Struct UseIntersectionObserver 

pub struct UseIntersectionObserver {
    pub target: NodeRef<Element>,
    pub visible: Signal<bool>,
    pub ratio: Signal<f64>,
    /* private fields */
}

Reactive state for an element’s visibility.

The handle carries the element the hook watches — a NodeRef the caller attaches to its own markup — and the signals that report whether the element is intersecting the viewport and how much of it is visible.

This is the cheap way to defer the work of an off-screen element: the signal only changes when the element actually crosses the viewport, so a render closure that reads it stays quiet while the element scrolls past.

Fields

target: NodeRef<Element>

The element the hook watches.

Attach it to the caller’s markup with the ref: attribute.

visible: Signal<bool>

Whether the element is currently intersecting the viewport.

ratio: Signal<f64>

The fraction of the element that is visible, from 0 to 1.

Implementations

impl UseIntersectionObserver

Inherent implementation of UseIntersectionObserver.

pub fn is_visible(&self) -> bool

Returns the current visibility as a snapshot.

Returns

• bool - true when the element is intersecting the viewport.

pub fn current_ratio(&self) -> f64

Returns the current visible fraction as a snapshot.

Returns

• f64 - The visible fraction, from 0 to 1.

impl UseIntersectionObserver

pub fn get_target(&self) -> &NodeRef<Element>

pub fn get_mut_target(&mut self) -> &mut NodeRef<Element>

pub fn set_target(&mut self, val: NodeRef<Element>) -> &mut Self

pub fn get_visible(&self) -> Signal<bool>

pub fn get_mut_visible(&mut self) -> &mut Signal<bool>

pub fn set_visible(&mut self, val: Signal<bool>) -> &mut Self

pub fn get_ratio(&self) -> Signal<f64>

pub fn get_mut_ratio(&mut self) -> &mut Signal<f64>

pub fn set_ratio(&mut self, val: Signal<f64>) -> &mut Self

pub fn get_mut_teardown(&mut self) -> &mut Rc<RefCell<Option<Box<dyn Fn()>>>>

pub fn set_teardown( &mut self, val: Rc<RefCell<Option<Box<dyn Fn()>>>>, ) -> &mut Self

Trait Implementations

impl Clone for UseIntersectionObserver

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for UseIntersectionObserver

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

Formats the struct fields as a debug struct, skipping excluded fields.

Arguments

• &mut std::fmt::Formatter<'_> - The formatter to write the representation into.

Returns

• std::fmt::Result - Success or failure of the formatting operation.