Lens

1<script lang="ts">
2	import { motion, AnimatePresence } from "motion-sv";
3	import { cn } from "$UTILS$";
4	import type { Snippet } from "svelte";
5 
6	interface Position {
7		/** The x coordinate of the lens */
8		x: number;
9		/** The y coordinate of the lens */
10		y: number;
11	}
12 
13	interface LensProps {
14		children: Snippet;
15		/** The zoom factor of the lens */
16		zoomFactor?: number;
17		/** The size of the lens */
18		lensSize?: number;
19		/** The position of the lens */
20		position?: Position;
21		/** The default position of the lens */
22		defaultPosition?: Position;
23		/** Whether the lens is static */
24		isStatic?: boolean;
25		/** The duration of the animation */
26		duration?: number;
27		/** The color of the lens */
28		lensColor?: string;
29		/** The aria label of the lens */
30		ariaLabel?: string;
31		class?: string;
32	}
33 
34	let {
35		children,
36		zoomFactor = 1.3,
37		lensSize = 170,
38		isStatic = false,
39		position = { x: 0, y: 0 },
40		defaultPosition,
41		duration = 0.1,
42		lensColor = "black",
43		ariaLabel = "Zoom Area",
44		class: className,
45	}: LensProps = $props();
46 
47	// Validation
48	$effect(() => {
49		if (zoomFactor < 1) {
50			throw new Error("zoomFactor must be greater than 1");
51		}
52		if (lensSize < 0) {
53			throw new Error("lensSize must be greater than 0");
54		}
55	});
56 
57	let isHovering = $state(false);
58	let mousePosition: Position = $derived(position);
59	let containerRef: HTMLDivElement | null = $state(null);
60 
61	const currentPosition = $derived.by(() => {
62		if (isStatic) return position;
63		if (defaultPosition && !isHovering) return defaultPosition;
64		return mousePosition;
65	});
66 
67	const handleMouseMove = (e: MouseEvent) => {
68		if (!containerRef) return;
69		const rect = containerRef.getBoundingClientRect();
70		mousePosition = {
71			x: e.clientX - rect.left,
72			y: e.clientY - rect.top,
73		};
74	};
75 
76	const handleKeyDown = (e: KeyboardEvent) => {
77		if (e.key === "Escape") isHovering = false;
78	};
79 
80	const maskImage = $derived(
81		`radial-gradient(circle ${lensSize / 2}px at ${currentPosition.x}px ${currentPosition.y}px, ${lensColor} 100%, transparent 100%)`
82	);
83 
84	const transformOrigin = $derived(`${currentPosition.x}px ${currentPosition.y}px`);
85 
86	const lensStyle = $derived({
87		maskImage,
88		WebkitMaskImage: maskImage,
89		transformOrigin,
90		zIndex: 50,
91	});
92 
93	const zoomStyleString = $derived(
94		`transform: scale(${zoomFactor}); transform-origin: ${transformOrigin};`
95	);
96</script>
97 
98<!-- svelte-ignore a11y_no_noninteractive_tabindex -->
99<!-- svelte-ignore a11y_no_noninteractive_element_interactions -->
100<div
101// … truncated