Struct LayoutRoot 

pub(crate) struct LayoutRoot<'dom> {
    node: ServoLayoutNode<'dom>,
}

A data structure to track a layout root.

Layout roots are places in the fragment tree where fragment tree layout can start. These are fragments that isolate fragment damage from their ancestors sufficiently that their ancestors can be preserved from one fragment tree layout to the next. Currently, this only includes absolutely-or-fixed-positioned fragments that do not have any escaping fixed position fragments..

During damage propagation, upward flowing fragment tree Relayout damage can be converted into DescendantCollectedAsLayoutRoot damage. When an ancestor of a layout root has fragment tree layout damage, DescendantCollectedAsLayoutRoot damage is converted back into Relayout and propagated up to the next layout root or the root of the DOM.

This is only possible because the damage propagation traversal ensures that damage above the absolute (which might shift its static position) is converted back into Relayout damage. This means that the absolute should be placed with the fully adjusted static positioning rectangle between two layouts.

It’s possible that upon laying out a layout root again, a new fixed position element has started to escape from the layout root. In that case, a full fragment tree layout becomes necessary to rebuild the fragment properly.

Fields

node: ServoLayoutNode<'dom>

Implementations

impl LayoutRoot<'_>

pub(crate) fn try_layout(&self, layout_context: &LayoutContext<'_>) -> bool

Trait Implementations

impl<'dom> TryFrom<ServoLayoutNode<'dom>> for LayoutRoot<'dom>

type Error = ()

The type returned in the event of a conversion error.

fn try_from(node: ServoLayoutNode<'dom>) -> Result<Self, Self::Error>

Performs the conversion.