LibWeb: Reorder paintable hit-testing to account for pointer-events

Instead of ignoring any paintable immediately when they're invisible to
hit-testing, consider every candidate and while the most specific
candidate is invisible to hit-testing, traverse up to its parent
paintable.

This more closely reflects the behavior expected when wrapping block
elements inside inline elements, where although the block element might
have `pointer-events: none`, it still becomes part of the hit-test body
of the inline parent.

This makes the following link work as expected:

  <a href="https://ladybird.org">
    <div style="pointer-events: none">Ladybird</div>
  </a>
This commit is contained in:
Jelle Raaijmakers 2025-01-21 15:24:46 +01:00 committed by Jelle Raaijmakers
commit b7a554d1f2
Notes: github-actions[bot] 2025-01-23 08:34:09 +00:00
4 changed files with 76 additions and 10 deletions

View file

@ -965,9 +965,6 @@ TraversalDecision PaintableBox::hit_test(CSSPixelPoint position, HitTestType typ
return TraversalDecision::Break;
}
if (!visible_for_hit_testing())
return TraversalDecision::Continue;
if (!absolute_border_box_rect().contains(position_adjusted_by_scroll_offset))
return TraversalDecision::Continue;
@ -978,18 +975,38 @@ Optional<HitTestResult> PaintableBox::hit_test(CSSPixelPoint position, HitTestTy
{
Optional<HitTestResult> result;
(void)PaintableBox::hit_test(position, type, [&](HitTestResult candidate) {
if (candidate.paintable->visible_for_hit_testing()) {
if (!result.has_value()
|| candidate.vertical_distance.value_or(CSSPixels::max_integer_value) < result->vertical_distance.value_or(CSSPixels::max_integer_value)
|| candidate.horizontal_distance.value_or(CSSPixels::max_integer_value) < result->horizontal_distance.value_or(CSSPixels::max_integer_value)) {
result = move(candidate);
}
if (!result.has_value()
|| candidate.vertical_distance.value_or(CSSPixels::max_integer_value) < result->vertical_distance.value_or(CSSPixels::max_integer_value)
|| candidate.horizontal_distance.value_or(CSSPixels::max_integer_value) < result->horizontal_distance.value_or(CSSPixels::max_integer_value)) {
result = move(candidate);
}
if (result.has_value() && (type == HitTestType::Exact || (result->vertical_distance == 0 && result->horizontal_distance == 0)))
return TraversalDecision::Break;
return TraversalDecision::Continue;
});
// If our hit-testing has resulted in a hit on a paintable, we know that it is the most specific hit. If that
// paintable turns out to be invisible for hit-testing, we need to traverse up the paintable tree to find the next
// paintable that is visible for hit-testing. This implements the behavior expected for pointer-events.
while (result.has_value() && !result->paintable->visible_for_hit_testing()) {
result->index_in_node = result->paintable->dom_node() ? result->paintable->dom_node()->index() : 0;
result->paintable = result->paintable->parent();
// If the new parent is an anonymous box part of a continuation, we need to follow the chain to the inline node
// that spawned the anonymous "middle" part of the continuation, since that inline node is the actual parent.
if (is<PaintableBox>(*result->paintable)) {
auto const& box_layout_node = static_cast<PaintableBox&>(*result->paintable).layout_node_with_style_and_box_metrics();
if (box_layout_node.is_anonymous() && box_layout_node.continuation_of_node()) {
auto const* original_inline_node = &box_layout_node;
while (original_inline_node->continuation_of_node())
original_inline_node = original_inline_node->continuation_of_node();
result->paintable = const_cast<Paintable*>(original_inline_node->first_paintable());
}
}
}
return result;
}