From 1de55ebe0bc01592f414fd1526368595ec112f53 Mon Sep 17 00:00:00 2001
From: syuilo <4439005+syuilo@users.noreply.github.com>
Date: Fri, 23 Aug 2024 13:24:37 +0900
Subject: [PATCH] wip

---
 .../src/components/EmPagination.vue           |   6 +-
 .../frontend-embed/src/to-be-shared/scroll.ts | 144 ++++++++++++++++++
 .../to-be-shared/use-document-visibility.ts   |  24 +++
 .../src/to-be-shared/use-interval.ts          |  46 ++++++
 4 files changed, 217 insertions(+), 3 deletions(-)
 create mode 100644 packages/frontend-embed/src/to-be-shared/scroll.ts
 create mode 100644 packages/frontend-embed/src/to-be-shared/use-document-visibility.ts
 create mode 100644 packages/frontend-embed/src/to-be-shared/use-interval.ts

diff --git a/packages/frontend-embed/src/components/EmPagination.vue b/packages/frontend-embed/src/components/EmPagination.vue
index 4696dc377e..35224ab01b 100644
--- a/packages/frontend-embed/src/components/EmPagination.vue
+++ b/packages/frontend-embed/src/components/EmPagination.vue
@@ -45,9 +45,9 @@ SPDX-License-Identifier: AGPL-3.0-only
 <script lang="ts">
 import { computed, ComputedRef, isRef, nextTick, onActivated, onBeforeMount, onBeforeUnmount, onDeactivated, ref, shallowRef, watch } from 'vue';
 import * as Misskey from 'misskey-js';
-import { misskeyApi } from '@/scripts/misskey-api.js';
-import { onScrollTop, isTopVisible, getBodyScrollHeight, getScrollContainer, onScrollBottom, scrollToBottom, scroll, isBottomVisible } from '@/scripts/scroll.js';
-import { useDocumentVisibility } from '@/scripts/use-document-visibility.js';
+import { misskeyApi } from '@/misskey-api.js';
+import { onScrollTop, isTopVisible, getBodyScrollHeight, getScrollContainer, onScrollBottom, scrollToBottom, scroll, isBottomVisible } from '@/to-be-shared/scroll.js';
+import { useDocumentVisibility } from '@/to-be-shared/use-document-visibility.js';
 import { i18n } from '@/i18n.js';
 
 const SECOND_FETCH_LIMIT = 30;
diff --git a/packages/frontend-embed/src/to-be-shared/scroll.ts b/packages/frontend-embed/src/to-be-shared/scroll.ts
new file mode 100644
index 0000000000..f0274034b5
--- /dev/null
+++ b/packages/frontend-embed/src/to-be-shared/scroll.ts
@@ -0,0 +1,144 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+type ScrollBehavior = 'auto' | 'smooth' | 'instant';
+
+export function getScrollContainer(el: HTMLElement | null): HTMLElement | null {
+	if (el == null || el.tagName === 'HTML') return null;
+	const overflow = window.getComputedStyle(el).getPropertyValue('overflow-y');
+	if (overflow === 'scroll' || overflow === 'auto') {
+		return el;
+	} else {
+		return getScrollContainer(el.parentElement);
+	}
+}
+
+export function getStickyTop(el: HTMLElement, container: HTMLElement | null = null, top = 0) {
+	if (!el.parentElement) return top;
+	const data = el.dataset.stickyContainerHeaderHeight;
+	const newTop = data ? Number(data) + top : top;
+	if (el === container) return newTop;
+	return getStickyTop(el.parentElement, container, newTop);
+}
+
+export function getStickyBottom(el: HTMLElement, container: HTMLElement | null = null, bottom = 0) {
+	if (!el.parentElement) return bottom;
+	const data = el.dataset.stickyContainerFooterHeight;
+	const newBottom = data ? Number(data) + bottom : bottom;
+	if (el === container) return newBottom;
+	return getStickyBottom(el.parentElement, container, newBottom);
+}
+
+export function getScrollPosition(el: HTMLElement | null): number {
+	const container = getScrollContainer(el);
+	return container == null ? window.scrollY : container.scrollTop;
+}
+
+export function onScrollTop(el: HTMLElement, cb: () => unknown, tolerance = 1, once = false) {
+	// とりあえず評価してみる
+	if (el.isConnected && isTopVisible(el)) {
+		cb();
+		if (once) return null;
+	}
+
+	const container = getScrollContainer(el) ?? window;
+
+	const onScroll = ev => {
+		if (!document.body.contains(el)) return;
+		if (isTopVisible(el, tolerance)) {
+			cb();
+			if (once) removeListener();
+		}
+	};
+
+	function removeListener() { container.removeEventListener('scroll', onScroll); }
+
+	container.addEventListener('scroll', onScroll, { passive: true });
+	return removeListener;
+}
+
+export function onScrollBottom(el: HTMLElement, cb: () => unknown, tolerance = 1, once = false) {
+	const container = getScrollContainer(el);
+
+	// とりあえず評価してみる
+	if (el.isConnected && isBottomVisible(el, tolerance, container)) {
+		cb();
+		if (once) return null;
+	}
+
+	const containerOrWindow = container ?? window;
+	const onScroll = ev => {
+		if (!document.body.contains(el)) return;
+		if (isBottomVisible(el, 1, container)) {
+			cb();
+			if (once) removeListener();
+		}
+	};
+
+	function removeListener() {
+		containerOrWindow.removeEventListener('scroll', onScroll);
+	}
+
+	containerOrWindow.addEventListener('scroll', onScroll, { passive: true });
+	return removeListener;
+}
+
+export function scroll(el: HTMLElement, options: ScrollToOptions | undefined) {
+	const container = getScrollContainer(el);
+	if (container == null) {
+		window.scroll(options);
+	} else {
+		container.scroll(options);
+	}
+}
+
+/**
+ * Scroll to Top
+ * @param el Scroll container element
+ * @param options Scroll options
+ */
+export function scrollToTop(el: HTMLElement, options: { behavior?: ScrollBehavior; } = {}) {
+	scroll(el, { top: 0, ...options });
+}
+
+/**
+ * Scroll to Bottom
+ * @param el Content element
+ * @param options Scroll options
+ * @param container Scroll container element
+ */
+export function scrollToBottom(
+	el: HTMLElement,
+	options: ScrollToOptions = {},
+	container = getScrollContainer(el),
+) {
+	if (container) {
+		container.scroll({ top: el.scrollHeight - container.clientHeight + getStickyTop(el, container) || 0, ...options });
+	} else {
+		window.scroll({
+			top: (el.scrollHeight - window.innerHeight + getStickyTop(el, container) + (window.innerWidth <= 500 ? 96 : 0)) || 0,
+			...options,
+		});
+	}
+}
+
+export function isTopVisible(el: HTMLElement, tolerance = 1): boolean {
+	const scrollTop = getScrollPosition(el);
+	return scrollTop <= tolerance;
+}
+
+export function isBottomVisible(el: HTMLElement, tolerance = 1, container = getScrollContainer(el)) {
+	if (container) return el.scrollHeight <= container.clientHeight + Math.abs(container.scrollTop) + tolerance;
+	return el.scrollHeight <= window.innerHeight + window.scrollY + tolerance;
+}
+
+// https://ja.javascript.info/size-and-scroll-window#ref-932
+export function getBodyScrollHeight() {
+	return Math.max(
+		document.body.scrollHeight, document.documentElement.scrollHeight,
+		document.body.offsetHeight, document.documentElement.offsetHeight,
+		document.body.clientHeight, document.documentElement.clientHeight,
+	);
+}
diff --git a/packages/frontend-embed/src/to-be-shared/use-document-visibility.ts b/packages/frontend-embed/src/to-be-shared/use-document-visibility.ts
new file mode 100644
index 0000000000..a8f4d5e03a
--- /dev/null
+++ b/packages/frontend-embed/src/to-be-shared/use-document-visibility.ts
@@ -0,0 +1,24 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { onMounted, onUnmounted, ref, Ref } from 'vue';
+
+export function useDocumentVisibility(): Ref<DocumentVisibilityState> {
+	const visibility = ref(document.visibilityState);
+
+	const onChange = (): void => {
+		visibility.value = document.visibilityState;
+	};
+
+	onMounted(() => {
+		document.addEventListener('visibilitychange', onChange);
+	});
+
+	onUnmounted(() => {
+		document.removeEventListener('visibilitychange', onChange);
+	});
+
+	return visibility;
+}
diff --git a/packages/frontend-embed/src/to-be-shared/use-interval.ts b/packages/frontend-embed/src/to-be-shared/use-interval.ts
new file mode 100644
index 0000000000..b50e78c3cc
--- /dev/null
+++ b/packages/frontend-embed/src/to-be-shared/use-interval.ts
@@ -0,0 +1,46 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { onActivated, onDeactivated, onMounted, onUnmounted } from 'vue';
+
+export function useInterval(fn: () => void, interval: number, options: {
+	immediate: boolean;
+	afterMounted: boolean;
+}): (() => void) | undefined {
+	if (Number.isNaN(interval)) return;
+
+	let intervalId: number | null = null;
+
+	if (options.afterMounted) {
+		onMounted(() => {
+			if (options.immediate) fn();
+			intervalId = window.setInterval(fn, interval);
+		});
+	} else {
+		if (options.immediate) fn();
+		intervalId = window.setInterval(fn, interval);
+	}
+
+	const clear = () => {
+		if (intervalId) window.clearInterval(intervalId);
+		intervalId = null;
+	};
+
+	onActivated(() => {
+		if (intervalId) return;
+		if (options.immediate) fn();
+		intervalId = window.setInterval(fn, interval);
+	});
+
+	onDeactivated(() => {
+		clear();
+	});
+
+	onUnmounted(() => {
+		clear();
+	});
+
+	return clear;
+}