Struct NavLayout 

pub struct NavLayout {
    pub sizes: Rc<RefCell<HashMap<RNode, Size>>>,
    pub presentation: Rc<Cell<NavPresentation>>,
    pub sidebar: Rc<Cell<Option<RNode>>>,
    pub list: Rc<Cell<Option<RNode>>>,
    pub list_width: f64,
    pub list_visible: Rc<Cell<bool>>,
}

Navigation host (docs/navigation.md): page frames are native-owned (splitter panes, nav-controller views), so set_frame on pages is a toolkit no-op; Day lays each page’s content within the size the toolkit last reported via Event::FrameChanged, falling back to a sidebar/detail split (or the full host) of the host bounds.

Fields

sizes: Rc<RefCell<HashMap<RNode, Size>>>

presentation: Rc<Cell<NavPresentation>>

The presentation as last resolved. Shared with the piece rather than copied, so a re-present (NavPatch::Presentation) changes the fallback split without rebuilding the layout object the host was realized with.

sidebar: Rc<Cell<Option<RNode>>>

The host’s sidebar page, once it has one. Identity, not position: after a re-present the pages keep their roles but a backend may have re-homed them in a different order.

list: Rc<Cell<Option<RNode>>>

The host’s content-list page (Pane::List), once it has one; shared like sidebar.

list_width: f64

The content-list pane’s preferred width (NavProps::list_width), for the fallback split.

list_visible: Rc<Cell<bool>>

Whether the pane is showing (NavPatch::ListVisible), shared with the piece so a collapsed pane stops narrowing the detail’s fallback immediately, rather than one FrameChanged report later.

Implementations

impl NavLayout

pub fn stack(sizes: Rc<RefCell<HashMap<RNode, Size>>>) -> Self

A host with no sidebar pane and no re-presenting to do: a tab strip’s page area, or a nav_stack piece, both of which stay stacked at every size.

Trait Implementations

impl Layout for NavLayout

fn measure( &self, _cx: &mut dyn LayoutOps, _children: &[RNode], p: Proposal, ) -> Size

fn place(&self, cx: &mut dyn LayoutOps, children: &[RNode], bounds: Rect)

fn baseline( &self, _cx: &mut dyn LayoutOps, _children: &[RNode], _size: Size, ) -> Option<f64>

Where this node’s own first text baseline falls, measured from the top of a box of size (docs/baseline.md). None (the default) means the node has no baseline to offer, so a baseline-aligned parent falls back to box alignment for it.