hippofish/packages/frontend/src/directives/get-size.ts
Shun Sakai c2370a1be6
chore: 著作権とライセンスについての情報を各ファイルに追加する (#11348)
* chore: Add the SPDX information to each file

Add copyright and licensing information as defined in version 3.0 of
the REUSE Specification.

* tweak format

---------

Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
2023-07-27 14:31:52 +09:00

59 lines
1.4 KiB
TypeScript

/*
* SPDX-FileCopyrightText: syuilo and other misskey contributors
* SPDX-License-Identifier: AGPL-3.0-only
*/
import { Directive } from 'vue';
const mountings = new Map<Element, {
resize: ResizeObserver;
intersection?: IntersectionObserver;
fn: (w: number, h: number) => void;
}>();
function calc(src: Element) {
const info = mountings.get(src);
const height = src.clientHeight;
const width = src.clientWidth;
if (!info) return;
// アクティベート前などでsrcが描画されていない場合
if (!height) {
// IntersectionObserverで表示検出する
if (!info.intersection) {
info.intersection = new IntersectionObserver(entries => {
if (entries.some(entry => entry.isIntersecting)) calc(src);
});
}
info.intersection.observe(src);
return;
}
if (info.intersection) {
info.intersection.disconnect();
delete info.intersection;
}
info.fn(width, height);
}
export default {
mounted(src, binding, vn) {
const resize = new ResizeObserver((entries, observer) => {
calc(src);
});
resize.observe(src);
mountings.set(src, { resize, fn: binding.value });
calc(src);
},
unmounted(src, binding, vn) {
binding.value(0, 0);
const info = mountings.get(src);
if (!info) return;
info.resize.disconnect();
if (info.intersection) info.intersection.disconnect();
mountings.delete(src);
},
} as Directive<Element, (w: number, h: number) => void>;