Bug 1153156 part.2 Make WidgetWheelEvent store if overriding system scroll speed is allowed and it shouldn't be allowed if scroll speed isn't system default settings on Windows r=smaug+jimm

widget/MouseEvents.h

@@ -462,6 +462,7 @@ private:
     , overflowDeltaY(0.0)
     , mViewPortIsOverscrolled(false)
     , mCanTriggerSwipe(false)
+    , mAllowToOverrideSystemScrollSpeed(false)
   {
   }
 
@@ -485,6 +486,7 @@ public:
     , overflowDeltaY(0.0)
     , mViewPortIsOverscrolled(false)
     , mCanTriggerSwipe(false)
+    , mAllowToOverrideSystemScrollSpeed(true)
   {
   }
 
@@ -599,6 +601,11 @@ public:
   // viewport.
   bool mCanTriggerSwipe;
 
+  // If mAllowToOverrideSystemScrollSpeed is true, the scroll speed may be
+  // overridden.  Otherwise, the scroll speed won't be overridden even if
+  // it's enabled by the pref.
+  bool mAllowToOverrideSystemScrollSpeed;
+
   void AssignWheelEventData(const WidgetWheelEvent& aEvent, bool aCopyTargets)
   {
     AssignMouseEventBaseData(aEvent, aCopyTargets);
@@ -618,6 +625,8 @@ public:
     overflowDeltaY = aEvent.overflowDeltaY;
     mViewPortIsOverscrolled = aEvent.mViewPortIsOverscrolled;
     mCanTriggerSwipe = aEvent.mCanTriggerSwipe;
+    mAllowToOverrideSystemScrollSpeed =
+      aEvent.mAllowToOverrideSystemScrollSpeed;
   }
 
   // System scroll speed settings may be too slow at using Gecko.  In such

widget/WidgetEventImpl.cpp

@@ -384,12 +384,18 @@ WidgetWheelEvent::ComputeOverriddenDelta(double aDelta, bool aIsForVertical)
 double
 WidgetWheelEvent::OverriddenDeltaX() const
 {
+  if (!mAllowToOverrideSystemScrollSpeed) {
+    return deltaX;
+  }
   return ComputeOverriddenDelta(deltaX, false);
 }
 
 double
 WidgetWheelEvent::OverriddenDeltaY() const
 {
+  if (!mAllowToOverrideSystemScrollSpeed) {
+    return deltaY;
+  }
   return ComputeOverriddenDelta(deltaY, true);
 }
 

widget/nsGUIEventIPC.h

@@ -175,6 +175,7 @@ struct ParamTraits<mozilla::WidgetWheelEvent>
     WriteParam(aMsg, aParam.overflowDeltaY);
     WriteParam(aMsg, aParam.mViewPortIsOverscrolled);
     WriteParam(aMsg, aParam.mCanTriggerSwipe);
+    WriteParam(aMsg, aParam.mAllowToOverrideSystemScrollSpeed);
   }
 
   static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
@@ -197,7 +198,8 @@ struct ParamTraits<mozilla::WidgetWheelEvent>
       ReadParam(aMsg, aIter, &aResult->overflowDeltaX) &&
       ReadParam(aMsg, aIter, &aResult->overflowDeltaY) &&
       ReadParam(aMsg, aIter, &aResult->mViewPortIsOverscrolled) &&
-      ReadParam(aMsg, aIter, &aResult->mCanTriggerSwipe);
+      ReadParam(aMsg, aIter, &aResult->mCanTriggerSwipe) &&
+      ReadParam(aMsg, aIter, &aResult->mAllowToOverrideSystemScrollSpeed);
     aResult->scrollType =
       static_cast<mozilla::WidgetWheelEvent::ScrollType>(scrollType);
     return rv;

widget/windows/WinMouseScrollHandler.cpp

@@ -613,7 +613,7 @@ MouseScrollHandler::HandleMouseWheelMessage(nsWindowBase* aWidget,
 
   // If it's not allowed to cache system settings, we need to reset the cache
   // before handling the mouse wheel message.
-  mSystemSettings.TrustedScrollSettingsDriver(aMessage == MOZ_WM_MOUSEVWHEEL);
+  mSystemSettings.TrustedScrollSettingsDriver();
 
   EventInfo eventInfo(aWidget, WinUtils::GetNativeMessage(aMessage),
                       aWParam, aLParam);
@@ -863,11 +863,16 @@ MouseScrollHandler::LastEventInfo::InitWheelEvent(
   mAccumulatedDelta -=
     lineOrPageDelta * orienter * RoundDelta(nativeDeltaPerUnit);
 
+  aWheelEvent.mAllowToOverrideSystemScrollSpeed =
+    MouseScrollHandler::sInstance->
+      mSystemSettings.IsOverridingSystemScrollSpeedAllowed();
+
   MOZ_LOG(gMouseScrollLog, LogLevel::Info,
     ("MouseScroll::LastEventInfo::InitWheelEvent: aWidget=%p, "
      "aWheelEvent { refPoint: { x: %d, y: %d }, deltaX: %f, deltaY: %f, "
      "lineOrPageDeltaX: %d, lineOrPageDeltaY: %d, "
-     "isShift: %s, isControl: %s, isAlt: %s, isMeta: %s }, "
+     "isShift: %s, isControl: %s, isAlt: %s, isMeta: %s, "
+     "mAllowToOverrideSystemScrollSpeed: %s }, "
      "mAccumulatedDelta: %d",
      aWidget, aWheelEvent.refPoint.x, aWheelEvent.refPoint.y,
      aWheelEvent.deltaX, aWheelEvent.deltaY,
@@ -875,7 +880,9 @@ MouseScrollHandler::LastEventInfo::InitWheelEvent(
      GetBoolName(aWheelEvent.IsShift()),
      GetBoolName(aWheelEvent.IsControl()),
      GetBoolName(aWheelEvent.IsAlt()),
-     GetBoolName(aWheelEvent.IsMeta()), mAccumulatedDelta));
+     GetBoolName(aWheelEvent.IsMeta()),
+     GetBoolName(aWheelEvent.mAllowToOverrideSystemScrollSpeed),
+     mAccumulatedDelta));
 
   return (delta != 0);
 }
@@ -994,9 +1001,10 @@ MouseScrollHandler::SystemSettings::MarkDirty()
 }
 
 void
-MouseScrollHandler::SystemSettings::RefreshCache(bool aForVertical)
+MouseScrollHandler::SystemSettings::RefreshCache()
 {
-  bool isChanged = aForVertical ? InitScrollLines() : InitScrollChars();
+  bool isChanged = InitScrollLines();
+  isChanged = InitScrollChars() || isChanged;
   if (!isChanged) {
     return;
   }
@@ -1007,16 +1015,14 @@ MouseScrollHandler::SystemSettings::RefreshCache(bool aForVertical)
 }
 
 void
-MouseScrollHandler::SystemSettings::TrustedScrollSettingsDriver(
-                                      bool aIsVertical)
+MouseScrollHandler::SystemSettings::TrustedScrollSettingsDriver()
 {
   if (!mInitialized) {
     return;
   }
 
   // if the cache is initialized with prefs, we don't need to refresh it.
-  if ((aIsVertical && mIsReliableScrollLines) ||
-      (!aIsVertical && mIsReliableScrollChars)) {
+  if (mIsReliableScrollLines && mIsReliableScrollChars) {
     return;
   }
 
@@ -1025,7 +1031,7 @@ MouseScrollHandler::SystemSettings::TrustedScrollSettingsDriver(
 
   // If system settings cache is disabled, we should always refresh them.
   if (!userPrefs.IsSystemSettingCacheEnabled()) {
-    RefreshCache(aIsVertical);
+    RefreshCache();
     return;
   }
 
@@ -1039,13 +1045,23 @@ MouseScrollHandler::SystemSettings::TrustedScrollSettingsDriver(
   // ::SystemParametersInfo() and returns different value from system settings.
   if (Device::SynTP::IsDriverInstalled() ||
       Device::Apoint::IsDriverInstalled()) {
-    RefreshCache(aIsVertical);
+    RefreshCache();
     return;
   }
 
   // XXX We're not sure about other touchpad drivers...
 }
 
+bool
+MouseScrollHandler::SystemSettings::IsOverridingSystemScrollSpeedAllowed()
+{
+  // The default vertical and horizontal scrolling speed is 3, this is defined
+  // on the document of SystemParametersInfo in MSDN.
+  const uint32_t kSystemDefaultScrollingSpeed = 3;
+  return mScrollLines == kSystemDefaultScrollingSpeed &&
+         (!IsVistaOrLater() || mScrollChars == kSystemDefaultScrollingSpeed);
+}
+
 /******************************************************************************
  *
  * UserPrefs

widget/windows/WinMouseScrollHandler.h

@@ -279,7 +279,13 @@ private:
     // changed without WM_SETTINGCHANGE message.  For avoiding this trouble,
     // we need to modify cache of system settings at every wheel message
     // handling if we meet known device whose utility may hook the API.
-    void TrustedScrollSettingsDriver(bool aIsVertical);
+    void TrustedScrollSettingsDriver();
+
+    // Returns true if the system scroll may be overridden for faster scroll.
+    // Otherwise, false.  For example, if the user maybe uses an expensive
+    // mouse which supports acceleration of scroll speed, faster scroll makes
+    // the user inconvenient.
+    bool IsOverridingSystemScrollSpeedAllowed();
 
     int32_t GetScrollAmount(bool aForVertical) const
     {
@@ -310,7 +316,7 @@ private:
     bool InitScrollLines();
     bool InitScrollChars();
 
-    void RefreshCache(bool aForVertical);
+    void RefreshCache();
   };
 
   SystemSettings mSystemSettings;

widget/windows/nsWindow.cpp

@@ -3726,52 +3726,6 @@ nsWindow::OverrideSystemMouseScrollSpeed(double aOriginalDeltaX,
   // on the document of SystemParametersInfo in MSDN.
   const uint32_t kSystemDefaultScrollingSpeed = 3;
 
-  double absOriginDeltaX = Abs(aOriginalDeltaX);
-  double absOriginDeltaY = Abs(aOriginalDeltaY);
-
-  // Compute the simple overridden speed.
-  double absComputedOverriddenDeltaX, absComputedOverriddenDeltaY;
-  nsresult rv =
-    nsBaseWidget::OverrideSystemMouseScrollSpeed(absOriginDeltaX,
-                                                 absOriginDeltaY,
-                                                 absComputedOverriddenDeltaX,
-                                                 absComputedOverriddenDeltaY);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  aOverriddenDeltaX = aOriginalDeltaX;
-  aOverriddenDeltaY = aOriginalDeltaY;
-
-  if (absComputedOverriddenDeltaX == absOriginDeltaX &&
-      absComputedOverriddenDeltaY == absOriginDeltaY) {
-    // We don't override now.
-    return NS_OK;
-  }
-
-  // Otherwise, we should check whether the user customized the system settings
-  // or not.  If the user did it, we should respect the will.
-  UINT systemSpeed;
-  if (!::SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &systemSpeed, 0)) {
-    return NS_ERROR_FAILURE;
-  }
-  // The default vertical scrolling speed is 3, this is defined on the document
-  // of SystemParametersInfo in MSDN.
-  if (systemSpeed != kSystemDefaultScrollingSpeed) {
-    return NS_OK;
-  }
-
-  // Only Vista and later, Windows has the system setting of horizontal
-  // scrolling by the mouse wheel.
-  if (IsVistaOrLater()) {
-    if (!::SystemParametersInfo(SPI_GETWHEELSCROLLCHARS, 0, &systemSpeed, 0)) {
-      return NS_ERROR_FAILURE;
-    }
-    // The default horizontal scrolling speed is 3, this is defined on the
-    // document of SystemParametersInfo in MSDN.
-    if (systemSpeed != kSystemDefaultScrollingSpeed) {
-      return NS_OK;
-    }
-  }
-
   // Limit the overridden delta value from the system settings.  The mouse
   // driver might accelerate the scrolling speed already.  If so, we shouldn't
   // override the scrolling speed for preventing the unexpected high speed