enhance(client): Better element visible detection
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@ -1,5 +1,4 @@
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import Vue from 'vue';
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import { getScrollPosition, onScrollTop } from './scroll';
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import { onScrollTop, isTopVisible } from './scroll';
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const SECOND_FETCH_LIMIT = 30;
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@ -148,7 +147,7 @@ export default (opts) => ({
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},
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prepend(item) {
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const isTop = this.isBackTop || (document.body.contains(this.$el) && (getScrollPosition(this.$el) === 0));
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const isTop = this.isBackTop || (document.body.contains(this.$el) && isTopVisible(this.$el));
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if (isTop) {
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// Prepend the item
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@ -13,12 +13,18 @@ export function getScrollPosition(el: Element | null): number {
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return container == null ? window.scrollY : container.scrollTop;
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}
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export function isTopVisible(el: Element | null): boolean {
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const scrollTop = getScrollPosition(el);
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const topPosition = el.offsetTop; // TODO: container内でのelの相対位置を取得できればより正確になる
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return scrollTop <= topPosition;
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}
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export function onScrollTop(el: Element, cb) {
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const container = getScrollContainer(el) || window;
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const onScroll = ev => {
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if (!document.body.contains(el)) return;
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const pos = getScrollPosition(el);
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if (pos === 0) {
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if (isTopVisible(el)) {
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cb();
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container.removeEventListener('scroll', onScroll);
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}
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