widget/windows/WinMouseScrollHandler.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/DebugOnly.h"
   8
   9 #include "mozilla/Logging.h"
  10
  11 #include "WinMouseScrollHandler.h"
  12 #include "nsWindow.h"
  13 #include "nsWindowDefs.h"
  14 #include "KeyboardLayout.h"
  15 #include "WinUtils.h"
  16 #include "nsGkAtoms.h"
  17 #include "nsIDOMWindowUtils.h"
  18
  19 #include "mozilla/MiscEvents.h"
  20 #include "mozilla/MouseEvents.h"
  21 #include "mozilla/Preferences.h"
  22 #include "mozilla/dom/WheelEventBinding.h"
  23 #include "mozilla/StaticPrefs_mousewheel.h"
  24
  25 #include <psapi.h>
  26
  27 namespace mozilla {
  28 namespace widget {
  29
  30 LazyLogModule gMouseScrollLog("MouseScrollHandlerWidgets");
  31
  32 static const char* GetBoolName(bool aBool) { return aBool ? "TRUE" : "FALSE"; }
  33
  34 MouseScrollHandler* MouseScrollHandler::sInstance = nullptr;
  35
  36 bool MouseScrollHandler::Device::sFakeScrollableWindowNeeded = false;
  37
  38 bool MouseScrollHandler::Device::SynTP::sInitialized = false;
  39 int32_t MouseScrollHandler::Device::SynTP::sMajorVersion = 0;
  40 int32_t MouseScrollHandler::Device::SynTP::sMinorVersion = -1;
  41
  42 bool MouseScrollHandler::Device::Elantech::sUseSwipeHack = false;
  43 bool MouseScrollHandler::Device::Elantech::sUsePinchHack = false;
  44 DWORD MouseScrollHandler::Device::Elantech::sZoomUntil = 0;
  45
  46 bool MouseScrollHandler::Device::Apoint::sInitialized = false;
  47 int32_t MouseScrollHandler::Device::Apoint::sMajorVersion = 0;
  48 int32_t MouseScrollHandler::Device::Apoint::sMinorVersion = -1;
  49
  50 bool MouseScrollHandler::Device::SetPoint::sMightBeUsing = false;
  51
  52 // The duration until timeout of events transaction.  The value is 1.5 sec,
  53 // it's just a magic number, it was suggested by Logitech's engineer, see
  54 // bug 605648 comment 90.
  55 #define DEFAULT_TIMEOUT_DURATION 1500
  56
  57 /******************************************************************************
  58  *
  59  * MouseScrollHandler
  60  *
  61  ******************************************************************************/
  62
  63 /* static */
  64 POINTS
  65 MouseScrollHandler::GetCurrentMessagePos() {
  66   if (SynthesizingEvent::IsSynthesizing()) {
  67     return sInstance->mSynthesizingEvent->GetCursorPoint();
  68   }
  69   DWORD pos = ::GetMessagePos();
  70   return MAKEPOINTS(pos);
  71 }
  72
  73 // Get rid of the GetMessagePos() API.
  74 #define GetMessagePos()
  75
  76 /* static */
  77 void MouseScrollHandler::Initialize() { Device::Init(); }
  78
  79 /* static */
  80 void MouseScrollHandler::Shutdown() {
  81   delete sInstance;
  82   sInstance = nullptr;
  83 }
  84
  85 /* static */
  86 MouseScrollHandler* MouseScrollHandler::GetInstance() {
  87   if (!sInstance) {
  88     sInstance = new MouseScrollHandler();
  89   }
  90   return sInstance;
  91 }
  92
  93 MouseScrollHandler::MouseScrollHandler()
  94     : mIsWaitingInternalMessage(false), mSynthesizingEvent(nullptr) {
  95   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
  96           ("MouseScroll: Creating an instance, this=%p, sInstance=%p", this,
  97            sInstance));
  98 }
  99
 100 MouseScrollHandler::~MouseScrollHandler() {
 101   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 102           ("MouseScroll: Destroying an instance, this=%p, sInstance=%p", this,
 103            sInstance));
 104
 105   delete mSynthesizingEvent;
 106 }
 107
 108 /* static */
 109 void MouseScrollHandler::MaybeLogKeyState() {
 110   if (!MOZ_LOG_TEST(gMouseScrollLog, LogLevel::Debug)) {
 111     return;
 112   }
 113   BYTE keyboardState[256];
 114   if (::GetKeyboardState(keyboardState)) {
 115     for (size_t i = 0; i < ArrayLength(keyboardState); i++) {
 116       if (keyboardState[i]) {
 117         MOZ_LOG(gMouseScrollLog, LogLevel::Debug,
 118                 ("    Current key state: keyboardState[0x%02zX]=0x%02X (%s)", i,
 119                  keyboardState[i],
 120                  ((keyboardState[i] & 0x81) == 0x81) ? "Pressed and Toggled"
 121                  : (keyboardState[i] & 0x80)         ? "Pressed"
 122                  : (keyboardState[i] & 0x01)         ? "Toggled"
 123                                                      : "Unknown"));
 124       }
 125     }
 126   } else {
 127     MOZ_LOG(
 128         gMouseScrollLog, LogLevel::Debug,
 129         ("MouseScroll::MaybeLogKeyState(): Failed to print current keyboard "
 130          "state"));
 131   }
 132 }
 133
 134 /* static */
 135 bool MouseScrollHandler::NeedsMessage(UINT aMsg) {
 136   switch (aMsg) {
 137     case WM_SETTINGCHANGE:
 138     case WM_MOUSEWHEEL:
 139     case WM_MOUSEHWHEEL:
 140     case WM_HSCROLL:
 141     case WM_VSCROLL:
 142     case MOZ_WM_MOUSEVWHEEL:
 143     case MOZ_WM_MOUSEHWHEEL:
 144     case MOZ_WM_HSCROLL:
 145     case MOZ_WM_VSCROLL:
 146     case WM_KEYDOWN:
 147     case WM_KEYUP:
 148       return true;
 149   }
 150   return false;
 151 }
 152
 153 /* static */
 154 bool MouseScrollHandler::ProcessMessage(nsWindow* aWidget, UINT msg,
 155                                         WPARAM wParam, LPARAM lParam,
 156                                         MSGResult& aResult) {
 157   Device::Elantech::UpdateZoomUntil();
 158
 159   switch (msg) {
 160     case WM_SETTINGCHANGE:
 161       if (!sInstance) {
 162         return false;
 163       }
 164       if (wParam == SPI_SETWHEELSCROLLLINES ||
 165           wParam == SPI_SETWHEELSCROLLCHARS) {
 166         sInstance->mSystemSettings.MarkDirty();
 167       }
 168       return false;
 169
 170     case WM_MOUSEWHEEL:
 171     case WM_MOUSEHWHEEL:
 172       GetInstance()->ProcessNativeMouseWheelMessage(aWidget, msg, wParam,
 173                                                     lParam);
 174       sInstance->mSynthesizingEvent->NotifyNativeMessageHandlingFinished();
 175       // We don't need to call next wndproc for WM_MOUSEWHEEL and
 176       // WM_MOUSEHWHEEL.  We should consume them always.  If the messages
 177       // would be handled by our window again, it caused making infinite
 178       // message loop.
 179       aResult.mConsumed = true;
 180       aResult.mResult = (msg != WM_MOUSEHWHEEL);
 181       return true;
 182
 183     case WM_HSCROLL:
 184     case WM_VSCROLL:
 185       aResult.mConsumed = GetInstance()->ProcessNativeScrollMessage(
 186           aWidget, msg, wParam, lParam);
 187       sInstance->mSynthesizingEvent->NotifyNativeMessageHandlingFinished();
 188       aResult.mResult = 0;
 189       return true;
 190
 191     case MOZ_WM_MOUSEVWHEEL:
 192     case MOZ_WM_MOUSEHWHEEL:
 193       GetInstance()->HandleMouseWheelMessage(aWidget, msg, wParam, lParam);
 194       sInstance->mSynthesizingEvent->NotifyInternalMessageHandlingFinished();
 195       // Doesn't need to call next wndproc for internal wheel message.
 196       aResult.mConsumed = true;
 197       return true;
 198
 199     case MOZ_WM_HSCROLL:
 200     case MOZ_WM_VSCROLL:
 201       GetInstance()->HandleScrollMessageAsMouseWheelMessage(aWidget, msg,
 202                                                             wParam, lParam);
 203       sInstance->mSynthesizingEvent->NotifyInternalMessageHandlingFinished();
 204       // Doesn't need to call next wndproc for internal scroll message.
 205       aResult.mConsumed = true;
 206       return true;
 207
 208     case WM_KEYDOWN:
 209     case WM_KEYUP:
 210       MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 211               ("MouseScroll::ProcessMessage(): aWidget=%p, "
 212                "msg=%s(0x%04X), wParam=0x%02zX, ::GetMessageTime()=%ld",
 213                aWidget,
 214                msg == WM_KEYDOWN ? "WM_KEYDOWN"
 215                : msg == WM_KEYUP ? "WM_KEYUP"
 216                                  : "Unknown",
 217                msg, wParam, ::GetMessageTime()));
 218       MaybeLogKeyState();
 219       if (Device::Elantech::HandleKeyMessage(aWidget, msg, wParam, lParam)) {
 220         aResult.mResult = 0;
 221         aResult.mConsumed = true;
 222         return true;
 223       }
 224       return false;
 225
 226     default:
 227       return false;
 228   }
 229 }
 230
 231 /* static */
 232 nsresult MouseScrollHandler::SynthesizeNativeMouseScrollEvent(
 233     nsWindow* aWidget, const LayoutDeviceIntPoint& aPoint,
 234     uint32_t aNativeMessage, int32_t aDelta, uint32_t aModifierFlags,
 235     uint32_t aAdditionalFlags) {
 236   bool useFocusedWindow = !(
 237       aAdditionalFlags & nsIDOMWindowUtils::MOUSESCROLL_PREFER_WIDGET_AT_POINT);
 238
 239   POINT pt;
 240   pt.x = aPoint.x;
 241   pt.y = aPoint.y;
 242
 243   HWND target = useFocusedWindow ? ::WindowFromPoint(pt) : ::GetFocus();
 244   NS_ENSURE_TRUE(target, NS_ERROR_FAILURE);
 245
 246   WPARAM wParam = 0;
 247   LPARAM lParam = 0;
 248   switch (aNativeMessage) {
 249     case WM_MOUSEWHEEL:
 250     case WM_MOUSEHWHEEL: {
 251       lParam = MAKELPARAM(pt.x, pt.y);
 252       WORD mod = 0;
 253       if (aModifierFlags & (nsIWidget::CTRL_L | nsIWidget::CTRL_R)) {
 254         mod |= MK_CONTROL;
 255       }
 256       if (aModifierFlags & (nsIWidget::SHIFT_L | nsIWidget::SHIFT_R)) {
 257         mod |= MK_SHIFT;
 258       }
 259       wParam = MAKEWPARAM(mod, aDelta);
 260       break;
 261     }
 262     case WM_VSCROLL:
 263     case WM_HSCROLL:
 264       lParam = (aAdditionalFlags &
 265                 nsIDOMWindowUtils::MOUSESCROLL_WIN_SCROLL_LPARAM_NOT_NULL)
 266                    ? reinterpret_cast<LPARAM>(target)
 267                    : 0;
 268       wParam = aDelta;
 269       break;
 270     default:
 271       return NS_ERROR_INVALID_ARG;
 272   }
 273
 274   // Ensure to make the instance.
 275   GetInstance();
 276
 277   BYTE kbdState[256];
 278   memset(kbdState, 0, sizeof(kbdState));
 279
 280   AutoTArray<KeyPair, 10> keySequence;
 281   WinUtils::SetupKeyModifiersSequence(&keySequence, aModifierFlags,
 282                                       aNativeMessage);
 283
 284   for (uint32_t i = 0; i < keySequence.Length(); ++i) {
 285     uint8_t key = keySequence[i].mGeneral;
 286     uint8_t keySpecific = keySequence[i].mSpecific;
 287     kbdState[key] = 0x81;  // key is down and toggled on if appropriate
 288     if (keySpecific) {
 289       kbdState[keySpecific] = 0x81;
 290     }
 291   }
 292
 293   if (!sInstance->mSynthesizingEvent) {
 294     sInstance->mSynthesizingEvent = new SynthesizingEvent();
 295   }
 296
 297   POINTS pts;
 298   pts.x = static_cast<SHORT>(pt.x);
 299   pts.y = static_cast<SHORT>(pt.y);
 300   return sInstance->mSynthesizingEvent->Synthesize(pts, target, aNativeMessage,
 301                                                    wParam, lParam, kbdState);
 302 }
 303
 304 /* static */
 305 void MouseScrollHandler::InitEvent(nsWindow* aWidget, WidgetGUIEvent& aEvent,
 306                                    LPARAM* aPoint) {
 307   NS_ENSURE_TRUE_VOID(aWidget);
 308
 309   // If a point is provided, use it; otherwise, get current message point or
 310   // synthetic point
 311   POINTS pointOnScreen;
 312   if (aPoint != nullptr) {
 313     pointOnScreen = MAKEPOINTS(*aPoint);
 314   } else {
 315     pointOnScreen = GetCurrentMessagePos();
 316   }
 317
 318   // InitEvent expects the point to be in window coordinates, so translate the
 319   // point from screen coordinates.
 320   POINT pointOnWindow;
 321   POINTSTOPOINT(pointOnWindow, pointOnScreen);
 322   ::ScreenToClient(aWidget->GetWindowHandle(), &pointOnWindow);
 323
 324   LayoutDeviceIntPoint point;
 325   point.x = pointOnWindow.x;
 326   point.y = pointOnWindow.y;
 327
 328   aWidget->InitEvent(aEvent, &point);
 329 }
 330
 331 /* static */
 332 ModifierKeyState MouseScrollHandler::GetModifierKeyState(UINT aMessage) {
 333   ModifierKeyState result;
 334   // Assume the Control key is down if the Elantech touchpad has sent the
 335   // mis-ordered WM_KEYDOWN/WM_MOUSEWHEEL messages.  (See the comment in
 336   // MouseScrollHandler::Device::Elantech::HandleKeyMessage().)
 337   if ((aMessage == MOZ_WM_MOUSEVWHEEL || aMessage == WM_MOUSEWHEEL) &&
 338       !result.IsControl() && Device::Elantech::IsZooming()) {
 339     // XXX Do we need to unset MODIFIER_SHIFT, MODIFIER_ALT, MODIFIER_META too?
 340     //     If one of them are true, the default action becomes not zooming.
 341     result.Unset(MODIFIER_ALTGRAPH);
 342     result.Set(MODIFIER_CONTROL);
 343   }
 344   return result;
 345 }
 346
 347 POINT
 348 MouseScrollHandler::ComputeMessagePos(UINT aMessage, WPARAM aWParam,
 349                                       LPARAM aLParam) {
 350   POINT point;
 351   if (Device::SetPoint::IsGetMessagePosResponseValid(aMessage, aWParam,
 352                                                      aLParam)) {
 353     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 354             ("MouseScroll::ComputeMessagePos: Using ::GetCursorPos()"));
 355     ::GetCursorPos(&point);
 356   } else {
 357     POINTS pts = GetCurrentMessagePos();
 358     point.x = pts.x;
 359     point.y = pts.y;
 360   }
 361   return point;
 362 }
 363
 364 void MouseScrollHandler::ProcessNativeMouseWheelMessage(nsWindow* aWidget,
 365                                                         UINT aMessage,
 366                                                         WPARAM aWParam,
 367                                                         LPARAM aLParam) {
 368   if (SynthesizingEvent::IsSynthesizing()) {
 369     mSynthesizingEvent->NativeMessageReceived(aWidget, aMessage, aWParam,
 370                                               aLParam);
 371   }
 372
 373   POINT point = ComputeMessagePos(aMessage, aWParam, aLParam);
 374
 375   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 376           ("MouseScroll::ProcessNativeMouseWheelMessage: aWidget=%p, "
 377            "aMessage=%s, wParam=0x%08zX, lParam=0x%08" PRIXLPTR
 378            ", point: { x=%ld, y=%ld }",
 379            aWidget,
 380            aMessage == WM_MOUSEWHEEL    ? "WM_MOUSEWHEEL"
 381            : aMessage == WM_MOUSEHWHEEL ? "WM_MOUSEHWHEEL"
 382            : aMessage == WM_VSCROLL     ? "WM_VSCROLL"
 383                                         : "WM_HSCROLL",
 384            aWParam, aLParam, point.x, point.y));
 385   MaybeLogKeyState();
 386
 387   HWND underCursorWnd = ::WindowFromPoint(point);
 388   if (!underCursorWnd) {
 389     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 390             ("MouseScroll::ProcessNativeMouseWheelMessage: "
 391              "No window is not found under the cursor"));
 392     return;
 393   }
 394
 395   if (Device::Elantech::IsPinchHackNeeded() &&
 396       Device::Elantech::IsHelperWindow(underCursorWnd)) {
 397     // The Elantech driver places a window right underneath the cursor
 398     // when sending a WM_MOUSEWHEEL event to us as part of a pinch-to-zoom
 399     // gesture.  We detect that here, and search for our window that would
 400     // be beneath the cursor if that window wasn't there.
 401     underCursorWnd = WinUtils::FindOurWindowAtPoint(point);
 402     if (!underCursorWnd) {
 403       MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 404               ("MouseScroll::ProcessNativeMouseWheelMessage: "
 405                "Our window is not found under the Elantech helper window"));
 406       return;
 407     }
 408   }
 409
 410   // Handle most cases first.  If the window under mouse cursor is our window
 411   // except plugin window (MozillaWindowClass), we should handle the message
 412   // on the window.
 413   if (WinUtils::IsOurProcessWindow(underCursorWnd)) {
 414     nsWindow* destWindow = WinUtils::GetNSWindowPtr(underCursorWnd);
 415     if (!destWindow) {
 416       MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 417               ("MouseScroll::ProcessNativeMouseWheelMessage: "
 418                "Found window under the cursor isn't managed by nsWindow..."));
 419       HWND wnd = ::GetParent(underCursorWnd);
 420       for (; wnd; wnd = ::GetParent(wnd)) {
 421         destWindow = WinUtils::GetNSWindowPtr(wnd);
 422         if (destWindow) {
 423           break;
 424         }
 425       }
 426       if (!wnd) {
 427         MOZ_LOG(
 428             gMouseScrollLog, LogLevel::Info,
 429             ("MouseScroll::ProcessNativeMouseWheelMessage: Our window which is "
 430              "managed by nsWindow is not found under the cursor"));
 431         return;
 432       }
 433     }
 434
 435     MOZ_ASSERT(destWindow, "destWindow must not be NULL");
 436
 437     // Some odd touchpad utils sets focus to window under the mouse cursor.
 438     // this emulates the odd behavior for debug.
 439     if (mUserPrefs.ShouldEmulateToMakeWindowUnderCursorForeground() &&
 440         (aMessage == WM_MOUSEWHEEL || aMessage == WM_MOUSEHWHEEL) &&
 441         ::GetForegroundWindow() != destWindow->GetWindowHandle()) {
 442       ::SetForegroundWindow(destWindow->GetWindowHandle());
 443     }
 444
 445     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 446             ("MouseScroll::ProcessNativeMouseWheelMessage: Succeeded, "
 447              "Posting internal message to an nsWindow (%p)...",
 448              destWindow));
 449     mIsWaitingInternalMessage = true;
 450     UINT internalMessage = WinUtils::GetInternalMessage(aMessage);
 451     ::PostMessage(destWindow->GetWindowHandle(), internalMessage, aWParam,
 452                   aLParam);
 453     return;
 454   }
 455
 456   // If the window under cursor is not in our process, it means:
 457   // 1. The window may be a plugin window (GeckoPluginWindow or its descendant).
 458   // 2. The window may be another application's window.
 459   HWND pluginWnd = WinUtils::FindOurProcessWindow(underCursorWnd);
 460   if (!pluginWnd) {
 461     // If there is no plugin window in ancestors of the window under cursor,
 462     // the window is for another applications (case 2).
 463     // We don't need to handle this message.
 464     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 465             ("MouseScroll::ProcessNativeMouseWheelMessage: "
 466              "Our window is not found under the cursor"));
 467     return;
 468   }
 469
 470   // If the window is a part of plugin, we should post the message to it.
 471   MOZ_LOG(
 472       gMouseScrollLog, LogLevel::Info,
 473       ("MouseScroll::ProcessNativeMouseWheelMessage: Succeeded, "
 474        "Redirecting the message to a window which is a plugin child window"));
 475   ::PostMessage(underCursorWnd, aMessage, aWParam, aLParam);
 476 }
 477
 478 bool MouseScrollHandler::ProcessNativeScrollMessage(nsWindow* aWidget,
 479                                                     UINT aMessage,
 480                                                     WPARAM aWParam,
 481                                                     LPARAM aLParam) {
 482   if (aLParam || mUserPrefs.IsScrollMessageHandledAsWheelMessage()) {
 483     // Scroll message generated by Thinkpad Trackpoint Driver or similar
 484     // Treat as a mousewheel message and scroll appropriately
 485     ProcessNativeMouseWheelMessage(aWidget, aMessage, aWParam, aLParam);
 486     // Always consume the scroll message if we try to emulate mouse wheel
 487     // action.
 488     return true;
 489   }
 490
 491   if (SynthesizingEvent::IsSynthesizing()) {
 492     mSynthesizingEvent->NativeMessageReceived(aWidget, aMessage, aWParam,
 493                                               aLParam);
 494   }
 495
 496   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 497           ("MouseScroll::ProcessNativeScrollMessage: aWidget=%p, "
 498            "aMessage=%s, wParam=0x%08zX, lParam=0x%08" PRIXLPTR,
 499            aWidget, aMessage == WM_VSCROLL ? "WM_VSCROLL" : "WM_HSCROLL",
 500            aWParam, aLParam));
 501
 502   // Scroll message generated by external application
 503   WidgetContentCommandEvent commandEvent(true, eContentCommandScroll, aWidget);
 504   commandEvent.mScroll.mIsHorizontal = (aMessage == WM_HSCROLL);
 505
 506   switch (LOWORD(aWParam)) {
 507     case SB_LINEUP:  // SB_LINELEFT
 508       commandEvent.mScroll.mUnit =
 509           WidgetContentCommandEvent::eCmdScrollUnit_Line;
 510       commandEvent.mScroll.mAmount = -1;
 511       break;
 512     case SB_LINEDOWN:  // SB_LINERIGHT
 513       commandEvent.mScroll.mUnit =
 514           WidgetContentCommandEvent::eCmdScrollUnit_Line;
 515       commandEvent.mScroll.mAmount = 1;
 516       break;
 517     case SB_PAGEUP:  // SB_PAGELEFT
 518       commandEvent.mScroll.mUnit =
 519           WidgetContentCommandEvent::eCmdScrollUnit_Page;
 520       commandEvent.mScroll.mAmount = -1;
 521       break;
 522     case SB_PAGEDOWN:  // SB_PAGERIGHT
 523       commandEvent.mScroll.mUnit =
 524           WidgetContentCommandEvent::eCmdScrollUnit_Page;
 525       commandEvent.mScroll.mAmount = 1;
 526       break;
 527     case SB_TOP:  // SB_LEFT
 528       commandEvent.mScroll.mUnit =
 529           WidgetContentCommandEvent::eCmdScrollUnit_Whole;
 530       commandEvent.mScroll.mAmount = -1;
 531       break;
 532     case SB_BOTTOM:  // SB_RIGHT
 533       commandEvent.mScroll.mUnit =
 534           WidgetContentCommandEvent::eCmdScrollUnit_Whole;
 535       commandEvent.mScroll.mAmount = 1;
 536       break;
 537     default:
 538       return false;
 539   }
 540   // XXX If this is a plugin window, we should dispatch the event from
 541   //     parent window.
 542   aWidget->DispatchContentCommandEvent(&commandEvent);
 543   return true;
 544 }
 545
 546 void MouseScrollHandler::HandleMouseWheelMessage(nsWindow* aWidget,
 547                                                  UINT aMessage, WPARAM aWParam,
 548                                                  LPARAM aLParam) {
 549   MOZ_ASSERT((aMessage == MOZ_WM_MOUSEVWHEEL || aMessage == MOZ_WM_MOUSEHWHEEL),
 550              "HandleMouseWheelMessage must be called with "
 551              "MOZ_WM_MOUSEVWHEEL or MOZ_WM_MOUSEHWHEEL");
 552
 553   MOZ_LOG(
 554       gMouseScrollLog, LogLevel::Info,
 555       ("MouseScroll::HandleMouseWheelMessage: aWidget=%p, "
 556        "aMessage=MOZ_WM_MOUSE%sWHEEL, aWParam=0x%08zX, aLParam=0x%08" PRIXLPTR,
 557        aWidget, aMessage == MOZ_WM_MOUSEVWHEEL ? "V" : "H", aWParam, aLParam));
 558
 559   mIsWaitingInternalMessage = false;
 560
 561   // If it's not allowed to cache system settings, we need to reset the cache
 562   // before handling the mouse wheel message.
 563   mSystemSettings.TrustedScrollSettingsDriver();
 564
 565   EventInfo eventInfo(aWidget, WinUtils::GetNativeMessage(aMessage), aWParam,
 566                       aLParam);
 567   if (!eventInfo.CanDispatchWheelEvent()) {
 568     MOZ_LOG(
 569         gMouseScrollLog, LogLevel::Info,
 570         ("MouseScroll::HandleMouseWheelMessage: Cannot dispatch the events"));
 571     mLastEventInfo.ResetTransaction();
 572     return;
 573   }
 574
 575   // Discard the remaining delta if current wheel message and last one are
 576   // received by different window or to scroll different direction or
 577   // different unit scroll.  Furthermore, if the last event was too old.
 578   if (!mLastEventInfo.CanContinueTransaction(eventInfo)) {
 579     mLastEventInfo.ResetTransaction();
 580   }
 581
 582   mLastEventInfo.RecordEvent(eventInfo);
 583
 584   ModifierKeyState modKeyState = GetModifierKeyState(aMessage);
 585
 586   // Grab the widget, it might be destroyed by a DOM event handler.
 587   RefPtr<nsWindow> kungFuDethGrip(aWidget);
 588
 589   WidgetWheelEvent wheelEvent(true, eWheel, aWidget);
 590   if (mLastEventInfo.InitWheelEvent(aWidget, wheelEvent, modKeyState,
 591                                     aLParam)) {
 592     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 593             ("MouseScroll::HandleMouseWheelMessage: dispatching "
 594              "eWheel event"));
 595     aWidget->DispatchWheelEvent(&wheelEvent);
 596     if (aWidget->Destroyed()) {
 597       MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 598               ("MouseScroll::HandleMouseWheelMessage: The window was destroyed "
 599                "by eWheel event"));
 600       mLastEventInfo.ResetTransaction();
 601       return;
 602     }
 603   } else {
 604     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 605             ("MouseScroll::HandleMouseWheelMessage: eWheel event is not "
 606              "dispatched"));
 607   }
 608 }
 609
 610 void MouseScrollHandler::HandleScrollMessageAsMouseWheelMessage(
 611     nsWindow* aWidget, UINT aMessage, WPARAM aWParam, LPARAM aLParam) {
 612   MOZ_ASSERT((aMessage == MOZ_WM_VSCROLL || aMessage == MOZ_WM_HSCROLL),
 613              "HandleScrollMessageAsMouseWheelMessage must be called with "
 614              "MOZ_WM_VSCROLL or MOZ_WM_HSCROLL");
 615
 616   mIsWaitingInternalMessage = false;
 617
 618   ModifierKeyState modKeyState = GetModifierKeyState(aMessage);
 619
 620   WidgetWheelEvent wheelEvent(true, eWheel, aWidget);
 621   double& delta =
 622       (aMessage == MOZ_WM_VSCROLL) ? wheelEvent.mDeltaY : wheelEvent.mDeltaX;
 623   int32_t& lineOrPageDelta = (aMessage == MOZ_WM_VSCROLL)
 624                                  ? wheelEvent.mLineOrPageDeltaY
 625                                  : wheelEvent.mLineOrPageDeltaX;
 626
 627   delta = 1.0;
 628   lineOrPageDelta = 1;
 629
 630   switch (LOWORD(aWParam)) {
 631     case SB_PAGEUP:
 632       delta = -1.0;
 633       lineOrPageDelta = -1;
 634       [[fallthrough]];
 635     case SB_PAGEDOWN:
 636       wheelEvent.mDeltaMode = dom::WheelEvent_Binding::DOM_DELTA_PAGE;
 637       break;
 638
 639     case SB_LINEUP:
 640       delta = -1.0;
 641       lineOrPageDelta = -1;
 642       [[fallthrough]];
 643     case SB_LINEDOWN:
 644       wheelEvent.mDeltaMode = dom::WheelEvent_Binding::DOM_DELTA_LINE;
 645       break;
 646
 647     default:
 648       return;
 649   }
 650   modKeyState.InitInputEvent(wheelEvent);
 651
 652   // Current mouse position may not be same as when the original message
 653   // is received. However, this data is not available with the original
 654   // message, which is why nullptr is passed in. We need to know the actual
 655   // mouse cursor position when the original message was received.
 656   InitEvent(aWidget, wheelEvent, nullptr);
 657
 658   MOZ_LOG(
 659       gMouseScrollLog, LogLevel::Info,
 660       ("MouseScroll::HandleScrollMessageAsMouseWheelMessage: aWidget=%p, "
 661        "aMessage=MOZ_WM_%sSCROLL, aWParam=0x%08zX, aLParam=0x%08" PRIXLPTR ", "
 662        "wheelEvent { mRefPoint: { x: %d, y: %d }, mDeltaX: %f, mDeltaY: %f, "
 663        "mLineOrPageDeltaX: %d, mLineOrPageDeltaY: %d, "
 664        "isShift: %s, isControl: %s, isAlt: %s, isMeta: %s }",
 665        aWidget, (aMessage == MOZ_WM_VSCROLL) ? "V" : "H", aWParam, aLParam,
 666        wheelEvent.mRefPoint.x.value, wheelEvent.mRefPoint.y.value,
 667        wheelEvent.mDeltaX, wheelEvent.mDeltaY, wheelEvent.mLineOrPageDeltaX,
 668        wheelEvent.mLineOrPageDeltaY, GetBoolName(wheelEvent.IsShift()),
 669        GetBoolName(wheelEvent.IsControl()), GetBoolName(wheelEvent.IsAlt()),
 670        GetBoolName(wheelEvent.IsMeta())));
 671
 672   aWidget->DispatchWheelEvent(&wheelEvent);
 673 }
 674
 675 /******************************************************************************
 676  *
 677  * EventInfo
 678  *
 679  ******************************************************************************/
 680
 681 MouseScrollHandler::EventInfo::EventInfo(nsWindow* aWidget, UINT aMessage,
 682                                          WPARAM aWParam, LPARAM aLParam) {
 683   MOZ_ASSERT(
 684       aMessage == WM_MOUSEWHEEL || aMessage == WM_MOUSEHWHEEL,
 685       "EventInfo must be initialized with WM_MOUSEWHEEL or WM_MOUSEHWHEEL");
 686
 687   MouseScrollHandler::GetInstance()->mSystemSettings.Init();
 688
 689   mIsVertical = (aMessage == WM_MOUSEWHEEL);
 690   mIsPage =
 691       MouseScrollHandler::sInstance->mSystemSettings.IsPageScroll(mIsVertical);
 692   mDelta = (short)HIWORD(aWParam);
 693   mWnd = aWidget->GetWindowHandle();
 694   mTimeStamp = TimeStamp::Now();
 695 }
 696
 697 bool MouseScrollHandler::EventInfo::CanDispatchWheelEvent() const {
 698   if (!GetScrollAmount()) {
 699     // XXX I think that we should dispatch mouse wheel events even if the
 700     // operation will not scroll because the wheel operation really happened
 701     // and web application may want to handle the event for non-scroll action.
 702     return false;
 703   }
 704
 705   return (mDelta != 0);
 706 }
 707
 708 int32_t MouseScrollHandler::EventInfo::GetScrollAmount() const {
 709   if (mIsPage) {
 710     return 1;
 711   }
 712   return MouseScrollHandler::sInstance->mSystemSettings.GetScrollAmount(
 713       mIsVertical);
 714 }
 715
 716 /******************************************************************************
 717  *
 718  * LastEventInfo
 719  *
 720  ******************************************************************************/
 721
 722 bool MouseScrollHandler::LastEventInfo::CanContinueTransaction(
 723     const EventInfo& aNewEvent) {
 724   int32_t timeout = MouseScrollHandler::sInstance->mUserPrefs
 725                         .GetMouseScrollTransactionTimeout();
 726   return !mWnd ||
 727          (mWnd == aNewEvent.GetWindowHandle() &&
 728           IsPositive() == aNewEvent.IsPositive() &&
 729           mIsVertical == aNewEvent.IsVertical() &&
 730           mIsPage == aNewEvent.IsPage() &&
 731           (timeout < 0 || TimeStamp::Now() - mTimeStamp <=
 732                               TimeDuration::FromMilliseconds(timeout)));
 733 }
 734
 735 void MouseScrollHandler::LastEventInfo::ResetTransaction() {
 736   if (!mWnd) {
 737     return;
 738   }
 739
 740   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 741           ("MouseScroll::LastEventInfo::ResetTransaction()"));
 742
 743   mWnd = nullptr;
 744   mAccumulatedDelta = 0;
 745 }
 746
 747 void MouseScrollHandler::LastEventInfo::RecordEvent(const EventInfo& aEvent) {
 748   mWnd = aEvent.GetWindowHandle();
 749   mDelta = aEvent.GetNativeDelta();
 750   mIsVertical = aEvent.IsVertical();
 751   mIsPage = aEvent.IsPage();
 752   mTimeStamp = TimeStamp::Now();
 753 }
 754
 755 /* static */
 756 int32_t MouseScrollHandler::LastEventInfo::RoundDelta(double aDelta) {
 757   return (aDelta >= 0) ? (int32_t)floor(aDelta) : (int32_t)ceil(aDelta);
 758 }
 759
 760 bool MouseScrollHandler::LastEventInfo::InitWheelEvent(
 761     nsWindow* aWidget, WidgetWheelEvent& aWheelEvent,
 762     const ModifierKeyState& aModKeyState, LPARAM aLParam) {
 763   MOZ_ASSERT(aWheelEvent.mMessage == eWheel);
 764
 765   if (StaticPrefs::mousewheel_ignore_cursor_position_in_lparam()) {
 766     InitEvent(aWidget, aWheelEvent, nullptr);
 767   } else {
 768     InitEvent(aWidget, aWheelEvent, &aLParam);
 769   }
 770
 771   aModKeyState.InitInputEvent(aWheelEvent);
 772
 773   // Our positive delta value means to bottom or right.
 774   // But positive native delta value means to top or right.
 775   // Use orienter for computing our delta value with native delta value.
 776   int32_t orienter = mIsVertical ? -1 : 1;
 777
 778   aWheelEvent.mDeltaMode = mIsPage ? dom::WheelEvent_Binding::DOM_DELTA_PAGE
 779                                    : dom::WheelEvent_Binding::DOM_DELTA_LINE;
 780
 781   double ticks = double(mDelta) * orienter / double(WHEEL_DELTA);
 782   if (mIsVertical) {
 783     aWheelEvent.mWheelTicksY = ticks;
 784   } else {
 785     aWheelEvent.mWheelTicksX = ticks;
 786   }
 787
 788   double& delta = mIsVertical ? aWheelEvent.mDeltaY : aWheelEvent.mDeltaX;
 789   int32_t& lineOrPageDelta = mIsVertical ? aWheelEvent.mLineOrPageDeltaY
 790                                          : aWheelEvent.mLineOrPageDeltaX;
 791
 792   double nativeDeltaPerUnit =
 793       mIsPage ? double(WHEEL_DELTA) : double(WHEEL_DELTA) / GetScrollAmount();
 794
 795   delta = double(mDelta) * orienter / nativeDeltaPerUnit;
 796   mAccumulatedDelta += mDelta;
 797   lineOrPageDelta =
 798       mAccumulatedDelta * orienter / RoundDelta(nativeDeltaPerUnit);
 799   mAccumulatedDelta -=
 800       lineOrPageDelta * orienter * RoundDelta(nativeDeltaPerUnit);
 801
 802   if (aWheelEvent.mDeltaMode != dom::WheelEvent_Binding::DOM_DELTA_LINE) {
 803     // If the scroll delta mode isn't per line scroll, we shouldn't allow to
 804     // override the system scroll speed setting.
 805     aWheelEvent.mAllowToOverrideSystemScrollSpeed = false;
 806   }
 807
 808   MOZ_LOG(
 809       gMouseScrollLog, LogLevel::Info,
 810       ("MouseScroll::LastEventInfo::InitWheelEvent: aWidget=%p, "
 811        "aWheelEvent { mRefPoint: { x: %d, y: %d }, mDeltaX: %f, mDeltaY: %f, "
 812        "mLineOrPageDeltaX: %d, mLineOrPageDeltaY: %d, "
 813        "isShift: %s, isControl: %s, isAlt: %s, isMeta: %s, "
 814        "mAllowToOverrideSystemScrollSpeed: %s }, "
 815        "mAccumulatedDelta: %d",
 816        aWidget, aWheelEvent.mRefPoint.x.value, aWheelEvent.mRefPoint.y.value,
 817        aWheelEvent.mDeltaX, aWheelEvent.mDeltaY, aWheelEvent.mLineOrPageDeltaX,
 818        aWheelEvent.mLineOrPageDeltaY, GetBoolName(aWheelEvent.IsShift()),
 819        GetBoolName(aWheelEvent.IsControl()), GetBoolName(aWheelEvent.IsAlt()),
 820        GetBoolName(aWheelEvent.IsMeta()),
 821        GetBoolName(aWheelEvent.mAllowToOverrideSystemScrollSpeed),
 822        mAccumulatedDelta));
 823
 824   return (delta != 0);
 825 }
 826
 827 /******************************************************************************
 828  *
 829  * SystemSettings
 830  *
 831  ******************************************************************************/
 832
 833 void MouseScrollHandler::SystemSettings::Init() {
 834   if (mInitialized) {
 835     return;
 836   }
 837
 838   InitScrollLines();
 839   InitScrollChars();
 840
 841   mInitialized = true;
 842
 843   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 844           ("MouseScroll::SystemSettings::Init(): initialized, "
 845            "mScrollLines=%d, mScrollChars=%d",
 846            mScrollLines, mScrollChars));
 847 }
 848
 849 bool MouseScrollHandler::SystemSettings::InitScrollLines() {
 850   int32_t oldValue = mInitialized ? mScrollLines : 0;
 851   mIsReliableScrollLines = false;
 852   mScrollLines = MouseScrollHandler::sInstance->mUserPrefs
 853                      .GetOverriddenVerticalScrollAmout();
 854   if (mScrollLines >= 0) {
 855     // overridden by the pref.
 856     mIsReliableScrollLines = true;
 857     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 858             ("MouseScroll::SystemSettings::InitScrollLines(): mScrollLines is "
 859              "overridden by the pref: %d",
 860              mScrollLines));
 861   } else if (!::SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &mScrollLines,
 862                                      0)) {
 863     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 864             ("MouseScroll::SystemSettings::InitScrollLines(): "
 865              "::SystemParametersInfo("
 866              "SPI_GETWHEELSCROLLLINES) failed"));
 867     mScrollLines = DefaultScrollLines();
 868   }
 869
 870   if (mScrollLines > WHEEL_DELTA) {
 871     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 872             ("MouseScroll::SystemSettings::InitScrollLines(): the result of "
 873              "::SystemParametersInfo(SPI_GETWHEELSCROLLLINES) is too large: %d",
 874              mScrollLines));
 875     // sScrollLines usually equals 3 or 0 (for no scrolling)
 876     // However, if sScrollLines > WHEEL_DELTA, we assume that
 877     // the mouse driver wants a page scroll.  The docs state that
 878     // sScrollLines should explicitly equal WHEEL_PAGESCROLL, but
 879     // since some mouse drivers use an arbitrary large number instead,
 880     // we have to handle that as well.
 881     mScrollLines = WHEEL_PAGESCROLL;
 882   }
 883
 884   return oldValue != mScrollLines;
 885 }
 886
 887 bool MouseScrollHandler::SystemSettings::InitScrollChars() {
 888   int32_t oldValue = mInitialized ? mScrollChars : 0;
 889   mIsReliableScrollChars = false;
 890   mScrollChars = MouseScrollHandler::sInstance->mUserPrefs
 891                      .GetOverriddenHorizontalScrollAmout();
 892   if (mScrollChars >= 0) {
 893     // overridden by the pref.
 894     mIsReliableScrollChars = true;
 895     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 896             ("MouseScroll::SystemSettings::InitScrollChars(): mScrollChars is "
 897              "overridden by the pref: %d",
 898              mScrollChars));
 899   } else if (!::SystemParametersInfo(SPI_GETWHEELSCROLLCHARS, 0, &mScrollChars,
 900                                      0)) {
 901     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 902             ("MouseScroll::SystemSettings::InitScrollChars(): "
 903              "::SystemParametersInfo("
 904              "SPI_GETWHEELSCROLLCHARS) failed, this is unexpected on Vista or "
 905              "later"));
 906     // XXX Should we use DefaultScrollChars()?
 907     mScrollChars = 1;
 908   }
 909
 910   if (mScrollChars > WHEEL_DELTA) {
 911     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 912             ("MouseScroll::SystemSettings::InitScrollChars(): the result of "
 913              "::SystemParametersInfo(SPI_GETWHEELSCROLLCHARS) is too large: %d",
 914              mScrollChars));
 915     // See the comments for the case mScrollLines > WHEEL_DELTA.
 916     mScrollChars = WHEEL_PAGESCROLL;
 917   }
 918
 919   return oldValue != mScrollChars;
 920 }
 921
 922 void MouseScrollHandler::SystemSettings::MarkDirty() {
 923   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
 924           ("MouseScrollHandler::SystemSettings::MarkDirty(): "
 925            "Marking SystemSettings dirty"));
 926   mInitialized = false;
 927   // When system settings are changed, we should reset current transaction.
 928   MOZ_ASSERT(sInstance,
 929              "Must not be called at initializing MouseScrollHandler");
 930   MouseScrollHandler::sInstance->mLastEventInfo.ResetTransaction();
 931 }
 932
 933 void MouseScrollHandler::SystemSettings::RefreshCache() {
 934   bool isChanged = InitScrollLines();
 935   isChanged = InitScrollChars() || isChanged;
 936   if (!isChanged) {
 937     return;
 938   }
 939   // If the scroll amount is changed, we should reset current transaction.
 940   MOZ_ASSERT(sInstance,
 941              "Must not be called at initializing MouseScrollHandler");
 942   MouseScrollHandler::sInstance->mLastEventInfo.ResetTransaction();
 943 }
 944
 945 void MouseScrollHandler::SystemSettings::TrustedScrollSettingsDriver() {
 946   if (!mInitialized) {
 947     return;
 948   }
 949
 950   // if the cache is initialized with prefs, we don't need to refresh it.
 951   if (mIsReliableScrollLines && mIsReliableScrollChars) {
 952     return;
 953   }
 954
 955   MouseScrollHandler::UserPrefs& userPrefs =
 956       MouseScrollHandler::sInstance->mUserPrefs;
 957
 958   // If system settings cache is disabled, we should always refresh them.
 959   if (!userPrefs.IsSystemSettingCacheEnabled()) {
 960     RefreshCache();
 961     return;
 962   }
 963
 964   // If pref is set to as "always trust the cache", we shouldn't refresh them
 965   // in any environments.
 966   if (userPrefs.IsSystemSettingCacheForciblyEnabled()) {
 967     return;
 968   }
 969
 970   // If SynTP of Synaptics or Apoint of Alps is installed, it may hook
 971   // ::SystemParametersInfo() and returns different value from system settings.
 972   if (Device::SynTP::IsDriverInstalled() ||
 973       Device::Apoint::IsDriverInstalled()) {
 974     RefreshCache();
 975     return;
 976   }
 977
 978   // XXX We're not sure about other touchpad drivers...
 979 }
 980
 981 /******************************************************************************
 982  *
 983  * UserPrefs
 984  *
 985  ******************************************************************************/
 986
 987 MouseScrollHandler::UserPrefs::UserPrefs() : mInitialized(false) {
 988   // We need to reset mouse wheel transaction when all of mousewheel related
 989   // prefs are changed.
 990   DebugOnly<nsresult> rv =
 991       Preferences::RegisterPrefixCallback(OnChange, "mousewheel.", this);
 992   MOZ_ASSERT(NS_SUCCEEDED(rv), "Failed to register callback for mousewheel.");
 993 }
 994
 995 MouseScrollHandler::UserPrefs::~UserPrefs() {
 996   DebugOnly<nsresult> rv =
 997       Preferences::UnregisterPrefixCallback(OnChange, "mousewheel.", this);
 998   MOZ_ASSERT(NS_SUCCEEDED(rv), "Failed to unregister callback for mousewheel.");
 999 }
1000
1001 void MouseScrollHandler::UserPrefs::Init() {
1002   if (mInitialized) {
1003     return;
1004   }
1005
1006   mInitialized = true;
1007
1008   mScrollMessageHandledAsWheelMessage =
1009       Preferences::GetBool("mousewheel.emulate_at_wm_scroll", false);
1010   mEnableSystemSettingCache =
1011       Preferences::GetBool("mousewheel.system_settings_cache.enabled", true);
1012   mForceEnableSystemSettingCache = Preferences::GetBool(
1013       "mousewheel.system_settings_cache.force_enabled", false);
1014   mEmulateToMakeWindowUnderCursorForeground = Preferences::GetBool(
1015       "mousewheel.debug.make_window_under_cursor_foreground", false);
1016   mOverriddenVerticalScrollAmount =
1017       Preferences::GetInt("mousewheel.windows.vertical_amount_override", -1);
1018   mOverriddenHorizontalScrollAmount =
1019       Preferences::GetInt("mousewheel.windows.horizontal_amount_override", -1);
1020   mMouseScrollTransactionTimeout = Preferences::GetInt(
1021       "mousewheel.windows.transaction.timeout", DEFAULT_TIMEOUT_DURATION);
1022
1023   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1024           ("MouseScroll::UserPrefs::Init(): initialized, "
1025            "mScrollMessageHandledAsWheelMessage=%s, "
1026            "mEnableSystemSettingCache=%s, "
1027            "mForceEnableSystemSettingCache=%s, "
1028            "mEmulateToMakeWindowUnderCursorForeground=%s, "
1029            "mOverriddenVerticalScrollAmount=%d, "
1030            "mOverriddenHorizontalScrollAmount=%d, "
1031            "mMouseScrollTransactionTimeout=%d",
1032            GetBoolName(mScrollMessageHandledAsWheelMessage),
1033            GetBoolName(mEnableSystemSettingCache),
1034            GetBoolName(mForceEnableSystemSettingCache),
1035            GetBoolName(mEmulateToMakeWindowUnderCursorForeground),
1036            mOverriddenVerticalScrollAmount, mOverriddenHorizontalScrollAmount,
1037            mMouseScrollTransactionTimeout));
1038 }
1039
1040 void MouseScrollHandler::UserPrefs::MarkDirty() {
1041   MOZ_LOG(
1042       gMouseScrollLog, LogLevel::Info,
1043       ("MouseScrollHandler::UserPrefs::MarkDirty(): Marking UserPrefs dirty"));
1044   mInitialized = false;
1045   // Some prefs might override system settings, so, we should mark them dirty.
1046   MouseScrollHandler::sInstance->mSystemSettings.MarkDirty();
1047   // When user prefs for mousewheel are changed, we should reset current
1048   // transaction.
1049   MOZ_ASSERT(sInstance,
1050              "Must not be called at initializing MouseScrollHandler");
1051   MouseScrollHandler::sInstance->mLastEventInfo.ResetTransaction();
1052 }
1053
1054 /******************************************************************************
1055  *
1056  * Device
1057  *
1058  ******************************************************************************/
1059
1060 /* static */
1061 bool MouseScrollHandler::Device::GetWorkaroundPref(const char* aPrefName,
1062                                                    bool aValueIfAutomatic) {
1063   if (!aPrefName) {
1064     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1065             ("MouseScroll::Device::GetWorkaroundPref(): Failed, aPrefName is "
1066              "NULL"));
1067     return aValueIfAutomatic;
1068   }
1069
1070   int32_t lHackValue = 0;
1071   if (NS_FAILED(Preferences::GetInt(aPrefName, &lHackValue))) {
1072     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1073             ("MouseScroll::Device::GetWorkaroundPref(): Preferences::GetInt() "
1074              "failed,"
1075              " aPrefName=\"%s\", aValueIfAutomatic=%s",
1076              aPrefName, GetBoolName(aValueIfAutomatic)));
1077     return aValueIfAutomatic;
1078   }
1079
1080   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1081           ("MouseScroll::Device::GetWorkaroundPref(): Succeeded, "
1082            "aPrefName=\"%s\", aValueIfAutomatic=%s, lHackValue=%d",
1083            aPrefName, GetBoolName(aValueIfAutomatic), lHackValue));
1084
1085   switch (lHackValue) {
1086     case 0:  // disabled
1087       return false;
1088     case 1:  // enabled
1089       return true;
1090     default:  // -1: autodetect
1091       return aValueIfAutomatic;
1092   }
1093 }
1094
1095 /* static */
1096 void MouseScrollHandler::Device::Init() {
1097   // FYI: Thinkpad's TrackPoint is Apoint of Alps and UltraNav is SynTP of
1098   //      Synaptics.  So, those drivers' information should be initialized
1099   //      before calling methods of TrackPoint and UltraNav.
1100   SynTP::Init();
1101   Elantech::Init();
1102   Apoint::Init();
1103
1104   sFakeScrollableWindowNeeded = GetWorkaroundPref(
1105       "ui.trackpoint_hack.enabled", (TrackPoint::IsDriverInstalled() ||
1106                                      UltraNav::IsObsoleteDriverInstalled()));
1107
1108   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1109           ("MouseScroll::Device::Init(): sFakeScrollableWindowNeeded=%s",
1110            GetBoolName(sFakeScrollableWindowNeeded)));
1111 }
1112
1113 /******************************************************************************
1114  *
1115  * Device::SynTP
1116  *
1117  ******************************************************************************/
1118
1119 /* static */
1120 void MouseScrollHandler::Device::SynTP::Init() {
1121   if (sInitialized) {
1122     return;
1123   }
1124
1125   sInitialized = true;
1126   sMajorVersion = 0;
1127   sMinorVersion = -1;
1128
1129   wchar_t buf[40];
1130   bool foundKey = WinUtils::GetRegistryKey(
1131       HKEY_LOCAL_MACHINE, L"Software\\Synaptics\\SynTP\\Install",
1132       L"DriverVersion", buf, sizeof buf);
1133   if (!foundKey) {
1134     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1135             ("MouseScroll::Device::SynTP::Init(): "
1136              "SynTP driver is not found"));
1137     return;
1138   }
1139
1140   sMajorVersion = wcstol(buf, nullptr, 10);
1141   sMinorVersion = 0;
1142   wchar_t* p = wcschr(buf, L'.');
1143   if (p) {
1144     sMinorVersion = wcstol(p + 1, nullptr, 10);
1145   }
1146   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1147           ("MouseScroll::Device::SynTP::Init(): "
1148            "found driver version = %d.%d",
1149            sMajorVersion, sMinorVersion));
1150 }
1151
1152 /******************************************************************************
1153  *
1154  * Device::Elantech
1155  *
1156  ******************************************************************************/
1157
1158 /* static */
1159 void MouseScrollHandler::Device::Elantech::Init() {
1160   int32_t version = GetDriverMajorVersion();
1161   bool needsHack = Device::GetWorkaroundPref(
1162       "ui.elantech_gesture_hacks.enabled", version != 0);
1163   sUseSwipeHack = needsHack && version <= 7;
1164   sUsePinchHack = needsHack && version <= 8;
1165
1166   MOZ_LOG(
1167       gMouseScrollLog, LogLevel::Info,
1168       ("MouseScroll::Device::Elantech::Init(): version=%d, sUseSwipeHack=%s, "
1169        "sUsePinchHack=%s",
1170        version, GetBoolName(sUseSwipeHack), GetBoolName(sUsePinchHack)));
1171 }
1172
1173 /* static */
1174 int32_t MouseScrollHandler::Device::Elantech::GetDriverMajorVersion() {
1175   wchar_t buf[40];
1176   // The driver version is found in one of these two registry keys.
1177   bool foundKey = WinUtils::GetRegistryKey(HKEY_CURRENT_USER,
1178                                            L"Software\\Elantech\\MainOption",
1179                                            L"DriverVersion", buf, sizeof buf);
1180   if (!foundKey) {
1181     foundKey =
1182         WinUtils::GetRegistryKey(HKEY_CURRENT_USER, L"Software\\Elantech",
1183                                  L"DriverVersion", buf, sizeof buf);
1184   }
1185
1186   if (!foundKey) {
1187     return 0;
1188   }
1189
1190   // Assume that the major version number can be found just after a space
1191   // or at the start of the string.
1192   for (wchar_t* p = buf; *p; p++) {
1193     if (*p >= L'0' && *p <= L'9' && (p == buf || *(p - 1) == L' ')) {
1194       return wcstol(p, nullptr, 10);
1195     }
1196   }
1197
1198   return 0;
1199 }
1200
1201 /* static */
1202 bool MouseScrollHandler::Device::Elantech::IsHelperWindow(HWND aWnd) {
1203   // The helper window cannot be distinguished based on its window class, so we
1204   // need to check if it is owned by the helper process, ETDCtrl.exe.
1205
1206   const wchar_t* filenameSuffix = L"\\etdctrl.exe";
1207   const int filenameSuffixLength = 12;
1208
1209   DWORD pid;
1210   ::GetWindowThreadProcessId(aWnd, &pid);
1211
1212   HANDLE hProcess = ::OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid);
1213   if (!hProcess) {
1214     return false;
1215   }
1216
1217   bool result = false;
1218   wchar_t path[256] = {L'\0'};
1219   if (::GetProcessImageFileNameW(hProcess, path, ArrayLength(path))) {
1220     int pathLength = lstrlenW(path);
1221     if (pathLength >= filenameSuffixLength) {
1222       if (lstrcmpiW(path + pathLength - filenameSuffixLength, filenameSuffix) ==
1223           0) {
1224         result = true;
1225       }
1226     }
1227   }
1228   ::CloseHandle(hProcess);
1229
1230   return result;
1231 }
1232
1233 /* static */
1234 bool MouseScrollHandler::Device::Elantech::HandleKeyMessage(nsWindow* aWidget,
1235                                                             UINT aMsg,
1236                                                             WPARAM aWParam,
1237                                                             LPARAM aLParam) {
1238   // The Elantech touchpad driver understands three-finger swipe left and
1239   // right gestures, and translates them into Page Up and Page Down key
1240   // events for most applications.  For Firefox 3.6, it instead sends
1241   // Alt+Left and Alt+Right to trigger browser back/forward actions.  As
1242   // with the Thinkpad Driver hack in nsWindow::Create, the change in
1243   // HWND structure makes Firefox not trigger the driver's heuristics
1244   // any longer.
1245   //
1246   // The Elantech driver actually sends these messages for a three-finger
1247   // swipe right:
1248   //
1249   //   WM_KEYDOWN virtual_key = 0xCC or 0xFF ScanCode = 00
1250   //   WM_KEYDOWN virtual_key = VK_NEXT      ScanCode = 00
1251   //   WM_KEYUP   virtual_key = VK_NEXT      ScanCode = 00
1252   //   WM_KEYUP   virtual_key = 0xCC or 0xFF ScanCode = 00
1253   //
1254   // Whether 0xCC or 0xFF is sent is suspected to depend on the driver
1255   // version.  7.0.4.12_14Jul09_WHQL, 7.0.5.10, and 7.0.6.0 generate 0xCC.
1256   // 7.0.4.3 from Asus on EeePC generates 0xFF.
1257   //
1258   // On some hardware, IS_VK_DOWN(0xFF) returns true even when Elantech
1259   // messages are not involved, meaning that alone is not enough to
1260   // distinguish the gesture from a regular Page Up or Page Down key press.
1261   // The ScanCode is therefore also tested to detect the gesture.
1262   // We then pretend that we should dispatch "Go Forward" command.  Similarly
1263   // for VK_PRIOR and "Go Back" command.
1264   if (sUseSwipeHack && (aWParam == VK_NEXT || aWParam == VK_PRIOR) &&
1265       WinUtils::GetScanCode(aLParam) == 0 &&
1266       (IS_VK_DOWN(0xFF) || IS_VK_DOWN(0xCC))) {
1267     if (aMsg == WM_KEYDOWN) {
1268       MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1269               ("MouseScroll::Device::Elantech::HandleKeyMessage(): Dispatching "
1270                "%s command event",
1271                aWParam == VK_NEXT ? "Forward" : "Back"));
1272
1273       WidgetCommandEvent appCommandEvent(
1274           true, (aWParam == VK_NEXT) ? nsGkAtoms::Forward : nsGkAtoms::Back,
1275           aWidget);
1276
1277       // In this scenario, the coordinate of the event isn't supplied, so pass
1278       // nullptr as an argument to indicate using the coordinate from the last
1279       // available window message.
1280       InitEvent(aWidget, appCommandEvent, nullptr);
1281       aWidget->DispatchWindowEvent(appCommandEvent);
1282     } else {
1283       MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1284               ("MouseScroll::Device::Elantech::HandleKeyMessage(): Consumed"));
1285     }
1286     return true;  // consume the message (doesn't need to dispatch key events)
1287   }
1288
1289   // Version 8 of the Elantech touchpad driver sends these messages for
1290   // zoom gestures:
1291   //
1292   //   WM_KEYDOWN    virtual_key = 0xCC        time = 10
1293   //   WM_KEYDOWN    virtual_key = VK_CONTROL  time = 10
1294   //   WM_MOUSEWHEEL                           time = ::GetTickCount()
1295   //   WM_KEYUP      virtual_key = VK_CONTROL  time = 10
1296   //   WM_KEYUP      virtual_key = 0xCC        time = 10
1297   //
1298   // The result of this is that we process all of the WM_KEYDOWN/WM_KEYUP
1299   // messages first because their timestamps make them appear to have
1300   // been sent before the WM_MOUSEWHEEL message.  To work around this,
1301   // we store the current time when we process the WM_KEYUP message and
1302   // assume that any WM_MOUSEWHEEL message with a timestamp before that
1303   // time is one that should be processed as if the Control key was down.
1304   if (sUsePinchHack && aMsg == WM_KEYUP && aWParam == VK_CONTROL &&
1305       ::GetMessageTime() == 10) {
1306     // We look only at the bottom 31 bits of the system tick count since
1307     // GetMessageTime returns a LONG, which is signed, so we want values
1308     // that are more easily comparable.
1309     sZoomUntil = ::GetTickCount() & 0x7FFFFFFF;
1310
1311     MOZ_LOG(
1312         gMouseScrollLog, LogLevel::Info,
1313         ("MouseScroll::Device::Elantech::HandleKeyMessage(): sZoomUntil=%lu",
1314          sZoomUntil));
1315   }
1316
1317   return false;
1318 }
1319
1320 /* static */
1321 void MouseScrollHandler::Device::Elantech::UpdateZoomUntil() {
1322   if (!sZoomUntil) {
1323     return;
1324   }
1325
1326   // For the Elantech Touchpad Zoom Gesture Hack, we should check that the
1327   // system time (32-bit milliseconds) hasn't wrapped around.  Otherwise we
1328   // might get into the situation where wheel events for the next 50 days of
1329   // system uptime are assumed to be Ctrl+Wheel events.  (It is unlikely that
1330   // we would get into that state, because the system would already need to be
1331   // up for 50 days and the Control key message would need to be processed just
1332   // before the system time overflow and the wheel message just after.)
1333   //
1334   // We also take the chance to reset sZoomUntil if we simply have passed that
1335   // time.
1336   LONG msgTime = ::GetMessageTime();
1337   if ((sZoomUntil >= 0x3fffffffu && DWORD(msgTime) < 0x40000000u) ||
1338       (sZoomUntil < DWORD(msgTime))) {
1339     sZoomUntil = 0;
1340
1341     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1342             ("MouseScroll::Device::Elantech::UpdateZoomUntil(): "
1343              "sZoomUntil was reset"));
1344   }
1345 }
1346
1347 /* static */
1348 bool MouseScrollHandler::Device::Elantech::IsZooming() {
1349   // Assume the Control key is down if the Elantech touchpad has sent the
1350   // mis-ordered WM_KEYDOWN/WM_MOUSEWHEEL messages.  (See the comment in
1351   // OnKeyUp.)
1352   return (sZoomUntil && static_cast<DWORD>(::GetMessageTime()) < sZoomUntil);
1353 }
1354
1355 /******************************************************************************
1356  *
1357  * Device::Apoint
1358  *
1359  ******************************************************************************/
1360
1361 /* static */
1362 void MouseScrollHandler::Device::Apoint::Init() {
1363   if (sInitialized) {
1364     return;
1365   }
1366
1367   sInitialized = true;
1368   sMajorVersion = 0;
1369   sMinorVersion = -1;
1370
1371   wchar_t buf[40];
1372   bool foundKey =
1373       WinUtils::GetRegistryKey(HKEY_LOCAL_MACHINE, L"Software\\Alps\\Apoint",
1374                                L"ProductVer", buf, sizeof buf);
1375   if (!foundKey) {
1376     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1377             ("MouseScroll::Device::Apoint::Init(): "
1378              "Apoint driver is not found"));
1379     return;
1380   }
1381
1382   sMajorVersion = wcstol(buf, nullptr, 10);
1383   sMinorVersion = 0;
1384   wchar_t* p = wcschr(buf, L'.');
1385   if (p) {
1386     sMinorVersion = wcstol(p + 1, nullptr, 10);
1387   }
1388   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1389           ("MouseScroll::Device::Apoint::Init(): "
1390            "found driver version = %d.%d",
1391            sMajorVersion, sMinorVersion));
1392 }
1393
1394 /******************************************************************************
1395  *
1396  * Device::TrackPoint
1397  *
1398  ******************************************************************************/
1399
1400 /* static */
1401 bool MouseScrollHandler::Device::TrackPoint::IsDriverInstalled() {
1402   if (WinUtils::HasRegistryKey(HKEY_CURRENT_USER,
1403                                L"Software\\Lenovo\\TrackPoint")) {
1404     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1405             ("MouseScroll::Device::TrackPoint::IsDriverInstalled(): "
1406              "Lenovo's TrackPoint driver is found"));
1407     return true;
1408   }
1409
1410   if (WinUtils::HasRegistryKey(HKEY_CURRENT_USER,
1411                                L"Software\\Alps\\Apoint\\TrackPoint")) {
1412     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1413             ("MouseScroll::Device::TrackPoint::IsDriverInstalled(): "
1414              "Alps's TrackPoint driver is found"));
1415   }
1416
1417   return false;
1418 }
1419
1420 /******************************************************************************
1421  *
1422  * Device::UltraNav
1423  *
1424  ******************************************************************************/
1425
1426 /* static */
1427 bool MouseScrollHandler::Device::UltraNav::IsObsoleteDriverInstalled() {
1428   if (WinUtils::HasRegistryKey(HKEY_CURRENT_USER,
1429                                L"Software\\Lenovo\\UltraNav")) {
1430     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1431             ("MouseScroll::Device::UltraNav::IsObsoleteDriverInstalled(): "
1432              "Lenovo's UltraNav driver is found"));
1433     return true;
1434   }
1435
1436   bool installed = false;
1437   if (WinUtils::HasRegistryKey(HKEY_CURRENT_USER,
1438                                L"Software\\Synaptics\\SynTPEnh\\UltraNavUSB")) {
1439     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1440             ("MouseScroll::Device::UltraNav::IsObsoleteDriverInstalled(): "
1441              "Synaptics's UltraNav (USB) driver is found"));
1442     installed = true;
1443   } else if (WinUtils::HasRegistryKey(
1444                  HKEY_CURRENT_USER,
1445                  L"Software\\Synaptics\\SynTPEnh\\UltraNavPS2")) {
1446     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1447             ("MouseScroll::Device::UltraNav::IsObsoleteDriverInstalled(): "
1448              "Synaptics's UltraNav (PS/2) driver is found"));
1449     installed = true;
1450   }
1451
1452   if (!installed) {
1453     return false;
1454   }
1455
1456   int32_t majorVersion = Device::SynTP::GetDriverMajorVersion();
1457   if (!majorVersion) {
1458     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1459             ("MouseScroll::Device::UltraNav::IsObsoleteDriverInstalled(): "
1460              "Failed to get UltraNav driver version"));
1461     return false;
1462   }
1463   int32_t minorVersion = Device::SynTP::GetDriverMinorVersion();
1464   return majorVersion < 15 || (majorVersion == 15 && minorVersion == 0);
1465 }
1466
1467 /******************************************************************************
1468  *
1469  * Device::SetPoint
1470  *
1471  ******************************************************************************/
1472
1473 /* static */
1474 bool MouseScrollHandler::Device::SetPoint::IsGetMessagePosResponseValid(
1475     UINT aMessage, WPARAM aWParam, LPARAM aLParam) {
1476   if (aMessage != WM_MOUSEHWHEEL) {
1477     return false;
1478   }
1479
1480   POINTS pts = MouseScrollHandler::GetCurrentMessagePos();
1481   LPARAM messagePos = MAKELPARAM(pts.x, pts.y);
1482
1483   // XXX We should check whether SetPoint is installed or not by registry.
1484
1485   // SetPoint, Logitech (Logicool) mouse driver, (confirmed with 4.82.11 and
1486   // MX-1100) always sets 0 to the lParam of WM_MOUSEHWHEEL.  The driver SENDs
1487   // one message at first time, this time, ::GetMessagePos() works fine.
1488   // Then, we will return 0 (0 means we process it) to the message. Then, the
1489   // driver will POST the same messages continuously during the wheel tilted.
1490   // But ::GetMessagePos() API always returns (0, 0) for them, even if the
1491   // actual mouse cursor isn't 0,0.  Therefore, we cannot trust the result of
1492   // ::GetMessagePos API if the sender is SetPoint.
1493   if (!sMightBeUsing && !aLParam && aLParam != messagePos &&
1494       ::InSendMessage()) {
1495     sMightBeUsing = true;
1496     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1497             ("MouseScroll::Device::SetPoint::IsGetMessagePosResponseValid(): "
1498              "Might using SetPoint"));
1499   } else if (sMightBeUsing && aLParam != 0 && ::InSendMessage()) {
1500     // The user has changed the mouse from Logitech's to another one (e.g.,
1501     // the user has changed to the touchpad of the notebook.
1502     sMightBeUsing = false;
1503     MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1504             ("MouseScroll::Device::SetPoint::IsGetMessagePosResponseValid(): "
1505              "Might stop using SetPoint"));
1506   }
1507   return (sMightBeUsing && !aLParam && !messagePos);
1508 }
1509
1510 /******************************************************************************
1511  *
1512  * SynthesizingEvent
1513  *
1514  ******************************************************************************/
1515
1516 /* static */
1517 bool MouseScrollHandler::SynthesizingEvent::IsSynthesizing() {
1518   return MouseScrollHandler::sInstance &&
1519          MouseScrollHandler::sInstance->mSynthesizingEvent &&
1520          MouseScrollHandler::sInstance->mSynthesizingEvent->mStatus !=
1521              NOT_SYNTHESIZING;
1522 }
1523
1524 nsresult MouseScrollHandler::SynthesizingEvent::Synthesize(
1525     const POINTS& aCursorPoint, HWND aWnd, UINT aMessage, WPARAM aWParam,
1526     LPARAM aLParam, const BYTE (&aKeyStates)[256]) {
1527   MOZ_LOG(
1528       gMouseScrollLog, LogLevel::Info,
1529       ("MouseScrollHandler::SynthesizingEvent::Synthesize(): aCursorPoint: { "
1530        "x: %d, y: %d }, aWnd=0x%p, aMessage=0x%04X, aWParam=0x%08zX, "
1531        "aLParam=0x%08" PRIXLPTR ", IsSynthesized()=%s, mStatus=%s",
1532        aCursorPoint.x, aCursorPoint.y, aWnd, aMessage, aWParam, aLParam,
1533        GetBoolName(IsSynthesizing()), GetStatusName()));
1534
1535   if (IsSynthesizing()) {
1536     return NS_ERROR_NOT_AVAILABLE;
1537   }
1538
1539   ::GetKeyboardState(mOriginalKeyState);
1540
1541   // Note that we cannot use ::SetCursorPos() because it works asynchronously.
1542   // We should SEND the message for reducing the possibility of receiving
1543   // unexpected message which were not sent from here.
1544   mCursorPoint = aCursorPoint;
1545
1546   mWnd = aWnd;
1547   mMessage = aMessage;
1548   mWParam = aWParam;
1549   mLParam = aLParam;
1550
1551   memcpy(mKeyState, aKeyStates, sizeof(mKeyState));
1552   ::SetKeyboardState(mKeyState);
1553
1554   mStatus = SENDING_MESSAGE;
1555
1556   // Don't assume that aWnd is always managed by nsWindow.  It might be
1557   // a plugin window.
1558   ::SendMessage(aWnd, aMessage, aWParam, aLParam);
1559
1560   return NS_OK;
1561 }
1562
1563 void MouseScrollHandler::SynthesizingEvent::NativeMessageReceived(
1564     nsWindow* aWidget, UINT aMessage, WPARAM aWParam, LPARAM aLParam) {
1565   if (mStatus == SENDING_MESSAGE && mMessage == aMessage &&
1566       mWParam == aWParam && mLParam == aLParam) {
1567     mStatus = NATIVE_MESSAGE_RECEIVED;
1568     if (aWidget && aWidget->GetWindowHandle() == mWnd) {
1569       return;
1570     }
1571     // Otherwise, the message may not be sent by us.
1572   }
1573
1574   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1575           ("MouseScrollHandler::SynthesizingEvent::NativeMessageReceived(): "
1576            "aWidget=%p, aWidget->GetWindowHandle()=0x%p, mWnd=0x%p, "
1577            "aMessage=0x%04X, aWParam=0x%08zX, aLParam=0x%08" PRIXLPTR
1578            ", mStatus=%s",
1579            aWidget, aWidget ? aWidget->GetWindowHandle() : nullptr, mWnd,
1580            aMessage, aWParam, aLParam, GetStatusName()));
1581
1582   // We failed to receive our sent message, we failed to do the job.
1583   Finish();
1584
1585   return;
1586 }
1587
1588 void MouseScrollHandler::SynthesizingEvent::
1589     NotifyNativeMessageHandlingFinished() {
1590   if (!IsSynthesizing()) {
1591     return;
1592   }
1593
1594   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1595           ("MouseScrollHandler::SynthesizingEvent::"
1596            "NotifyNativeMessageHandlingFinished(): IsWaitingInternalMessage=%s",
1597            GetBoolName(MouseScrollHandler::IsWaitingInternalMessage())));
1598
1599   if (MouseScrollHandler::IsWaitingInternalMessage()) {
1600     mStatus = INTERNAL_MESSAGE_POSTED;
1601     return;
1602   }
1603
1604   // If the native message handler didn't post our internal message,
1605   // we our job is finished.
1606   // TODO: When we post the message to plugin window, there is remaning job.
1607   Finish();
1608 }
1609
1610 void MouseScrollHandler::SynthesizingEvent::
1611     NotifyInternalMessageHandlingFinished() {
1612   if (!IsSynthesizing()) {
1613     return;
1614   }
1615
1616   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1617           ("MouseScrollHandler::SynthesizingEvent::"
1618            "NotifyInternalMessageHandlingFinished()"));
1619
1620   Finish();
1621 }
1622
1623 void MouseScrollHandler::SynthesizingEvent::Finish() {
1624   if (!IsSynthesizing()) {
1625     return;
1626   }
1627
1628   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
1629           ("MouseScrollHandler::SynthesizingEvent::Finish()"));
1630
1631   // Restore the original key state.
1632   ::SetKeyboardState(mOriginalKeyState);
1633
1634   mStatus = NOT_SYNTHESIZING;
1635 }
1636
1637 }  // namespace widget
1638 }  // namespace mozilla