LibWeb: Add "position: sticky" support

Sticky positioning is implemented by modifying the algorithm for
assigning and refreshing scroll frames. Now, elements with
"position: sticky" are assigned their own scroll frame, and their
position is refreshed independently from regular scroll boxes.
Refreshing the scroll offsets for sticky boxes does not require display
list invalidation.

A separate hash map is used for the scroll frames of sticky boxes. This
is necessary because a single paintable box can have two scroll frames
if it 1) has "position: sticky" and 2) contains scrollable overflow.
This commit is contained in:
Aliaksandr Kalenik 2024-08-24 19:20:31 +02:00 committed by Alexander Kalenik
commit 30b636e90b
Notes: github-actions[bot] 2024-08-30 17:03:56 +00:00
20 changed files with 705 additions and 2 deletions

View file

@ -262,6 +262,14 @@ bool Node::is_fixed_position() const
return position == CSS::Positioning::Fixed;
}
bool Node::is_sticky_position() const
{
if (!has_style())
return false;
auto position = computed_values().position();
return position == CSS::Positioning::Sticky;
}
NodeWithStyle::NodeWithStyle(DOM::Document& document, DOM::Node* node, NonnullRefPtr<CSS::StyleProperties> computed_style)
: Node(document, node)
, m_computed_values(make<CSS::ComputedValues>())