1 files changed, 79 insertions, 0 deletions
diff --git a/apps/web/src/hooks/use-focus-lock.ts b/apps/web/src/hooks/use-focus-lock.ts
new file mode 100644
index 00000000..80baebdb
--- /dev/null
+++ b/apps/web/src/hooks/use-focus-lock.ts
@@ -0,0 +1,79 @@
+import { useEffect, useRef } from "react";
+
+type FocusLockCursor = "text" | "default" | "pointer" | "crosshair";
+
+const DATA_ATTR = "data-focus-locked";
+
+function buildFocusLockCSS({
+	cursor,
+	allowSelector,
+}: {
+	cursor: FocusLockCursor;
+	allowSelector?: string;
+}) {
+	const rules = [
+		`*, *::before, *::after { pointer-events: none !important; cursor: ${cursor} !important; }`,
+		`[${DATA_ATTR}], [${DATA_ATTR}] * { pointer-events: auto !important; cursor: auto !important; }`,
+	];
+
+	if (allowSelector) {
+		rules.push(
+			`${allowSelector} { pointer-events: auto !important; cursor: auto !important; }`,
+		);
+	}
+
+	return rules.join("\n");
+}
+
+export function useFocusLock<T extends HTMLElement = HTMLElement>({
+	isActive,
+	onDismiss,
+	cursor = "default",
+	allowSelector,
+}: {
+	isActive: boolean;
+	onDismiss: () => void;
+	cursor?: FocusLockCursor;
+	allowSelector?: string;
+}) {
+	const containerRef = useRef<T>(null);
+	const onDismissRef = useRef(onDismiss);
+	onDismissRef.current = onDismiss;
+
+	useEffect(() => {
+		if (!isActive) return;
+		const container = containerRef.current;
+		if (!container) return;
+
+		container.setAttribute(DATA_ATTR, "");
+
+		const focusLockStyle = document.createElement("style");
+		focusLockStyle.textContent = buildFocusLockCSS({ cursor, allowSelector });
+		document.head.appendChild(focusLockStyle);
+
+		const handleOutsidePointerDown = (event: PointerEvent) => {
+			if (event.button !== 0) return;
+			if (container.contains(event.target as Node)) return;
+
+			const target = event.target as Element | null;
+			const isAllowedTarget = allowSelector && target?.closest(allowSelector);
+			if (isAllowedTarget) return;
+
+			onDismissRef.current();
+		};
+
+		document.addEventListener("pointerdown", handleOutsidePointerDown, true);
+
+		return () => {
+			document.removeEventListener(
+				"pointerdown",
+				handleOutsidePointerDown,
+				true,
+			);
+			container.removeAttribute(DATA_ATTR);
+			focusLockStyle.remove();
+		};
+	}, [isActive, cursor, allowSelector]);
+
+	return { containerRef };
+}