Struct Lazy 

pub struct Lazy<'a, W, Dependency> { /* private fields */ }

A widget that only rebuilds its contents when necessary.

Implementations

impl<'a, W, Dependency> Lazy<'a, W, Dependency>

where Dependency: Hash + 'a,

pub fn new( dependency: Dependency, view: impl Fn(&Dependency) -> W + 'a, ) -> Lazy<'a, W, Dependency>

Creates a new Lazy widget with the given data Dependency and a closure that can turn this data into a widget tree.

Trait Implementations

impl<W, Dependency> Meta for Lazy<'_, W, Dependency>

fn is_void(&self) -> bool

Returns whether the Widget is Void.

impl<'a, W, Message, Theme, Renderer, Dependency> Widget<Message, Theme, Renderer> for Lazy<'a, W, Dependency>

where W: Widget<Message, Theme, Renderer> + 'static, Dependency: Hash + 'a, Renderer: Renderer,

fn tag(&self) -> Tag

Returns the Tag of the Widget.

fn state(&self) -> State

Returns the State of the Widget.

fn diff(&mut self, tree: &mut Tree)

Reconciles the Widget with the provided Tree.

fn size(&self) -> Size<Length>

Returns the Size of the Widget in lengths.

fn layout(&mut self, tree: &mut Tree, renderer: &Renderer, limits: &Limits)

Lays out the Widget.

fn operate( &mut self, tree: &mut Tree, layout: Layout, viewport: &Rectangle, renderer: &Renderer, operation: &mut dyn Operation, )

Applies an Operation to the Widget.

fn update( &mut self, tree: &mut Tree, event: &Event, layout: Layout, cursor: Cursor, renderer: &Renderer, shell: &mut Shell<'_, Message>, viewport: &Rectangle, )

Processes a runtime Event.

fn mouse_interaction( &self, tree: &Tree, layout: Layout, cursor: Cursor, viewport: &Rectangle, renderer: &Renderer, ) -> Interaction

Returns the current mouse::Interaction of the Widget.

fn draw( &self, tree: &Tree, renderer: &mut Renderer, theme: &Theme, style: &Style, layout: Layout, cursor: Cursor, viewport: &Rectangle, )

Draws the Widget using the associated Renderer.

fn overlay<'b>( &'b mut self, tree: &'b mut Tree, layout: Layout, renderer: &Renderer, viewport: &Rectangle, translation: Vector, window: Size, ) -> Vec<Element<'b, Message, Theme, Renderer>>

Returns the overlays of the Widget.

fn _map<F, B>(self, f: F) -> Map<Self, F, Message>

where Self: Sized, F: Fn(Message) -> B,

Applies a transformation to the produced message of this Widget, returning a Map.

fn _boxed<'a>(self) -> Element<'a, Message, Theme, Renderer>

where Self: Sized + 'a,

Boxes this Widget, turning it into a generic Element.