 0x2008:
      return NS_LITERAL_CSTRING("PUNCTUATION SPACE (0x2008)");
    case 0x2009:
      return NS_LITERAL_CSTRING("THIN SPACE (0x2009)");
    case 0x200A:
      return NS_LITERAL_CSTRING("HAIR SPACE (0x200A)");
    case 0x200B:
      return NS_LITERAL_CSTRING("ZERO WIDTH SPACE (0x200B)");
    case 0x200C:
      return NS_LITERAL_CSTRING("ZERO WIDTH NON-JOINER (0x200C)");
    case 0x200D:
      return NS_LITERAL_CSTRING("ZERO WIDTH JOINER (0x200D)");
    case 0x200E:
      return NS_LITERAL_CSTRING("LEFT-TO-RIGHT MARK (0x200E)");
    case 0x200F:
      return NS_LITERAL_CSTRING("RIGHT-TO-LEFT MARK (0x200F)");
    case 0x2029:
      return NS_LITERAL_CSTRING("PARAGRAPH SEPARATOR (0x2029)");
    case 0x202A:
      return NS_LITERAL_CSTRING("LEFT-TO-RIGHT EMBEDDING (0x202A)");
    case 0x202B:
      return NS_LITERAL_CSTRING("RIGHT-TO-LEFT EMBEDDING (0x202B)");
    case 0x202D:
      return NS_LITERAL_CSTRING("LEFT-TO-RIGHT OVERRIDE (0x202D)");
    case 0x202E:
      return NS_LITERAL_CSTRING("RIGHT-TO-LEFT OVERRIDE (0x202E)");
    case 0x202F:
      return NS_LITERAL_CSTRING("NARROW NO-BREAK SPACE (0x202F)");
    case 0x205F:
      return NS_LITERAL_CSTRING("MEDIUM MATHEMATICAL SPACE (0x205F)");
    case 0x2060:
      return NS_LITERAL_CSTRING("WORD JOINER (0x2060)");
    case 0x2066:
      return NS_LITERAL_CSTRING("LEFT-TO-RIGHT ISOLATE (0x2066)");
    case 0x2067:
      return NS_LITERAL_CSTRING("RIGHT-TO-LEFT ISOLATE (0x2067)");
    case 0x3000:
      return NS_LITERAL_CSTRING("IDEOGRAPHIC SPACE (0x3000)");
    case 0xFEFF:
      return NS_LITERAL_CSTRING("ZERO WIDTH NO-BREAK SPACE (0xFEFF)");
    default: {
      if (aCharCode < ' ' ||
          (aCharCode >= 0x80 && aCharCode < 0xA0)) {
        return nsPrintfCString("control (0x%04X)", aCharCode);
      }
      if (NS_IS_HIGH_SURROGATE(aCharCode)) {
        return nsPrintfCString("high surrogate (0x%04X)", aCharCode);
      }
      if (NS_IS_LOW_SURROGATE(aCharCode)) {
        return nsPrintfCString("low surrogate (0x%04X)", aCharCode);
      }
      return IS_IN_BMP(aCharCode) ?
        nsPrintfCString("'%s' (0x%04X)",
          NS_ConvertUTF16toUTF8(nsAutoString(aCharCode)).get(), aCharCode) :
        nsPrintfCString("'%s' (0x%08X)",
          NS_ConvertUTF16toUTF8(nsAutoString(aCharCode)).get(), aCharCode);
    }
  }
}

static const nsCString
GetKeyLocationName(uint32_t aLocation)
{
  switch (aLocation) {
    case nsIDOMKeyEvent::DOM_KEY_LOCATION_LEFT:
      return NS_LITERAL_CSTRING("KEY_LOCATION_LEFT");
    case nsIDOMKeyEvent::DOM_KEY_LOCATION_RIGHT:
      return NS_LITERAL_CSTRING("KEY_LOCATION_RIGHT");
    case nsIDOMKeyEvent::DOM_KEY_LOCATION_STANDARD:
      return NS_LITERAL_CSTRING("KEY_LOCATION_STANDARD");
    case nsIDOMKeyEvent::DOM_KEY_LOCATION_NUMPAD:
      return NS_LITERAL_CSTRING("KEY_LOCATION_NUMPAD");
    default:
      return nsPrintfCString("Unknown (0x%04X)", aLocation);
  }
}

static const nsCString
GetCharacterCodeName(char16_t* aChars, uint32_t aLength)
{
  if (!aLength) {
    return NS_LITERAL_CSTRING("");
  }
  nsAutoCString result;
  for (uint32_t i = 0; i < aLength; ++i) {
    if (!result.IsEmpty()) {
      result.AppendLiteral(", ");
    } else {
      result.AssignLiteral("\"");
    }
    result.Append(GetCharacterCodeName(aChars[i]));
  }
  result.AppendLiteral("\"");
  return result;
}

class MOZ_STACK_CLASS GetShiftStateName final : public nsAutoCString
{
public:
  explicit GetShiftStateName(VirtualKey::ShiftState aShiftState)
  {
    if (!aShiftState) {
      AssignLiteral("none");
      return;
    }
    if (aShiftState & VirtualKey::STATE_SHIFT) {
      AssignLiteral("Shift");
      aShiftState &= ~VirtualKey::STATE_SHIFT;
    }
    if (aShiftState & VirtualKey::STATE_CONTROL) {
      MaybeAppendSeparator();
      AssignLiteral("Ctrl");
      aShiftState &= ~VirtualKey::STATE_CONTROL;
    }
    if (aShiftState & VirtualKey::STATE_ALT) {
      MaybeAppendSeparator();
      AssignLiteral("Alt");
      aShiftState &= ~VirtualKey::STATE_ALT;
    }
    if (aShiftState & VirtualKey::STATE_CAPSLOCK) {
      MaybeAppendSeparator();
      AssignLiteral("CapsLock");
      aShiftState &= ~VirtualKey::STATE_CAPSLOCK;
    }
    MOZ_ASSERT(!aShiftState);
  }

private:
  void MaybeAppendSeparator()
  {
    if (!IsEmpty()) {
      AppendLiteral(" | ");
    }
  }
};

static const nsCString
GetMessageName(UINT aMessage)
{
  switch (aMessage) {
    case WM_NULL:
      return NS_LITERAL_CSTRING("WM_NULL");
    case WM_KEYDOWN:
      return NS_LITERAL_CSTRING("WM_KEYDOWN");
    case WM_KEYUP:
      return NS_LITERAL_CSTRING("WM_KEYUP");
    case WM_SYSKEYDOWN:
      return NS_LITERAL_CSTRING("WM_SYSKEYDOWN");
    case WM_SYSKEYUP:
      return NS_LITERAL_CSTRING("WM_SYSKEYUP");
    case WM_CHAR:
      return NS_LITERAL_CSTRING("WM_CHAR");
    case WM_UNICHAR:
      return NS_LITERAL_CSTRING("WM_UNICHAR");
    case WM_SYSCHAR:
      return NS_LITERAL_CSTRING("WM_SYSCHAR");
    case WM_DEADCHAR:
      return NS_LITERAL_CSTRING("WM_DEADCHAR");
    case WM_SYSDEADCHAR:
      return NS_LITERAL_CSTRING("WM_SYSDEADCHAR");
    case MOZ_WM_KEYDOWN:
      return NS_LITERAL_CSTRING("MOZ_WM_KEYDOWN");
    case MOZ_WM_KEYUP:
      return NS_LITERAL_CSTRING("MOZ_WM_KEYUP");
    case WM_APPCOMMAND:
      return NS_LITERAL_CSTRING("WM_APPCOMMAND");
    case WM_QUIT:
      return NS_LITERAL_CSTRING("WM_QUIT");
    default:
      return nsPrintfCString("Unknown Message (0x%04X)", aMessage);
  }
}

static const nsCString
GetVirtualKeyCodeName(WPARAM aVK)
{
  if (aVK >= ArrayLength(kVirtualKeyName)) {
    return nsPrintfCString("Invalid (0x%08X)", aVK);
  }
  return nsCString(kVirtualKeyName[aVK]);
}

static const nsCString
GetAppCommandName(WPARAM aCommand)
{
  switch (aCommand) {
    case APPCOMMAND_BASS_BOOST:
      return NS_LITERAL_CSTRING("APPCOMMAND_BASS_BOOST");
    case APPCOMMAND_BASS_DOWN:
      return NS_LITERAL_CSTRING("APPCOMMAND_BASS_DOWN");
    case APPCOMMAND_BASS_UP:
      return NS_LITERAL_CSTRING("APPCOMMAND_BASS_UP");
    case APPCOMMAND_BROWSER_BACKWARD:
      return NS_LITERAL_CSTRING("APPCOMMAND_BROWSER_BACKWARD");
    case APPCOMMAND_BROWSER_FAVORITES:
      return NS_LITERAL_CSTRING("APPCOMMAND_BROWSER_FAVORITES");
    case APPCOMMAND_BROWSER_FORWARD:
      return NS_LITERAL_CSTRING("APPCOMMAND_BROWSER_FORWARD");
    case APPCOMMAND_BROWSER_HOME:
      return NS_LITERAL_CSTRING("APPCOMMAND_BROWSER_HOME");
    case APPCOMMAND_BROWSER_REFRESH:
      return NS_LITERAL_CSTRING("APPCOMMAND_BROWSER_REFRESH");
    case APPCOMMAND_BROWSER_SEARCH:
      return NS_LITERAL_CSTRING("APPCOMMAND_BROWSER_SEARCH");
    case APPCOMMAND_BROWSER_STOP:
      return NS_LITERAL_CSTRING("APPCOMMAND_BROWSER_STOP");
    case APPCOMMAND_CLOSE:
      return NS_LITERAL_CSTRING("APPCOMMAND_CLOSE");
    case APPCOMMAND_COPY:
      return NS_LITERAL_CSTRING("APPCOMMAND_COPY");
    case APPCOMMAND_CORRECTION_LIST:
      return NS_LITERAL_CSTRING("APPCOMMAND_CORRECTION_LIST");
    case APPCOMMAND_CUT:
      return NS_LITERAL_CSTRING("APPCOMMAND_CUT");
    case APPCOMMAND_DICTATE_OR_COMMAND_CONTROL_TOGGLE:
      return NS_LITERAL_CSTRING("APPCOMMAND_DICTATE_OR_COMMAND_CONTROL_TOGGLE");
    case APPCOMMAND_FIND:
      return NS_LITERAL_CSTRING("APPCOMMAND_FIND");
    case APPCOMMAND_FORWARD_MAIL:
      return NS_LITERAL_CSTRING("APPCOMMAND_FORWARD_MAIL");
    case APPCOMMAND_HELP:
      return NS_LITERAL_CSTRING("APPCOMMAND_HELP");
    case APPCOMMAND_LAUNCH_APP1:
      return NS_LITERAL_CSTRING("APPCOMMAND_LAUNCH_APP1");
    case APPCOMMAND_LAUNCH_APP2:
      return NS_LITERAL_CSTRING("APPCOMMAND_LAUNCH_APP2");
    case APPCOMMAND_LAUNCH_MAIL:
      return NS_LITERAL_CSTRING("APPCOMMAND_LAUNCH_MAIL");
    case APPCOMMAND_LAUNCH_MEDIA_SELECT:
      return NS_LITERAL_CSTRING("APPCOMMAND_LAUNCH_MEDIA_SELECT");
    case APPCOMMAND_MEDIA_CHANNEL_DOWN:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_CHANNEL_DOWN");
    case APPCOMMAND_MEDIA_CHANNEL_UP:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_CHANNEL_UP");
    case APPCOMMAND_MEDIA_FAST_FORWARD:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_FAST_FORWARD");
    case APPCOMMAND_MEDIA_NEXTTRACK:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_NEXTTRACK");
    case APPCOMMAND_MEDIA_PAUSE:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_PAUSE");
    case APPCOMMAND_MEDIA_PLAY:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_PLAY");
    case APPCOMMAND_MEDIA_PLAY_PAUSE:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_PLAY_PAUSE");
    case APPCOMMAND_MEDIA_PREVIOUSTRACK:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_PREVIOUSTRACK");
    case APPCOMMAND_MEDIA_RECORD:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_RECORD");
    case APPCOMMAND_MEDIA_REWIND:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_REWIND");
    case APPCOMMAND_MEDIA_STOP:
      return NS_LITERAL_CSTRING("APPCOMMAND_MEDIA_STOP");
    case APPCOMMAND_MIC_ON_OFF_TOGGLE:
      return NS_LITERAL_CSTRING("APPCOMMAND_MIC_ON_OFF_TOGGLE");
    case APPCOMMAND_MICROPHONE_VOLUME_DOWN:
      return NS_LITERAL_CSTRING("APPCOMMAND_MICROPHONE_VOLUME_DOWN");
    case APPCOMMAND_MICROPHONE_VOLUME_MUTE:
      return NS_LITERAL_CSTRING("APPCOMMAND_MICROPHONE_VOLUME_MUTE");
    case APPCOMMAND_MICROPHONE_VOLUME_UP:
      return NS_LITERAL_CSTRING("APPCOMMAND_MICROPHONE_VOLUME_UP");
    case APPCOMMAND_NEW:
      return NS_LITERAL_CSTRING("APPCOMMAND_NEW");
    case APPCOMMAND_OPEN:
      return NS_LITERAL_CSTRING("APPCOMMAND_OPEN");
    case APPCOMMAND_PASTE:
      return NS_LITERAL_CSTRING("APPCOMMAND_PASTE");
    case APPCOMMAND_PRINT:
      return NS_LITERAL_CSTRING("APPCOMMAND_PRINT");
    case APPCOMMAND_REDO:
      return NS_LITERAL_CSTRING("APPCOMMAND_REDO");
    case APPCOMMAND_REPLY_TO_MAIL:
      return NS_LITERAL_CSTRING("APPCOMMAND_REPLY_TO_MAIL");
    case APPCOMMAND_SAVE:
      return NS_LITERAL_CSTRING("APPCOMMAND_SAVE");
    case APPCOMMAND_SEND_MAIL:
      return NS_LITERAL_CSTRING("APPCOMMAND_SEND_MAIL");
    case APPCOMMAND_SPELL_CHECK:
      return NS_LITERAL_CSTRING("APPCOMMAND_SPELL_CHECK");
    case APPCOMMAND_TREBLE_DOWN:
      return NS_LITERAL_CSTRING("APPCOMMAND_TREBLE_DOWN");
    case APPCOMMAND_TREBLE_UP:
      return NS_LITERAL_CSTRING("APPCOMMAND_TREBLE_UP");
    case APPCOMMAND_UNDO:
      return NS_LITERAL_CSTRING("APPCOMMAND_UNDO");
    case APPCOMMAND_VOLUME_DOWN:
      return NS_LITERAL_CSTRING("APPCOMMAND_VOLUME_DOWN");
    case APPCOMMAND_VOLUME_MUTE:
      return NS_LITERAL_CSTRING("APPCOMMAND_VOLUME_MUTE");
    case APPCOMMAND_VOLUME_UP:
      return NS_LITERAL_CSTRING("APPCOMMAND_VOLUME_UP");
    default:
      return nsPrintfCString("Unknown app command (0x%08X)", aCommand);
  }
}

static const nsCString
GetAppCommandDeviceName(LPARAM aDevice)
{
  switch (aDevice) {
    case FAPPCOMMAND_KEY:
      return NS_LITERAL_CSTRING("FAPPCOMMAND_KEY");
    case FAPPCOMMAND_MOUSE:
      return NS_LITERAL_CSTRING("FAPPCOMMAND_MOUSE");
    case FAPPCOMMAND_OEM:
      return NS_LITERAL_CSTRING("FAPPCOMMAND_OEM");
    default:
      return nsPrintfCString("Unknown app command device (0x%04X)", aDevice);
  }
};

class MOZ_STACK_CLASS GetAppCommandKeysName final : public nsAutoCString
{
public:
  explicit GetAppCommandKeysName(WPARAM aKeys)
  {
    if (aKeys & MK_CONTROL) {
      AppendLiteral("MK_CONTROL");
      aKeys &= ~MK_CONTROL;
    }
    if (aKeys & MK_LBUTTON) {
      MaybeAppendSeparator();
      AppendLiteral("MK_LBUTTON");
      aKeys &= ~MK_LBUTTON;
    }
    if (aKeys & MK_MBUTTON) {
      MaybeAppendSeparator();
      AppendLiteral("MK_MBUTTON");
      aKeys &= ~MK_MBUTTON;
    }
    if (aKeys & MK_RBUTTON) {
      MaybeAppendSeparator();
      AppendLiteral("MK_RBUTTON");
      aKeys &= ~MK_RBUTTON;
    }
    if (aKeys & MK_SHIFT) {
      MaybeAppendSeparator();
      AppendLiteral("MK_SHIFT");
      aKeys &= ~MK_SHIFT;
    }
    if (aKeys & MK_XBUTTON1) {
      MaybeAppendSeparator();
      AppendLiteral("MK_XBUTTON1");
      aKeys &= ~MK_XBUTTON1;
    }
    if (aKeys & MK_XBUTTON2) {
      MaybeAppendSeparator();
      AppendLiteral("MK_XBUTTON2");
      aKeys &= ~MK_XBUTTON2;
    }
    if (aKeys) {
      MaybeAppendSeparator();
      AppendPrintf("Unknown Flags (0x%04X)", aKeys);
    }
    if (IsEmpty()) {
      AssignLiteral("none (0x0000)");
    }
  }

private:
  void MaybeAppendSeparator()
  {
    if (!IsEmpty()) {
      AppendLiteral(" | ");
    }
  }
};

static const nsCString
ToString(const MSG& aMSG)
{
  nsAutoCString result;
  result.AssignLiteral("{ message=");
  result.Append(GetMessageName(aMSG.message).get());
  result.AppendLiteral(", ");
  switch (aMSG.message) {
    case WM_KEYDOWN:
    case WM_KEYUP:
    case WM_SYSKEYDOWN:
    case WM_SYSKEYUP:
    case MOZ_WM_KEYDOWN:
    case MOZ_WM_KEYUP:
      result.AppendPrintf(
               "virtual keycode=%s, repeat count=%d, "
               "scancode=0x%02X, extended key=%s, "
               "context code=%s, previous key state=%s, "
               "transition state=%s",
               GetVirtualKeyCodeName(aMSG.wParam).get(),
               aMSG.lParam & 0xFFFF,
               WinUtils::GetScanCode(aMSG.lParam),
               GetBoolName(WinUtils::IsExtendedScanCode(aMSG.lParam)),
               GetBoolName((aMSG.lParam & (1 << 29)) != 0),
               GetBoolName((aMSG.lParam & (1 << 30)) != 0),
               GetBoolName((aMSG.lParam & (1 << 31)) != 0));
      break;
    case WM_CHAR:
    case WM_DEADCHAR:
    case WM_SYSCHAR:
    case WM_SYSDEADCHAR:
      result.AppendPrintf(
               "character code=%s, repeat count=%d, "
               "scancode=0x%02X, extended key=%s, "
               "context code=%s, previous key state=%s, "
               "transition state=%s",
               GetCharacterCodeName(aMSG.wParam).get(),
               aMSG.lParam & 0xFFFF,
               WinUtils::GetScanCode(aMSG.lParam),
               GetBoolName(WinUtils::IsExtendedScanCode(aMSG.lParam)),
               GetBoolName((aMSG.lParam & (1 << 29)) != 0),
               GetBoolName((aMSG.lParam & (1 << 30)) != 0),
               GetBoolName((aMSG.lParam & (1 << 31)) != 0));
      break;
    case WM_APPCOMMAND:
      result.AppendPrintf(
               "window handle=0x%p, app command=%s, device=%s, dwKeys=%s",
               aMSG.wParam,
               GetAppCommandName(GET_APPCOMMAND_LPARAM(aMSG.lParam)).get(),
               GetAppCommandDeviceName(GET_DEVICE_LPARAM(aMSG.lParam)).get(),
               GetAppCommandKeysName(GET_KEYSTATE_LPARAM(aMSG.lParam)).get());
      break;
    default:
      result.AppendPrintf("wParam=%u, lParam=%u", aMSG.wParam, aMSG.lParam);
      break;
  }
  result.AppendPrintf(", hwnd=0x%p", aMSG.hwnd);
  return result;
}

static const nsCString
ToString(const UniCharsAndModifiers& aUniCharsAndModifiers)
{
  if (aUniCharsAndModifiers.IsEmpty()) {
    return NS_LITERAL_CSTRING("{}");
  }
  nsAutoCString result;
  result.AssignLiteral("{ ");
  result.Append(GetCharacterCodeName(aUniCharsAndModifiers.CharAt(0)));
  for (size_t i = 1; i < aUniCharsAndModifiers.Length(); ++i) {
    if (aUniCharsAndModifiers.ModifiersAt(i - 1) !=
          aUniCharsAndModifiers.ModifiersAt(i)) {
      result.AppendLiteral(" [");
      result.Append(GetModifiersName(aUniCharsAndModifiers.ModifiersAt(0)));
      result.AppendLiteral("]");
    }
    result.AppendLiteral(", ");
    result.Append(GetCharacterCodeName(aUniCharsAndModifiers.CharAt(i)));
  }
  result.AppendLiteral(" [");
  uint32_t lastIndex = aUniCharsAndModifiers.Length() - 1;
  result.Append(GetModifiersName(aUniCharsAndModifiers.ModifiersAt(lastIndex)));
  result.AppendLiteral("] }");
  return result;
}

const nsCString
ToString(const ModifierKeyState& aModifierKeyState)
{
  nsAutoCString result;
  result.AssignLiteral("{ ");
  result.Append(GetModifiersName(aModifierKeyState.GetModifiers()).get());
  result.AppendLiteral(" }");
  return result;
}

// Unique id counter associated with a keydown / keypress events. Used in
// identifing keypress events for removal from async event dispatch queue
// in metrofx after preventDefault is called on keydown events.
static uint32_t sUniqueKeyEventId = 0;

struct DeadKeyEntry
{
  char16_t BaseChar;
  char16_t CompositeChar;
};


class DeadKeyTable
{
  friend class KeyboardLayout;

  uint16_t mEntries;
  // KeyboardLayout::AddDeadKeyTable() will allocate as many entries as
  // required.  It is the only way to create new DeadKeyTable instances.
  DeadKeyEntry mTable[1];

  void Init(const DeadKeyEntry* aDeadKeyArray, uint32_t aEntries)
  {
    mEntries = aEntries;
    memcpy(mTable, aDeadKeyArray, aEntries * sizeof(DeadKeyEntry));
  }

  static uint32_t SizeInBytes(uint32_t aEntries)
  {
    return offsetof(DeadKeyTable, mTable) + aEntries * sizeof(DeadKeyEntry);
  }

public:
  uint32_t Entries() const
  {
    return mEntries;
  }

  bool IsEqual(const DeadKeyEntry* aDeadKeyArray, uint32_t aEntries) const
  {
    return (mEntries == aEntries &&
            !memcmp(mTable, aDeadKeyArray,
                    aEntries * sizeof(DeadKeyEntry)));
  }

  char16_t GetCompositeChar(char16_t aBaseChar) const;
};


/*****************************************************************************
 * mozilla::widget::ModifierKeyState
 *****************************************************************************/

ModifierKeyState::ModifierKeyState()
{
  Update();
}

ModifierKeyState::ModifierKeyState(bool aIsShiftDown,
                                   bool aIsControlDown,
                                   bool aIsAltDown)
{
  Update();
  Unset(MODIFIER_SHIFT | MODIFIER_CONTROL | MODIFIER_ALT | MODIFIER_ALTGRAPH);
  Modifiers modifiers = 0;
  if (aIsShiftDown) {
    modifiers |= MODIFIER_SHIFT;
  }
  if (aIsControlDown) {
    modifiers |= MODIFIER_CONTROL;
  }
  if (aIsAltDown) {
    modifiers |= MODIFIER_ALT;
  }
  if (modifiers) {
    Set(modifiers);
  }
}

ModifierKeyState::ModifierKeyState(Modifiers aModifiers) :
  mModifiers(aModifiers)
{
  EnsureAltGr();
}

void
ModifierKeyState::Update()
{
  mModifiers = 0;
  if (IS_VK_DOWN(VK_SHIFT)) {
    mModifiers |= MODIFIER_SHIFT;
  }
  if (IS_VK_DOWN(VK_CONTROL)) {
    mModifiers |= MODIFIER_CONTROL;
  }
  if (IS_VK_DOWN(VK_MENU)) {
    mModifiers |= MODIFIER_ALT;
  }
  if (IS_VK_DOWN(VK_LWIN) || IS_VK_DOWN(VK_RWIN)) {
    mModifiers |= MODIFIER_OS;
  }
  if (::GetKeyState(VK_CAPITAL) & 1) {
    mModifiers |= MODIFIER_CAPSLOCK;
  }
  if (::GetKeyState(VK_NUMLOCK) & 1) {
    mModifiers |= MODIFIER_NUMLOCK;
  }
  if (::GetKeyState(VK_SCROLL) & 1) {
    mModifiers |= MODIFIER_SCROLLLOCK;
  }

  EnsureAltGr();
}

void
ModifierKeyState::Unset(Modifiers aRemovingModifiers)
{
  mModifiers &= ~aRemovingModifiers;
  // Note that we don't need to unset AltGr flag here automatically.
  // For EditorBase, we need to remove Alt and Control flags but AltGr isn't
  // checked in EditorBase, so, it can be kept.
}

void
ModifierKeyState::Set(Modifiers aAddingModifiers)
{
  mModifiers |= aAddingModifiers;
  EnsureAltGr();
}

void
ModifierKeyState::InitInputEvent(WidgetInputEvent& aInputEvent) const
{
  aInputEvent.mModifiers = mModifiers;

  switch(aInputEvent.mClass) {
    case eMouseEventClass:
    case eMouseScrollEventClass:
    case eWheelEventClass:
    case eDragEventClass:
    case eSimpleGestureEventClass:
      InitMouseEvent(aInputEvent);
      break;
    default:
      break;
  }
}

void
ModifierKeyState::InitMouseEvent(WidgetInputEvent& aMouseEvent) const
{
  NS_ASSERTION(aMouseEvent.mClass == eMouseEventClass ||
               aMouseEvent.mClass == eWheelEventClass ||
               aMouseEvent.mClass == eDragEventClass ||
               aMouseEvent.mClass == eSimpleGestureEventClass,
               "called with non-mouse event");

  WidgetMouseEventBase& mouseEvent = *aMouseEvent.AsMouseEventBase();
  mouseEvent.buttons = 0;
  if (::GetKeyState(VK_LBUTTON) < 0) {
    mouseEvent.buttons |= WidgetMouseEvent::eLeftButtonFlag;
  }
  if (::GetKeyState(VK_RBUTTON) < 0) {
    mouseEvent.buttons |= WidgetMouseEvent::eRightButtonFlag;
  }
  if (::GetKeyState(VK_MBUTTON) < 0) {
    mouseEvent.buttons |= WidgetMouseEvent::eMiddleButtonFlag;
  }
  if (::GetKeyState(VK_XBUTTON1) < 0) {
    mouseEvent.buttons |= WidgetMouseEvent::e4thButtonFlag;
  }
  if (::GetKeyState(VK_XBUTTON2) < 0) {
    mouseEvent.buttons |= WidgetMouseEvent::e5thButtonFlag;
  }
}

bool
ModifierKeyState::IsShift() const
{
  return (mModifiers & MODIFIER_SHIFT) != 0;
}

bool
ModifierKeyState::IsControl() const
{
  return (mModifiers & MODIFIER_CONTROL) != 0;
}

bool
ModifierKeyState::IsAlt() const
{
  return (mModifiers & MODIFIER_ALT) != 0;
}

bool
ModifierKeyState::IsAltGr() const
{
  return IsControl() && IsAlt();
}

bool
ModifierKeyState::IsWin() const
{
  return (mModifiers & MODIFIER_OS) != 0;
}

bool
ModifierKeyState::MaybeMatchShortcutKey() const
{
  // If Windows key is pressed, even if both Ctrl key and Alt key are pressed,
  // it's possible to match a shortcut key.
  if (IsWin()) {
    return true;
  }
  // Otherwise, when both Ctrl key and Alt key are pressed, it shouldn't be
  // a shortcut key for Windows since it means pressing AltGr key on
  // some keyboard layouts.
  if (IsControl() ^ IsAlt()) {
    return true;
  }
  // If no modifier key is active except a lockable modifier nor Shift key,
  // the key shouldn't match any shortcut keys (there are Space and
  // Shift+Space, though, let's ignore these special case...).
  return false;
}

bool
ModifierKeyState::IsCapsLocked() const
{
  return (mModifiers & MODIFIER_CAPSLOCK) != 0;
}

bool
ModifierKeyState::IsNumLocked() const
{
  return (mModifiers & MODIFIER_NUMLOCK) != 0;
}

bool
ModifierKeyState::IsScrollLocked() const
{
  return (mModifiers & MODIFIER_SCROLLLOCK) != 0;
}

void
ModifierKeyState::EnsureAltGr()
{
  // If both Control key and Alt key are pressed, it means AltGr is pressed.
  // Ideally, we should check whether the current keyboard layout has AltGr
  // or not.  However, setting AltGr flags for keyboard which doesn't have
  // AltGr must not be serious bug.  So, it should be OK for now.
  if (IsAltGr()) {
    mModifiers |= MODIFIER_ALTGRAPH;
  }
}

/*****************************************************************************
 * mozilla::widget::UniCharsAndModifiers
 *****************************************************************************/

void
UniCharsAndModifiers::Append(char16_t aUniChar, Modifiers aModifiers)
{
  mChars.Append(aUniChar);
  mModifiers.AppendElement(aModifiers);
}

void
UniCharsAndModifiers::FillModifiers(Modifiers aModifiers)
{
  for (size_t i = 0; i < Length(); i++) {
    mModifiers[i] = aModifiers;
  }
}

void
UniCharsAndModifiers::OverwriteModifiersIfBeginsWith(
                        const UniCharsAndModifiers& aOther)
{
  if (!BeginsWith(aOther)) {
    return;
  }
  for (size_t i = 0; i < aOther.Length(); ++i) {
    mModifiers[i] = aOther.mModifiers[i];
  }
}

bool
UniCharsAndModifiers::UniCharsEqual(const UniCharsAndModifiers& aOther) const
{
  return mChars.Equals(aOther.mChars);
}

bool
UniCharsAndModifiers::UniCharsCaseInsensitiveEqual(
                        const UniCharsAndModifiers& aOther) const
{
  nsCaseInsensitiveStringComparator comp;
  return mChars.Equals(aOther.mChars, comp);
}

bool
UniCharsAndModifiers::BeginsWith(const UniCharsAndModifiers& aOther) const
{
  return StringBeginsWith(mChars, aOther.mChars);
}

UniCharsAndModifiers&
UniCharsAndModifiers::operator+=(const UniCharsAndModifiers& aOther)
{
  mChars.Append(aOther.mChars);
  mModifiers.AppendElements(aOther.mModifiers);
  return *this;
}

UniCharsAndModifiers
UniCharsAndModifiers::operator+(const UniCharsAndModifiers& aOther) const
{
  UniCharsAndModifiers result(*this);
  result += aOther;
  return result;
}

/*****************************************************************************
 * mozilla::widget::VirtualKey
 *****************************************************************************/

// static
VirtualKey::ShiftState
VirtualKey::ModifiersToShiftState(Modifiers aModifiers)
{
  ShiftState state = 0;
  if (aModifiers & MODIFIER_SHIFT) {
    state |= STATE_SHIFT;
  }
  if (aModifiers & MODIFIER_CONTROL) {
    state |= STATE_CONTROL;
  }
  if (aModifiers & MODIFIER_ALT) {
    state |= STATE_ALT;
  }
  if (aModifiers & MODIFIER_CAPSLOCK) {
    state |= STATE_CAPSLOCK;
  }
  return state;
}

// static
Modifiers
VirtualKey::ShiftStateToModifiers(ShiftState aShiftState)
{
  Modifiers modifiers = 0;
  if (aShiftState & STATE_SHIFT) {
    modifiers |= MODIFIER_SHIFT;
  }
  if (aShiftState & STATE_CONTROL) {
    modifiers |= MODIFIER_CONTROL;
  }
  if (aShiftState & STATE_ALT) {
    modifiers |= MODIFIER_ALT;
  }
  if (aShiftState & STATE_CAPSLOCK) {
    modifiers |= MODIFIER_CAPSLOCK;
  }
  if ((modifiers & (MODIFIER_ALT | MODIFIER_CONTROL)) ==
         (MODIFIER_ALT | MODIFIER_CONTROL)) {
    modifiers |= MODIFIER_ALTGRAPH;
  }
  return modifiers;
}

inline char16_t
VirtualKey::GetCompositeChar(ShiftState aShiftState, char16_t aBaseChar) const
{
  return mShiftStates[aShiftState].DeadKey.Table->GetCompositeChar(aBaseChar);
}

const DeadKeyTable*
VirtualKey::MatchingDeadKeyTable(const DeadKeyEntry* aDeadKeyArray,
                                 uint32_t aEntries) const
{
  if (!mIsDeadKey) {
    return nullptr;
  }

  for (ShiftState shiftState = 0; shiftState < 16; shiftState++) {
    if (!IsDeadKey(shiftState)) {
      continue;
    }
    const DeadKeyTable* dkt = mShiftStates[shiftState].DeadKey.Table;
    if (dkt && dkt->IsEqual(aDeadKeyArray, aEntries)) {
      return dkt;
    }
  }

  return nullptr;
}

void
VirtualKey::SetNormalChars(ShiftState aShiftState,
                           const char16_t* aChars,
                           uint32_t aNumOfChars)
{
  NS_ASSERTION(aShiftState < ArrayLength(mShiftStates), "invalid index");

  SetDeadKey(aShiftState, false);

  for (uint32_t index = 0; index < aNumOfChars; index++) {
    // Ignore legacy non-printable control characters
    mShiftStates[aShiftState].Normal.Chars[index] =
      (aChars[index] >= 0x20) ? aChars[index] : 0;
  }

  uint32_t len = ArrayLength(mShiftStates[aShiftState].Normal.Chars);
  for (uint32_t index = aNumOfChars; index < len; index++) {
    mShiftStates[aShiftState].Normal.Chars[index] = 0;
  }
}

void
VirtualKey::SetDeadChar(ShiftState aShiftState, char16_t aDeadChar)
{
  NS_ASSERTION(aShiftState < ArrayLength(mShiftStates), "invalid index");

  SetDeadKey(aShiftState, true);

  mShiftStates[aShiftState].DeadKey.DeadChar = aDeadChar;
  mShiftStates[aShiftState].DeadKey.Table = nullptr;
}

UniCharsAndModifiers
VirtualKey::GetUniChars(ShiftState aShiftState) const
{
  UniCharsAndModifiers result = GetNativeUniChars(aShiftState);

  const ShiftState STATE_ALT_CONTROL = (STATE_ALT | STATE_CONTROL);
  if (!(aShiftState & STATE_ALT_CONTROL)) {
    return result;
  }

  if (result.IsEmpty()) {
    result = GetNativeUniChars(aShiftState & ~STATE_ALT_CONTROL);
    result.FillModifiers(ShiftStateToModifiers(aShiftState));
    return result;
  }

  if ((aShiftState & STATE_ALT_CONTROL) == STATE_ALT_CONTROL) {
    // Even if the shifted chars and the unshifted chars are same, we
    // should consume the Alt key state and the Ctrl key state when
    // AltGr key is pressed. Because if we don't consume them, the input
    // events are ignored on EditorBase. (I.e., Users cannot input the
    // characters with this key combination.)
    Modifiers finalModifiers = ShiftStateToModifiers(aShiftState);
    finalModifiers &= ~(MODIFIER_ALT | MODIFIER_CONTROL);
    result.FillModifiers(finalModifiers);
    return result;
  }

  UniCharsAndModifiers unmodifiedReslt =
    GetNativeUniChars(aShiftState & ~STATE_ALT_CONTROL);
  if (!result.UniCharsEqual(unmodifiedReslt)) {
    // Otherwise, we should consume the Alt key state and the Ctrl key state
    // only when the shifted chars and unshifted chars are different.
    Modifiers finalModifiers = ShiftStateToModifiers(aShiftState);
    finalModifiers &= ~(MODIFIER_ALT | MODIFIER_CONTROL);
    result.FillModifiers(finalModifiers);
  }
  return result;
}


UniCharsAndModifiers
VirtualKey::GetNativeUniChars(ShiftState aShiftState) const
{
#ifdef DEBUG
  if (aShiftState >= ArrayLength(mShiftStates)) {
    nsPrintfCString warning("Shift state is out of range: "
                            "aShiftState=%d, ArrayLength(mShiftState)=%d",
                            aShiftState, ArrayLength(mShiftStates));
    NS_WARNING(warning.get());
  }
#endif

  UniCharsAndModifiers result;
  Modifiers modifiers = ShiftStateToModifiers(aShiftState);
  if (IsDeadKey(aShiftState)) {
    result.Append(mShiftStates[aShiftState].DeadKey.DeadChar, modifiers);
    return result;
  }

  uint32_t index;
  uint32_t len = ArrayLength(mShiftStates[aShiftState].Normal.Chars);
  for (index = 0;
       index < len && mShiftStates[aShiftState].Normal.Chars[index]; index++) {
    result.Append(mShiftStates[aShiftState].Normal.Chars[index], modifiers);
  }
  return result;
}

// static
void
VirtualKey::FillKbdState(PBYTE aKbdState,
                         const ShiftState aShiftState)
{
  NS_ASSERTION(aShiftState < 16, "aShiftState out of range");

  if (aShiftState & STATE_SHIFT) {
    aKbdState[VK_SHIFT] |= 0x80;
  } else {
    aKbdState[VK_SHIFT]  &= ~0x80;
    aKbdState[VK_LSHIFT] &= ~0x80;
    aKbdState[VK_RSHIFT] &= ~0x80;
  }

  if (aShiftState & STATE_CONTROL) {
    aKbdState[VK_CONTROL] |= 0x80;
  } else {
    aKbdState[VK_CONTROL]  &= ~0x80;
    aKbdState[VK_LCONTROL] &= ~0x80;
    aKbdState[VK_RCONTROL] &= ~0x80;
  }

  if (aShiftState & STATE_ALT) {
    aKbdState[VK_MENU] |= 0x80;
  } else {
    aKbdState[VK_MENU]  &= ~0x80;
    aKbdState[VK_LMENU] &= ~0x80;
    aKbdState[VK_RMENU] &= ~0x80;
  }

  if (aShiftState & STATE_CAPSLOCK) {
    aKbdState[VK_CAPITAL] |= 0x01;
  } else {
    aKbdState[VK_CAPITAL] &= ~0x01;
  }
}

/*****************************************************************************
 * mozilla::widget::NativeKey
 *****************************************************************************/

uint8_t NativeKey::sDispatchedKeyOfAppCommand = 0;
NativeKey* NativeKey::sLatestInstance = nullptr;
const MSG NativeKey::sEmptyMSG = {};

LazyLogModule sNativeKeyLogger("NativeKeyWidgets");

NativeKey::NativeKey(nsWindowBase* aWidget,
                     const MSG& aMessage,
                     const ModifierKeyState& aModKeyState,
                     HKL aOverrideKeyboardLayout,
                     nsTArray<FakeCharMsg>* aFakeCharMsgs)
  : mLastInstance(sLatestInstance)
  , mRemovingMsg(sEmptyMSG)
  , mReceivedMsg(sEmptyMSG)
  , mWidget(aWidget)
  , mDispatcher(aWidget->GetTextEventDispatcher())
  , mMsg(aMessage)
  , mFocusedWndBeforeDispatch(::GetFocus())
  , mDOMKeyCode(0)
  , mKeyNameIndex(KEY_NAME_INDEX_Unidentified)
  , mCodeNameIndex(CODE_NAME_INDEX_UNKNOWN)
  , mModKeyState(aModKeyState)
  , mVirtualKeyCode(0)
  , mOriginalVirtualKeyCode(0)
  , mShiftedLatinChar(0)
  , mUnshiftedLatinChar(0)
  , mScanCode(0)
  , mIsExtended(false)
  , mIsDeadKey(false)
  , mFakeCharMsgs(aFakeCharMsgs && aFakeCharMsgs->Length() ?
                    aFakeCharMsgs : nullptr)
{
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p NativeKey::NativeKey(aWidget=0x%p { GetWindowHandle()=0x%p }, "
     "aMessage=%s, aModKeyState=%s), sLatestInstance=0x%p",
     this, aWidget, aWidget->GetWindowHandle(), ToString(aMessage).get(),
     ToString(aModKeyState).get(), sLatestInstance));

  MOZ_ASSERT(aWidget);
  MOZ_ASSERT(mDispatcher);
  sLatestInstance = this;
  KeyboardLayout* keyboardLayout = KeyboardLayout::GetInstance();
  mKeyboardLayout = keyboardLayout->GetLayout();
  if (aOverrideKeyboardLayout && mKeyboardLayout != aOverrideKeyboardLayout) {
    keyboardLayout->OverrideLayout(aOverrideKeyboardLayout);
    mKeyboardLayout = keyboardLayout->GetLayout();
    MOZ_ASSERT(mKeyboardLayout == aOverrideKeyboardLayout);
    mIsOverridingKeyboardLayout = true;
  } else {
    mIsOverridingKeyboardLayout = false;
  }

  if (mMsg.message == WM_APPCOMMAND) {
    InitWithAppCommand();
  } else {
    InitWithKeyChar();
  }

  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::NativeKey(), mKeyboardLayout=0x%08X, "
     "mFocusedWndBeforeDispatch=0x%p, mDOMKeyCode=0x%04X, "
     "mKeyNameIndex=%s, mCodeNameIndex=%s, mModKeyState=%s, "
     "mVirtualKeyCode=%s, mOriginalVirtualKeyCode=%s, "
     "mCommittedCharsAndModifiers=%s, mInputtingStringAndModifiers=%s, "
     "mShiftedString=%s, mUnshiftedString=%s, mShiftedLatinChar=%s, "
     "mUnshiftedLatinChar=%s, mScanCode=0x%04X, mIsExtended=%s, "
     "mIsDeadKey=%s, mIsPrintableKey=%s, mIsOverridingKeyboardLayout=%s",
     this, mKeyboardLayout, mFocusedWndBeforeDispatch,
     GetDOMKeyCodeName(mDOMKeyCode).get(), ToString(mKeyNameIndex).get(),
     ToString(mCodeNameIndex).get(),
     ToString(mModKeyState).get(),
     GetVirtualKeyCodeName(mVirtualKeyCode).get(),
     GetVirtualKeyCodeName(mOriginalVirtualKeyCode).get(),
     ToString(mCommittedCharsAndModifiers).get(),
     ToString(mInputtingStringAndModifiers).get(),
     ToString(mShiftedString).get(), ToString(mUnshiftedString).get(),
     GetCharacterCodeName(mShiftedLatinChar).get(),
     GetCharacterCodeName(mUnshiftedLatinChar).get(),
     mScanCode, GetBoolName(mIsExtended), GetBoolName(mIsDeadKey),
     GetBoolName(mIsPrintableKey), GetBoolName(mIsOverridingKeyboardLayout)));
}

void
NativeKey::InitWithKeyChar()
{
  mScanCode = WinUtils::GetScanCode(mMsg.lParam);
  mIsExtended = WinUtils::IsExtendedScanCode(mMsg.lParam);
  switch (mMsg.message) {
    case WM_KEYDOWN:
    case WM_SYSKEYDOWN:
    case WM_KEYUP:
    case WM_SYSKEYUP:
    case MOZ_WM_KEYDOWN:
    case MOZ_WM_KEYUP: {
      // First, resolve the IME converted virtual keycode to its original
      // keycode.
      if (mMsg.wParam == VK_PROCESSKEY) {
        mOriginalVirtualKeyCode =
          static_cast<uint8_t>(::ImmGetVirtualKey(mMsg.hwnd));
      } else {
        mOriginalVirtualKeyCode = static_cast<uint8_t>(mMsg.wParam);
      }

      // If the key message is sent from other application like a11y tools, the
      // scancode value might not be set proper value.  Then, probably the value
      // is 0.
      // NOTE: If the virtual keycode can be caused by both non-extended key
      //       and extended key, the API returns the non-extended key's
      //       scancode.  E.g., VK_LEFT causes "4" key on numpad.
      if (!mScanCode && mOriginalVirtualKeyCode != VK_PACKET) {
        uint16_t scanCodeEx = ComputeScanCodeExFromVirtualKeyCode(mMsg.wParam);
        if (scanCodeEx) {
          mScanCode = static_cast<uint8_t>(scanCodeEx & 0xFF);
          uint8_t extended = static_cast<uint8_t>((scanCodeEx & 0xFF00) >> 8);
          mIsExtended = (extended == 0xE0) || (extended == 0xE1);
        }
      }

      // Most keys are not distinguished as left or right keys.
      bool isLeftRightDistinguishedKey = false;

      // mOriginalVirtualKeyCode must not distinguish left or right of
      // Shift, Control or Alt.
      switch (mOriginalVirtualKeyCode) {
        case VK_SHIFT:
        case VK_CONTROL:
        case VK_MENU:
          isLeftRightDistinguishedKey = true;
          break;
        case VK_LSHIFT:
        case VK_RSHIFT:
          mVirtualKeyCode = mOriginalVirtualKeyCode;
          mOriginalVirtualKeyCode = VK_SHIFT;
          isLeftRightDistinguishedKey = true;
          break;
        case VK_LCONTROL:
        case VK_RCONTROL:
          mVirtualKeyCode = mOriginalVirtualKeyCode;
          mOriginalVirtualKeyCode = VK_CONTROL;
          isLeftRightDistinguishedKey = true;
          break;
        case VK_LMENU:
        case VK_RMENU:
          mVirtualKeyCode = mOriginalVirtualKeyCode;
          mOriginalVirtualKeyCode = VK_MENU;
          isLeftRightDistinguishedKey = true;
          break;
      }

      // If virtual keycode (left-right distinguished keycode) is already
      // computed, we don't need to do anymore.
      if (mVirtualKeyCode) {
        break;
      }

      // If the keycode doesn't have LR distinguished keycode, we just set
      // mOriginalVirtualKeyCode to mVirtualKeyCode.  Note that don't compute
      // it from MapVirtualKeyEx() because the scan code might be wrong if
      // the message is sent/posted by other application.  Then, we will compute
      // unexpected keycode from the scan code.
      if (!isLeftRightDistinguishedKey) {
        break;
      }

      NS_ASSERTION(!mVirtualKeyCode,
                   "mVirtualKeyCode has been computed already");

      // Otherwise, compute the virtual keycode with MapVirtualKeyEx().
      mVirtualKeyCode = ComputeVirtualKeyCodeFromScanCodeEx();

      // Following code shouldn't be used now because we compute scancode value
      // if we detect that the sender doesn't set proper scancode.
      // However, the detection might fail. Therefore, let's keep using this.
      switch (mOriginalVirtualKeyCode) {
        case VK_CONTROL:
          if (mVirtualKeyCode != VK_LCONTROL &&
              mVirtualKeyCode != VK_RCONTROL) {
            mVirtualKeyCode = mIsExtended ? VK_RCONTROL : VK_LCONTROL;
          }
          break;
        case VK_MENU:
          if (mVirtualKeyCode != VK_LMENU && mVirtualKeyCode != VK_RMENU) {
            mVirtualKeyCode = mIsExtended ? VK_RMENU : VK_LMENU;
          }
          break;
        case VK_SHIFT:
          if (mVirtualKeyCode != VK_LSHIFT && mVirtualKeyCode != VK_RSHIFT) {
            // Neither left shift nor right shift is an extended key,
            // let's use VK_LSHIFT for unknown mapping.
            mVirtualKeyCode = VK_LSHIFT;
          }
          break;
        default:
          MOZ_CRASH("Unsupported mOriginalVirtualKeyCode");
      }
      break;
    }
    case WM_CHAR:
    case WM_UNICHAR:
    case WM_SYSCHAR:
      // If there is another instance and it is trying to remove a char message
      // from the queue, this message should be handled in the old instance.
      if (IsAnotherInstanceRemovingCharMessage()) {
        // XXX Do we need to make mReceivedMsg an array?
        MOZ_ASSERT(IsEmptyMSG(mLastInstance->mReceivedMsg));
        MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
          ("%p   NativeKey::InitWithKeyChar(), WARNING, detecting another "
           "instance is trying to remove a char message, so, this instance "
           "should do nothing, mLastInstance=0x%p, mRemovingMsg=%s, "
           "mReceivedMsg=%s",
           this, mLastInstance, ToString(mLastInstance->mRemovingMsg).get(),
           ToString(mLastInstance->mReceivedMsg).get()));
        mLastInstance->mReceivedMsg = mMsg;
        return;
      }

      // NOTE: If other applications like a11y tools sends WM_*CHAR without
      //       scancode, we cannot compute virtual keycode.  I.e., with such
      //       applications, we cannot generate proper KeyboardEvent.code value.

      mVirtualKeyCode = mOriginalVirtualKeyCode =
        ComputeVirtualKeyCodeFromScanCodeEx();
      NS_ASSERTION(mVirtualKeyCode, "Failed to compute virtual keycode");
      break;
    default:
      MOZ_CRASH("Unsupported message");
  }

  if (!mVirtualKeyCode) {
    mVirtualKeyCode = mOriginalVirtualKeyCode;
  }

  KeyboardLayout* keyboardLayout = KeyboardLayout::GetInstance();
  mDOMKeyCode =
    keyboardLayout->ConvertNativeKeyCodeToDOMKeyCode(mOriginalVirtualKeyCode);
  // Be aware, keyboard utilities can change non-printable keys to printable
  // keys.  In such case, we should make the key value as a printable key.
  // FYI: IsFollowedByPrintableCharMessage() returns true only when it's
  //      handling a keydown message.
  mKeyNameIndex = IsFollowedByPrintableCharMessage() ?
    KEY_NAME_INDEX_USE_STRING :
    keyboardLayout->ConvertNativeKeyCodeToKeyNameIndex(mOriginalVirtualKeyCode);
  mCodeNameIndex =
    KeyboardLayout::ConvertScanCodeToCodeNameIndex(
      GetScanCodeWithExtendedFlag());

  // If next message of WM_(SYS)KEYDOWN is WM_*CHAR message and the key
  // combination is not reserved by the system, let's consume it now.
  // TODO: We cannot initialize mCommittedCharsAndModifiers for VK_PACKET
  //       if the message is WM_KEYUP because we don't have preceding
  //       WM_CHAR message.
  // TODO: Like Edge, we shouldn't dispatch two sets of keyboard events
  //       for a Unicode character in non-BMP because its key value looks
  //       broken and not good thing for our editor if only one keydown or
  //       keypress event's default is prevented.  I guess, we should store
  //       key message information globally and we should wait following
  //       WM_KEYDOWN if following WM_CHAR is a part of a Unicode character.
  if ((mMsg.message == WM_KEYDOWN || mMsg.message == WM_SYSKEYDOWN) &&
      !IsReservedBySystem()) {
    MSG charMsg;
    while (GetFollowingCharMessage(charMsg)) {
      // Although, got message shouldn't be WM_NULL in desktop apps,
      // we should keep checking this.  FYI: This was added for Metrofox.
      if (charMsg.message == WM_NULL) {
        continue;
      }
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::InitWithKeyChar(), removed char message, %s",
         this, ToString(charMsg).get()));
      NS_WARN_IF(charMsg.hwnd != mMsg.hwnd);
      mFollowingCharMsgs.AppendElement(charMsg);
    }
  }

  keyboardLayout->InitNativeKey(*this, mModKeyState);

  mIsDeadKey =
    (IsFollowedByDeadCharMessage() ||
     keyboardLayout->IsDeadKey(mOriginalVirtualKeyCode, mModKeyState));
  mIsPrintableKey =
    mKeyNameIndex == KEY_NAME_INDEX_USE_STRING ||
    KeyboardLayout::IsPrintableCharKey(mOriginalVirtualKeyCode);

  if (IsKeyDownMessage()) {
    // Compute some strings which may be inputted by the key with various
    // modifier state if this key event won't cause text input actually.
    // They will be used for setting mAlternativeCharCodes in the callback
    // method which will be called by TextEventDispatcher.
    if (!IsFollowedByPrintableCharMessage()) {
      ComputeInputtingStringWithKeyboardLayout();
    }
    // Remove odd char messages if there are.
    RemoveFollowingOddCharMessages();
  }
}

void
NativeKey::InitCommittedCharsAndModifiersWithFollowingCharMessages(
             const ModifierKeyState& aModKeyState)
{
  mCommittedCharsAndModifiers.Clear();
  // This should cause inputting text in focused editor.  However, it
  // ignores keypress events whose altKey or ctrlKey is true.
  // Therefore, we need to remove these modifier state here.
  Modifiers modifiers = aModKeyState.GetModifiers();
  if (IsFollowedByPrintableCharMessage()) {
    modifiers &= ~(MODIFIER_ALT | MODIFIER_CONTROL);
  }
  // NOTE: This method assumes that WM_CHAR and WM_SYSCHAR are never retrieved
  //       at same time.
  for (size_t i = 0; i < mFollowingCharMsgs.Length(); ++i) {
    // Ignore non-printable char messages.
    if (!IsPrintableCharOrSysCharMessage(mFollowingCharMsgs[i])) {
      continue;
    }
    char16_t ch = static_cast<char16_t>(mFollowingCharMsgs[i].wParam);
    mCommittedCharsAndModifiers.Append(ch, modifiers);
  }
}

NativeKey::~NativeKey()
{
  MOZ_LOG(sNativeKeyLogger, LogLevel::Debug,
    ("%p   NativeKey::~NativeKey(), destroyed", this));
  if (mIsOverridingKeyboardLayout) {
    KeyboardLayout* keyboardLayout = KeyboardLayout::GetInstance();
    keyboardLayout->RestoreLayout();
  }
  sLatestInstance = mLastInstance;
}

void
NativeKey::InitWithAppCommand()
{
  if (GET_DEVICE_LPARAM(mMsg.lParam) != FAPPCOMMAND_KEY) {
    return;
  }

  uint32_t appCommand = GET_APPCOMMAND_LPARAM(mMsg.lParam);
  switch (GET_APPCOMMAND_LPARAM(mMsg.lParam)) {

#undef NS_APPCOMMAND_TO_DOM_KEY_NAME_INDEX
#define NS_APPCOMMAND_TO_DOM_KEY_NAME_INDEX(aAppCommand, aKeyNameIndex) \
    case aAppCommand: \
      mKeyNameIndex = aKeyNameIndex; \
      break;

#include "NativeKeyToDOMKeyName.h"

#undef NS_APPCOMMAND_TO_DOM_KEY_NAME_INDEX

    default:
      mKeyNameIndex = KEY_NAME_INDEX_Unidentified;
  }

  // Guess the virtual keycode which caused this message.
  switch (appCommand) {
    case APPCOMMAND_BROWSER_BACKWARD:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_BROWSER_BACK;
      break;
    case APPCOMMAND_BROWSER_FORWARD:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_BROWSER_FORWARD;
      break;
    case APPCOMMAND_BROWSER_REFRESH:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_BROWSER_REFRESH;
      break;
    case APPCOMMAND_BROWSER_STOP:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_BROWSER_STOP;
      break;
    case APPCOMMAND_BROWSER_SEARCH:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_BROWSER_SEARCH;
      break;
    case APPCOMMAND_BROWSER_FAVORITES:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_BROWSER_FAVORITES;
      break;
    case APPCOMMAND_BROWSER_HOME:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_BROWSER_HOME;
      break;
    case APPCOMMAND_VOLUME_MUTE:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_VOLUME_MUTE;
      break;
    case APPCOMMAND_VOLUME_DOWN:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_VOLUME_DOWN;
      break;
    case APPCOMMAND_VOLUME_UP:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_VOLUME_UP;
      break;
    case APPCOMMAND_MEDIA_NEXTTRACK:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_MEDIA_NEXT_TRACK;
      break;
    case APPCOMMAND_MEDIA_PREVIOUSTRACK:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_MEDIA_PREV_TRACK;
      break;
    case APPCOMMAND_MEDIA_STOP:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_MEDIA_STOP;
      break;
    case APPCOMMAND_MEDIA_PLAY_PAUSE:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_MEDIA_PLAY_PAUSE;
      break;
    case APPCOMMAND_LAUNCH_MAIL:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_LAUNCH_MAIL;
      break;
    case APPCOMMAND_LAUNCH_MEDIA_SELECT:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_LAUNCH_MEDIA_SELECT;
      break;
    case APPCOMMAND_LAUNCH_APP1:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_LAUNCH_APP1;
      break;
    case APPCOMMAND_LAUNCH_APP2:
      mVirtualKeyCode = mOriginalVirtualKeyCode = VK_LAUNCH_APP2;
      break;
    default:
      return;
  }

  uint16_t scanCodeEx = ComputeScanCodeExFromVirtualKeyCode(mVirtualKeyCode);
  mScanCode = static_cast<uint8_t>(scanCodeEx & 0xFF);
  uint8_t extended = static_cast<uint8_t>((scanCodeEx & 0xFF00) >> 8);
  mIsExtended = (extended == 0xE0) || (extended == 0xE1);
  mDOMKeyCode =
    KeyboardLayout::GetInstance()->
      ConvertNativeKeyCodeToDOMKeyCode(mOriginalVirtualKeyCode);
  mCodeNameIndex =
    KeyboardLayout::ConvertScanCodeToCodeNameIndex(
      GetScanCodeWithExtendedFlag());
}

// static
bool
NativeKey::IsControlChar(char16_t aChar)
{
  static const char16_t U_SPACE = 0x20;
  static const char16_t U_DELETE = 0x7F;
  return aChar < U_SPACE || aChar == U_DELETE;
}

bool
NativeKey::IsFollowedByDeadCharMessage() const
{
  if (mFollowingCharMsgs.IsEmpty()) {
    return false;
  }
  return IsDeadCharMessage(mFollowingCharMsgs[0]);
}

bool
NativeKey::IsFollowedByPrintableCharMessage() const
{
  for (size_t i = 0; i < mFollowingCharMsgs.Length(); ++i) {
    if (IsPrintableCharMessage(mFollowingCharMsgs[i])) {
      return true;
    }
  }
  return false;
}

bool
NativeKey::IsFollowedByPrintableCharOrSysCharMessage() const
{
  for (size_t i = 0; i < mFollowingCharMsgs.Length(); ++i) {
    if (IsPrintableCharOrSysCharMessage(mFollowingCharMsgs[i])) {
      return true;
    }
  }
  return false;
}

bool
NativeKey::IsReservedBySystem() const
{
  // Alt+Space key is handled by OS, we shouldn't touch it.
  if (mModKeyState.IsAlt() && !mModKeyState.IsControl() &&
      mVirtualKeyCode == VK_SPACE) {
    return true;
  }

  // XXX How about Alt+F4? We receive WM_SYSKEYDOWN for F4 before closing the
  //     window.  Although, we don't prevent to close the window but the key
  //     event shouldn't be exposed to the web.

  return false;
}

bool
NativeKey::IsIMEDoingKakuteiUndo() const
{
  // Following message pattern is caused by "Kakutei-Undo" of ATOK or WXG:
  // ---------------------------------------------------------------------------
  // WM_KEYDOWN              * n (wParam = VK_BACK, lParam = 0x1)
  // WM_KEYUP                * 1 (wParam = VK_BACK, lParam = 0xC0000001) # ATOK
  // WM_IME_STARTCOMPOSITION * 1 (wParam = 0x0, lParam = 0x0)
  // WM_IME_COMPOSITION      * 1 (wParam = 0x0, lParam = 0x1BF)
  // WM_CHAR                 * n (wParam = VK_BACK, lParam = 0x1)
  // WM_KEYUP                * 1 (wParam = VK_BACK, lParam = 0xC00E0001)
  // ---------------------------------------------------------------------------
  // This doesn't match usual key message pattern such as:
  //   WM_KEYDOWN -> WM_CHAR -> WM_KEYDOWN -> WM_CHAR -> ... -> WM_KEYUP
  // See following bugs for the detail.
  // https://bugzilla.mozilla.gr.jp/show_bug.cgi?id=2885 (written in Japanese)
  // https://bugzilla.mozilla.org/show_bug.cgi?id=194559 (written in English)
  MSG startCompositionMsg, compositionMsg, charMsg;
  return WinUtils::PeekMessage(&startCompositionMsg, mMsg.hwnd,
                               WM_IME_STARTCOMPOSITION, WM_IME_STARTCOMPOSITION,
                               PM_NOREMOVE | PM_NOYIELD) &&
         WinUtils::PeekMessage(&compositionMsg, mMsg.hwnd, WM_IME_COMPOSITION,
                               WM_IME_COMPOSITION, PM_NOREMOVE | PM_NOYIELD) &&
         WinUtils::PeekMessage(&charMsg, mMsg.hwnd, WM_CHAR, WM_CHAR,
                               PM_NOREMOVE | PM_NOYIELD) &&
         startCompositionMsg.wParam == 0x0 &&
         startCompositionMsg.lParam == 0x0 &&
         compositionMsg.wParam == 0x0 &&
         compositionMsg.lParam == 0x1BF &&
         charMsg.wParam == VK_BACK && charMsg.lParam == 0x1 &&
         startCompositionMsg.time <= compositionMsg.time &&
         compositionMsg.time <= charMsg.time;
}

void
NativeKey::RemoveFollowingOddCharMessages()
{
  MOZ_ASSERT(IsKeyDownMessage());

  // If the keydown message is synthesized for automated tests, there is
  // nothing to do here.
  if (mFakeCharMsgs) {
    return;
  }

  // If there are some following char messages before another key message,
  // there is nothing to do here.
  if (!mFollowingCharMsgs.IsEmpty()) {
    return;
  }

  // If the handling key isn't Backspace, there is nothing to do here.
  if (mOriginalVirtualKeyCode != VK_BACK) {
    return;
  }

  // If we don't see the odd message pattern, there is nothing to do here.
  if (!IsIMEDoingKakuteiUndo()) {
    return;
  }

  // Otherwise, we need to remove odd WM_CHAR messages for ATOK or WXG (both
  // of them are Japanese IME).
  MSG msg;
  while (WinUtils::PeekMessage(&msg, mMsg.hwnd, WM_CHAR, WM_CHAR,
                               PM_REMOVE | PM_NOYIELD)) {
    if (msg.message != WM_CHAR) {
      MOZ_RELEASE_ASSERT(msg.message == WM_NULL,
                         "Unexpected message was removed");
      continue;
    }
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::RemoveFollowingOddCharMessages(), removed odd char "
       "message, %s",
       this, ToString(msg).get()));
    mRemovedOddCharMsgs.AppendElement(msg);
  }
}

UINT
NativeKey::GetScanCodeWithExtendedFlag() const
{
  if (!mIsExtended) {
    return mScanCode;
  }
  return (0xE000 | mScanCode);
}

uint32_t
NativeKey::GetKeyLocation() const
{
  switch (mVirtualKeyCode) {
    case VK_LSHIFT:
    case VK_LCONTROL:
    case VK_LMENU:
    case VK_LWIN:
      return nsIDOMKeyEvent::DOM_KEY_LOCATION_LEFT;

    case VK_RSHIFT:
    case VK_RCONTROL:
    case VK_RMENU:
    case VK_RWIN:
      return nsIDOMKeyEvent::DOM_KEY_LOCATION_RIGHT;

    case VK_RETURN:
      // XXX This code assumes that all keyboard drivers use same mapping.
      return !mIsExtended ? nsIDOMKeyEvent::DOM_KEY_LOCATION_STANDARD :
                            nsIDOMKeyEvent::DOM_KEY_LOCATION_NUMPAD;

    case VK_INSERT:
    case VK_DELETE:
    case VK_END:
    case VK_DOWN:
    case VK_NEXT:
    case VK_LEFT:
    case VK_CLEAR:
    case VK_RIGHT:
    case VK_HOME:
    case VK_UP:
    case VK_PRIOR:
      // XXX This code assumes that all keyboard drivers use same mapping.
      return mIsExtended ? nsIDOMKeyEvent::DOM_KEY_LOCATION_STANDARD :
                           nsIDOMKeyEvent::DOM_KEY_LOCATION_NUMPAD;

    // NumLock key isn't included due to IE9's behavior.
    case VK_NUMPAD0:
    case VK_NUMPAD1:
    case VK_NUMPAD2:
    case VK_NUMPAD3:
    case VK_NUMPAD4:
    case VK_NUMPAD5:
    case VK_NUMPAD6:
    case VK_NUMPAD7:
    case VK_NUMPAD8:
    case VK_NUMPAD9:
    case VK_DECIMAL:
    case VK_DIVIDE:
    case VK_MULTIPLY:
    case VK_SUBTRACT:
    case VK_ADD:
    // Separator key of Brazilian keyboard or JIS keyboard for Mac
    case VK_ABNT_C2:
      return nsIDOMKeyEvent::DOM_KEY_LOCATION_NUMPAD;

    case VK_SHIFT:
    case VK_CONTROL:
    case VK_MENU:
      NS_WARNING("Failed to decide the key location?");

    default:
      return nsIDOMKeyEvent::DOM_KEY_LOCATION_STANDARD;
  }
}

uint8_t
NativeKey::ComputeVirtualKeyCodeFromScanCode() const
{
  return static_cast<uint8_t>(
           ::MapVirtualKeyEx(mScanCode, MAPVK_VSC_TO_VK, mKeyboardLayout));
}

uint8_t
NativeKey::ComputeVirtualKeyCodeFromScanCodeEx() const
{
  // MapVirtualKeyEx() has been improved for supporting extended keys since
  // Vista.  When we call it for mapping a scancode of an extended key and
  // a virtual keycode, we need to add 0xE000 to the scancode.
  return static_cast<uint8_t>(
           ::MapVirtualKeyEx(GetScanCodeWithExtendedFlag(), MAPVK_VSC_TO_VK_EX,
                             mKeyboardLayout));
}

uint16_t
NativeKey::ComputeScanCodeExFromVirtualKeyCode(UINT aVirtualKeyCode) const
{
  return static_cast<uint16_t>(
           ::MapVirtualKeyEx(aVirtualKeyCode,
                             MAPVK_VK_TO_VSC_EX,
                             mKeyboardLayout));
}

char16_t
NativeKey::ComputeUnicharFromScanCode() const
{
  return static_cast<char16_t>(
           ::MapVirtualKeyEx(ComputeVirtualKeyCodeFromScanCode(),
                             MAPVK_VK_TO_CHAR, mKeyboardLayout));
}

nsEventStatus
NativeKey::InitKeyEvent(WidgetKeyboardEvent& aKeyEvent,
                        const MSG* aMsgSentToPlugin) const
{
  return InitKeyEvent(aKeyEvent, mModKeyState, aMsgSentToPlugin);
}

nsEventStatus
NativeKey::InitKeyEvent(WidgetKeyboardEvent& aKeyEvent,
                        const ModifierKeyState& aModKeyState,
                        const MSG* aMsgSentToPlugin) const
{
  if (mWidget->Destroyed()) {
    MOZ_CRASH("NativeKey tries to dispatch a key event on destroyed widget");
  }

  LayoutDeviceIntPoint point(0, 0);
  mWidget->InitEvent(aKeyEvent, &point);

  switch (aKeyEvent.mMessage) {
    case eKeyDown:
    case eKeyDownOnPlugin:
      aKeyEvent.mKeyCode = mDOMKeyCode;
      // Unique id for this keydown event and its associated keypress.
      sUniqueKeyEventId++;
      aKeyEvent.mUniqueId = sUniqueKeyEventId;
      break;
    case eKeyUp:
    case eKeyUpOnPlugin:
      aKeyEvent.mKeyCode = mDOMKeyCode;
      // Set defaultPrevented of the key event if the VK_MENU is not a system
      // key release, so that the menu bar does not trigger.  This helps avoid
      // triggering the menu bar for ALT key accelerators used in assistive
      // technologies such as Window-Eyes and ZoomText or for switching open
      // state of IME.
      if (mOriginalVirtualKeyCode == VK_MENU && mMsg.message != WM_SYSKEYUP) {
        aKeyEvent.PreventDefaultBeforeDispatch();
      }
      break;
    case eKeyPress:
      aKeyEvent.mUniqueId = sUniqueKeyEventId;
      break;
    default:
      MOZ_CRASH("Invalid event message");
  }

  aKeyEvent.mIsRepeat = IsRepeat();
  aKeyEvent.mKeyNameIndex = mKeyNameIndex;
  if (mKeyNameIndex == KEY_NAME_INDEX_USE_STRING) {
    aKeyEvent.mKeyValue = mCommittedCharsAndModifiers.ToString();
  }
  aKeyEvent.mCodeNameIndex = mCodeNameIndex;
  MOZ_ASSERT(mCodeNameIndex != CODE_NAME_INDEX_USE_STRING);
  aKeyEvent.mLocation = GetKeyLocation();
  aModKeyState.InitInputEvent(aKeyEvent);

  if (aMsgSentToPlugin) {
    MaybeInitPluginEventOfKeyEvent(aKeyEvent, *aMsgSentToPlugin);
  }

  KeyboardLayout::NotifyIdleServiceOfUserActivity();

  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::InitKeyEvent(), initialized, aKeyEvent={ "
     "mMessage=%s, mKeyNameIndex=%s, mKeyValue=\"%s\", mCodeNameIndex=%s, "
     "mKeyCode=%s, mLocation=%s, mModifiers=%s, DefaultPrevented()=%s }",
     this, ToChar(aKeyEvent.mMessage),
     ToString(aKeyEvent.mKeyNameIndex).get(),
     NS_ConvertUTF16toUTF8(aKeyEvent.mKeyValue).get(),
     ToString(aKeyEvent.mCodeNameIndex).get(),
     GetDOMKeyCodeName(aKeyEvent.mKeyCode).get(),
     GetKeyLocationName(aKeyEvent.mLocation).get(),
     GetModifiersName(aKeyEvent.mModifiers).get(),
     GetBoolName(aKeyEvent.DefaultPrevented())));

  return aKeyEvent.DefaultPrevented() ? nsEventStatus_eConsumeNoDefault :
                                        nsEventStatus_eIgnore;
}

void
NativeKey::MaybeInitPluginEventOfKeyEvent(WidgetKeyboardEvent& aKeyEvent,
                                          const MSG& aMsgSentToPlugin) const
{
  if (mWidget->GetInputContext().mIMEState.mEnabled != IMEState::PLUGIN) {
    return;
  }
  NPEvent pluginEvent;
  pluginEvent.event = aMsgSentToPlugin.message;
  pluginEvent.wParam = aMsgSentToPlugin.wParam;
  pluginEvent.lParam = aMsgSentToPlugin.lParam;
  aKeyEvent.mPluginEvent.Copy(pluginEvent);
}

bool
NativeKey::DispatchCommandEvent(uint32_t aEventCommand) const
{
  nsCOMPtr<nsIAtom> command;
  switch (aEventCommand) {
    case APPCOMMAND_BROWSER_BACKWARD:
      command = nsGkAtoms::Back;
      break;
    case APPCOMMAND_BROWSER_FORWARD:
      command = nsGkAtoms::Forward;
      break;
    case APPCOMMAND_BROWSER_REFRESH:
      command = nsGkAtoms::Reload;
      break;
    case APPCOMMAND_BROWSER_STOP:
      command = nsGkAtoms::Stop;
      break;
    case APPCOMMAND_BROWSER_SEARCH:
      command = nsGkAtoms::Search;
      break;
    case APPCOMMAND_BROWSER_FAVORITES:
      command = nsGkAtoms::Bookmarks;
      break;
    case APPCOMMAND_BROWSER_HOME:
      command = nsGkAtoms::Home;
      break;
    case APPCOMMAND_CLOSE:
      command = nsGkAtoms::Close;
      break;
    case APPCOMMAND_FIND:
      command = nsGkAtoms::Find;
      break;
    case APPCOMMAND_HELP:
      command = nsGkAtoms::Help;
      break;
    case APPCOMMAND_NEW:
      command = nsGkAtoms::New;
      break;
    case APPCOMMAND_OPEN:
      command = nsGkAtoms::Open;
      break;
    case APPCOMMAND_PRINT:
      command = nsGkAtoms::Print;
      break;
    case APPCOMMAND_SAVE:
      command = nsGkAtoms::Save;
      break;
    case APPCOMMAND_FORWARD_MAIL:
      command = nsGkAtoms::ForwardMail;
      break;
    case APPCOMMAND_REPLY_TO_MAIL:
      command = nsGkAtoms::ReplyToMail;
      break;
    case APPCOMMAND_SEND_MAIL:
      command = nsGkAtoms::SendMail;
      break;
    case APPCOMMAND_MEDIA_NEXTTRACK:
      command = nsGkAtoms::NextTrack;
      break;
    case APPCOMMAND_MEDIA_PREVIOUSTRACK:
      command = nsGkAtoms::PreviousTrack;
      break;
    case APPCOMMAND_MEDIA_STOP:
      command = nsGkAtoms::MediaStop;
      break;
    case APPCOMMAND_MEDIA_PLAY_PAUSE:
      command = nsGkAtoms::PlayPause;
      break;
    default:
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::DispatchCommandEvent(), doesn't dispatch command "
         "event", this));
      return false;
  }
  WidgetCommandEvent commandEvent(true, nsGkAtoms::onAppCommand,
                                  command, mWidget);

  mWidget->InitEvent(commandEvent);
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::DispatchCommandEvent(), dispatching %s command event...",
     this, nsAtomCString(command).get()));
  bool ok = mWidget->DispatchWindowEvent(&commandEvent) || mWidget->Destroyed();
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::DispatchCommandEvent(), dispatched command event, "
     "result=%s, mWidget->Destroyed()=%s",
     this, GetBoolName(ok), GetBoolName(mWidget->Destroyed())));
  return ok;
}

bool
NativeKey::HandleAppCommandMessage() const
{
  // If the widget has gone, we should do nothing.
  if (mWidget->Destroyed()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
      ("%p   NativeKey::HandleAppCommandMessage(), WARNING, not handled due to "
       "destroyed the widget", this));
    return false;
  }

  // NOTE: Typical behavior of WM_APPCOMMAND caused by key is, WM_APPCOMMAND
  //       message is _sent_ first.  Then, the DefaultWndProc will _post_
  //       WM_KEYDOWN message and WM_KEYUP message if the keycode for the
  //       command is available (i.e., mVirtualKeyCode is not 0).

  // NOTE: IntelliType (Microsoft's keyboard utility software) always consumes
  //       WM_KEYDOWN and WM_KEYUP.

  // Let's dispatch keydown message before our chrome handles the command
  // when the message is caused by a keypress.  This behavior makes handling
  // WM_APPCOMMAND be a default action of the keydown event.  This means that
  // web applications can handle multimedia keys and prevent our default action.
  // This allow web applications to provide better UX for multimedia keyboard
  // users.
  bool dispatchKeyEvent = (GET_DEVICE_LPARAM(mMsg.lParam) == FAPPCOMMAND_KEY);
  if (dispatchKeyEvent) {
    // If a plug-in window has focus but it didn't consume the message, our
    // window receive WM_APPCOMMAND message.  In this case, we shouldn't
    // dispatch KeyboardEvents because an event handler may access the
    // plug-in process synchronously.
    dispatchKeyEvent =
      WinUtils::IsOurProcessWindow(reinterpret_cast<HWND>(mMsg.wParam));
  }

  bool consumed = false;

  if (dispatchKeyEvent) {
    nsresult rv = mDispatcher->BeginNativeInputTransaction();
    if (NS_WARN_IF(NS_FAILED(rv))) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
        ("%p   NativeKey::HandleAppCommandMessage(), FAILED due to "
         "BeginNativeInputTransaction() failure", this));
      return true;
    }
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleAppCommandMessage(), initializing keydown "
       "event...", this));
    WidgetKeyboardEvent keydownEvent(true, eKeyDown, mWidget);
    nsEventStatus status = InitKeyEvent(keydownEvent, mModKeyState, &mMsg);
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleAppCommandMessage(), tries to dispatch "
       "keydown event...", this));
    // NOTE: If the keydown event is consumed by web contents, we shouldn't
    //       continue to handle the command.
    if (!mDispatcher->DispatchKeyboardEvent(eKeyDown, keydownEvent, status,
                                            const_cast<NativeKey*>(this))) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleAppCommandMessage(), keydown event isn't "
         "dispatched", this));
      // If keyboard event wasn't fired, there must be composition.
      // So, we don't need to dispatch a command event.
      return true;
    }
    consumed = status == nsEventStatus_eConsumeNoDefault;
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleAppCommandMessage(), keydown event was "
       "dispatched, consumed=%s",
       this, GetBoolName(consumed)));
    sDispatchedKeyOfAppCommand = mVirtualKeyCode;
    if (mWidget->Destroyed()) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleAppCommandMessage(), keydown event caused "
         "destroying the widget", this));
      return true;
    }
  }

  // Dispatch a command event or a content command event if the command is
  // supported.
  if (!consumed) {
    uint32_t appCommand = GET_APPCOMMAND_LPARAM(mMsg.lParam);
    EventMessage contentCommandMessage = eVoidEvent;
    switch (appCommand) {
      case APPCOMMAND_BROWSER_BACKWARD:
      case APPCOMMAND_BROWSER_FORWARD:
      case APPCOMMAND_BROWSER_REFRESH:
      case APPCOMMAND_BROWSER_STOP:
      case APPCOMMAND_BROWSER_SEARCH:
      case APPCOMMAND_BROWSER_FAVORITES:
      case APPCOMMAND_BROWSER_HOME:
      case APPCOMMAND_CLOSE:
      case APPCOMMAND_FIND:
      case APPCOMMAND_HELP:
      case APPCOMMAND_NEW:
      case APPCOMMAND_OPEN:
      case APPCOMMAND_PRINT:
      case APPCOMMAND_SAVE:
      case APPCOMMAND_FORWARD_MAIL:
      case APPCOMMAND_REPLY_TO_MAIL:
      case APPCOMMAND_SEND_MAIL:
      case APPCOMMAND_MEDIA_NEXTTRACK:
      case APPCOMMAND_MEDIA_PREVIOUSTRACK:
      case APPCOMMAND_MEDIA_STOP:
      case APPCOMMAND_MEDIA_PLAY_PAUSE:
        // We shouldn't consume the message always because if we don't handle
        // the message, the sender (typically, utility of keyboard or mouse)
        // may send other key messages which indicate well known shortcut key.
        consumed = DispatchCommandEvent(appCommand);
        break;

      // Use content command for following commands:
      case APPCOMMAND_COPY:
        contentCommandMessage = eContentCommandCopy;
        break;
      case APPCOMMAND_CUT:
        contentCommandMessage = eContentCommandCut;
        break;
      case APPCOMMAND_PASTE:
        contentCommandMessage = eContentCommandPaste;
        break;
      case APPCOMMAND_REDO:
        contentCommandMessage = eContentCommandRedo;
        break;
      case APPCOMMAND_UNDO:
        contentCommandMessage = eContentCommandUndo;
        break;
    }

    if (contentCommandMessage) {
      MOZ_ASSERT(!mWidget->Destroyed());
      WidgetContentCommandEvent contentCommandEvent(true, contentCommandMessage,
                                                    mWidget);
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleAppCommandMessage(), dispatching %s event...",
         this, ToChar(contentCommandMessage)));
      mWidget->DispatchWindowEvent(&contentCommandEvent);
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleAppCommandMessage(), dispatched %s event",
         this, ToChar(contentCommandMessage)));
      consumed = true;

      if (mWidget->Destroyed()) {
        MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
          ("%p   NativeKey::HandleAppCommandMessage(), %s event caused "
           "destroying the widget",
           this, ToChar(contentCommandMessage)));
        return true;
      }
    } else {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleAppCommandMessage(), doesn't dispatch content "
         "command event", this));
    }
  }

  // Dispatch a keyup event if the command is caused by pressing a key and
  // the key isn't mapped to a virtual keycode.
  if (dispatchKeyEvent && !mVirtualKeyCode) {
    MOZ_ASSERT(!mWidget->Destroyed());
    nsresult rv = mDispatcher->BeginNativeInputTransaction();
    if (NS_WARN_IF(NS_FAILED(rv))) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
        ("%p   NativeKey::HandleAppCommandMessage(), FAILED due to "
         "BeginNativeInputTransaction() failure", this));
      return true;
    }
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleAppCommandMessage(), initializing keyup "
       "event...", this));
    WidgetKeyboardEvent keyupEvent(true, eKeyUp, mWidget);
    nsEventStatus status = InitKeyEvent(keyupEvent, mModKeyState, &mMsg);
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleAppCommandMessage(), dispatching keyup event...",
       this));
    // NOTE: Ignore if the keyup event is consumed because keyup event
    //       represents just a physical key event state change.
    mDispatcher->DispatchKeyboardEvent(eKeyUp, keyupEvent, status,
                                       const_cast<NativeKey*>(this));
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleAppCommandMessage(), dispatched keyup event",
       this));
    if (mWidget->Destroyed()) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleAppCommandMessage(), %s event caused "
         "destroying the widget", this));
      return true;
    }
  }

  return consumed;
}

bool
NativeKey::HandleKeyDownMessage(bool* aEventDispatched) const
{
  MOZ_ASSERT(IsKeyDownMessage());

  if (aEventDispatched) {
    *aEventDispatched = false;
  }

  if (sDispatchedKeyOfAppCommand &&
      sDispatchedKeyOfAppCommand == mOriginalVirtualKeyCode) {
    // The multimedia key event has already been dispatch from
    // HandleAppCommandMessage().
    sDispatchedKeyOfAppCommand = 0;
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), doesn't dispatch keydown "
       "event due to already dispatched from HandleAppCommandMessage(), ",
       this));
    if (RedirectedKeyDownMessageManager::IsRedirectedMessage(mMsg)) {
      RedirectedKeyDownMessageManager::Forget();
    }
    return true;
  }

  if (IsReservedBySystem()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), doesn't dispatch keydown "
       "event because the key combination is reserved by the system", this));
    if (RedirectedKeyDownMessageManager::IsRedirectedMessage(mMsg)) {
      RedirectedKeyDownMessageManager::Forget();
    }
    return false;
  }

  // If the widget has gone, we should do nothing.
  if (mWidget->Destroyed()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
      ("%p   NativeKey::HandleKeyDownMessage(), WARNING, not handled due to "
       "destroyed the widget", this));
    if (RedirectedKeyDownMessageManager::IsRedirectedMessage(mMsg)) {
      RedirectedKeyDownMessageManager::Forget();
    }
    return false;
  }

  bool defaultPrevented = false;
  if (mFakeCharMsgs || IsKeyMessageOnPlugin() ||
      !RedirectedKeyDownMessageManager::IsRedirectedMessage(mMsg)) {
    nsresult rv = mDispatcher->BeginNativeInputTransaction();
    if (NS_WARN_IF(NS_FAILED(rv))) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
        ("%p   NativeKey::HandleKeyDownMessage(), FAILED due to "
         "BeginNativeInputTransaction() failure", this));
      return true;
    }

    bool isIMEEnabled = WinUtils::IsIMEEnabled(mWidget->GetInputContext());

    MOZ_LOG(sNativeKeyLogger, LogLevel::Debug,
      ("%p   NativeKey::HandleKeyDownMessage(), initializing keydown "
       "event...", this));

    EventMessage keyDownMessage =
      IsKeyMessageOnPlugin() ? eKeyDownOnPlugin : eKeyDown;
    WidgetKeyboardEvent keydownEvent(true, keyDownMessage, mWidget);
    nsEventStatus status = InitKeyEvent(keydownEvent, mModKeyState, &mMsg);
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), dispatching keydown event...",
       this));
    bool dispatched =
      mDispatcher->DispatchKeyboardEvent(keyDownMessage, keydownEvent, status,
                                         const_cast<NativeKey*>(this));
    if (aEventDispatched) {
      *aEventDispatched = dispatched;
    }
    if (!dispatched) {
      // If the keydown event wasn't fired, there must be composition.
      // we don't need to do anything anymore.
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleKeyDownMessage(), doesn't dispatch keypress "
         "event(s) because keydown event isn't dispatched actually", this));
      return false;
    }
    defaultPrevented = status == nsEventStatus_eConsumeNoDefault;

    // We don't need to handle key messages on plugin for eKeyPress since
    // eKeyDownOnPlugin is handled as both eKeyDown and eKeyPress.
    if (IsKeyMessageOnPlugin()) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleKeyDownMessage(), doesn't dispatch keypress "
         "event(s) because it's a keydown message on windowed plugin, "
         "defaultPrevented=%s",
         this, GetBoolName(defaultPrevented)));
      return defaultPrevented;
    }

    if (mWidget->Destroyed() || IsFocusedWindowChanged()) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleKeyDownMessage(), keydown event caused "
         "destroying the widget", this));
      return true;
    }

    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), dispatched keydown event, "
       "dispatched=%s, defaultPrevented=%s",
       this, GetBoolName(dispatched), GetBoolName(defaultPrevented)));

    // If IMC wasn't associated to the window but is associated it now (i.e.,
    // focus is moved from a non-editable editor to an editor by keydown
    // event handler), WM_CHAR and WM_SYSCHAR shouldn't cause first character
    // inputting if IME is opened.  But then, we should redirect the native
    // keydown message to IME.
    // However, note that if focus has been already moved to another
    // application, we shouldn't redirect the message to it because the keydown
    // message is processed by us, so, nobody shouldn't process it.
    HWND focusedWnd = ::GetFocus();
    if (!defaultPrevented && !mFakeCharMsgs && !IsKeyMessageOnPlugin() &&
        focusedWnd && !mWidget->PluginHasFocus() && !isIMEEnabled &&
        WinUtils::IsIMEEnabled(mWidget->GetInputContext())) {
      RedirectedKeyDownMessageManager::RemoveNextCharMessage(focusedWnd);

      INPUT keyinput;
      keyinput.type = INPUT_KEYBOARD;
      keyinput.ki.wVk = mOriginalVirtualKeyCode;
      keyinput.ki.wScan = mScanCode;
      keyinput.ki.dwFlags = KEYEVENTF_SCANCODE;
      if (mIsExtended) {
        keyinput.ki.dwFlags |= KEYEVENTF_EXTENDEDKEY;
      }
      keyinput.ki.time = 0;
      keyinput.ki.dwExtraInfo = 0;

      RedirectedKeyDownMessageManager::WillRedirect(mMsg, defaultPrevented);

      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleKeyDownMessage(), redirecting %s...",
         this, ToString(mMsg).get()));

      ::SendInput(1, &keyinput, sizeof(keyinput));

      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::HandleKeyDownMessage(), redirected %s",
         this, ToString(mMsg).get()));

      // Return here.  We shouldn't dispatch keypress event for this WM_KEYDOWN.
      // If it's needed, it will be dispatched after next (redirected)
      // WM_KEYDOWN.
      return true;
    }
  } else {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), received a redirected %s",
       this, ToString(mMsg).get()));

    defaultPrevented = RedirectedKeyDownMessageManager::DefaultPrevented();
    // If this is redirected keydown message, we have dispatched the keydown
    // event already.
    if (aEventDispatched) {
      *aEventDispatched = true;
    }
  }

  RedirectedKeyDownMessageManager::Forget();

  MOZ_ASSERT(!mWidget->Destroyed());

  // If the key was processed by IME, we shouldn't dispatch keypress event.
  if (mOriginalVirtualKeyCode == VK_PROCESSKEY) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), not dispatching keypress "
       "event because the key was already handled by IME, defaultPrevented=%s",
       this, GetBoolName(defaultPrevented)));
    return defaultPrevented;
  }

  if (defaultPrevented) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), not dispatching keypress "
       "event because preceding keydown event was consumed",
       this));
    MaybeDispatchPluginEventsForRemovedCharMessages();
    return true;
  }

  // If mCommittedCharsAndModifiers was initialized with following char
  // messages, we should dispatch keypress events with its information.
  if (IsFollowedByPrintableCharOrSysCharMessage()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), tries to be dispatching "
       "keypress events with retrieved char messages...", this));
    return DispatchKeyPressEventsWithRetrievedCharMessages();
  }

  // If we won't be getting a WM_CHAR, WM_SYSCHAR or WM_DEADCHAR, synthesize a
  // keypress for almost all keys
  if (NeedsToHandleWithoutFollowingCharMessages()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), tries to be dispatching "
       "keypress events...", this));
    return (MaybeDispatchPluginEventsForRemovedCharMessages() ||
            DispatchKeyPressEventsWithoutCharMessage());
  }

  // If WM_KEYDOWN of VK_PACKET isn't followed by WM_CHAR, we don't need to
  // dispatch keypress events.
  if (mVirtualKeyCode == VK_PACKET) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), not dispatching keypress event "
       "because the key is VK_PACKET and there are no char messages",
       this));
    return false;
  }

  if (!mModKeyState.IsControl() && !mModKeyState.IsAlt() &&
      !mModKeyState.IsWin() && mIsPrintableKey) {
    // If this is simple KeyDown event but next message is not WM_CHAR,
    // this event may not input text, so we should ignore this event.
    // See bug 314130.
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), not dispatching keypress event "
       "because the key event is simple printable key's event but not followed "
       "by char messages", this));
    return false;
  }

  if (mIsDeadKey) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyDownMessage(), not dispatching keypress event "
       "because the key is a dead key and not followed by char messages",
       this));
    return false;
  }

  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::HandleKeyDownMessage(), tries to be dispatching "
     "keypress events due to no following char messages...", this));
  return DispatchKeyPressEventsWithoutCharMessage();
}

bool
NativeKey::HandleCharMessage(bool* aEventDispatched) const
{
  MOZ_ASSERT(IsCharOrSysCharMessage(mMsg));
  return HandleCharMessage(mMsg, aEventDispatched);
}

bool
NativeKey::HandleCharMessage(const MSG& aCharMsg,
                             bool* aEventDispatched) const
{
  MOZ_ASSERT(IsKeyDownMessage() || IsCharOrSysCharMessage(mMsg));
  MOZ_ASSERT(IsCharOrSysCharMessage(aCharMsg.message));

  if (aEventDispatched) {
    *aEventDispatched = false;
  }

  if (IsCharOrSysCharMessage(mMsg) && IsAnotherInstanceRemovingCharMessage()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
      ("%p   NativeKey::HandleCharMessage(), WARNING, does nothing because "
       "the message should be handled in another instance removing this "
       "message", this));
    // Consume this for now because it will be handled by another instance.
    return true;
  }

  // If the key combinations is reserved by the system, we shouldn't dispatch
  // eKeyPress event for it and passes the message to next wndproc.
  if (IsReservedBySystem()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleCharMessage(), doesn't dispatch keypress "
       "event because the key combination is reserved by the system", this));
    return false;
  }

  // If the widget has gone, we should do nothing.
  if (mWidget->Destroyed()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
      ("%p   NativeKey::HandleCharMessage(), WARNING, not handled due to "
       "destroyed the widget", this));
    return false;
  }

  // When a control key is inputted by a key, it should be handled without
  // WM_*CHAR messages at receiving WM_*KEYDOWN message.  So, when we receive
  // WM_*CHAR message directly, we see a control character here.
  if (IsControlCharMessage(aCharMsg)) {
    // In this case, we don't need to dispatch eKeyPress event because:
    // 1. We're the only browser which dispatches "keypress" event for
    //    non-printable characters (Although, both Chrome and Edge dispatch
    //    "keypress" event for some keys accidentally.  For example, "IntlRo"
    //    key with Ctrl of Japanese keyboard layout).
    // 2. Currently, we may handle shortcut keys with "keydown" event if
    //    it's reserved or something.  So, we shouldn't dispatch "keypress"
    //    event without it.
    // Note that this does NOT mean we stop dispatching eKeyPress event for
    // key presses causes a control character when Ctrl is pressed.  In such
    // case, DispatchKeyPressEventsWithoutCharMessage() dispatches eKeyPress
    // instead of this method.
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleCharMessage(), doesn't dispatch keypress "
       "event because received a control character input without WM_KEYDOWN",
       this));
    return false;
  }

  // XXXmnakano I think that if mMsg is WM_CHAR, i.e., it comes without
  //            preceding WM_KEYDOWN, we should should dispatch composition
  //            events instead of eKeyPress because they are not caused by
  //            actual keyboard operation.

  // First, handle normal text input or non-printable key case here.
  WidgetKeyboardEvent keypressEvent(true, eKeyPress, mWidget);
  keypressEvent.mCharCode = static_cast<uint32_t>(aCharMsg.wParam);
  nsresult rv = mDispatcher->BeginNativeInputTransaction();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
      ("%p   NativeKey::HandleCharMessage(), FAILED due to "
       "BeginNativeInputTransaction() failure", this));
    return true;
  }

  MOZ_LOG(sNativeKeyLogger, LogLevel::Debug,
    ("%p   NativeKey::HandleCharMessage(), initializing keypress "
     "event...", this));

  ModifierKeyState modKeyState(mModKeyState);
  // When AltGr is pressed, both Alt and Ctrl are active.  However, when they
  // are active, EditorBase won't treat the keypress event as inputting a
  // character.  Therefore, when AltGr is pressed and the key tries to input
  // a character, let's set them to false.
  if (modKeyState.IsAltGr() && IsPrintableCharMessage(aCharMsg)) {
    modKeyState.Unset(MODIFIER_ALT | MODIFIER_CONTROL);
  }
  nsEventStatus status = InitKeyEvent(keypressEvent, modKeyState, &aCharMsg);
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::HandleCharMessage(), dispatching keypress event...",
     this));
  bool dispatched =
    mDispatcher->MaybeDispatchKeypressEvents(keypressEvent, status,
                                             const_cast<NativeKey*>(this));
  if (aEventDispatched) {
    *aEventDispatched = dispatched;
  }
  if (mWidget->Destroyed()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleCharMessage(), keypress event caused "
       "destroying the widget", this));
    return true;
  }
  bool consumed = status == nsEventStatus_eConsumeNoDefault;
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::HandleCharMessage(), dispatched keypress event, "
     "dispatched=%s, consumed=%s",
     this, GetBoolName(dispatched), GetBoolName(consumed)));
  return consumed;
}

bool
NativeKey::HandleKeyUpMessage(bool* aEventDispatched) const
{
  MOZ_ASSERT(IsKeyUpMessage());

  if (aEventDispatched) {
    *aEventDispatched = false;
  }

  // If the key combinations is reserved by the system, we shouldn't dispatch
  // eKeyUp event for it and passes the message to next wndproc.
  if (IsReservedBySystem()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyUpMessage(), doesn't dispatch keyup "
       "event because the key combination is reserved by the system", this));
    return false;
  }

  // If the widget has gone, we should do nothing.
  if (mWidget->Destroyed()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
      ("%p   NativeKey::HandleKeyUpMessage(), WARNING, not handled due to "
       "destroyed the widget", this));
    return false;
  }

  nsresult rv = mDispatcher->BeginNativeInputTransaction();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
      ("%p   NativeKey::HandleKeyUpMessage(), FAILED due to "
       "BeginNativeInputTransaction() failure", this));
    return true;
  }

  MOZ_LOG(sNativeKeyLogger, LogLevel::Debug,
    ("%p   NativeKey::HandleKeyUpMessage(), initializing keyup event...",
     this));
  EventMessage keyUpMessage = IsKeyMessageOnPlugin() ? eKeyUpOnPlugin : eKeyUp;
  WidgetKeyboardEvent keyupEvent(true, keyUpMessage, mWidget);
  nsEventStatus status = InitKeyEvent(keyupEvent, mModKeyState, &mMsg);
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::HandleKeyUpMessage(), dispatching keyup event...",
     this));
  bool dispatched =
    mDispatcher->DispatchKeyboardEvent(keyUpMessage, keyupEvent, status,
                                       const_cast<NativeKey*>(this));
  if (aEventDispatched) {
    *aEventDispatched = dispatched;
  }
  if (mWidget->Destroyed()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::HandleKeyUpMessage(), keyup event caused "
       "destroying the widget", this));
    return true;
  }
  bool consumed = status == nsEventStatus_eConsumeNoDefault;
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::HandleKeyUpMessage(), dispatched keyup event, "
     "dispatched=%s, consumed=%s",
     this, GetBoolName(dispatched), GetBoolName(consumed)));
  return consumed;
}

bool
NativeKey::NeedsToHandleWithoutFollowingCharMessages() const
{
  MOZ_ASSERT(IsKeyDownMessage());

  // We cannot know following char messages of key messages in a plugin
  // process.  So, let's compute the character to be inputted with every
  // printable key should be computed with the keyboard layout.
  if (IsKeyMessageOnPlugin()) {
    return true;
  }

  // If the key combination is reserved by the system, the caller shouldn't
  // do anything with following WM_*CHAR messages.  So, let's return true here.
  if (IsReservedBySystem()) {
    return true;
  }

  // If the keydown message is generated for inputting some Unicode characters
  // via SendInput() API, we need to handle it only with WM_*CHAR messages.
  if (mVirtualKeyCode == VK_PACKET) {
    return false;
  }

  // If following char message is for a control character, it should be handled
  // without WM_CHAR message.  This is typically Ctrl + [a-z].
  if (mFollowingCharMsgs.Length() == 1 &&
      IsControlCharMessage(mFollowingCharMsgs[0])) {
    return true;
  }

  // If keydown message is followed by WM_CHAR or WM_SYSCHAR whose wParam isn't
  // a control character, we should dispatch keypress event with the char
  // message even with any modifier state.
  if (IsFollowedByPrintableCharOrSysCharMessage()) {
    return false;
  }

  // If any modifier keys which may cause printable keys becoming non-printable
  // are not pressed, we don't need special handling for the key.
  if (!mModKeyState.IsControl() && !mModKeyState.IsAlt() &&
      !mModKeyState.IsWin()) {
    return false;
  }

  // If the key event causes dead key event, we don't need to dispatch keypress
  // event.
  if (mIsDeadKey && mCommittedCharsAndModifiers.IsEmpty()) {
    return false;
  }

  // Even if the key is a printable key, it might cause non-printable character
  // input with modifier key(s).
  return mIsPrintableKey;
}

#ifdef MOZ_CRASHREPORTER

static nsCString
GetResultOfInSendMessageEx()
{
  DWORD ret = ::InSendMessageEx(nullptr);
  if (!ret) {
    return NS_LITERAL_CSTRING("ISMEX_NOSEND");
  }
  nsAutoCString result;
  if (ret & ISMEX_CALLBACK) {
    result = "ISMEX_CALLBACK";
  }
  if (ret & ISMEX_NOTIFY) {
    if (!result.IsEmpty()) {
      result += " | ";
    }
    result += "ISMEX_NOTIFY";
  }
  if (ret & ISMEX_REPLIED) {
    if (!result.IsEmpty()) {
      result += " | ";
    }
    result += "ISMEX_REPLIED";
  }
  if (ret & ISMEX_SEND) {
    if (!result.IsEmpty()) {
      result += " | ";
    }
    result += "ISMEX_SEND";
  }
  return result;
}

#endif // #ifdef MOZ_CRASHREPORTER

bool
NativeKey::MayBeSameCharMessage(const MSG& aCharMsg1,
                                const MSG& aCharMsg2) const
{
  // NOTE: Although, we don't know when this case occurs, the scan code value
  //       in lParam may be changed from 0 to something.  The changed value
  //       is different from the scan code of handling keydown message.
  static const LPARAM kScanCodeMask = 0x00FF0000;
  return
    aCharMsg1.message == aCharMsg2.message &&
    aCharMsg1.wParam == aCharMsg2.wParam &&
    (aCharMsg1.lParam & ~kScanCodeMask) == (aCharMsg2.lParam & ~kScanCodeMask);
}

bool
NativeKey::GetFollowingCharMessage(MSG& aCharMsg)
{
  MOZ_ASSERT(IsKeyDownMessage());
  MOZ_ASSERT(!IsKeyMessageOnPlugin());

  aCharMsg.message = WM_NULL;

  if (mFakeCharMsgs) {
    for (size_t i = 0; i < mFakeCharMsgs->Length(); i++) {
      FakeCharMsg& fakeCharMsg = mFakeCharMsgs->ElementAt(i);
      if (fakeCharMsg.mConsumed) {
        continue;
      }
      MSG charMsg = fakeCharMsg.GetCharMsg(mMsg.hwnd);
      fakeCharMsg.mConsumed = true;
      if (!IsCharMessage(charMsg)) {
        return false;
      }
      aCharMsg = charMsg;
      return true;
    }
    return false;
  }

  // If next key message is not char message, we should give up to find a
  // related char message for the handling keydown event for now.
  // Note that it's possible other applications may send other key message
  // after we call TranslateMessage(). That may cause PeekMessage() failing
  // to get char message for the handling keydown message.
  MSG nextKeyMsg;
  if (!WinUtils::PeekMessage(&nextKeyMsg, mMsg.hwnd, WM_KEYFIRST, WM_KEYLAST,
                             PM_NOREMOVE | PM_NOYIELD) ||
      !IsCharMessage(nextKeyMsg)) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Verbose,
      ("%p   NativeKey::GetFollowingCharMessage(), there are no char messages",
       this));
    return false;
  }

  AutoRestore<MSG> saveLastRemovingMsg(mRemovingMsg);
  mRemovingMsg = nextKeyMsg;

  mReceivedMsg = sEmptyMSG;
  AutoRestore<MSG> ensureToClearRecivedMsg(mReceivedMsg);

  // On Metrofox, PeekMessage() sometimes returns WM_NULL even if we specify
  // the message range.  So, if it returns WM_NULL, we should retry to get
  // the following char message it was found above.
  for (uint32_t i = 0; i < 5; i++) {
    MSG removedMsg, nextKeyMsgInAllWindows;
    bool doCrash = false;
    if (!WinUtils::PeekMessage(&removedMsg, mMsg.hwnd,
                               nextKeyMsg.message, nextKeyMsg.message,
                               PM_REMOVE | PM_NOYIELD)) {
      // We meets unexpected case.  We should collect the message queue state
      // and crash for reporting the bug.
      doCrash = true;

      // If another instance was created for the removing message during trying
      // to remove a char message, the instance didn't handle it for preventing
      // recursive handling.  So, let's handle it in this instance.
      if (!IsEmptyMSG(mReceivedMsg)) {
        // If focus is moved to different window, we shouldn't handle it on
        // the widget.  Let's discard it for now.
        if (mReceivedMsg.hwnd != nextKeyMsg.hwnd) {
          MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
            ("%p   NativeKey::GetFollowingCharMessage(), WARNING, received a "
             "char message during removing it from the queue, but it's for "
             "different window, mReceivedMsg=%s, nextKeyMsg=%s",
             this, ToString(mReceivedMsg).get(), ToString(nextKeyMsg).get()));
          // There might still exist char messages, the loop of calling
          // this method should be continued.
          aCharMsg.message = WM_NULL;
          return true;
        }
        // Even if the received message is different from what we tried to
        // remove from the queue, let's take the received message as a part of
        // the result of this key sequence.
        if (mReceivedMsg.message != nextKeyMsg.message ||
            mReceivedMsg.wParam != nextKeyMsg.wParam ||
            mReceivedMsg.lParam != nextKeyMsg.lParam) {
          MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
            ("%p   NativeKey::GetFollowingCharMessage(), WARNING, received a "
             "char message during removing it from the queue, but it's "
             "differnt from what trying to remove from the queue, "
             "aCharMsg=%s, nextKeyMsg=%s",
             this, ToString(mReceivedMsg).get(), ToString(nextKeyMsg).get()));
        } else {
          MOZ_LOG(sNativeKeyLogger, LogLevel::Verbose,
            ("%p   NativeKey::GetFollowingCharMessage(), succeeded to retrieve "
             "next char message via another instance, aCharMsg=%s",
             this, ToString(mReceivedMsg).get()));
        }
        aCharMsg = mReceivedMsg;
        return true;
      }

      // The char message is redirected to different thread's window by focus
      // move or something or just cancelled by external application.
      if (!WinUtils::PeekMessage(&nextKeyMsgInAllWindows, 0,
                                 WM_KEYFIRST, WM_KEYLAST,
                                 PM_NOREMOVE | PM_NOYIELD)) {
        MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
          ("%p   NativeKey::GetFollowingCharMessage(), WARNING, failed to "
           "remove a char message, but it's already gone from all message "
           "queues, nextKeyMsg=%s",
           this, ToString(nextKeyMsg).get()));
        return true;
      }
      if (MayBeSameCharMessage(nextKeyMsgInAllWindows, nextKeyMsg)) {
        // The char message is redirected to different window created by our
        // thread.
        if (nextKeyMsgInAllWindows.hwnd != mMsg.hwnd) {
          aCharMsg = nextKeyMsgInAllWindows;
          MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
            ("%p   NativeKey::GetFollowingCharMessage(), WARNING, failed to "
             "remove a char message, but found in another message queue, "
             "nextKeyMsgInAllWindows=%s",
             this, ToString(nextKeyMsgInAllWindows).get()));
          return true;
        }
        // The found char message still in the queue, but PeekMessage() failed
        // to remove it only with PM_REMOVE.  Although, we don't know why this
        // occurs.  However, this occurs acctually.
        // Try to remove the char message with GetMessage() again.
        if (WinUtils::GetMessage(&removedMsg, mMsg.hwnd,
                                 nextKeyMsg.message, nextKeyMsg.message)) {
          MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
            ("%p   NativeKey::GetFollowingCharMessage(), WARNING, failed to "
             "remove a char message, but succeeded with GetMessage(), "
             "removedMsg=%s",
             this, ToString(removedMsg).get()));
          // Cancel to crash, but we need to check the removed message value.
          doCrash = false;
        }
      }
      MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
        ("%p   NativeKey::GetFollowingCharMessage(), FAILED, lost target "
         "message to remove, nextKeyMsg=%s",
         this, ToString(nextKeyMsg).get()));
    }

    if (doCrash) {
#ifdef MOZ_CRASHREPORTER
      nsPrintfCString info("\nPeekMessage() failed to remove char message! "
                           "\nActive keyboard layout=0x%08X (%s), "
                           "\nHandling message: %s, InSendMessageEx()=%s, "
                           "\nFound message: %s, "
                           "\nWM_NULL has been removed: %d, "
                           "\nNext key message in all windows: %s, "
                           "time=%d, ",
                           KeyboardLayout::GetActiveLayout(),
                           KeyboardLayout::GetActiveLayoutName().get(),
                           ToString(mMsg).get(),
                           GetResultOfInSendMessageEx().get(),
                           ToString(nextKeyMsg).get(), i,
                           ToString(nextKeyMsgInAllWindows).get(),
                           nextKeyMsgInAllWindows.time);
      CrashReporter::AppendAppNotesToCrashReport(info);
      MSG nextMsg;
      if (WinUtils::PeekMessage(&nextMsg, 0, 0, 0,
                                PM_NOREMOVE | PM_NOYIELD)) {
        nsPrintfCString info("\nNext message in all windows: %s, time=%d",
                             ToString(nextMsg).get(), nextMsg.time);
        CrashReporter::AppendAppNotesToCrashReport(info);
      } else {
        CrashReporter::AppendAppNotesToCrashReport(
          NS_LITERAL_CSTRING("\nThere is no message in any window"));
      }
#endif // #ifdef MOZ_CRASHREPORTER
      MOZ_CRASH("We lost the following char message");
    }

    // Retry for the strange case.
    if (removedMsg.message == WM_NULL) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
        ("%p   NativeKey::GetFollowingCharMessage(), WARNING, failed to "
         "remove a char message, instead, removed WM_NULL message, ",
         "removedMsg=%s",
         this, ToString(removedMsg).get()));
      continue;
    }

    // Typically, this case occurs with WM_DEADCHAR.  If the removed message's
    // wParam becomes 0, that means that the key event shouldn't cause text
    // input.  So, let's ignore the strange char message.
    if (removedMsg.message == nextKeyMsg.message && !removedMsg.wParam) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
        ("%p   NativeKey::GetFollowingCharMessage(), WARNING, succeeded to "
         "remove a char message, but the removed message's wParam is 0, "
         "removedMsg=%s",
         this, ToString(removedMsg).get()));
      return false;
    }

    // NOTE: Although, we don't know when this case occurs, the scan code value
    //       in lParam may be changed from 0 to something.  The changed value
    //       is different from the scan code of handling keydown message.
    if (!MayBeSameCharMessage(removedMsg, nextKeyMsg)) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
        ("%p   NativeKey::GetFollowingCharMessage(), FAILED, removed message "
         "is really different from what we have already found, removedMsg=%s, "
         "nextKeyMsg=%s",
         this, ToString(removedMsg).get(), ToString(nextKeyMsg).get()));
#ifdef MOZ_CRASHREPORTER
      nsPrintfCString info("\nPeekMessage() removed unexpcted char message! "
                           "\nActive keyboard layout=0x%08X (%s), "
                           "\nHandling message: %s, InSendMessageEx()=%s, "
                           "\nFound message: %s, "
                           "\nRemoved message: %s, ",
                           KeyboardLayout::GetActiveLayout(),
                           KeyboardLayout::GetActiveLayoutName().get(),
                           ToString(mMsg).get(),
                           GetResultOfInSendMessageEx().get(),
                           ToString(nextKeyMsg).get(),
                           ToString(removedMsg).get());
      CrashReporter::AppendAppNotesToCrashReport(info);
      // What's the next key message?
      MSG nextKeyMsgAfter;
      if (WinUtils::PeekMessage(&nextKeyMsgAfter, mMsg.hwnd,
                                WM_KEYFIRST, WM_KEYLAST,
                                PM_NOREMOVE | PM_NOYIELD)) {
        nsPrintfCString info("\nNext key message after unexpected char message "
                             "removed: %s, ",
                             ToString(nextKeyMsgAfter).get());
        CrashReporter::AppendAppNotesToCrashReport(info);
      } else {
        CrashReporter::AppendAppNotesToCrashReport(
          NS_LITERAL_CSTRING("\nThere is no key message after unexpected char "
                             "message removed, "));
      }
      // Another window has a key message?
      MSG nextKeyMsgInAllWindows;
      if (WinUtils::PeekMessage(&nextKeyMsgInAllWindows, 0,
                                WM_KEYFIRST, WM_KEYLAST,
                                PM_NOREMOVE | PM_NOYIELD)) {
        nsPrintfCString info("\nNext key message in all windows: %s.",
                             ToString(nextKeyMsgInAllWindows).get());
        CrashReporter::AppendAppNotesToCrashReport(info);
      } else {
        CrashReporter::AppendAppNotesToCrashReport(
          NS_LITERAL_CSTRING("\nThere is no key message in any windows."));
      }
#endif // #ifdef MOZ_CRASHREPORTER
      MOZ_CRASH("PeekMessage() removed unexpected message");
    }

    aCharMsg = removedMsg;
    MOZ_LOG(sNativeKeyLogger, LogLevel::Verbose,
      ("%p   NativeKey::GetFollowingCharMessage(), succeeded to retrieve next "
       "char message, aCharMsg=%s",
       this, ToString(aCharMsg).get()));
    return true;
  }
  MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
    ("%p   NativeKey::GetFollowingCharMessage(), FAILED, removed messages "
     "are all WM_NULL, nextKeyMsg=%s",
     this, ToString(nextKeyMsg).get()));
#ifdef MOZ_CRASHREPORTER
  nsPrintfCString info("\nWe lost following char message! "
                       "\nActive keyboard layout=0x%08X (%s), "
                       "\nHandling message: %s, InSendMessageEx()=%s, \n"
                       "Found message: %s, removed a lot of WM_NULL",
                       KeyboardLayout::GetActiveLayout(),
                       KeyboardLayout::GetActiveLayoutName().get(),
                       ToString(mMsg).get(),
                       GetResultOfInSendMessageEx().get(),
                       ToString(nextKeyMsg).get());
  CrashReporter::AppendAppNotesToCrashReport(info);
#endif // #ifdef MOZ_CRASHREPORTER
  MOZ_CRASH("We lost the following char message");
  return false;
}

bool
NativeKey::MaybeDispatchPluginEventsForRemovedCharMessages() const
{
  MOZ_ASSERT(IsKeyDownMessage());
  MOZ_ASSERT(!IsKeyMessageOnPlugin());

  for (size_t i = 0;
       i < mFollowingCharMsgs.Length() && mWidget->ShouldDispatchPluginEvent();
       ++i) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::MaybeDispatchPluginEventsForRemovedCharMessages(), "
       "dispatching %uth plugin event for %s...",
       this, i + 1, ToString(mFollowingCharMsgs[i]).get()));
    MOZ_RELEASE_ASSERT(!mWidget->Destroyed(),
      "NativeKey tries to dispatch a plugin event on destroyed widget");
    mWidget->DispatchPluginEvent(mFollowingCharMsgs[i]);
    if (mWidget->Destroyed() || IsFocusedWindowChanged()) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::MaybeDispatchPluginEventsForRemovedCharMessages(), "
         "%uth plugin event caused %s",
         this, i + 1, mWidget->Destroyed() ? "destroying the widget" :
                                             "focus change"));
      return true;
    }
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::MaybeDispatchPluginEventsForRemovedCharMessages(), "
       "dispatched %uth plugin event",
       this, i + 1));
  }

  // Dispatch odd char messages which are caused by ATOK or WXG (both of them
  // are Japanese IME) and removed by RemoveFollowingOddCharMessages().
  for (size_t i = 0;
       i < mRemovedOddCharMsgs.Length() && mWidget->ShouldDispatchPluginEvent();
       ++i) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::MaybeDispatchPluginEventsForRemovedCharMessages(), "
       "dispatching %uth plugin event for odd char message, %s...",
       this, i + 1, ToString(mFollowingCharMsgs[i]).get()));
    MOZ_RELEASE_ASSERT(!mWidget->Destroyed(),
      "NativeKey tries to dispatch a plugin event on destroyed widget");
    mWidget->DispatchPluginEvent(mRemovedOddCharMsgs[i]);
    if (mWidget->Destroyed() || IsFocusedWindowChanged()) {
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::MaybeDispatchPluginEventsForRemovedCharMessages(), "
         "%uth plugin event for odd char message caused %s",
         this, i + 1, mWidget->Destroyed() ? "destroying the widget" :
                                             "focus change"));
      return true;
    }
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::MaybeDispatchPluginEventsForRemovedCharMessages(), "
       "dispatched %uth plugin event for odd char message",
       this, i + 1));
  }

  return false;
}

void
NativeKey::ComputeInputtingStringWithKeyboardLayout()
{
  KeyboardLayout* keyboardLayout = KeyboardLayout::GetInstance();

  if (KeyboardLayout::IsPrintableCharKey(mVirtualKeyCode)) {
    mInputtingStringAndModifiers = mCommittedCharsAndModifiers;
  } else {
    mInputtingStringAndModifiers.Clear();
  }
  mShiftedString.Clear();
  mUnshiftedString.Clear();
  mShiftedLatinChar = mUnshiftedLatinChar = 0;

  // XXX How about when Win key is pressed?
  if (mModKeyState.IsControl() == mModKeyState.IsAlt()) {
    return;
  }

  ModifierKeyState capsLockState(
                     mModKeyState.GetModifiers() & MODIFIER_CAPSLOCK);

  mUnshiftedString =
    keyboardLayout->GetUniCharsAndModifiers(mVirtualKeyCode, capsLockState);
  capsLockState.Set(MODIFIER_SHIFT);
  mShiftedString =
    keyboardLayout->GetUniCharsAndModifiers(mVirtualKeyCode, capsLockState);

  // The current keyboard cannot input alphabets or numerics,
  // we should append them for Shortcut/Access keys.
  // E.g., for Cyrillic keyboard layout.
  capsLockState.Unset(MODIFIER_SHIFT);
  WidgetUtils::GetLatinCharCodeForKeyCode(mDOMKeyCode,
                                          capsLockState.GetModifiers(),
                                          &mUnshiftedLatinChar,
                                          &mShiftedLatinChar);

  // If the mShiftedLatinChar isn't 0, the key code is NS_VK_[A-Z].
  if (mShiftedLatinChar) {
    // If the produced characters of the key on current keyboard layout
    // are same as computed Latin characters, we shouldn't append the
    // Latin characters to alternativeCharCode.
    if (mUnshiftedLatinChar == mUnshiftedString.CharAt(0) &&
        mShiftedLatinChar == mShiftedString.CharAt(0)) {
      mShiftedLatinChar = mUnshiftedLatinChar = 0;
    }
  } else if (mUnshiftedLatinChar) {
    // If the mShiftedLatinChar is 0, the mKeyCode doesn't produce
    // alphabet character.  At that time, the character may be produced
    // with Shift key.  E.g., on French keyboard layout, NS_VK_PERCENT
    // key produces LATIN SMALL LETTER U WITH GRAVE (U+00F9) without
    // Shift key but with Shift key, it produces '%'.
    // If the mUnshiftedLatinChar is produced by the key on current
    // keyboard layout, we shouldn't append it to alternativeCharCode.
    if (mUnshiftedLatinChar == mUnshiftedString.CharAt(0) ||
        mUnshiftedLatinChar == mShiftedString.CharAt(0)) {
      mUnshiftedLatinChar = 0;
    }
  }

  if (!mModKeyState.IsControl()) {
    return;
  }

  // If the mCharCode is not ASCII character, we should replace the
  // mCharCode with ASCII character only when Ctrl is pressed.
  // But don't replace the mCharCode when the mCharCode is not same as
  // unmodified characters. In such case, Ctrl is sometimes used for a
  // part of character inputting key combination like Shift.
  uint32_t ch =
    mModKeyState.IsShift() ? mShiftedLatinChar : mUnshiftedLatinChar;
  if (!ch) {
    return;
  }
  if (mInputtingStringAndModifiers.IsEmpty() ||
      mInputtingStringAndModifiers.UniCharsCaseInsensitiveEqual(
        mModKeyState.IsShift() ? mShiftedString : mUnshiftedString)) {
    mInputtingStringAndModifiers.Clear();
    mInputtingStringAndModifiers.Append(ch, mModKeyState.GetModifiers());
  }
}

bool
NativeKey::DispatchKeyPressEventsWithRetrievedCharMessages() const
{
  MOZ_ASSERT(IsKeyDownMessage());
  MOZ_ASSERT(IsFollowedByPrintableCharOrSysCharMessage());
  MOZ_ASSERT(!mWidget->Destroyed());

  nsresult rv = mDispatcher->BeginNativeInputTransaction();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
      ("%p   NativeKey::DispatchKeyPressEventsWithRetrievedCharMessages(), "
       "FAILED due to BeginNativeInputTransaction() failure", this));
    return true;
  }
  WidgetKeyboardEvent keypressEvent(true, eKeyPress, mWidget);
  MOZ_LOG(sNativeKeyLogger, LogLevel::Debug,
    ("%p   NativeKey::DispatchKeyPressEventsWithRetrievedCharMessages(), "
     "initializing keypress event...", this));
  ModifierKeyState modKeyState(mModKeyState);
  if (IsFollowedByPrintableCharMessage()) {
    // If eKeyPress event should cause inputting text in focused editor,
    // we need to remove Alt and Ctrl state.
    modKeyState.Unset(MODIFIER_ALT | MODIFIER_CONTROL);
  }
  // We don't need to send char message here if there are two or more retrieved
  // messages because we need to set each message to each eKeyPress event.
  bool needsCallback = mFollowingCharMsgs.Length() > 1;
  nsEventStatus status =
    InitKeyEvent(keypressEvent, modKeyState,
                 !needsCallback ? &mFollowingCharMsgs[0] : nullptr);
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::DispatchKeyPressEventsWithRetrievedCharMessages(), "
     "dispatching keypress event(s)...", this));
  bool dispatched =
    mDispatcher->MaybeDispatchKeypressEvents(keypressEvent, status,
                                             const_cast<NativeKey*>(this),
                                             needsCallback);
  if (mWidget->Destroyed()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::DispatchKeyPressEventsWithRetrievedCharMessages(), "
       "keypress event(s) caused destroying the widget", this));
    return true;
  }
  bool consumed = status == nsEventStatus_eConsumeNoDefault;
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::DispatchKeyPressEventsWithRetrievedCharMessages(), "
     "dispatched keypress event(s), dispatched=%s, consumed=%s",
     this, GetBoolName(dispatched), GetBoolName(consumed)));
  return consumed;
}

bool
NativeKey::DispatchKeyPressEventsWithoutCharMessage() const
{
  MOZ_ASSERT(IsKeyDownMessage());
  MOZ_ASSERT(!mIsDeadKey || !mCommittedCharsAndModifiers.IsEmpty());
  MOZ_ASSERT(!mWidget->Destroyed());

  nsresult rv = mDispatcher->BeginNativeInputTransaction();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Error,
      ("%p   NativeKey::DispatchKeyPressEventsWithoutCharMessage(), FAILED due "
       "to BeginNativeInputTransaction() failure", this));
    return true;
  }

  WidgetKeyboardEvent keypressEvent(true, eKeyPress, mWidget);
  if (mInputtingStringAndModifiers.IsEmpty() &&
      mShiftedString.IsEmpty() && mUnshiftedString.IsEmpty()) {
    keypressEvent.mKeyCode = mDOMKeyCode;
  }
  MOZ_LOG(sNativeKeyLogger, LogLevel::Debug,
    ("%p   NativeKey::DispatchKeyPressEventsWithoutCharMessage(), initializing "
     "keypress event...", this));
  nsEventStatus status = InitKeyEvent(keypressEvent, mModKeyState);
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::DispatchKeyPressEventsWithoutCharMessage(), dispatching "
     "keypress event(s)...", this));
  bool dispatched =
    mDispatcher->MaybeDispatchKeypressEvents(keypressEvent, status,
                                             const_cast<NativeKey*>(this));
  if (mWidget->Destroyed()) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::DispatchKeyPressEventsWithoutCharMessage(), "
       "keypress event(s) caused destroying the widget", this));
    return true;
  }
  bool consumed = status == nsEventStatus_eConsumeNoDefault;
  MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
    ("%p   NativeKey::DispatchKeyPressEventsWithoutCharMessage(), dispatched "
     "keypress event(s), dispatched=%s, consumed=%s",
     this, GetBoolName(dispatched), GetBoolName(consumed)));
  return consumed;
}

void
NativeKey::WillDispatchKeyboardEvent(WidgetKeyboardEvent& aKeyboardEvent,
                                     uint32_t aIndex)
{
  // If it's an eKeyPress event and it's generated from retrieved char message,
  // we need to set raw message information for plugins.
  if (aKeyboardEvent.mMessage == eKeyPress &&
      IsFollowedByPrintableCharOrSysCharMessage()) {
    MOZ_RELEASE_ASSERT(aIndex < mCommittedCharsAndModifiers.Length());
    uint32_t foundPrintableCharMessages = 0;
    for (size_t i = 0; i < mFollowingCharMsgs.Length(); ++i) {
      if (!IsPrintableCharOrSysCharMessage(mFollowingCharMsgs[i])) {
        // XXX Should we dispatch a plugin event for WM_*DEADCHAR messages and
        //     WM_CHAR with a control character here?  But we're not sure
        //     how can we create such message queue (i.e., WM_CHAR or
        //     WM_SYSCHAR with a printable character and such message are
        //     generated by a keydown).  So, let's ignore such case until
        //     we'd get some bug reports.
        MOZ_LOG(sNativeKeyLogger, LogLevel::Warning,
          ("%p   NativeKey::WillDispatchKeyboardEvent(), WARNING, "
           "ignoring %uth message due to non-printable char message, %s",
           this, i + 1, ToString(mFollowingCharMsgs[i]).get()));
        continue;
      }
      if (foundPrintableCharMessages++ == aIndex) {
        // Found message which caused the eKeyPress event.  Let's set the
        // message for plugin if it's necessary.
        MaybeInitPluginEventOfKeyEvent(aKeyboardEvent, mFollowingCharMsgs[i]);
        break;
      }
    }
    // Set modifier state from mCommittedCharsAndModifiers because some of them
    // might be different.  For example, Shift key was pressed at inputting
    // dead char but Shift key was released before inputting next character.
    ModifierKeyState modKeyState(mModKeyState);
    modKeyState.Unset(MODIFIER_SHIFT | MODIFIER_CONTROL | MODIFIER_ALT |
                      MODIFIER_ALTGRAPH | MODIFIER_CAPSLOCK);
    modKeyState.Set(mCommittedCharsAndModifiers.ModifiersAt(aIndex));
    modKeyState.InitInputEvent(aKeyboardEvent);
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::WillDispatchKeyboardEvent(), "
       "setting %uth modifier state to %s",
       this, aIndex + 1, ToString(modKeyState).get()));
  }
  size_t longestLength =
    std::max(mInputtingStringAndModifiers.Length(),
             std::max(mShiftedString.Length(), mUnshiftedString.Length()));
  size_t skipUniChars = longestLength - mInputtingStringAndModifiers.Length();
  size_t skipShiftedChars = longestLength - mShiftedString.Length();
  size_t skipUnshiftedChars = longestLength - mUnshiftedString.Length();
  if (aIndex >= longestLength) {
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::WillDispatchKeyboardEvent(), does nothing for %uth "
       "%s event",
       this, aIndex + 1, ToChar(aKeyboardEvent.mMessage)));
    return;
  }

  // Check if aKeyboardEvent is the last event for a key press.
  // So, if it's not an eKeyPress event, it's always the last event.
  // Otherwise, check if the index is the last character of
  // mCommittedCharsAndModifiers.
  bool isLastIndex =
    aKeyboardEvent.mMessage != eKeyPress ||
    mCommittedCharsAndModifiers.IsEmpty() ||
    mCommittedCharsAndModifiers.Length() - 1 == aIndex;

  nsTArray<AlternativeCharCode>& altArray =
    aKeyboardEvent.mAlternativeCharCodes;

  // Set charCode and adjust modifier state for every eKeyPress event.
  // This is not necessary for the other keyboard events because the other
  // keyboard events shouldn't have non-zero charCode value and should have
  // current modifier state.
  if (aKeyboardEvent.mMessage == eKeyPress && skipUniChars <= aIndex) {
    // XXX Modifying modifier state of aKeyboardEvent is illegal, but no way
    //     to set different modifier state per keypress event except this
    //     hack.  Note that ideally, dead key should cause composition events
    //     instead of keypress events, though.
    if (aIndex - skipUniChars  < mInputtingStringAndModifiers.Length()) {
      ModifierKeyState modKeyState(mModKeyState);
      // If key in combination with Alt and/or Ctrl produces a different
      // character than without them then do not report these flags
      // because it is separate keyboard layout shift state. If dead-key
      // and base character does not produce a valid composite character
      // then both produced dead-key character and following base
      // character may have different modifier flags, too.
      modKeyState.Unset(MODIFIER_SHIFT | MODIFIER_CONTROL | MODIFIER_ALT |
                        MODIFIER_ALTGRAPH | MODIFIER_CAPSLOCK);
      modKeyState.Set(
        mInputtingStringAndModifiers.ModifiersAt(aIndex - skipUniChars));
      modKeyState.InitInputEvent(aKeyboardEvent);
      MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
        ("%p   NativeKey::WillDispatchKeyboardEvent(), "
         "setting %uth modifier state to %s",
         this, aIndex + 1, ToString(modKeyState).get()));
    }
    uint16_t uniChar =
      mInputtingStringAndModifiers.CharAt(aIndex - skipUniChars);

    // The mCharCode was set from mKeyValue. However, for example, when Ctrl key
    // is pressed, its value should indicate an ASCII character for backward
    // compatibility rather than inputting character without the modifiers.
    // Therefore, we need to modify mCharCode value here.
    aKeyboardEvent.SetCharCode(uniChar);
    MOZ_LOG(sNativeKeyLogger, LogLevel::Info,
      ("%p   NativeKey::WillDispatchKeyboardEvent(), "
       "setting %uth charCode to %s",
       this, aIndex + 1, GetCharacterCodeName(uniChar).get()));
  }

  // We need to append alterntaive charCode values:
  //   - if the event is eKeyPress, we need to append for the index because
  //     eKeyPress event is dispatched for every character inputted by a
  //     key press.
  //   - if the event is not eKeyPress, we need to append for all characters
  //     inputted by the key press because the other keyboard events (e.g.,
  //     eKeyDown are eKeyUp) are fired only once for a key press.
  size_t count;
  if (aKeyboardEvent.mMessage == eKeyPress) {
    // Basically, append alternative charCode values only for the index.
    count = 1;
    // However, if it's the last eKeyPress event but different shift state
    // can input longer string, the last eKeyPress event should have all
    // remaining alternative charCode values.
    if (isLastIndex) {
      count = longestLength - aIndex;
    }
  } else {
    count = longestLength;
  }
  for (size_t i = 0; i < count; ++i) {
    uint16_t shiftedChar = 0, unshiftedChar = 0;
    if (skipShiftedChars <= aIndex + i) {
      shiftedChar = mShiftedString.CharAt(aIndex + i - skipShiftedChars);
    }
    if (skipUnshiftedChars <= aIndex + i) {
      unshiftedChar = mUnshiftedString.CharAt(aIndex + i - skipUnshiftedChars);
    }

    if (shiftedChar || unshiftedChar) {
      AlternativeCharCode chars(unshiftedChar, shiftedChar);
      altArray.AppendElement(chars);
    }

    if (!isLastIndex) {
      continue;
    }

    if (mUnshiftedLatinChar || mShiftedLatinChar) {
      AlternativeCharCode chars(mUnshiftedLatinChar, mShiftedLatinChar);
      altArray.AppendElement(chars);
    }

    // Typically, following virtual keycodes are used for a key which can
    // input the character.  However, these keycodes are also used for
    // other keys on some keyboard layout.  E.g., in spite of Shift+'1'
    // inputs '+' on Thai keyboard layout, a key which is at '=/+'
    // key on ANSI keyboard layout is VK_OEM_PLUS.  Native applications
    // handle it as '+' key if Ctrl key is pressed.
    char16_t charForOEMKeyCode = 0;
    switch (mVirtualKeyCode) {
      case VK_OEM_PLUS:   charForOEMKeyCode = '+'; break;
      case VK_OEM_COMMA:  charForOEMKeyCode = ','; break;
      case VK_OEM_MINUS:  charForOEMKeyCode = '-'; break;
      case VK_OEM_PERIOD: charForOEMKeyCode = '.'; break;
    }
    if (charForOEMKeyCode &&
        charForOEMKeyCode != mUnshiftedString.CharAt(0) &&
        charForOEMKeyCode != mShiftedString.CharAt(0) &&
        charForOEMKeyCode != mUnshiftedLatinChar &&
        charForOEMKeyCode != mShiftedLatinChar) {
      AlternativeCharCode OEMChars(charForOEMKeyCode, charForOEMKeyCode);
      altArray.AppendElement(OEMChars);
    }
  }
}

/*****************************************************************************
 * mozilla::widget::KeyboardLayout
 *****************************************************************************/

KeyboardLayout* KeyboardLayout::sInstance = nullptr;
nsIIdleServiceInternal* KeyboardLayout::sIdleService = nullptr;

// This log is very noisy if you don't want to retrieve the mapping table
// of specific keyboard layout.  LogLevel::Debug and LogLevel::Verbose are
// used to log the layout mapping.  If you need to log some behavior of
// KeyboardLayout class, you should use LogLevel::Info or lower level.
LazyLogModule sKeyboardLayoutLogger("KeyboardLayoutWidgets");

// static
KeyboardLayout*
KeyboardLayout::GetInstance()
{
  if (!sInstance) {
    sInstance = new KeyboardLayout();
    nsCOMPtr<nsIIdleServiceInternal> idleService =
      do_GetService("@mozilla.org/widget/idleservice;1");
    // The refcount will be decreased at shut down.
    sIdleService = idleService.forget().take();
  }
  return sInstance;
}

// static
void
KeyboardLayout::Shutdown()
{
  delete sInstance;
  sInstance = nullptr;
  NS_IF_RELEASE(sIdleService);
}

// static
void
KeyboardLayout::NotifyIdleServiceOfUserActivity()
{
  sIdleService->ResetIdleTimeOut(0);
}

KeyboardLayout::KeyboardLayout()
  : mKeyboardLayout(0)
  , mIsOverridden(false)
  , mIsPendingToRestoreKeyboardLayout(false)
{
  mDeadKeyTableListHead = nullptr;
  // A dead key sequence should be made from up to 5 keys.  Therefore, 4 is
  // enough and makes sense because the item is uint8_t.
  // (Although, even if it's possible to be 6 keys or more in a sequence,
  // this array will be re-allocated).
  mActiveDeadKeys.SetCapacity(4);
  mDeadKeyShiftStates.SetCapacity(4);

  // NOTE: LoadLayout() should be called via OnLayoutChange().
}

KeyboardLayout::~KeyboardLayout()
{
  ReleaseDeadKeyTables();
}

bool
KeyboardLayout::IsPrintableCharKey(uint8_t aVirtualKey)
{
  return GetKeyIndex(aVirtualKey) >= 0;
}

WORD
KeyboardLayout::ComputeScanCodeForVirtualKeyCode(uint8_t aVirtualKeyCode) const
{
  return static_cast<WORD>(
           ::MapVirtualKeyEx(aVirtualKeyCode, MAPVK_VK_TO_VSC, GetLayout()));
}

bool
KeyboardLayout::IsDeadKey(uint8_t aVirtualKey,
                          const ModifierKeyState& aModKeyState) const
{
  int32_t virtualKeyIndex = GetKeyIndex(aVirtualKey);

  // XXX KeyboardLayout class doesn't support unusual keyboard layout which
  //     maps some function keys as dead keys.
  if (virtualKeyIndex < 0) {
    return false;
  }

  return mVirtualKeys[virtualKeyIndex].IsDeadKey(
           VirtualKey::ModifiersToShiftState(aModKeyState.GetModifiers()));
}

bool
KeyboardLayout::IsSysKey(uint8_t aVirtualKey,
                         const ModifierKeyState& aModKeyState) const
{
  // If Alt key is not pressed, it's never a system key combination.
  // Additionally, if Ctrl key is pressed, it's never a system key combination
  // too.
  // FYI: Windows logo key state won't affect if it's a system key.
  if (!aModKeyState.IsAlt() || aModKeyState.IsControl()) {
    return false;
  }

  int32_t virtualKeyIndex = GetKeyIndex(aVirtualKey);
  if (virtualKeyIndex < 0) {
    return true;
  }

  UniCharsAndModifiers inputCharsAndModifiers =
    GetUniCharsAndModifiers(aVirtualKey, aModKeyState);
  if (inputCharsAndModifiers.IsEmpty()) {
    return true;
  }

  // If the Alt key state isn't consumed, that means that the key with Alt
  // doesn't cause text input.  So, the combination is a system key.
  return !!(inputCharsAndModifiers.ModifiersAt(0) & MODIFIER_ALT);
}

void
KeyboardLayout::InitNativeKey(NativeKey& aNativeKey,
                              const ModifierKeyState& aModKeyState)
{
  if (mIsPendingToRestoreKeyboardLayout) {
    LoadLayout(::GetKeyboardLayout(0));
  }

  // If the aNativeKey is initialized with WM_CHAR, the key information
  // should be discarded because mKeyValue should have the string to be
  // inputted.
  if (aNativeKey.mMsg.message == WM_CHAR) {
    char16_t ch = static_cast<char16_t>(aNativeKey.mMsg.wParam);
    // But don't set key value as printable key if the character is a control
    // character such as 0x0D at pressing Enter key.
    if (!NativeKey::IsControlChar(ch)) {
      aNativeKey.mKeyNameIndex = KEY_NAME_INDEX_USE_STRING;
      Modifiers modifiers =
        aModKeyState.GetModifiers() & ~(MODIFIER_ALT | MODIFIER_CONTROL);
      aNativeKey.mCommittedCharsAndModifiers.Append(ch, modifiers);
      return;
    }
  }

  // When it's followed by non-dead char message(s) for printable character(s),
  // aNativeKey should dispatch eKeyPress events for them rather than
  // information from keyboard layout because respecting WM_(SYS)CHAR messages
  // guarantees that we can always input characters which is expected by
  // the user even if the user uses odd keyboard layout.
  if (aNativeKey.IsFollowedByPrintableCharOrSysCharMessage()) {
    MOZ_ASSERT(!aNativeKey.IsCharMessage(aNativeKey.mMsg));
    // Initialize mCommittedCharsAndModifiers with following char messages.
    aNativeKey.
      InitCommittedCharsAndModifiersWithFollowingCharMessages(aModKeyState);
    MOZ_ASSERT(!aNativeKey.mCommittedCharsAndModifiers.IsEmpty());
    aNativeKey.mKeyNameIndex = KEY_NAME_INDEX_USE_STRING;

    // If it's not in dead key sequence, we don't need to do anymore here.
    if (!IsInDeadKeySequence()) {
      return;
    }

    // If it's in dead key sequence and dead char is inputted as is, we need to
    // set the previous modifier state which is stored when preceding dead key
    // is pressed.
    UniCharsAndModifiers deadChars = GetDeadUniCharsAndModifiers();
    aNativeKey.mCommittedCharsAndModifiers.
                 OverwriteModifiersIfBeginsWith(deadChars);
    // Finish the dead key sequence.
    DeactivateDeadKeyState();
    return;
  }

  // If it's a dead key, aNativeKey will be initialized by
  // MaybeInitNativeKeyAsDeadKey().
  if (MaybeInitNativeKeyAsDeadKey(aNativeKey, aModKeyState)) {
    return;
  }

  // If the key is not a usual printable key, KeyboardLayout class assume that
  // it's not cause dead char nor printable char.  Therefore, there are nothing
  // to do here fore such keys (e.g., function keys).
  // However, this should keep dead key state even if non-printable key is
  // pressed during a dead key sequence.
  if (!IsPrintableCharKey(aNativeKey.mOriginalVirtualKeyCode)) {
    return;
  }

  MOZ_ASSERT(aNativeKey.mOriginalVirtualKeyCode != VK_PACKET,
    "At handling VK_PACKET, we shouldn't refer keyboard layout");
  MOZ_ASSERT(aNativeKey.mKeyNameIndex == KEY_NAME_INDEX_USE_STRING,
    "Printable key's key name index must be KEY_NAME_INDEX_USE_STRING");

  // If it's in dead key handling and the pressed key causes a composite
  // character, aNativeKey will be initialized by
  // MaybeInitNativeKeyWithCompositeChar().
  if (MaybeInitNativeKeyWithCompositeChar(aNativeKey, aModKeyState)) {
    return;
  }

  UniCharsAndModifiers baseChars =
    GetUniCharsAndModifiers(aNativeKey.mOriginalVirtualKeyCode, aModKeyState);

  // If the key press isn't related to any dead keys, initialize aNativeKey
  // with the characters which should be caused by the key.
  if (!IsInDeadKeySequence()) {
    aNativeKey.mCommittedCharsAndModifiers = baseChars;
    return;
  }

  // If the key doesn't cause a composite character with preceding dead key,
  // initialize aNativeKey with the dead-key character followed by current
  // key's character.
  UniCharsAndModifiers deadChars = GetDeadUniCharsAndModifiers();
  aNativeKey.mCommittedCharsAndModifiers = deadChars + baseChars;
  if (aNativeKey.IsKeyDownMessage()) {
    DeactivateDeadKeyState();
  }
}

bool
KeyboardLayout::MaybeInitNativeKeyAsDeadKey(
                  NativeKey& aNativeKey,
                  const ModifierKeyState& aModKeyState)
{
  // Only when it's not in dead key sequence, we can trust IsDeadKey() result.
  if (!IsInDeadKeySequence() &&
      !IsDeadKey(aNativeKey.mOriginalVirtualKeyCode, aModKeyState)) {
    return false;
  }

  // When keydown message is followed by a dead char message, it should be
  // initialized as dead key.
  bool isDeadKeyDownEvent =
    aNativeKey.IsKeyDownMessage() &&
    aNativeKey.IsFollowedByDeadCharMessage();

  // When keyup message is received, let's check if it's one of preceding
  // dead keys because keydown message order and keyup message order may be
  // different.
  bool isDeadKeyUpEvent =
    !aNativeKey.IsKeyDownMessage() &&
    mActiveDeadKeys.Contains(aNativeKey.mOriginalVirtualKeyCode);

  if (isDeadKeyDownEvent || isDeadKeyUpEvent) {
    ActivateDeadKeyState(aNativeKey, aModKeyState);
    // Any dead key events don't generate characters.  So, a dead key should
    // cause only keydown event and keyup event whose KeyboardEvent.key
    // values are "Dead".
    aNativeKey.mCommittedCharsAndModifiers.Clear();
    aNativeKey.mKeyNameIndex = KEY_NAME_INDEX_Dead;
    return true;
  }

  // At keydown message handling, we need to forget the first dead key
  // because there is no guarantee coming WM_KEYUP for the second dead
  // key before next WM_KEYDOWN.  E.g., due to auto key repeat or pressing
  // another dead key before releasing current key.  Therefore, we can
  // set only a character for current key for keyup event.
  if (!IsInDeadKeySequence()) {
    aNativeKey.mCommittedCharsAndModifiers =
      GetUniCharsAndModifiers(aNativeKey.mOriginalVirtualKeyCode, aModKeyState);
    return true;
  }

  // When non-printable key event comes during a dead key sequence, that must
  // be a modifier key event.  So, such events shouldn't be handled as a part
  // of the dead key sequence.
  if (!IsDeadKey(aNativeKey.mOriginalVirtualKeyCode, aModKeyState)) {
    return false;
  }

  // FYI: Following code may run when the user doesn't input text actually
  //      but the key sequence is a dead key sequence.  For example,
  //      ` -> Ctrl+` with Spanish keyboard layout.  Let's keep using this
  //      complicated code for now because this runs really rarely.

  // Dead key followed by another dead key may cause a composed character
  // (e.g., "Russian - Mnemonic" keyboard layout's 's' -> 'c').
  if (MaybeInitNativeKeyWithCompositeChar(aNativeKey, aModKeyState)) {
    return true;
  }

  // Otherwise, dead key followed by another dead key causes inputting both
  // character.
  UniCharsAndModifiers prevDeadChars = GetDeadUniCharsAndModifiers();
  UniCharsAndModifiers newChars =
    GetUniCharsAndModifiers(aNativeKey.mOriginalVirtualKeyCode, aModKeyState);
  // But keypress events should be fired for each committed character.
  aNativeKey.mCommittedCharsAndModifiers = prevDeadChars + newChars;
  if (aNativeKey.IsKeyDownMessage()) {
    DeactivateDeadKeyState();
  }
  return true;
}

bool
KeyboardLayout::MaybeInitNativeKeyWithCompositeChar(
                  NativeKey& aNativeKey,
                  const ModifierKeyState& aModKeyState)
{
  if (!IsInDeadKeySequence()) {
    return false;
  }

  if (NS_WARN_IF(!IsPrintableCharKey(aNativeKey.mOriginalVirtualKeyCode))) {
    return false;
  }

  UniCharsAndModifiers baseChars =
    GetUniCharsAndModifiers(aNativeKey.mOriginalVirtualKeyCode, aModKeyState);
  if (baseChars.IsEmpty() || !baseChars.CharAt(0)) {
    return false;
  }

  char16_t compositeChar = GetCompositeChar(baseChars.CharAt(0));
  if (!compositeChar) {
    return false;
  }

  // Active dead-key and base character does produce exactly one composite
  // character.
  aNativeKey.mCommittedCharsAndModifiers.Append(compositeChar,
                                                baseChars.ModifiersAt(0));
  if (aNativeKey.IsKeyDownMessage()) {
    DeactivateDeadKeyState();
  }
  return true;
}

UniCharsAndModifiers
KeyboardLayout::GetUniCharsAndModifiers(
                  uint8_t aVirtualKey,
                  VirtualKey::ShiftState aShiftState) const
{
  UniCharsAndModifiers result;
  int32_t key = GetKeyIndex(aVirtualKey);
  if (key < 0) {
    return result;
  }
  return mVirtualKeys[key].GetUniChars(aShiftState);
}

UniCharsAndModifiers
KeyboardLayout::GetNativeUniCharsAndModifiers(
                  uint8_t aVirtualKey,
                  const ModifierKeyState& aModKeyState) const
{
  int32_t key = GetKeyIndex(aVirtualKey);
  if (key < 0) {
    return UniCharsAndModifiers();
  }
  VirtualKey::ShiftState shiftState =
    VirtualKey::ModifierKeyStateToShiftState(aModKeyState);
  return mVirtualKeys[key].GetNativeUniChars(shiftState);
}

UniCharsAndModifiers
KeyboardLayout::GetDeadUniCharsAndModifiers() const
{
  MOZ_RELEASE_ASSERT(mActiveDeadKeys.Length() == mDeadKeyShiftStates.Length());

  if (NS_WARN_IF(mActiveDeadKeys.IsEmpty())) {
    return UniCharsAndModifiers();
  }

  UniCharsAndModifiers result;
  for (size_t i = 0; i < mActiveDeadKeys.Length(); ++i) {
    result +=
      GetUniCharsAndModifiers(mActiveDeadKeys[i], mDeadKeyShiftStates[i]);
  }
  return result;
}

char16_t
KeyboardLayout::GetCompositeChar(char16_t aBaseChar) const
{
  if (NS_WARN_IF(mActiveDeadKeys.IsEmpty())) {
    return 0;
  }
  // XXX Currently, we don't support computing a composite character with
  //     two or more dead keys since it needs big table for supporting
  //     long chained dead keys.  However, this should be a minor bug
  //     because this runs only when the latest keydown event does not cause
  //     WM_(SYS)CHAR messages.  So, when user wants to input a character,
  //     this path never runs.
  if (mActiveDeadKeys.Length() > 1) {
    return 0;
  }
  int32_t key = GetKeyIndex(mActiveDeadKeys[0]);
  if (key < 0) {
    return 0;
  }
  return mVirtualKeys[key].GetCompositeChar(mDeadKeyShiftStates[0], aBaseChar);
}

// static
HKL
KeyboardLayout::GetActiveLayout()
{
  return GetInstance()->mKeyboardLayout;
}

// static
nsCString
KeyboardLayout::GetActiveLayoutName()
{
  return GetInstance()->GetLayoutName(GetActiveLayout());
}

static bool IsValidKeyboardLayoutsChild(const nsAString& aChildName)
{
  if (aChildName.Length() != 8) {
    return false;
  }
  for (size_t i = 0; i < aChildName.Length(); i++) {
    if ((aChildName[i] >= '0' && aChildName[i] <= '9') ||
        (aChildName[i] >= 'a' && aChildName[i] <= 'f') ||
        (aChildName[i] >= 'A' && aChildName[i] <= 'F')) {
      continue;
    }
    return false;
  }
  return true;
}

nsCString
KeyboardLayout::GetLayoutName(HKL aLayout) const
{
  const wchar_t kKeyboardLayouts[] =
    L"SYSTEM\\CurrentControlSet\\Control\\Keyboard Layouts\\";
  uint16_t language = reinterpret_cast<uintptr_t>(aLayout) & 0xFFFF;
  uint16_t layout = (reinterpret_cast<uintptr_t>(aLayout) >> 16) & 0xFFFF;
  // If the layout is less than 0xA000XXXX (normal keyboard layout for the
  // language) or 0xEYYYXXXX (IMM-IME), we can retrieve its name simply.
  if (layout < 0xA000 || (layout & 0xF000) == 0xE000) {
    nsAutoString key(kKeyboardLayouts);
    key.AppendPrintf("%08X", layout < 0xA000 ?
                               layout : reinterpret_cast<uintptr_t>(aLayout));
    wchar_t buf[256];
    if (NS_WARN_IF(!WinUtils::GetRegistryKey(HKEY_LOCAL_MACHINE,
                                             key.get(), L"Layout Text",
                                             buf, sizeof(buf)))) {
      return NS_LITERAL_CSTRING("No name or too long name");
    }
    return NS_ConvertUTF16toUTF8(buf);
  }

  if (NS_WARN_IF((layout & 0xF000) != 0xF000)) {
    nsAutoCString result;
    result.AppendPrintf("Odd HKL: 0x%08X",
                        reinterpret_cast<uintptr_t>(aLayout));
    return result;
  }

  // Otherwise, we need to walk the registry under "Keyboard Layouts".
  nsCOMPtr<nsIWindowsRegKey> regKey =
    do_CreateInstance("@mozilla.org/windows-registry-key;1");
  if (NS_WARN_IF(!regKey)) {
    return EmptyCString();
  }
  nsresult rv = regKey->Open(nsIWindowsRegKey::ROOT_KEY_LOCAL_MACHINE,
                             nsString(kKeyboardLayouts),
                             nsIWindowsRegKey::ACCESS_READ);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return EmptyCString();
  }
  uint32_t childCount = 0;
  if (NS_WARN_IF(NS_FAILED(regKey->GetChildCount(&childCount))) ||
      NS_WARN_IF(!childCount)) {
    return EmptyCString();
  }
  for (uint32_t i = 0; i < childCount; i++) {
    nsAutoString childName;
    if (NS_WARN_IF(NS_FAILED(regKey->GetChildName(i, childName))) ||
        !IsValidKeyboardLayoutsChild(childName)) {
      continue;
    }
    uint32_t childNum = static_cast<uint32_t>(childName.ToInteger64(&rv, 16));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      continue;
    }
    // Ignore normal keyboard layouts for each language.
    if (childNum <= 0xFFFF) {
      continue;
    }
    // If it doesn't start with 'A' nor 'a', language should be matched.
    if ((childNum & 0xFFFF) != language &&
        (childNum & 0xF0000000) != 0xA0000000) {
      continue;
    }
    // Then, the child should have "Layout Id" which is "YYY" of 0xFYYYXXXX.
    nsAutoString key(kKeyboardLayouts);
    key += childName;
    wchar_t buf[256];
    if (NS_WARN_IF(!WinUtils::GetRegistryKey(HKEY_LOCAL_MACHINE,
                                             key.get(), L"Layout Id",
                                             buf, sizeof(buf)))) {
      continue;
    }
    uint16_t layoutId = wcstol(buf, nullptr, 16);
    if (layoutId != (layout & 0x0FFF)) {
      continue;
    }
    if (NS_WARN_IF(!WinUtils::GetRegistryKey(HKEY_LOCAL_MACHINE,
                                             key.get(), L"Layout Text",
                                             buf, sizeof(buf)))) {
      continue;
    }
    return NS_ConvertUTF16toUTF8(buf);
  }
  return EmptyCString();
}

void
KeyboardLayout::LoadLayout(HKL aLayout)
{
  mIsPendingToRestoreKeyboardLayout = false;

  if (mKeyboardLayout == aLayout) {
    return;
  }

  mKeyboardLayout = aLayout;

  MOZ_LOG(sKeyboardLayoutLogger, LogLevel::Info,
    ("KeyboardLayout::LoadLayout(aLayout=0x%08X (%s))",
     aLayout, GetLayoutName(aLayout).get()));

  BYTE kbdState[256];
  memset(kbdState, 0, sizeof(kbdState));

  BYTE originalKbdState[256];
  // Bitfield with all shift states that have at least one dead-key.
  uint16_t shiftStatesWithDeadKeys = 0;
  // Bitfield with all shift states that produce any possible dead-key base
  // characters.
  uint16_t shiftStatesWithBaseChars = 0;

  mActiveDeadKeys.Clear();
  mDeadKeyShiftStates.Clear();

  ReleaseDeadKeyTables();

  ::GetKeyboardState(originalKbdState);

  // For each shift state gather all printable characters that are produced
  // for normal case when no any dead-key is active.

  for (VirtualKey::ShiftState shiftState = 0; shiftState < 16; shiftState++) {
    VirtualKey::FillKbdState(kbdState, shiftState);
    for (uint32_t virtualKey = 0; virtualKey < 256; virtualKey++) {
      int32_t vki = GetKeyIndex(virtualKey);
      if (vki < 0) {
        continue;
      }
      NS_ASSERTION(uint32_t(vki) < ArrayLength(mVirtualKeys), "invalid index");
      char16_t uniChars[5];
      int32_t ret =
        ::ToUnicodeEx(virtualKey, 0, kbdState, (LPWSTR)uniChars,
                      ArrayLength(uniChars), 0, mKeyboardLayout);
      // dead-key
      if (ret < 0) {
        shiftStatesWithDeadKeys |= (1 << shiftState);
        // Repeat dead-key to deactivate it and get its character
        // representation.
        char16_t deadChar[2];
        ret = ::ToUnicodeEx(virtualKey, 0, kbdState, (LPWSTR)deadChar,
                            ArrayLength(deadChar), 0, mKeyboardLayout);
        NS_ASSERTION(ret == 2, "Expecting twice repeated dead-key character");
        mVirtualKeys[vki].SetDeadChar(shiftState, deadChar[0]);

        MOZ_LOG(sKeyboardLayoutLogger, LogLevel::Debug,
          ("  %s (%d): DeadChar(%s, %s) (ret=%d)",
           kVirtualKeyName[virtualKey], vki,
           GetShiftStateName(shiftState).get(),
           GetCharacterCodeName(deadChar, 1).get(), ret));
      } else {
        if (ret == 1) {
          // dead-key can pair only with exactly one base character.
          shiftStatesWithBaseChars |= (1 << shiftState);
        }
        mVirtualKeys[vki].SetNormalChars(shiftState, uniChars, ret);
        MOZ_LOG(sKeyboardLayoutLogger, LogLevel::Verbose,
          ("  %s (%d): NormalChar(%s, %s) (ret=%d)",
           kVirtualKeyName[virtualKey], vki,
           GetShiftStateName(shiftState).get(),
           GetCharacterCodeName(uniChars, ret).get(), ret));
      }
    }
  }

  // Now process each dead-key to find all its base characters and resulting
  // composite characters.
  for (VirtualKey::ShiftState shiftState = 0; shiftState < 16; shiftState++) {
    if (!(shiftStatesWithDeadKeys & (1 << shiftState))) {
      continue;
    }

    VirtualKey::FillKbdState(kbdState, shiftState);

    for (uint32_t virtualKey = 0; virtualKey < 256; virtualKey++) {
      int32_t vki = GetKeyIndex(virtualKey);
      if (vki >= 0 && mVirtualKeys[vki].IsDeadKey(shiftState)) {
        DeadKeyEntry deadKeyArray[256];
        int32_t n = GetDeadKeyCombinations(virtualKey, kbdState,
                                           shiftStatesWithBaseChars,
                                           deadKeyArray,
                                           ArrayLength(deadKeyArray));
        const DeadKeyTable* dkt =
          mVirtualKeys[vki].MatchingDeadKeyTable(deadKeyArray, n);
        if (!dkt) {
          dkt = AddDeadKeyTable(deadKeyArray, n);
        }
        mVirtualKeys[vki].AttachDeadKeyTable(shiftState, dkt);
      }
    }
  }

  ::SetKeyboardState(originalKbdState);

  if (MOZ_LOG_TEST(sKeyboardLayoutLogger, LogLevel::Verbose)) {
    static const UINT kExtendedScanCode[] = { 0x0000, 0xE000 };
    static const UINT kMapType = MAPVK_VSC_TO_VK_EX;
    MOZ_LOG(sKeyboardLayoutLogger, LogLevel::Verbose,
      ("Logging virtual keycode values for scancode (0x%p)...",
       mKeyboardLayout));
    for (uint32_t i = 0; i < ArrayLength(kExtendedScanCode); i++) {
      for (uint32_t j = 1; j <= 0xFF; j++) {
        UINT scanCode = kExtendedScanCode[i] + j;
        UINT virtualKeyCode =
          ::MapVirtualKeyEx(scanCode, kMapType, mKeyboardLayout);
        MOZ_LOG(sKeyboardLayoutLogger, LogLevel::Verbose,
          ("0x%04X, %s", scanCode, kVirtualKeyName[virtualKeyCode]));
      }
    }
  }
}

inline int32_t
KeyboardLayout::GetKeyIndex(uint8_t aVirtualKey)
{
// Currently these 68 (NS_NUM_OF_KEYS) virtual keys are assumed
// to produce visible representation:
// 0x20 - VK_SPACE          ' '
// 0x30..0x39               '0'..'9'
// 0x41..0x5A               'A'..'Z'
// 0x60..0x69               '0'..'9' on numpad
// 0x6A - VK_MULTIPLY       '*' on numpad
// 0x6B - VK_ADD            '+' on numpad
// 0x6D - VK_SUBTRACT       '-' on numpad
// 0x6E - VK_DECIMAL        '.' on numpad
// 0x6F - VK_DIVIDE         '/' on numpad
// 0x6E - VK_DECIMAL        '.'
// 0xBA - VK_OEM_1          ';:' for US
// 0xBB - VK_OEM_PLUS       '+' any country
// 0xBC - VK_OEM_COMMA      ',' any country
// 0xBD - VK_OEM_MINUS      '-' any country
// 0xBE - VK_OEM_PERIOD     '.' any country
// 0xBF - VK_OEM_2          '/?' for US
// 0xC0 - VK_OEM_3          '`~' for US
// 0xC1 - VK_ABNT_C1        '/?' for Brazilian
// 0xC2 - VK_ABNT_C2        separator key on numpad (Brazilian or JIS for Mac)
// 0xDB - VK_OEM_4          '[{' for US
// 0xDC - VK_OEM_5          '\|' for US
// 0xDD - VK_OEM_6          ']}' for US
// 0xDE - VK_OEM_7          ''"' for US
// 0xDF - VK_OEM_8
// 0xE1 - no name
// 0xE2 - VK_OEM_102        '\_' for JIS
// 0xE3 - no name
// 0xE4 - no name

  static const int8_t xlat[256] =
  {
  // 0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
  //-----------------------------------------------------------------------
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // 00
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // 10
     0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // 20
     1,  2,  3,  4,  5,  6,  7,  8,  9, 10, -1, -1, -1, -1, -1, -1,   // 30
    -1, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,   // 40
    26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, -1, -1, -1, -1, -1,   // 50
    37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, -1, 49, 50, 51,   // 60
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // 70
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // 80
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // 90
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // A0
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 52, 53, 54, 55, 56, 57,   // B0
    58, 59, 60, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // C0
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 61, 62, 63, 64, 65,   // D0
    -1, 66, 67, 68, 69, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,   // E0
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1    // F0
  };

  return xlat[aVirtualKey];
}

int
KeyboardLayout::CompareDeadKeyEntries(const void* aArg1,
                                      const void* aArg2,
                                      void*)
{
  const DeadKeyEntry* arg1 = static_cast<const DeadKeyEntry*>(aArg1);
  const DeadKeyEntry* arg2 = static_cast<const DeadKeyEntry*>(aArg2);

  return arg1->BaseChar - arg2->BaseChar;
}

const DeadKeyTable*
KeyboardLayout::AddDeadKeyTable(const DeadKeyEntry* aDeadKeyArray,
                                uint32_t aEntries)
{
  DeadKeyTableListEntry* next = mDeadKeyTableListHead;

  const size_t bytes = offsetof(DeadKeyTableListEntry, data) +
    DeadKeyTable::SizeInBytes(aEntries);
  uint8_t* p = new uint8_t[bytes];

  mDeadKeyTableListHead = reinterpret_cast<DeadKeyTableListEntry*>(p);
  mDeadKeyTableListHead->next = next;

  DeadKeyTable* dkt =
    reinterpret_cast<DeadKeyTable*>(mDeadKeyTableListHead->data);

  dkt->Init(aDeadKeyArray, aEntries);

  return dkt;
}

void
KeyboardLayout::ReleaseDeadKeyTables()
{
  while (mDeadKeyTableListHead) {
    uint8_t* p = reinterpret_cast<uint8_t*>(mDeadKeyTableListHead);
    mDeadKeyTableListHead = mDeadKeyTableListHead->next;

    delete [] p;
  }
}

bool
KeyboardLayout::EnsureDeadKeyActive(bool aIsActive,
                                    uint8_t aDeadKey,
                                    const PBYTE aDeadKeyKbdState)
{
  int32_t ret;
  do {
    char16_t dummyChars[5];
    ret = ::ToUnicodeEx(aDeadKey, 0, (PBYTE)aDeadKeyKbdState,
                        (LPWSTR)dummyChars, ArrayLength(dummyChars), 0,
                        mKeyboardLayout);
    // returned values:
    // <0 - Dead key state is active. The keyboard driver will wait for next
    //      character.
    //  1 - Previous pressed key was a valid base character that produced
    //      exactly one composite character.
    // >1 - Previous pressed key does not produce any composite characters.
    //      Return dead-key character followed by base character(s).
  } while ((ret < 0) != aIsActive);

  return (ret < 0);
}

void
KeyboardLayout::ActivateDeadKeyState(const NativeKey& aNativeKey,
                                     const ModifierKeyState& aModKeyState)
{
  // Dead-key state should be activated at keydown.
  if (!aNativeKey.IsKeyDownMessage()) {
    return;
  }

  mActiveDeadKeys.AppendElement(aNativeKey.mOriginalVirtualKeyCode);
  mDeadKeyShiftStates.AppendElement(
    VirtualKey::ModifierKeyStateToShiftState(aModKeyState));
}

void
KeyboardLayout::DeactivateDeadKeyState()
{
  if (mActiveDeadKeys.IsEmpty()) {
    return;
  }

  BYTE kbdState[256];
  memset(kbdState, 0, sizeof(kbdState));

  // Assume that the last dead key can finish dead key sequence.
  VirtualKey::FillKbdState(kbdState, mDeadKeyShiftStates.LastElement());
  EnsureDeadKeyActive(false, mActiveDeadKeys.LastElement(), kbdState);
  mActiveDeadKeys.Clear();
  mDeadKeyShiftStates.Clear();
}

bool
KeyboardLayout::AddDeadKeyEntry(char16_t aBaseChar,
                                char16_t aCompositeChar,
                                DeadKeyEntry* aDeadKeyArray,
                                uint32_t aEntries)
{
  for (uint32_t index = 0; index < aEntries; index++) {
    if (aDeadKeyArray[index].BaseChar == aBaseChar) {
      return false;
    }
  }

  aDeadKeyArray[aEntries].BaseChar = aBaseChar;
  aDeadKeyArray[aEntries].CompositeChar = aCompositeChar;

  return true;
}

uint32_t
KeyboardLayout::GetDeadKeyCombinations(uint8_t aDeadKey,
                                       const PBYTE aDeadKeyKbdState,
                                       uint16_t aShiftStatesWithBaseChars,
                                       DeadKeyEntry* aDeadKeyArray,
                                       uint32_t aMaxEntries)
{
  bool deadKeyActive = false;
  uint32_t entries = 0;
  BYTE kbdState[256];
  memset(kbdState, 0, sizeof(kbdState));

  for (uint32_t shiftState = 0; shiftState < 16; shiftState++) {
    if (!(aShiftStatesWithBaseChars & (1 << shiftState))) {
      continue;
    }

    VirtualKey::FillKbdState(kbdState, shiftState);

    for (uint32_t virtualKey = 0; virtualKey < 256; virtualKey++) {
      int32_t vki = GetKeyIndex(virtualKey);
      // Dead-key can pair only with such key that produces exactly one base
      // character.
      if (vki >= 0 &&
          mVirtualKeys[vki].GetNativeUniChars(shiftState).Length() == 1) {
        // Ensure dead-key is in active state, when it swallows entered
        // character and waits for the next pressed key.
        if (!deadKeyActive) {
          deadKeyActive = EnsureDeadKeyActive(true, aDeadKey,
                                              aDeadKeyKbdState);
        }

        // Depending on the character the followed the dead-key, the keyboard
        // driver can produce one composite character, or a dead-key character
        // followed by a second character.
        char16_t compositeChars[5];
        int32_t ret =
          ::ToUnicodeEx(virtualKey, 0, kbdState, (LPWSTR)compositeChars,
                        ArrayLength(compositeChars), 0, mKeyboardLayout);
        switch (ret) {
          case 0:
            // This key combination does not produce any characters. The
            // dead-key is still in active state.
            break;
          case 1: {
            char16_t baseChars[5];
            ret = ::ToUnicodeEx(virtualKey, 0, kbdState, (LPWSTR)baseChars,
                                ArrayLength(baseChars), 0, mKeyboardLayout);
            if (entries < aMaxEntries) {
              switch (ret) {
                case 1:
                  // Exactly one composite character produced. Now, when
                  // dead-key is not active, repeat the last character one more
                  // time to determine the base character.
                  if (AddDeadKeyEntry(baseChars[0], compositeChars[0],
                                      aDeadKeyArray, entries)) {
                    entries++;
                  }
                  deadKeyActive = false;
                  break;
                case -1: {
                  // If pressing another dead-key produces different character,
                  // we should register the dead-key entry with first character
                  // produced by current key.

                  // First inactivate the dead-key state completely.
                  deadKeyActive =
                    EnsureDeadKeyActive(false, aDeadKey, aDeadKeyKbdState);
                  if (NS_WARN_IF(deadKeyActive)) {
                    MOZ_LOG(sKeyboardLayoutLogger, LogLevel::Error,
                      ("  failed to deactivating the dead-key state..."));
                    break;
                  }
                  for (int32_t i = 0; i < 5; ++i) {
                    ret = ::ToUnicodeEx(virtualKey, 0, kbdState,
                                        (LPWSTR)baseChars,
                                        ArrayLength(baseChars),
                                        0, mKeyboardLayout);
                    if (ret >= 0) {
                      break;
                    }
                  }
                  if (ret > 0 &&
                      AddDeadKeyEntry(baseChars[0], compositeChars[0],
                                      aDeadKeyArray, entries)) {
                    entries++;
                  }
                  // Inactivate dead-key state for current virtual keycode.
                  EnsureDeadKeyActive(false, virtualKey, kbdState);
                  break;
                }
                default:
                  NS_WARN_IF("File a bug for this dead-key handling!");
                  deadKeyActive = false;
                  break;
              }
            }
            MOZ_LOG(sKeyboardLayoutLogger, LogLevel::Debug,
              ("  %s -> %s (%d): DeadKeyEntry(%s, %s) (ret=%d)",
               kVirtualKeyName[aDeadKey], kVirtualKeyName[virtualKey], vki,
               GetCharacterCodeName(compositeChars, 1).get(),
               ret <= 0 ? "''" :
                 GetCharacterCodeName(baseChars, std::min(ret, 5)).get(), ret));
            break;
          }
          default:
            // 1. Unexpected dead-key. Dead-key chaining is not supported.
            // 2. More than one character generated. This is not a valid
            //    dead-key and base character combination.
            deadKeyActive = false;
            MOZ_LOG(sKeyboardLayoutLogger, LogLevel::Verbose,
              ("  %s -> %s (%d): Unsupport dead key type(%s) (ret=%d)",
               kVirtualKeyName[aDeadKey], kVirtualKeyName[virtualKey], vki,
               ret <= 0 ? "''" :
                 GetCharacterCodeName(compositeChars,
                                      std::min(ret, 5)).get(), ret));
            break;
        }
      }
    }
  }

  if (deadKeyActive) {
    deadKeyActive = EnsureDeadKeyActive(false, aDeadKey, aDeadKeyKbdState);
  }

  NS_QuickSort(aDeadKeyArray, entries, sizeof(DeadKeyEntry),
               CompareDeadKeyEntries, nullptr);
  return entries;
}

uint32_t
KeyboardLayout::ConvertNativeKeyCodeToDOMKeyCode(UINT aNativeKeyCode) const
{
  // Alphabet or Numeric or Numpad or Function keys
  if ((aNativeKeyCode >= 0x30 && aNativeKeyCode <= 0x39) ||
      (aNativeKeyCode >= 0x41 && aNativeKeyCode <= 0x5A) ||
      (aNativeKeyCode >= 0x60 && aNativeKeyCode <= 0x87)) {
    return static_cast<uint32_t>(aNativeKeyCode);
  }
  switch (aNativeKeyCode) {
    // Following keycodes are same as our DOM keycodes
    case VK_CANCEL:
    case VK_BACK:
    case VK_TAB:
    case VK_CLEAR:
    case VK_RETURN:
    case VK_SHIFT:
    case VK_CONTROL:
    case VK_MENU: // Alt
    case VK_PAUSE:
    case VK_CAPITAL: // CAPS LOCK
    case VK_KANA: // same as VK_HANGUL
    case VK_JUNJA:
    case VK_FINAL:
    case VK_HANJA: // same as VK_KANJI
    case VK_ESCAPE:
    case VK_CONVERT:
    case VK_NONCONVERT:
    case VK_ACCEPT:
    case VK_MODECHANGE:
    case VK_SPACE:
    case VK_PRIOR: // PAGE UP
    case VK_NEXT: // PAGE DOWN
    case VK_END:
    case VK_HOME:
    case VK_LEFT:
    case VK_UP:
    case VK_RIGHT:
    case VK_DOWN:
    case VK_SELECT:
    case VK_PRINT:
    case VK_EXECUTE:
    case VK_SNAPSHOT:
    case VK_INSERT:
    case VK_DELETE:
    case VK_APPS: // Context Menu
    case VK_SLEEP:
    case VK_NUMLOCK:
    case VK_SCROLL: // SCROLL LOCK
    case VK_ATTN: // Attension key of IBM midrange computers, e.g., AS/400
    case VK_CRSEL: // Cursor Selection
    case VK_EXSEL: // Extend Selection
    case VK_EREOF: // Erase EOF key of IBM 3270 keyboard layout
    case VK_PLAY:
    case VK_ZOOM:
    case VK_PA1: // PA1 key of IBM 3270 keyboard layout
      return uint32_t(aNativeKeyCode);

    case VK_HELP:
      return NS_VK_HELP;

    // Windows key should be mapped to a Win keycode
    // They should be able to be distinguished by DOM3 KeyboardEvent.location
    case VK_LWIN:
    case VK_RWIN:
      return NS_VK_WIN;

    case VK_VOLUME_MUTE:
      return NS_VK_VOLUME_MUTE;
    case VK_VOLUME_DOWN:
      return NS_VK_VOLUME_DOWN;
    case VK_VOLUME_UP:
      return NS_VK_VOLUME_UP;

    // Following keycodes are not defined in our DOM keycodes.
    case VK_BROWSER_BACK:
    case VK_BROWSER_FORWARD:
    case VK_BROWSER_REFRESH:
    case VK_BROWSER_STOP:
    case VK_BROWSER_SEARCH:
    case VK_BROWSER_FAVORITES:
    case VK_BROWSER_HOME:
    case VK_MEDIA_NEXT_TRACK:
    case VK_MEDIA_PREV_TRACK:
    case VK_MEDIA_STOP:
    case VK_MEDIA_PLAY_PAUSE:
    case VK_LAUNCH_MAIL:
    case VK_LAUNCH_MEDIA_SELECT:
    case VK_LAUNCH_APP1:
    case VK_LAUNCH_APP2:
      return 0;

    // Following OEM specific virtual keycodes should pass through DOM keyCode
    // for compatibility with the other browsers on Windows.

    // Following OEM specific virtual keycodes are defined for Fujitsu/OASYS.
    case VK_OEM_FJ_JISHO:
    case VK_OEM_FJ_MASSHOU:
    case VK_OEM_FJ_TOUROKU:
    case VK_OEM_FJ_LOYA:
    case VK_OEM_FJ_ROYA:
    // Not sure what means "ICO".
    case VK_ICO_HELP:
    case VK_ICO_00:
    case VK_ICO_CLEAR:
    // Following OEM specific virtual keycodes are defined for Nokia/Ericsson.
    case VK_OEM_RESET:
    case VK_OEM_JUMP:
    case VK_OEM_PA1:
    case VK_OEM_PA2:
    case VK_OEM_PA3:
    case VK_OEM_WSCTRL:
    case VK_OEM_CUSEL:
    case VK_OEM_ATTN:
    case VK_OEM_FINISH:
    case VK_OEM_COPY:
    case VK_OEM_AUTO:
    case VK_OEM_ENLW:
    case VK_OEM_BACKTAB:
    // VK_OEM_CLEAR is defined as not OEM specific, but let's pass though
    // DOM keyCode like other OEM specific virtual keycodes.
    case VK_OEM_CLEAR:
      return uint32_t(aNativeKeyCode);

    // 0xE1 is an OEM specific virtual keycode. However, the value is already
    // used in our DOM keyCode for AltGr on Linux. So, this virtual keycode
    // cannot pass through DOM keyCode.
    case 0xE1:
      return 0;

    // Following keycodes are OEM keys which are keycodes for non-alphabet and
    // non-numeric keys, we should compute each keycode of them from unshifted
    // character which is inputted by each key.  But if the unshifted character
    // is not an ASCII character but shifted character is an ASCII character,
    // we should refer it.
    case VK_OEM_1:
    case VK_OEM_PLUS:
    case VK_OEM_COMMA:
    case VK_OEM_MINUS:
    case VK_OEM_PERIOD:
    case VK_OEM_2:
    case VK_OEM_3:
    case VK_OEM_4:
    case VK_OEM_5:
    case VK_OEM_6:
    case VK_OEM_7:
    case VK_OEM_8:
    case VK_OEM_102:
    case VK_ABNT_C1:
    {
      NS_ASSERTION(IsPrintableCharKey(aNativeKeyCode),
                   "The key must be printable");
      ModifierKeyState modKeyState(0);
      UniCharsAndModifiers uniChars =
        GetUniCharsAndModifiers(aNativeKeyCode, modKeyState);
      if (uniChars.Length() != 1 ||
          uniChars.CharAt(0) < ' ' || uniChars.CharAt(0) > 0x7F) {
        modKeyState.Set(MODIFIER_SHIFT);
        uniChars = GetUniCharsAndModifiers(aNativeKeyCode, modKeyState);
        if (uniChars.Length() != 1 ||
            uniChars.CharAt(0) < ' ' || uniChars.CharAt(0) > 0x7F) {
          return 0;
        }
      }
      return WidgetUtils::ComputeKeyCodeFromChar(uniChars.CharAt(0));
    }

    // IE sets 0xC2 to the DOM keyCode for VK_ABNT_C2.  However, we're already
    // using NS_VK_SEPARATOR for the separator key on Mac and Linux.  Therefore,
    // We should keep consistency between Gecko on all platforms rather than
    // with other browsers since a lot of keyCode values are already different
    // between browsers.
    case VK_ABNT_C2:
      return NS_VK_SEPARATOR;

    // VK_PROCESSKEY means IME already consumed the key event.
    case VK_PROCESSKEY:
      return 0;
    // VK_PACKET is generated by SendInput() API, we don't need to
    // care this message as key event.
    case VK_PACKET:
      return 0;
    // If a key is not mapped to a virtual keycode, 0xFF is used.
    case 0xFF:
      NS_WARNING("The key is failed to be converted to a virtual keycode");
      return 0;
  }
#ifdef DEBUG
  nsPrintfCString warning("Unknown virtual keycode (0x%08X), please check the "
                          "latest MSDN document, there may be some new "
                          "keycodes we've never known.",
                          aNativeKeyCode);
  NS_WARNING(warning.get());
#endif
  return 0;
}

KeyNameIndex
KeyboardLayout::ConvertNativeKeyCodeToKeyNameIndex(uint8_t aVirtualKey) const
{
  if (IsPrintableCharKey(aVirtualKey) || aVirtualKey == VK_PACKET) {
    return KEY_NAME_INDEX_USE_STRING;
  }

  switch (aVirtualKey) {

#undef NS_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX
#define NS_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX(aNativeKey, aKeyNameIndex) \
    case aNativeKey: return aKeyNameIndex;

#include "NativeKeyToDOMKeyName.h"

#undef NS_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX

    default:
      break;
  }

  HKL layout = GetLayout();
  WORD langID = LOWORD(static_cast<HKL>(layout));
  WORD primaryLangID = PRIMARYLANGID(langID);

  if (primaryLangID == LANG_JAPANESE) {
    switch (aVirtualKey) {

#undef NS_JAPANESE_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX
#define NS_JAPANESE_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX(aNativeKey, aKeyNameIndex)\
      case aNativeKey: return aKeyNameIndex;

#include "NativeKeyToDOMKeyName.h"

#undef NS_JAPANESE_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX

      default:
        break;
    }
  } else if (primaryLangID == LANG_KOREAN) {
    switch (aVirtualKey) {

#undef NS_KOREAN_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX
#define NS_KOREAN_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX(aNativeKey, aKeyNameIndex)\
      case aNativeKey: return aKeyNameIndex;

#include "NativeKeyToDOMKeyName.h"

#undef NS_KOREAN_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX

      default:
        return KEY_NAME_INDEX_Unidentified;
    }
  }

  switch (aVirtualKey) {

#undef NS_OTHER_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX
#define NS_OTHER_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX(aNativeKey, aKeyNameIndex)\
    case aNativeKey: return aKeyNameIndex;

#include "NativeKeyToDOMKeyName.h"

#undef NS_OTHER_NATIVE_KEY_TO_DOM_KEY_NAME_INDEX

    default:
      return KEY_NAME_INDEX_Unidentified;
  }
}

// static
CodeNameIndex
KeyboardLayout::ConvertScanCodeToCodeNameIndex(UINT aScanCode)
{
  switch (aScanCode) {

#define NS_NATIVE_KEY_TO_DOM_CODE_NAME_INDEX(aNativeKey, aCodeNameIndex) \
    case aNativeKey: return aCodeNameIndex;

#include "NativeKeyToDOMCodeName.h"

#undef NS_NATIVE_KEY_TO_DOM_CODE_NAME_INDEX

    default:
      return CODE_NAME_INDEX_UNKNOWN;
  }
}

nsresult
KeyboardLayout::SynthesizeNativeKeyEvent(nsWindowBase* aWidget,
                                         int32_t aNativeKeyboardLayout,
                                         int32_t aNativeKeyCode,
                                         uint32_t aModifierFlags,
                                         const nsAString& aCharacters,
                                         const nsAString& aUnmodifiedCharacters)
{
  UINT keyboardLayoutListCount = ::GetKeyboardLayoutList(0, nullptr);
  NS_ASSERTION(keyboardLayoutListCount > 0,
               "One keyboard layout must be installed at least");
  HKL keyboardLayoutListBuff[50];
  HKL* keyboardLayoutList =
    keyboardLayoutListCount < 50 ? keyboardLayoutListBuff :
                                   new HKL[keyboardLayoutListCount];
  keyboardLayoutListCount =
    ::GetKeyboardLayoutList(keyboardLayoutListCount, keyboardLayoutList);
  NS_ASSERTION(keyboardLayoutListCount > 0,
               "Failed to get all keyboard layouts installed on the system");

  nsPrintfCString layoutName("%08x", aNativeKeyboardLayout);
  HKL loadedLayout = LoadKeyboardLayoutA(layoutName.get(), KLF_NOTELLSHELL);
  if (loadedLayout == nullptr) {
    if (keyboardLayoutListBuff != keyboardLayoutList) {
      delete [] keyboardLayoutList;
    }
    return NS_ERROR_NOT_AVAILABLE;
  }

  // Setup clean key state and load desired layout
  BYTE originalKbdState[256];
  ::GetKeyboardState(originalKbdState);
  BYTE kbdState[256];
  memset(kbdState, 0, sizeof(kbdState));
  // This changes the state of the keyboard for the current thread only,
  // and we'll restore it soon, so this should be OK.
  ::SetKeyboardState(kbdState);

  OverrideLayout(loadedLayout);

  uint8_t argumentKeySpecific = 0;
  switch (aNativeKeyCode & 0xFF) {
    case VK_SHIFT:
      aModifierFlags &= ~(nsIWidget::SHIFT_L | nsIWidget::SHIFT_R);
      argumentKeySpecific = VK_LSHIFT;
      break;
    case VK_LSHIFT:
      aModifierFlags &= ~nsIWidget::SHIFT_L;
      argumentKeySpecific = aNativeKeyCode & 0xFF;
      aNativeKeyCode = (aNativeKeyCode & 0xFFFF0000) | VK_SHIFT;
      break;
    case VK_RSHIFT:
      aModifierFlags &= ~nsIWidget::SHIFT_R;
      argumentKeySpecific = aNativeKeyCode & 0xFF;
      aNativeKeyCode = (aNativeKeyCode & 0xFFFF0000) | VK_SHIFT;
      break;
    case VK_CONTROL:
      aModifierFlags &= ~(nsIWidget::CTRL_L | nsIWidget::CTRL_R);
      argumentKeySpecific = VK_LCONTROL;
      break;
    case VK_LCONTROL:
      aModifierFlags &= ~nsIWidget::CTRL_L;
      argumentKeySpecific = aNativeKeyCode & 0xFF;
      aNativeKeyCode = (aNativeKeyCode & 0xFFFF0000) | VK_CONTROL;
      break;
    case VK_RCONTROL:
      aModifierFlags &= ~nsIWidget::CTRL_R;
      argumentKeySpecific = aNativeKeyCode & 0xFF;
      aNativeKeyCode = (aNativeKeyCode & 0xFFFF0000) | VK_CONTROL;
      break;
    case VK_MENU:
      aModifierFlags &= ~(nsIWidget::ALT_L | nsIWidget::ALT_R);
      argumentKeySpecific = VK_LMENU;
      break;
    case VK_LMENU:
      aModifierFlags &= ~nsIWidget::ALT_L;
      argumentKeySpecific = aNativeKeyCode & 0xFF;
      aNativeKeyCode = (aNativeKeyCode & 0xFFFF0000) | VK_MENU;
      break;
    case VK_RMENU:
      aModifierFlags &= ~nsIWidget::ALT_R;
      argumentKeySpecific = aNativeKeyCode & 0xFF;
      aNativeKeyCode = (aNativeKeyCode & 0xFFFF0000) | VK_MENU;
      break;
    case VK_CAPITAL:
      aModifierFlags &= ~nsIWidget::CAPS_LOCK;
      argumentKeySpecific = VK_CAPITAL;
      break;
    case VK_NUMLOCK:
      aModifierFlags &= ~nsIWidget::NUM_LOCK;
      argumentKeySpecific = VK_NUMLOCK;
      break;
  }

  AutoTArray<KeyPair,10> keySequence;
  WinUtils::SetupKeyModifiersSequence(&keySequence, aModifierFlags);
  keySequence.AppendElement(KeyPair(aNativeKeyCode, argumentKeySpecific));

  // Simulate the pressing of each modifier key and then the real key
  // FYI: Each NativeKey instance here doesn't need to override keyboard layout
  //      since this method overrides and restores the keyboard layout.
  for (uint32_t i = 0; i < keySequence.Length(); ++i) {
    uint8_t key = keySequence[i].mGeneral;
    uint8_t keySpecific = keySequence[i].mSpecific;
    uint16_t scanCode = keySequence[i].mScanCode;
    kbdState[key] = 0x81; // key is down and toggled on if appropriate
    if (keySpecific) {
      kbdState[keySpecific] = 0x81;
    }
    ::SetKeyboardState(kbdState);
    ModifierKeyState modKeyState;
    // If scan code isn't specified explicitly, let's compute it with current
    // keyboard layout.
    if (!scanCode) {
      scanCode =
        ComputeScanCodeForVirtualKeyCode(keySpecific ? keySpecific : key);
    }
    LPARAM lParam = static_cast<LPARAM>(scanCode << 16);
    // If the scan code is for an extended key, set extended key flag.
    if ((scanCode & 0xFF00) == 0xE000) {
      lParam |= 0x1000000;
    }
    bool makeSysKeyMsg = IsSysKey(key, modKeyState);
    MSG keyDownMsg =
      WinUtils::InitMSG(makeSysKeyMsg ? WM_SYSKEYDOWN : WM_KEYDOWN,
                        key, lParam, aWidget->GetWindowHandle());
    if (i == keySequence.Length() - 1) {
      bool makeDeadCharMsg =
        (IsDeadKey(key, modKeyState) && aCharacters.IsEmpty());
      nsAutoString chars(aCharacters);
      if (makeDeadCharMsg) {
        UniCharsAndModifiers deadChars =
          GetUniCharsAndModifiers(key, modKeyState);
        chars = deadChars.ToString();
        NS_ASSERTION(chars.Length() == 1,
                     "Dead char must be only one character");
      }
      if (chars.IsEmpty()) {
        NativeKey nativeKey(aWidget, keyDownMsg, modKeyState);
        nativeKey.HandleKeyDownMessage();
      } else {
        AutoTArray<NativeKey::FakeCharMsg, 10> fakeCharMsgs;
        for (uint32_t j = 0; j < chars.Length(); j++) {
          NativeKey::FakeCharMsg* fakeCharMsg = fakeCharMsgs.AppendElement();
          fakeCharMsg->mCharCode = chars.CharAt(j);
          fakeCharMsg->mScanCode = scanCode;
          fakeCharMsg->mIsSysKey = makeSysKeyMsg;
          fakeCharMsg->mIsDeadKey = makeDeadCharMsg;
        }
        NativeKey nativeKey(aWidget, keyDownMsg, modKeyState, 0, &fakeCharMsgs);
        bool dispatched;
        nativeKey.HandleKeyDownMessage(&dispatched);
        // If some char messages are not consumed, let's emulate the widget
        // receiving the message directly.
        for (uint32_t j = 1; j < fakeCharMsgs.Length(); j++) {
          if (fakeCharMsgs[j].mConsumed) {
            continue;
          }
          MSG charMsg = fakeCharMsgs[j].GetCharMsg(aWidget->GetWindowHandle());
          NativeKey nativeKey(aWidget, charMsg, modKeyState);
          nativeKey.HandleCharMessage(charMsg);
        }
      }
    } else {
      NativeKey nativeKey(aWidget, keyDownMsg, modKeyState);
      nativeKey.HandleKeyDownMessage();
    }
  }
  for (uint32_t i = keySequence.Length(); i > 0; --i) {
    uint8_t key = keySequence[i - 1].mGeneral;
    uint8_t keySpecific = keySequence[i - 1].mSpecific;
    uint16_t scanCode = keySequence[i - 1].mScanCode;
    kbdState[key] = 0; // key is up and toggled off if appropriate
    if (keySpecific) {
      kbdState[keySpecific] = 0;
    }
    ::SetKeyboardState(kbdState);
    ModifierKeyState modKeyState;
    // If scan code isn't specified explicitly, let's compute it with current
    // keyboard layout.
    if (!scanCode) {
      scanCode =
        ComputeScanCodeForVirtualKeyCode(keySpecific ? keySpecific : key);
    }
    LPARAM lParam = static_cast<LPARAM>(scanCode << 16);
    // If the scan code is for an extended key, set extended key flag.
    if ((scanCode & 0xFF00) == 0xE000) {
      lParam |= 0x1000000;
    }
    // Don't use WM_SYSKEYUP for Alt keyup.
    bool makeSysKeyMsg = IsSysKey(key, modKeyState) && key != VK_MENU;
    MSG keyUpMsg = WinUtils::InitMSG(makeSysKeyMsg ? WM_SYSKEYUP : WM_KEYUP,
                                     key, lParam,
                                     aWidget->GetWindowHandle());
    NativeKey nativeKey(aWidget, keyUpMsg, modKeyState);
    nativeKey.HandleKeyUpMessage();
  }

  // Restore old key state and layout
  ::SetKeyboardState(originalKbdState);
  RestoreLayout();

  // Don't unload the layout if it's installed actually.
  for (uint32_t i = 0; i < keyboardLayoutListCount; i++) {
    if (keyboardLayoutList[i] == loadedLayout) {
      loadedLayout = 0;
      break;
    }
  }
  if (keyboardLayoutListBuff != keyboardLayoutList) {
    delete [] keyboardLayoutList;
  }
  if (loadedLayout) {
    ::UnloadKeyboardLayout(loadedLayout);
  }
  return NS_OK;
}

/*****************************************************************************
 * mozilla::widget::DeadKeyTable
 *****************************************************************************/

char16_t
DeadKeyTable::GetCompositeChar(char16_t aBaseChar) const
{
  // Dead-key table is sorted by BaseChar in ascending order.
  // Usually they are too small to use binary search.

  for (uint32_t index = 0; index < mEntries; index++) {
    if (mTable[index].BaseChar == aBaseChar) {
      return mTable[index].CompositeChar;
    }
    if (mTable[index].BaseChar > aBaseChar) {
      break;
    }
  }

  return 0;
}

/*****************************************************************************
 * mozilla::widget::RedirectedKeyDownMessage
 *****************************************************************************/

MSG RedirectedKeyDownMessageManager::sRedirectedKeyDownMsg;
bool RedirectedKeyDownMessageManager::sDefaultPreventedOfRedirectedMsg = false;

// static
bool
RedirectedKeyDownMessageManager::IsRedirectedMessage(const MSG& aMsg)
{
  return (aMsg.message == WM_KEYDOWN || aMsg.message == WM_SYSKEYDOWN) &&
         (sRedirectedKeyDownMsg.message == aMsg.message &&
          WinUtils::GetScanCode(sRedirectedKeyDownMsg.lParam) ==
            WinUtils::GetScanCode(aMsg.lParam));
}

// static
void
RedirectedKeyDownMessageManager::RemoveNextCharMessage(HWND aWnd)
{
  MSG msg;
  if (WinUtils::PeekMessage(&msg, aWnd, WM_KEYFIRST, WM_KEYLAST,
                            PM_NOREMOVE | PM_NOYIELD) &&
      (msg.message == WM_CHAR || msg.message == WM_SYSCHAR)) {
    WinUtils::PeekMessage(&msg, aWnd, msg.message, msg.message,
                          PM_REMOVE | PM_NOYIELD);
  }
}

} // namespace widget
} // namespace mozilla