ladybird/Libraries/LibWeb/CSS/StyleInvalidation.h
Aliaksandr Kalenik 04c3ad669b LibWeb: Rebuild AccumulatedVisualContext on transform changes
Ensure AccumulatedVisualContext stays synchronized when CSS transform
properties change.

AccumulatedVisualContext copies transform and perspective matrices from
the paintable tree at assignment time. When CSS properties that affect
these matrices change (transform, rotate, scale, translate, perspective,
transform-origin, perspective-origin), we must rebuild the
AccumulatedVisualContext tree to reflect the new values.

This adds a rebuild_accumulated_visual_contexts flag to style
invalidation that triggers a full rebuild during the next paint.

Note: The current invalidation strategy is inefficient - it rebuilds
the entire tree even for single-element transform changes. This could
be improved by patching the AccumulatedVisualContext node in-place with
updated matrices, but only when the transform doesn't transition
from/to none (which would change the tree structure). This optimization
is left for future work.
2026-01-15 19:50:53 +01:00

36 lines
1.4 KiB
C++

/*
* Copyright (c) 2024, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibWeb/Forward.h>
namespace Web::CSS {
struct RequiredInvalidationAfterStyleChange {
bool repaint : 1 { false };
bool rebuild_stacking_context_tree : 1 { false };
bool relayout : 1 { false };
bool rebuild_layout_tree : 1 { false };
bool rebuild_accumulated_visual_contexts : 1 { false };
void operator|=(RequiredInvalidationAfterStyleChange const& other)
{
repaint |= other.repaint;
rebuild_stacking_context_tree |= other.rebuild_stacking_context_tree;
relayout |= other.relayout;
rebuild_layout_tree |= other.rebuild_layout_tree;
rebuild_accumulated_visual_contexts |= other.rebuild_accumulated_visual_contexts;
}
[[nodiscard]] bool is_none() const { return !repaint && !rebuild_stacking_context_tree && !relayout && !rebuild_layout_tree && !rebuild_accumulated_visual_contexts; }
[[nodiscard]] bool is_full() const { return repaint && rebuild_stacking_context_tree && relayout && rebuild_layout_tree; }
static RequiredInvalidationAfterStyleChange full() { return { true, true, true, true, false }; }
};
RequiredInvalidationAfterStyleChange compute_property_invalidation(CSS::PropertyID property_id, RefPtr<StyleValue const> const& old_value, RefPtr<StyleValue const> const& new_value);
}