dmaax/ladybird
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

UI: Increase mouse wheel scroll step from 24 to 40 pixels

Browse source 
Other engines converge on roughly 40 pixels per line as the per-line
step for discrete mouse wheel input (Chrome's kWheelDelta of 120 over
3 lines, WebKit's Scrollbar::pixelsPerLineStep of 40, Chrome's macOS
kScrollbarPixelsPerCocoaTick of 40). At a step of 24 we were scrolling
about 60% as far per tick as Chrome on the same input, which made the
browser feel sluggish under a regular wheel.

Bumping the constant to 40 in the Qt, Gtk, and AppKit frontends puts
us at 120 pixels per discrete tick on Linux (3 lines * 40 pixels) and
aligns the macOS imprecise-scroll multiplier with WebKit and Chrome.
High-precision (trackpad) input is unaffected on all platforms, since
those paths use pixel deltas directly without applying a multiplier.
This commit is contained in:
Andreas Kling 2026-05-12 19:06:33 +02:00 committed by Alexander Kalenik
parent 0a41859ae9
commit 49f694ea01
3 changed files with 3 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
UI/AppKit/Interface/Event.mm
View file

@ -54,7 +54,7 @@ Web::MouseEvent ns_event_to_mouse_event(Web::MouseEvent::Type type, NSEvent* eve
CGFloat delta_y = -[event scrollingDeltaY];
if (![event hasPreciseScrollingDeltas]) {
static constexpr CGFloat imprecise_scroll_multiplier = 24;
static constexpr CGFloat imprecise_scroll_multiplier = 40;
delta_x *= imprecise_scroll_multiplier;
delta_y *= imprecise_scroll_multiplier;

2
UI/Gtk/Widgets/LadybirdWebView.cpp
View file

@ -175,7 +175,7 @@ static gboolean on_scroll(GtkEventControllerScroll* controller, gdouble dx, gdou
wheel_delta_y = static_cast<int>(dy * device_pixel_ratio);
} else {
static constexpr double scroll_lines = 3.0;
static constexpr double scroll_step_size = 24.0;
static constexpr double scroll_step_size = 40.0;
wheel_delta_x = static_cast<int>(dx * scroll_lines * scroll_step_size * device_pixel_ratio);
wheel_delta_y = static_cast<int>(dy * scroll_lines * scroll_step_size * device_pixel_ratio);
}

2
UI/Qt/WebContentView.cpp
View file

@ -822,7 +822,7 @@ void WebContentView::enqueue_native_event(Web::MouseEvent::Type type, QSinglePoi
float delta_x = -static_cast<float>(angle_delta.x()) / 120.0f;
float delta_y = static_cast<float>(angle_delta.y()) / 120.0f;
static constexpr float scroll_step_size = 24;
static constexpr float scroll_step_size = 40;
auto step_x = delta_x * static_cast<float>(QApplication::wheelScrollLines()) * m_device_pixel_ratio;
auto step_y = delta_y * static_cast<float>(QApplication::wheelScrollLines()) * m_device_pixel_ratio;