Struct Sensor 

pub struct Sensor<'a, Key, Message, Theme = Theme, Renderer = Renderer> { /* private fields */ }

A widget that can generate messages when its content pops in and out of view.

It can even notify you with anticipation at a given distance!

Implementations

impl<'a, Message, Theme, Renderer> Sensor<'a, (), Message, Theme, Renderer>

where Renderer: Renderer,

pub fn new(content: impl Into<Element<'a, Message, Theme, Renderer>>) -> Self

Creates a new Sensor widget with the given content.

impl<'a, Key, Message, Theme, Renderer> Sensor<'a, Key, Message, Theme, Renderer>

where Key: Key, Renderer: Renderer,

pub fn on_show(self, on_show: impl Fn(Size) -> Message + 'a) -> Self

Sets the message to be produced when the content pops into view.

The closure will receive the Size of the content in that moment.

pub fn on_resize(self, on_resize: impl Fn(Size) -> Message + 'a) -> Self

Sets the message to be produced when the content changes Size once its in view.

The closure will receive the new Size of the content.

pub fn on_hide(self, on_hide: Message) -> Self

Sets the message to be produced when the content pops out of view.

pub fn key<K>(self, key: K) -> Sensor<'a, impl Key, Message, Theme, Renderer>

where K: Clone + PartialEq + 'static,

Sets the key of the Sensor widget, for continuity.

If the key changes, the Sensor widget will trigger again.

pub fn key_ref<K>( self, key: &'a K, ) -> Sensor<'a, &'a K, Message, Theme, Renderer>

where K: ToOwned + PartialEq<K::Owned> + ?Sized, K::Owned: 'static,

Sets the key of the Sensor, for continuity; using a reference.

If the key changes, the Sensor will trigger again.

pub fn anticipate(self, distance: impl Into<Pixels>) -> Self

Sets the distance in Pixels to use in anticipation of the content popping into view.

This can be quite useful to lazily load items in a long scrollable behind the scenes before the user can notice it!

pub fn delay(self, delay: impl Into<Duration>) -> Self

Sets the amount of time to wait before firing an on_show or on_hide event; after the content is shown or hidden.

When combined with key, this can be useful to debounce key changes.

Trait Implementations

impl<'a, Key, Message, Theme, Renderer> From<Sensor<'a, Key, Message, Theme, Renderer>> for Element<'a, Message, Theme, Renderer>

where Message: 'a, Key: Key + 'a, Renderer: Renderer + 'a, Theme: 'a,

fn from(pop: Sensor<'a, Key, Message, Theme, Renderer>) -> Self

Converts to this type from the input type.

impl<Key, Message, Theme, Renderer> Widget<Message, Theme, Renderer> for Sensor<'_, Key, Message, Theme, Renderer>

where Key: Key, Renderer: Renderer,

fn tag(&self) -> Tag

Returns the Tag of the Widget.

fn state(&self) -> State

Returns the State of the Widget.

fn children(&self) -> Vec<Tree>

Returns the state Tree of the children of the Widget.

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

Reconciles the Widget with the provided Tree.

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 size(&self) -> Size<Length>

Returns the Size of the Widget in lengths.

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

Returns a Size hint for laying out the Widget.

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

Returns the layout::Node 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 operate( &mut self, tree: &mut Tree, layout: Layout<'_>, renderer: &Renderer, operation: &mut dyn Operation, )

Applies an Operation to the Widget.

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

Returns the current mouse::Interaction of the Widget.

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

Returns the overlay of the Widget, if there is any.