Struct LayoutTree 

pub struct LayoutTree<C> { /* private fields */ }

A layout tree whose measured leaves carry a context C.

Implementations

impl<C> LayoutTree<C>

pub fn new() -> Self

Creates an empty tree.

use ravenrs_core::Size;
use ravenrs_layout::{Axis, LayoutStyle, LayoutTree};

let mut tree = LayoutTree::<()>::new();
let child = tree.node(LayoutStyle { height: Some(20.0), ..LayoutStyle::leaf() }, &[]).unwrap();
let root = tree.node(LayoutStyle { spacing: 8.0, ..LayoutStyle::stack(Axis::Vertical) }, &[child]).unwrap();
tree.compute(root, Size::new(200.0, 100.0), |_, _| Size::ZERO).unwrap();
assert_eq!(tree.frame(child).unwrap().height(), 20.0);

pub fn clear(&mut self)

Removes every node, keeping allocations for the next build.

pub fn node( &mut self, style: LayoutStyle, children: &[LayoutId], ) -> Result<LayoutId, LayoutError>

Adds a container (or a fixed-size leaf) with the given children.

pub fn measured_leaf( &mut self, style: LayoutStyle, context: C, ) -> Result<LayoutId, LayoutError>

Adds a leaf whose size comes from the measure callback given to Self::compute.

pub fn compute( &mut self, root: LayoutId, available: Size, measure: impl FnMut(&mut C, MeasureInput) -> Size, ) -> Result<(), LayoutError>

Computes the layout of root inside available logical pixels.

pub fn frame(&self, node: LayoutId) -> Result<Rect, LayoutError>

The node’s frame relative to its parent’s origin.

pub fn content_box(&self, node: LayoutId) -> Result<Rect, LayoutError>

The content box (frame minus padding) relative to the node’s own origin.

pub fn content_size(&self, node: LayoutId) -> Result<Size, LayoutError>

The size of the node’s content, which can exceed its frame when it overflows.

pub fn context_mut(&mut self, node: LayoutId) -> Option<&mut C>

Mutable access to a measured leaf’s context, or None for nodes without one.

pub fn node_count(&self) -> usize

Total number of nodes in the tree.

Trait Implementations

impl<C> Debug for LayoutTree<C>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<C> Default for LayoutTree<C>

fn default() -> Self

Returns the “default value” for a type.