Struct LayoutBuilder 

pub struct LayoutBuilder<S>
where
    S: AppState,
{
    pub id: Option<WidgetNodeId>,
    pub flex_grow: f32,
    pub flex_shrink: f32,
    /* private fields */
}

A closure-based widget that receives its parent’s BoxConstraints.

LayoutBuilder is the layout-aware counterpart of Builder. The closure receives the constraints from the previous frame (or a fallback derived from the viewport) so it can adapt its output to the available space.

Example

let widget = LayoutBuilder::new(|ctx, view, constraints| {
    let cols = if constraints.max_width > 600.0 { 3 } else { 1 };
    build_grid(ctx, view, cols)
})
.flex_grow(1.0);

Fields

id: Option<WidgetNodeId>

Optional stable identity for constraint look-up across frames.

flex_grow: f32

Flex grow factor.

flex_shrink: f32

Flex shrink factor.

Implementations

impl<S> LayoutBuilder<S>

where S: AppState,

pub fn new<F>(builder: F) -> LayoutBuilder<S>

where F: Fn(&mut BuildCtx<S>, &View<'_, S>, BoxConstraints) -> Node + Send + Sync + 'static,

pub fn id(self, id: WidgetNodeId) -> LayoutBuilder<S>

pub fn flex_grow(self, grow: f32) -> LayoutBuilder<S>

pub fn flex_shrink(self, shrink: f32) -> LayoutBuilder<S>

Trait Implementations

impl<S> Widget<S> for LayoutBuilder<S>

where S: AppState,

fn build(&self, ctx: &mut BuildCtx<S>, view: &View<'_, S>) -> Node

Build the widget’s node tree.