2 files changed, 198 insertions, 0 deletions
diff --git a/apps/web/src/selection/hooks/use-box-select.ts b/apps/web/src/selection/hooks/use-box-select.ts
new file mode 100644
index 00000000..90a584b5
--- /dev/null
+++ b/apps/web/src/selection/hooks/use-box-select.ts
@@ -0,0 +1,170 @@
+"use client";
+
+import { useCallback, useEffect, useRef, useState } from "react";
+import type {
+	BoxSelectionSnapshot,
+	ResolveIntersections,
+} from "@/selection/types";
+
+interface SelectionBoxState<TId> extends BoxSelectionSnapshot<TId> {
+	startPos: { x: number; y: number };
+	currentPos: { x: number; y: number };
+	isActive: boolean;
+	isAdditive: boolean;
+}
+
+export function useBoxSelect<TId>({
+	containerRef,
+	resolveIntersections,
+	selectedIds,
+	anchorId,
+	onSelectionChange,
+	shouldStartSelection,
+	getIsAdditiveSelection,
+	isEnabled = true,
+}: {
+	containerRef: React.RefObject<HTMLElement | null>;
+	resolveIntersections: ResolveIntersections<TId>;
+	selectedIds: TId[];
+	anchorId: TId | null;
+	onSelectionChange: (state: {
+		intersectedIds: TId[];
+		initialSelectedIds: TId[];
+		initialAnchorId: TId | null;
+		isAdditive: boolean;
+	}) => void;
+	shouldStartSelection?: (event: React.MouseEvent<Element>) => boolean;
+	getIsAdditiveSelection?: (event: React.MouseEvent<Element>) => boolean;
+	isEnabled?: boolean;
+}) {
+	const [selectionBox, setSelectionBox] =
+		useState<SelectionBoxState<TId> | null>(null);
+	const justFinishedSelectingRef = useRef(false);
+	const shouldStartSelectionCheck = shouldStartSelection ?? (() => true);
+	const getIsAdditiveSelectionCheck =
+		getIsAdditiveSelection ??
+		((event: React.MouseEvent<Element>) => event.ctrlKey || event.metaKey);
+
+	const handleMouseDown = useCallback(
+		(event: React.MouseEvent<Element>) => {
+			const canStartSelection = shouldStartSelectionCheck(event);
+			if (!isEnabled || event.button !== 0 || !canStartSelection) {
+				return;
+			}
+
+			setSelectionBox({
+				startPos: { x: event.clientX, y: event.clientY },
+				currentPos: { x: event.clientX, y: event.clientY },
+				isActive: false,
+				isAdditive: getIsAdditiveSelectionCheck(event),
+				initialSelectedIds: selectedIds,
+				initialAnchorId: anchorId,
+			});
+		},
+		[
+			anchorId,
+			getIsAdditiveSelectionCheck,
+			isEnabled,
+			selectedIds,
+			shouldStartSelectionCheck,
+		],
+	);
+
+	const updateSelection = useCallback(
+		({
+			startPos,
+			currentPos,
+			isAdditive,
+			initialSelectedIds,
+			initialAnchorId,
+		}: SelectionBoxState<TId>) => {
+			const intersectedIds = resolveIntersections({
+				startPos,
+				currentPos,
+			});
+			onSelectionChange({
+				intersectedIds,
+				initialSelectedIds,
+				initialAnchorId,
+				isAdditive,
+			});
+		},
+		[onSelectionChange, resolveIntersections],
+	);
+
+	useEffect(() => {
+		if (!selectionBox) {
+			return;
+		}
+
+		const handleMouseMove = ({ clientX, clientY }: MouseEvent) => {
+			const deltaX = Math.abs(clientX - selectionBox.startPos.x);
+			const deltaY = Math.abs(clientY - selectionBox.startPos.y);
+			const nextSelectionBox = {
+				...selectionBox,
+				currentPos: { x: clientX, y: clientY },
+				isActive: deltaX > 5 || deltaY > 5 || selectionBox.isActive,
+			};
+
+			setSelectionBox(nextSelectionBox);
+
+			if (!nextSelectionBox.isActive) {
+				return;
+			}
+
+			updateSelection(nextSelectionBox);
+		};
+
+		const handleMouseUp = () => {
+			if (selectionBox.isActive) {
+				justFinishedSelectingRef.current = true;
+				requestAnimationFrame(() => {
+					justFinishedSelectingRef.current = false;
+				});
+			}
+
+			setSelectionBox(null);
+		};
+
+		window.addEventListener("mousemove", handleMouseMove);
+		window.addEventListener("mouseup", handleMouseUp);
+
+		return () => {
+			window.removeEventListener("mousemove", handleMouseMove);
+			window.removeEventListener("mouseup", handleMouseUp);
+		};
+	}, [selectionBox, updateSelection]);
+
+	useEffect(() => {
+		if (!selectionBox) {
+			return;
+		}
+
+		const previousBodyUserSelect = document.body.style.userSelect;
+		const previousContainerUserSelect =
+			containerRef.current?.style.userSelect ?? "";
+
+		document.body.style.userSelect = "none";
+		if (containerRef.current) {
+			containerRef.current.style.userSelect = "none";
+		}
+
+		return () => {
+			document.body.style.userSelect = previousBodyUserSelect;
+			if (containerRef.current) {
+				containerRef.current.style.userSelect = previousContainerUserSelect;
+			}
+		};
+	}, [containerRef, selectionBox]);
+
+	const shouldIgnoreClick = useCallback(() => {
+		return justFinishedSelectingRef.current;
+	}, []);
+
+	return {
+		selectionBox,
+		handleMouseDown,
+		isSelecting: selectionBox?.isActive ?? false,
+		shouldIgnoreClick,
+	};
+}
diff --git a/apps/web/src/selection/hooks/use-selection-scope.ts b/apps/web/src/selection/hooks/use-selection-scope.ts
new file mode 100644
index 00000000..ad4d2ce8
--- /dev/null
+++ b/apps/web/src/selection/hooks/use-selection-scope.ts
@@ -0,0 +1,28 @@
+import { useEffect, useRef } from "react";
+import { useSelectionContext } from "@/selection/context";
+import { activateScope, type ScopeEntry } from "@/selection/scope";
+
+export function useSelectionScope() {
+	const { selectedIds, clearSelection } = useSelectionContext();
+	const hasSelectionRef = useRef(selectedIds.length > 0);
+	const clearSelectionRef = useRef(clearSelection);
+	const hasSelection = selectedIds.length > 0;
+
+	hasSelectionRef.current = hasSelection;
+	clearSelectionRef.current = clearSelection;
+
+	const entryRef = useRef<ScopeEntry>({
+		hasSelection: () => hasSelectionRef.current,
+		clear: () => {
+			clearSelectionRef.current();
+		},
+	});
+
+	useEffect(() => {
+		if (!hasSelection) {
+			return;
+		}
+
+		return activateScope({ entry: entryRef.current });
+	}, [hasSelection]);
+}