use js_sys::Array;
use wasm_bindgen::prelude::Closure;
use wasm_bindgen::JsCast;
use web_sys::{Element, IntersectionObserver, IntersectionObserverEntry};
pub(super) struct IntersectionObserverHandle {
observer: IntersectionObserver,
_closure: Closure<dyn FnMut(Array)>,
}
impl IntersectionObserverHandle {
pub fn new<F>(element: &Element, mut callback: F) -> Self
where
F: 'static + FnMut(bool),
{
let closure = Closure::new(move |entries: Array| {
let entry: IntersectionObserverEntry = entries.get(0).unchecked_into();
callback(entry.is_intersecting());
});
let observer = IntersectionObserver::new(closure.as_ref().unchecked_ref())
.expect("Invalid `options`");
observer.observe(element);
Self {
observer,
_closure: closure,
}
}
}
impl Drop for IntersectionObserverHandle {
fn drop(&mut self) {
self.observer.disconnect()
}
}