refactor: Move the scrollModifiers to ISecondaryScreen

src/lib/common/CMakeLists.txt

@@ -10,6 +10,7 @@ configure_file(Constants.h.in Constants.h @ONLY)
 configure_file(VersionInfo.h.in VersionInfo.h @ONLY)
 
 add_library(common STATIC
+  Coordinate.h
   Enums.h
   ExitCodes.h
   I18N.h

src/lib/common/Coordinate.h

@@ -0,0 +1,21 @@
+/*
+ * Deskflow -- mouse and keyboard sharing utility
+ * SPDX-FileCopyrightText: (C) 2026 Deskflow Developers
+ * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
+ */
+
+#pragma once
+
+#include <QObject>
+#include <cstdint>
+
+struct Coordinate
+{
+  Q_GADGET;
+
+public:
+  int32_t x;
+  int32_t y;
+};
+
+using ScrollDelta = Coordinate;

src/lib/deskflow/ISecondaryScreen.h

@@ -1,6 +1,6 @@
 /*
  * Deskflow -- mouse and keyboard sharing utility
- * SPDX-FileCopyrightText: (C) 2025 Deskflow Developers
+ * SPDX-FileCopyrightText: (C) 2025 - 2026 Deskflow Developers
  * SPDX-FileCopyrightText: (C) 2012 - 2016 Symless Ltd.
  * SPDX-FileCopyrightText: (C) 2003 Chris Schoeneman
  * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
@@ -8,6 +8,8 @@
 
 #pragma once
 
+#include "common/Coordinate.h"
+#include "common/Settings.h"
 #include "deskflow/MouseTypes.h"
 
 //! Secondary screen interface
@@ -18,6 +20,12 @@ secondary screen implementations.
 class ISecondaryScreen
 {
 public:
+  ISecondaryScreen()
+  {
+    m_invertScroll = Settings::value(Settings::Client::InvertScrollDirection).toBool();
+    m_scrollScale = std::clamp(Settings::value(Settings::Client::YScrollScale).toDouble(), 0.1, 10.0);
+  }
+
   virtual ~ISecondaryScreen() = default;
   //! @name accessors
   //@{
@@ -40,11 +48,37 @@ public:
   */
   virtual void fakeMouseRelativeMove(int32_t dx, int32_t dy) const = 0;
 
-  //! Fake mouse wheel
+  /**
-  /*!
+   * @brief Synthesize a mouse wheel event of amount
-  Synthesize a mouse wheel event of amount \c xDelta and \c yDelta.
+   * This method should include the use of `applyScrollModifier` before sending the delta
-  */
+   * @param xDelta
+   * @param yDelta
+   */
   virtual void fakeMouseWheel(int32_t xDelta, int32_t yDelta) const = 0;
 
+  /**
+   * @brief Applies any scroll modfifers to the provided delta, This should only be done inside the subclasses
+   * fakeMouseWheel impl
+   * @param delta a ScrollDelta to be modified
+   * @return the delta with inversion and scale applied
+   */
+  ScrollDelta applyScrollModifier(ScrollDelta delta) const
+  {
+    delta.y = static_cast<int32_t>(m_invertScroll ? delta.y * -m_scrollScale : delta.y * m_scrollScale);
+    return delta;
+  }
+
+private:
+  /**
+   * @brief this member is used to modify the scroll direction.
+   * It is used in the applyScrollModifier method
+   */
+  bool m_invertScroll = false;
+
+  /**
+   * @brief this member is used to modify the scroll scale.
+   * It is used in the applyScrollModifier method
+   */
+  double m_scrollScale = 1.0;
   //@}
 };

src/lib/deskflow/PlatformScreen.cpp

@@ -1,5 +1,6 @@
 /*
  * Deskflow -- mouse and keyboard sharing utility
+ * SPDX-FileCopyrightText: (C) 2026 Deskflow Developers
  * SPDX-FileCopyrightText: (C) 2012 - 2016 Symless Ltd.
  * SPDX-FileCopyrightText: (C) 2004 Chris Schoeneman
  * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
@@ -7,13 +8,11 @@
 
 #include "deskflow/PlatformScreen.h"
 #include "base/DirectionTypes.h"
-#include "common/Settings.h"
 #include "deskflow/App.h"
 
 PlatformScreen::PlatformScreen(IEventQueue *events) : IPlatformScreen(events)
 {
-  m_invertScrollDirection = Settings::value(Settings::Client::InvertScrollDirection).toBool();
+  // do nothing
-  m_yScrollScale = std::clamp(Settings::value(Settings::Client::YScrollScale).toDouble(), 0.1, 10.0);
 }
 
 void PlatformScreen::updateKeyMap()
@@ -89,13 +88,6 @@ void PlatformScreen::clearStaleModifiers()
   getKeyState()->clearStaleModifiers();
 }
 
-PlatformScreen::ScrollDelta PlatformScreen::applyClientScrollModifier(const PlatformScreen::ScrollDelta rawDelta) const
-{
-  ScrollDelta correctedDelta = rawDelta;
-  correctedDelta.yDelta *= m_invertScrollDirection ? -m_yScrollScale : m_yScrollScale;
-  return correctedDelta;
-}
-
 std::string PlatformScreen::sidesMaskToString(uint32_t sides)
 {
   using enum DirectionMask;

src/lib/deskflow/PlatformScreen.h

@@ -1,5 +1,6 @@
 /*
  * Deskflow -- mouse and keyboard sharing utility
+ * SPDX-FileCopyrightText: (C) 2026 Deskflow Developers
  * SPDX-FileCopyrightText: (C) 2012 - 2016 Symless Ltd.
  * SPDX-FileCopyrightText: (C) 2004 Chris Schoeneman
  * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
@@ -18,11 +19,6 @@ subclasses to implement the rest.
 class PlatformScreen : public IPlatformScreen
 {
 public:
-  struct ScrollDelta
-  {
-    int32_t xDelta;
-    int32_t yDelta;
-  };
   explicit PlatformScreen(IEventQueue *events);
   ~PlatformScreen() override = default;
 
@@ -100,13 +96,6 @@ protected:
   // IPlatformScreen overrides
   void handleSystemEvent(const Event &event) override = 0;
 
-  /*!
-   * \brief applyClientYScrollModifier
-   * Convert scroll according to client's scroll modifiers
-   * \return converted value according to the client's scroll modifiers
-   */
-  virtual ScrollDelta applyClientScrollModifier(const ScrollDelta rawDelta) const;
-
   /*!
   Converts a sides mask (e.g. LeftMask | RightMask) to a string representation (e.g. "LR").
    */

src/lib/platform/EiScreen.cpp

@@ -1,6 +1,6 @@
 /*
  * Deskflow -- mouse and keyboard sharing utility
- * SPDX-FileCopyrightText: (C) 2025 Deskflow Developers
+ * SPDX-FileCopyrightText: (C) 2025 - 2026 Deskflow Developers
  * SPDX-FileCopyrightText: (C) 2024 Symless Ltd.
  * SPDX-FileCopyrightText: (C) 2022 Red Hat, Inc.
  * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
@@ -318,11 +318,11 @@ void EiScreen::fakeMouseWheel(int32_t xDelta, int32_t yDelta) const
   if (!m_eiPointer)
     return;
 
-  auto adjustedDeltas = applyClientScrollModifier({xDelta, yDelta});
+  auto adjustedDeltas = applyScrollModifier({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, -adjustedDeltas.xDelta, -adjustedDeltas.yDelta);
+  ei_device_scroll_discrete(m_eiPointer, -adjustedDeltas.x, -adjustedDeltas.y);
   ei_device_frame(m_eiPointer, ei_now(m_ei));
 }
 

src/lib/platform/MSWindowsScreen.cpp

@@ -1,6 +1,6 @@
 /*
  * Deskflow -- mouse and keyboard sharing utility
- * SPDX-FileCopyrightText: (C) 2025 Deskflow Developers
+ * SPDX-FileCopyrightText: (C) 2025 - 2026 Deskflow Developers
  * SPDX-FileCopyrightText: (C) 2012 - 2016 Symless Ltd.
  * SPDX-FileCopyrightText: (C) 2002 Chris Schoeneman
  * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
@@ -708,8 +708,8 @@ void MSWindowsScreen::fakeMouseRelativeMove(int32_t dx, int32_t dy) const
 
 void MSWindowsScreen::fakeMouseWheel(int32_t xDelta, int32_t yDelta) const
 {
-  auto adjustedDeltas = applyClientScrollModifier({xDelta, yDelta});
+  auto adjustedDeltas = applyScrollModifier({xDelta, yDelta});
-  m_desks->fakeMouseWheel(adjustedDeltas.xDelta, adjustedDeltas.yDelta);
+  m_desks->fakeMouseWheel(adjustedDeltas.x, adjustedDeltas.y);
 }
 
 void MSWindowsScreen::updateKeys()

src/lib/platform/OSXScreen.mm

@@ -1,6 +1,6 @@
 /*
  * Deskflow -- mouse and keyboard sharing utility
- * SPDX-FileCopyrightText: (C) 2025 Deskflow Developers
+ * SPDX-FileCopyrightText: (C) 2025 - 2026 Deskflow Developers
  * SPDX-FileCopyrightText: (C) 2012 - 2016 Symless Ltd.
  * SPDX-FileCopyrightText: (C) 2004 Chris Schoeneman
  * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
@@ -589,13 +589,12 @@ 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(
+    auto adjustedDeltas =
-        {static_cast<int32_t>(3.0 * xDelta / 120.0), static_cast<int32_t>(3.0 * yDelta / 120.0)}
+        applyScrollModifier({static_cast<int32_t>(3.0 * xDelta / 120.0), static_cast<int32_t>(3.0 * y / 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, adjustedDeltas.yDelta, adjustedDeltas.xDelta);
+        CGEventCreateScrollWheelEvent(nullptr, kCGScrollEventUnitLine, 2, adjustedDeltas.y, adjustedDeltas.x);
 
     // Fix for sticky keys
     CGEventFlags modifiers = m_keyState->getModifierStateAsOSXFlags();

src/lib/platform/XWindowsScreen.cpp

@@ -1,6 +1,6 @@
 /*
  * Deskflow -- mouse and keyboard sharing utility
- * SPDX-FileCopyrightText: (C) 2025 Deskflow Developers
+ * SPDX-FileCopyrightText: (C) 2025 - 2026 Deskflow Developers
  * SPDX-FileCopyrightText: (C) 2012 - 2016 Symless Ltd.
  * SPDX-FileCopyrightText: (C) 2002 Chris Schoeneman
  * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
@@ -791,7 +791,7 @@ void XWindowsScreen::fakeMouseWheel(int32_t, int32_t yDelta) const
     return;
   }
 
-  yDelta = applyClientScrollModifier({0, yDelta}).yDelta;
+  yDelta = applyScrollModifier({0, yDelta}).y;
 
   // choose button depending on rotation direction
   const unsigned int xButton = mapButtonToX(yDelta >= 0 ? kX11ScrollWheelUp : kX11ScrollWheelDown);