mirror of
https://github.com/LadybirdBrowser/ladybird
synced 2026-05-14 02:46:57 +02:00
568b7ce7ea
The Paintable tree and its supplemental painting data structures were GC allocated because that was the easiest way to manage it and avoid leaks introduced by ref cycles. This included the Paintable subclasses themselves plus StackingContext, ChromeWidget, Scrollbar, ResizeHandle, and scroll-frame state. We are now trying to reduce GC allocation churn on layout and painting updates, so keeping this short-lived rendering tree outside the JS heap is a better fit. Move Paintable to RefCountedTreeNode, make painting helpers ref-counted or weakly reference Paintables, and update the layout and event-handler call sites to use RefPtr/WeakPtr ownership.
95 lines
3.3 KiB
C++
95 lines
3.3 KiB
C++
/*
|
|
* Copyright (c) 2026, Tim Flynn <trflynn89@ladybird.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/Math.h>
|
|
#include <LibWeb/DOM/Document.h>
|
|
#include <LibWeb/DOM/Element.h>
|
|
#include <LibWeb/Page/AutoScrollHandler.h>
|
|
#include <LibWeb/Page/MiddleButtonScrollHandler.h>
|
|
#include <LibWeb/Painting/Paintable.h>
|
|
#include <LibWeb/Painting/PaintableBox.h>
|
|
#include <LibWeb/Painting/ViewportPaintable.h>
|
|
|
|
namespace Web {
|
|
|
|
static constexpr double DEAD_ZONE_RADIUS { 15 };
|
|
static constexpr double SPEED_FACTOR = 5.0;
|
|
static constexpr double MAX_SPEED_PER_SECOND = 5000.0;
|
|
static constexpr double SCROLL_INTERVAL_MS = 16.0;
|
|
|
|
MiddleButtonScrollHandler::MiddleButtonScrollHandler(DOM::Element& container, CSSPixelPoint origin)
|
|
: m_container_element(container)
|
|
, m_origin(origin)
|
|
, m_mouse_position(origin)
|
|
{
|
|
if (auto paintable = m_container_element->document().paintable())
|
|
paintable->set_needs_repaint();
|
|
}
|
|
|
|
MiddleButtonScrollHandler::~MiddleButtonScrollHandler()
|
|
{
|
|
if (!m_container_element->document().layout_is_up_to_date())
|
|
return;
|
|
if (auto paintable = m_container_element->document().paintable())
|
|
paintable->set_needs_repaint();
|
|
}
|
|
|
|
void MiddleButtonScrollHandler::visit_edges(JS::Cell::Visitor& visitor) const
|
|
{
|
|
visitor.visit(m_container_element);
|
|
}
|
|
|
|
GC::Ptr<DOM::Element> MiddleButtonScrollHandler::find_scrollable_ancestor(DOM::Document& document, Painting::Paintable& paintable)
|
|
{
|
|
// AutoScrollHandler::find_scrollable_ancestor begins with the paintable's containing block. For middle mouse
|
|
// scrolling, we want to include the paintable itself. This allows clicking in dead space to being scrolling.
|
|
if (auto* paintable_box = as_if<Painting::PaintableBox>(paintable); paintable_box && paintable_box->could_be_scrolled_by_wheel_event()) {
|
|
if (auto* element = as_if<DOM::Element>(paintable_box->dom_node().ptr()))
|
|
return element;
|
|
}
|
|
|
|
if (auto container = AutoScrollHandler::find_scrollable_ancestor(paintable))
|
|
return container;
|
|
|
|
if (auto scrolling_element = document.scrolling_element())
|
|
return const_cast<DOM::Element*>(scrolling_element.ptr());
|
|
|
|
return {};
|
|
}
|
|
|
|
void MiddleButtonScrollHandler::perform_tick()
|
|
{
|
|
auto distance_x = (m_mouse_position.x() - m_origin.x()).to_double();
|
|
auto distance_y = (m_mouse_position.y() - m_origin.y()).to_double();
|
|
|
|
if (auto distance = AK::hypot(distance_x, distance_y); distance < DEAD_ZONE_RADIUS)
|
|
return;
|
|
|
|
m_container_element->document().update_layout(DOM::UpdateLayoutReason::AutoScrollSelection);
|
|
m_mouse_has_moved_beyond_dead_zone = true;
|
|
|
|
auto paintable_box = AutoScrollHandler::auto_scroll_paintable(m_container_element);
|
|
if (!paintable_box)
|
|
return;
|
|
|
|
auto speed_x = clamp(distance_x * SPEED_FACTOR, -MAX_SPEED_PER_SECOND, MAX_SPEED_PER_SECOND);
|
|
auto speed_y = clamp(distance_y * SPEED_FACTOR, -MAX_SPEED_PER_SECOND, MAX_SPEED_PER_SECOND);
|
|
auto elapsed_seconds = SCROLL_INTERVAL_MS / 1000.0;
|
|
|
|
m_fractional_delta += CSSPixelPoint {
|
|
CSSPixels(speed_x * elapsed_seconds),
|
|
CSSPixels(speed_y * elapsed_seconds),
|
|
};
|
|
|
|
auto scroll_x = m_fractional_delta.x().to_int();
|
|
auto scroll_y = m_fractional_delta.y().to_int();
|
|
m_fractional_delta -= CSSPixelPoint { scroll_x, scroll_y };
|
|
|
|
paintable_box->scroll_by(scroll_x, scroll_y);
|
|
}
|
|
|
|
}
|