refactor: rename PlatformScreen::mapClientScrollDirection -> PlatformScreen::applyClientScrollModifier

prepare for horizontal scroll support by having it handle pairs of x and y values

src/lib/deskflow/PlatformScreen.cpp

@@ -14,7 +14,7 @@ PlatformScreen::PlatformScreen(IEventQueue *events, bool invertScrolling)
     : IPlatformScreen(events),
       m_invertScrollDirection(invertScrolling)
 {
-  m_scrollScale = std::clamp(Settings::value(Settings::Client::YScrollScale).toDouble(), 0.1, 10.0);
+  m_yScrollScale = std::clamp(Settings::value(Settings::Client::YScrollScale).toDouble(), 0.1, 10.0);
 }
 
 void PlatformScreen::updateKeyMap()
@@ -90,10 +90,11 @@ void PlatformScreen::clearStaleModifiers()
   getKeyState()->clearStaleModifiers();
 }
 
-int32_t PlatformScreen::mapClientScrollDirection(int32_t x) const
+PlatformScreen::ScrollDelta PlatformScreen::applyClientScrollModifier(const PlatformScreen::ScrollDelta rawDelta) const
 {
-  x *= m_scrollScale;
-  return (m_invertScrollDirection ? -x : x);
+  ScrollDelta correctedDelta = rawDelta;
+  correctedDelta.yDelta *= m_invertScrollDirection ? -m_yScrollScale : m_yScrollScale;
+  return correctedDelta;
 }
 
 std::string PlatformScreen::sidesMaskToString(uint32_t sides)

src/lib/deskflow/PlatformScreen.h

@@ -18,6 +18,11 @@ subclasses to implement the rest.
 class PlatformScreen : public IPlatformScreen
 {
 public:
+  struct ScrollDelta
+  {
+    int32_t xDelta;
+    int32_t yDelta;
+  };
   explicit PlatformScreen(IEventQueue *events, bool invertScrollDirection);
   ~PlatformScreen() override = default;
 
@@ -96,11 +101,11 @@ protected:
   void handleSystemEvent(const Event &event) override = 0;
 
   /*!
-   * \brief mapClientScrollDirection
-   * Convert scroll according to client scroll directio
-   * \return converted value according to the client scroll direction
+   * \brief applyClientYScrollModifier
+   * Convert scroll according to client's scroll modifiers
+   * \return converted value according to the client's scroll modifiers
    */
-  virtual int32_t mapClientScrollDirection(int32_t) const;
+  virtual ScrollDelta applyClientScrollModifier(const ScrollDelta rawDelta) const;
 
   /*!
   Converts a sides mask (e.g. LeftMask | RightMask) to a string representation (e.g. "LR").
@@ -116,9 +121,9 @@ private:
   bool m_invertScrollDirection = false;
 
   /**
-   * @brief m_scrollScale
-   * This member is used to scale the scroll speed
+   * @brief m_yScrollScale
+   * This member is used to scale the y scroll speed
    * It is only used on the client side
    */
-  double m_scrollScale = 1.0;
+  double m_yScrollScale = 1.0;
 };

src/lib/platform/EiScreen.cpp

@@ -318,12 +318,11 @@ void EiScreen::fakeMouseWheel(int32_t xDelta, int32_t yDelta) const
   if (!m_eiPointer)
     return;
 
-  xDelta = mapClientScrollDirection(xDelta);
-  yDelta = mapClientScrollDirection(yDelta);
+  auto adjustedDeltas = applyClientScrollModifier({xDelta, yDelta});
   // libei and deskflow seem to use opposite directions, so we have
   // to send EI the opposite of the value received if we want to remain
   // compatible with other platforms (including X11).
-  ei_device_scroll_discrete(m_eiPointer, -xDelta, -yDelta);
+  ei_device_scroll_discrete(m_eiPointer, -adjustedDeltas.xDelta, -adjustedDeltas.yDelta);
   ei_device_frame(m_eiPointer, ei_now(m_ei));
 }
 

src/lib/platform/MSWindowsScreen.cpp

@@ -710,9 +710,8 @@ void MSWindowsScreen::fakeMouseRelativeMove(int32_t dx, int32_t dy) const
 
 void MSWindowsScreen::fakeMouseWheel(int32_t xDelta, int32_t yDelta) const
 {
-  xDelta = mapClientScrollDirection(xDelta);
-  yDelta = mapClientScrollDirection(yDelta);
-  m_desks->fakeMouseWheel(xDelta, yDelta);
+  auto adjustedDeltas = applyClientScrollModifier({xDelta, yDelta});
+  m_desks->fakeMouseWheel(adjustedDeltas.xDelta, adjustedDeltas.yDelta);
 }
 
 void MSWindowsScreen::updateKeys()

src/lib/platform/OSXScreen.h

@@ -139,9 +139,6 @@ private:
   // map mac scroll wheel value to a deskflow scroll wheel value
   int32_t mapScrollWheelToDeskflow(int32_t) const;
 
-  // map deskflow scroll wheel value to a mac scroll wheel value
-  int32_t mapScrollWheelFromDeskflow(int32_t) const;
-
   // get the current scroll wheel speed
   double getScrollSpeed() const;
 

src/lib/platform/OSXScreen.mm

@@ -587,11 +587,15 @@ void OSXScreen::fakeMouseRelativeMove(int32_t dx, int32_t dy) const
 void OSXScreen::fakeMouseWheel(int32_t xDelta, int32_t yDelta) const
 {
   if (xDelta != 0 || yDelta != 0) {
+    // use server's acceleration with a little boost since other platforms
+    // take one wheel step as a larger step than the mac does.
+    auto adjustedDeltas = applyClientScrollModifier(
+        {static_cast<int32_t>(3.0 * xDelta / 120.0), static_cast<int32_t>(3.0 * yDelta / 120.0)}
+    );
     // create a scroll event, post it and release it.  not sure if kCGScrollEventUnitLine
     // is the right choice here over kCGScrollEventUnitPixel
-    CGEventRef scrollEvent = CGEventCreateScrollWheelEvent(
-        nullptr, kCGScrollEventUnitLine, 2, mapScrollWheelFromDeskflow(yDelta), mapScrollWheelFromDeskflow(xDelta)
-    );
+    CGEventRef scrollEvent =
+        CGEventCreateScrollWheelEvent(nullptr, kCGScrollEventUnitLine, 2, adjustedDeltas.yDelta, adjustedDeltas.xDelta);
 
     // Fix for sticky keys
     CGEventFlags modifiers = m_keyState->getModifierStateAsOSXFlags();
@@ -1219,14 +1223,6 @@ int32_t OSXScreen::mapScrollWheelToDeskflow(int32_t x) const
   return static_cast<int32_t>(120.0 * d);
 }
 
-int32_t OSXScreen::mapScrollWheelFromDeskflow(int32_t x) const
-{
-  // use server's acceleration with a little boost since other platforms
-  // take one wheel step as a larger step than the mac does.
-  auto result = static_cast<int32_t>(3.0 * x / 120.0);
-  return mapClientScrollDirection(result);
-}
-
 double OSXScreen::getScrollSpeed() const
 {
   double scaling = 0.0;

src/lib/platform/XWindowsScreen.cpp

@@ -797,7 +797,7 @@ void XWindowsScreen::fakeMouseWheel(int32_t, int32_t yDelta) const
     return;
   }
 
-  yDelta = mapClientScrollDirection(yDelta);
+  yDelta = applyClientScrollModifier({0, yDelta}).yDelta;
 
   // choose button depending on rotation direction
   const unsigned int xButton = mapButtonToX(yDelta >= 0 ? kX11ScrollWheelUp : kX11ScrollWheelDown);