input: fix kinetic scroll (#13233)

src/managers/PointerManager.cpp

@@ -935,10 +935,11 @@ void CPointerManager::attachPointer(SP<IPointer> pointer) {
         PROTO::idle->onActivity();
     });
 
-    listener->axis = pointer->m_pointerEvents.axis.listen([weak = WP<IPointer>(pointer)](const IPointer::SAxisEvent& event) {
+    listener->axis  = pointer->m_pointerEvents.axis.listen([weak = WP<IPointer>(pointer)](const IPointer::SAxisEvent& event) {
         g_pInputManager->onMouseWheel(event, weak.lock());
         PROTO::idle->onActivity();
     });
+    listener->frame = pointer->m_pointerEvents.frame.listen([] { g_pInputManager->onPointerFrame(); });
 
     listener->swipeBegin = pointer->m_pointerEvents.swipeBegin.listen([](const IPointer::SSwipeBeginEvent& event) {
         g_pInputManager->onSwipeBegin(event);

src/managers/PointerManager.hpp

@@ -93,6 +93,7 @@ class CPointerManager {
         CHyprSignalListener motionAbsolute;
         CHyprSignalListener button;
         CHyprSignalListener axis;
+        CHyprSignalListener frame;
 
         CHyprSignalListener swipeBegin;
         CHyprSignalListener swipeEnd;

src/managers/input/InputManager.cpp

@@ -952,6 +952,22 @@ void CInputManager::onMouseWheel(IPointer::SAxisEvent e, SP<IPointer> pointer) {
     int32_t deltaDiscrete = std::abs(discrete) != 0 && std::abs(discrete) < 1 ? std::copysign(1, discrete) : std::round(discrete);
 
     g_pSeatManager->sendPointerAxis(e.timeMs, e.axis, delta, deltaDiscrete, value120, e.source, WL_POINTER_AXIS_RELATIVE_DIRECTION_IDENTICAL);
+
+    const bool deferPointerFrame = e.source == WL_POINTER_AXIS_SOURCE_FINGER || e.source == WL_POINTER_AXIS_SOURCE_CONTINUOUS;
+    if (deferPointerFrame) {
+        m_pointerAxisFramePending = true;
+        return;
+    }
+
+    m_pointerAxisFramePending = false;
+    g_pSeatManager->sendPointerFrame();
+}
+
+void CInputManager::onPointerFrame() {
+    if (!m_pointerAxisFramePending)
+        return;
+
+    m_pointerAxisFramePending = false;
     g_pSeatManager->sendPointerFrame();
 }
 

src/managers/input/InputManager.hpp

@@ -91,6 +91,7 @@ class CInputManager {
     void               onMouseWarp(IPointer::SMotionAbsoluteEvent);
     void               onMouseButton(IPointer::SButtonEvent);
     void               onMouseWheel(IPointer::SAxisEvent, SP<IPointer> pointer = nullptr);
+    void               onPointerFrame();
     void               onKeyboardKey(const IKeyboard::SKeyEvent&, SP<IKeyboard>);
     void               onKeyboardMod(SP<IKeyboard>);
 
@@ -299,6 +300,7 @@ class CInputManager {
         uint32_t lastEventTime     = 0;
         uint32_t accumulatedScroll = 0;
     } m_scrollWheelState;
+    bool                  m_pointerAxisFramePending = false;
 
     bool                  shareKeyFromAllKBs(uint32_t key, bool pressed);
     uint32_t              shareModsFromAllKBs(uint32_t depressed);