46 lines
1.2 KiB
Rust
46 lines
1.2 KiB
Rust
|
use js_sys::Array;
|
||
|
|
use wasm_bindgen::{prelude::Closure, 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 mut skip = true;
|
||
|
|
let closure = Closure::new(move |entries: Array| {
|
||
|
|
let entry: IntersectionObserverEntry = entries.get(0).unchecked_into();
|
||
|
|
|
||
|
|
let is_intersecting = entry.is_intersecting();
|
||
|
|
|
||
|
|
// skip first intersection
|
||
|
|
if skip && is_intersecting {
|
||
|
|
skip = false;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
callback(is_intersecting);
|
||
|
|
});
|
||
|
|
let observer = IntersectionObserver::new(closure.as_ref().unchecked_ref())
|
||
|
|
// we don't provide any `options`
|
||
|
|
.expect("Invalid `options`");
|
||
|
|
observer.observe(element);
|
||
|
|
|
||
|
|
Self {
|
||
|
|
observer,
|
||
|
|
_closure: closure,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
impl Drop for IntersectionObserverHandle {
|
||
|
|
fn drop(&mut self) {
|
||
|
|
self.observer.disconnect()
|
||
|
|
}
|
||
|
|
}
|