compare-plans animation POC

src/lib/actions/visible.ts

@@ -0,0 +1,60 @@
+import { isVisible } from '$lib/utils/isVisible';
+import type { Action } from 'svelte/action';
+
+type Args =
+	| {
+			top?: number;
+			bottom?: number;
+			left?: number;
+			right?: number;
+	  }
+	| undefined;
+
+export const visible: Action<
+	HTMLElement,
+	Args,
+	{ 'on:visible': (e: CustomEvent<boolean>) => void }
+> = (node, args) => {
+	let visible = false;
+
+	const createVisibilityHandler = (newArgs: Args) => {
+		const argsWithDefaults = {
+			top: 0,
+			bottom: window.innerHeight,
+			left: 0,
+			right: window.innerWidth,
+			...newArgs
+		};
+		return () => {
+			const prev = visible;
+			visible = isVisible(node, argsWithDefaults);
+			if (prev !== visible) {
+				node.dispatchEvent(new CustomEvent('visible', { detail: visible }));
+			}
+		};
+	};
+
+	let handleVisibility = createVisibilityHandler(args);
+
+	function destroy() {
+		window.removeEventListener('scroll', handleVisibility);
+		window.removeEventListener('resize', handleVisibility);
+	}
+
+	function update(args: Args) {
+		destroy();
+		handleVisibility = createVisibilityHandler(args);
+		window.addEventListener('scroll', handleVisibility);
+		window.addEventListener('resize', handleVisibility);
+	}
+
+	update(args);
+
+	return {
+		update,
+		destroy() {
+			window.removeEventListener('scroll', handleVisibility);
+			window.removeEventListener('resize', handleVisibility);
+		}
+	};
+};

src/lib/layouts/Main.svelte

@@ -8,6 +8,7 @@
 <script lang="ts">
 	import { browser } from '$app/environment';
 	import { MobileNav } from '$lib/components';
+	import { isVisible } from '$lib/utils/isVisible';
 	import { addEventListener } from '@melt-ui/svelte/internal/helpers';
 	import { onMount } from 'svelte';
 
@@ -33,12 +34,12 @@
 	}
 
 	function isInViewport(element: Element): boolean {
-		const rect = element.getBoundingClientRect();
-		const windowWidth = window.innerWidth || document.documentElement.clientWidth;
-		const vertInView = rect.top <= 32 && rect.bottom >= 32;
-		const horInView = rect.left <= windowWidth && rect.right >= 0;
-
-		return vertInView && horInView;
+		return isVisible(element, {
+			top: 32,
+			bottom: 32,
+			left: 0,
+			right: window.innerWidth
+		});
 	}
 
 	function getVisibleTheme() {

src/lib/utils/getScrollDir.ts

@@ -0,0 +1,8 @@
+let lastScrollPos = 0;
+
+export function getScrollDir() {
+	const scrollPos = window.scrollY;
+	const scrollDir = scrollPos > lastScrollPos ? 'down' : 'up';
+	lastScrollPos = scrollPos;
+	return scrollDir;
+}

src/lib/utils/isVisible.ts

@@ -0,0 +1,10 @@
+export function isVisible(
+	element: Element,
+	visRect: { left: number; right: number; top: number; bottom: number }
+) {
+	const rect = element.getBoundingClientRect();
+	const vertInView = rect.top <= visRect.bottom && rect.bottom >= visRect.top;
+	const horInView = rect.left <= visRect.right && rect.right >= visRect.left;
+
+	return vertInView && horInView;
+}

src/routes/pricing/compare-plans.svelte

@@ -1,7 +1,12 @@
 <script lang="ts">
+	import { browser } from '$app/environment';
 	import { Tabs } from '$lib/UI';
+	import { visible } from '$lib/actions/visible';
+	import { getScrollDir } from '$lib/utils/getScrollDir';
+	import { isVisible } from '$lib/utils/isVisible';
 	import { createAccordion, melt } from '@melt-ui/svelte';
-	import { slide } from 'svelte/transition';
+	import { writable } from 'svelte/store';
+	import { fly } from 'svelte/transition';
 
 	type Table = {
 		title: string;
@@ -290,8 +295,18 @@
 		multiple: true,
 		forceVisible: true
 	});
+
+	const visibleTables = writable([] as string[]);
+	$: activeTable = $visibleTables.sort((a, b) => {
+		return tables.findIndex((t) => t.title === a) - tables.findIndex((t) => t.title === b);
+	})[0];
+
+	let scrollDir = 'down';
+	$: console.log(scrollDir);
 </script>
 
+<svelte:window on:scroll={() => (scrollDir = getScrollDir())} />
+
 <div class="aw-big-padding-section-level-1 aw-white-section theme-light">
 	<div class="aw-big-padding-section-level-2">
 		<div class="u-position-relative">
@@ -327,8 +342,19 @@
 						aw-u-padding-block-start-80 aw-u-filter-blur-8 u-position-sticky u-z-index-5"
 						style="--inset-block-start:1rem"
 					>
-						<div class="aw-label aw-u-color-text-primary aw-u-cross-child-center" style="opacity:0">
-							Compare plans
+						<div
+							class="aw-label aw-u-color-text-primary aw-u-cross-child-center aw-u-relative"
+							style:opacity={browser ? 1 : 0}
+						>
+							{#key activeTable}
+								<div
+									style="position: absolute; top: 50%; "
+									in:fly={{ y: scrollDir === 'down' ? 16 : -16, delay: 500, duration: 500 }}
+									out:fly={{ y: scrollDir === 'down' ? -16 : 16, duration: 500 }}
+								>
+									{activeTable ?? ''}
+								</div>
+							{/key}
 						</div>
 						<div class="aw-mini-card">
 							<div class="u-flex u-cross-center u-gap-16 u-flex-wrap u-main-space-between">
@@ -363,10 +389,24 @@
 							class="aw-compare-table aw-sub-body-400"
 							class:is-open-in-mobile={isOpen}
 							use:melt={$item(table.title)}
+							use:visible={{
+								top: 128
+							}}
+							on:visible={(e) => {
+								const isVisible = e.detail;
+								visibleTables.update((p) => {
+									if (isVisible) {
+										return [...p, table.title];
+									} else {
+										return p.filter((t) => t !== table.title);
+									}
+								});
+							}}
 						>
 							<caption
 								class="aw-compare-table-caption aw-description aw-u-color-text-primary"
 								use:melt={$heading({ level: 3 })}
+								style:position={browser ? 'unset' : undefined}
 							>
 								<button class="aw-compare-table-caption-button" use:melt={$trigger(table.title)}>
 									<span>{table.title}</span>