yumechi-no-kuni/src/client/directives/follow-append.ts
2020-11-01 22:09:16 +09:00

25 lines
659 B
TypeScript

import { Directive } from 'vue';
import { getScrollContainer, getScrollPosition } from '@/scripts/scroll';
export default {
mounted(src, binding, vn) {
const ro = new ResizeObserver((entries, observer) => {
const pos = getScrollPosition(src);
const container = getScrollContainer(src);
const viewHeight = container.clientHeight;
const height = container.scrollHeight;
if (pos + viewHeight > height - 32) {
container.scrollTop = height;
}
});
ro.observe(src);
// TODO: 新たにプロパティを作るのをやめMapを使う
src._ro_ = ro;
},
unmounted(src, binding, vn) {
src._ro_.unobserve(src);
}
} as Directive;