diff options
| -rw-r--r-- | win32/ScintillaWin.cxx | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/win32/ScintillaWin.cxx b/win32/ScintillaWin.cxx index 5f989b781..cefa5a4f9 100644 --- a/win32/ScintillaWin.cxx +++ b/win32/ScintillaWin.cxx @@ -276,6 +276,20 @@ public: } }; +class MouseWheelDelta { + int wheelDelta = 0; +public: + bool Accumulate(WPARAM wParam) noexcept { + wheelDelta -= GET_WHEEL_DELTA_WPARAM(wParam); + return std::abs(wheelDelta) >= WHEEL_DELTA; + } + int Actions() noexcept { + const int actions = wheelDelta / WHEEL_DELTA; + wheelDelta = wheelDelta % WHEEL_DELTA; + return actions; + } +}; + struct HorizontalScrollRange { int pageWidth; int documentWidth; @@ -298,7 +312,7 @@ class ScintillaWin : SetCoalescableTimerSig SetCoalescableTimerFn; unsigned int linesPerScroll; ///< Intellimouse support - int wheelDelta; ///< Wheel delta from roll + MouseWheelDelta verticalWheelDelta; UINT dpi = USER_DEFAULT_SCREEN_DPI; ReverseArrowCursor reverseArrowCursor; @@ -511,7 +525,6 @@ ScintillaWin::ScintillaWin(HWND hwnd) { SetCoalescableTimerFn = nullptr; linesPerScroll = 0; - wheelDelta = 0; // Wheel delta from roll dpi = DpiForWindow(hwnd); @@ -1567,19 +1580,14 @@ sptr_t ScintillaWin::MouseMessage(unsigned int iMessage, uptr_t wParam, sptr_t l } if (iMessage == WM_MOUSEWHEEL) { // Either SCROLL vertically or ZOOM. We handle the wheel steppings calculation - wheelDelta -= GET_WHEEL_DELTA_WPARAM(wParam); - if (std::abs(wheelDelta) >= WHEEL_DELTA && linesPerScroll > 0) { + if (linesPerScroll != 0 && verticalWheelDelta.Accumulate(wParam)) { Sci::Line linesToScroll = linesPerScroll; if (linesPerScroll == WHEEL_PAGESCROLL) linesToScroll = LinesOnScreen() - 1; if (linesToScroll == 0) { linesToScroll = 1; } - linesToScroll *= (wheelDelta / WHEEL_DELTA); - if (wheelDelta >= 0) - wheelDelta = wheelDelta % WHEEL_DELTA; - else - wheelDelta = -(-wheelDelta % WHEEL_DELTA); + linesToScroll *= verticalWheelDelta.Actions(); if (wParam & MK_CONTROL) { // Zoom! We play with the font sizes in the styles. |