Struct LayoutFn 

pub struct LayoutFn(pub Arc<dyn Fn(LayoutCtx<'_>) -> Vec<Rect> + Send + Sync>);

Second escape hatch: author-supplied layout function.

When set on a node via El::layout, the layout pass calls this function instead of running the column/row/overlay distribution for that node’s direct children. The function returns one Rect per child (in source order), positioned anywhere inside the container. The library still recurses into each child (so descendants lay out normally) and still drives hit-test, focus, animation, scroll — those all read from UiState’s computed-rect side map, which receives the rects this function produces.

Authors typically write a free fn(LayoutCtx) -> Vec<Rect> and pass it directly: column(children).layout(my_layout).

What you get

• LayoutCtx::container — the rect available for placement (parent rect minus this node’s padding).
• LayoutCtx::children — read-only slice of the node’s children; index here matches the index in your returned Vec<Rect>.
• LayoutCtx::measure — call to get a child’s intrinsic (width, height) if you need it for sizing decisions.

Scope limits (will panic)

• The custom-layout node itself must size with Size::Fixed or Size::Fill on both axes. Size::Hug would require a separate intrinsic callback and is not yet supported.
• The returned Vec<Rect> length must equal children.len().

Tuple Fields

0: Arc<dyn Fn(LayoutCtx<'_>) -> Vec<Rect> + Send + Sync>

Implementations

impl LayoutFn

pub fn new<F>(f: F) -> Self

where F: Fn(LayoutCtx<'_>) -> Vec<Rect> + Send + Sync + 'static,

Trait Implementations

impl Clone for LayoutFn

fn clone(&self) -> LayoutFn

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LayoutFn

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

Formats the value using the given formatter.