misskey/packages/frontend/src/directives/appear.ts

28 lines
534 B
TypeScript

/*
* SPDX-FileCopyrightText: syuilo and misskey-project
* SPDX-License-Identifier: AGPL-3.0-only
*/
import { Directive } from 'vue';
export default {
mounted(src, binding, vn) {
const fn = binding.value;
if (fn == null) return;
const observer = new IntersectionObserver(entries => {
if (entries.some(entry => entry.isIntersecting)) {
fn();
}
});
observer.observe(src);
src._observer_ = observer;
},
unmounted(src, binding, vn) {
if (src._observer_) src._observer_.disconnect();
},
} as Directive;