From 621555f2ea6d9e53cf64c7606323d26d21156ae2 Mon Sep 17 00:00:00 2001
From: Kalle <38327916+Sendouc@users.noreply.github.com>
Date: Tue, 22 Sep 2026 21:54:04 +0300
Subject: [PATCH] Fix drag n drop jank in tier list maker

---
 .../components/DraggableItem.tsx              |  2 +-
 .../tier-list-maker/components/TierRow.tsx    | 12 +++---
 .../routes/tier-list-maker.tsx                | 41 +++++++++++++++++--
 ...2026-09-22-tier-list-maker-drag-preview.md |  5 +++
 4 files changed, 49 insertions(+), 11 deletions(-)
 create mode 100644 changelog/2026-09-22-tier-list-maker-drag-preview.md

diff --git a/app/features/tier-list-maker/components/DraggableItem.tsx b/app/features/tier-list-maker/components/DraggableItem.tsx
index d32aa6b50..93c81bace 100644
--- a/app/features/tier-list-maker/components/DraggableItem.tsx
+++ b/app/features/tier-list-maker/components/DraggableItem.tsx
@@ -24,7 +24,7 @@ export function DraggableItem({ item }: DraggableItemProps) {
 	});
 
 	const style = {
-		transform: CSS.Transform.toString(transform),
+		transform: CSS.Translate.toString(transform),
 		transition,
 		opacity: isDragging ? 0.3 : 1,
 	};
diff --git a/app/features/tier-list-maker/components/TierRow.tsx b/app/features/tier-list-maker/components/TierRow.tsx
index 912a310a7..991ba8906 100644
--- a/app/features/tier-list-maker/components/TierRow.tsx
+++ b/app/features/tier-list-maker/components/TierRow.tsx
@@ -1,6 +1,6 @@
 import { useDroppable } from "@dnd-kit/core";
 import {
-	horizontalListSortingStrategy,
+	rectSortingStrategy,
 	SortableContext,
 	useSortable,
 } from "@dnd-kit/sortable";
@@ -47,9 +47,12 @@ export function TierRow({ tier }: TierRowProps) {
 
 	const items = getItemsInTier(tier.id);
 	const { t } = useTranslation(["tier-list-maker", "common"]);
-	const { setNodeRef, isOver } = useDroppable({
+	const { setNodeRef, over } = useDroppable({
 		id: tier.id,
 	});
+	const itemIds = items.map(tierListItemId);
+	const isOver =
+		over !== null && (over.id === tier.id || itemIds.includes(String(over.id)));
 
 	const combinedRef = useLockedHeightWhileDragging({
 		setNodeRef,
@@ -193,10 +196,7 @@ export function TierRow({ tier }: TierRowProps) {
 							: t("tier-list-maker:dropItems")}
 					</div>
 				) : items.length > 0 ? (
-					<SortableContext
-						items={items.map(tierListItemId)}
-						strategy={horizontalListSortingStrategy}
-					>
+					<SortableContext items={itemIds} strategy={rectSortingStrategy}>
 						{items.map((item) => (
 							<DraggableItem key={tierListItemId(item)} item={item} />
 						))}
diff --git a/app/features/tier-list-maker/routes/tier-list-maker.tsx b/app/features/tier-list-maker/routes/tier-list-maker.tsx
index 21a2df76a..e61a3c970 100644
--- a/app/features/tier-list-maker/routes/tier-list-maker.tsx
+++ b/app/features/tier-list-maker/routes/tier-list-maker.tsx
@@ -1,4 +1,4 @@
-import type { CollisionDetection, Modifier } from "@dnd-kit/core";
+import type { ClientRect, CollisionDetection, Modifier } from "@dnd-kit/core";
 import {
 	closestCenter,
 	DndContext,
@@ -71,9 +71,30 @@ const tierAwareCollisionDetection: CollisionDetection = (args) => {
 			(tierIdFromSortableId(String(container.id)) !== null) === isTierDrag,
 	);
 
-	return isTierDrag
-		? closestCenter({ ...args, droppableContainers })
-		: pointerWithin({ ...args, droppableContainers });
+	if (isTierDrag) return closestCenter({ ...args, droppableContainers });
+
+	const pointerCollisions = pointerWithin({ ...args, droppableContainers });
+
+	// gaps between items would otherwise resolve to the tier itself, snapping the sort preview back
+	const tierZoneCollision = pointerCollisions.find((collision) =>
+		String(collision.id).startsWith("tier-"),
+	);
+	const tierZoneRect = tierZoneCollision
+		? args.droppableRects.get(tierZoneCollision.id)
+		: undefined;
+	if (!tierZoneCollision || !tierZoneRect) return pointerCollisions;
+
+	const itemsInTierZone = droppableContainers.filter((container) => {
+		const rect = args.droppableRects.get(container.id);
+		return (
+			container.id !== tierZoneCollision.id &&
+			rect !== undefined &&
+			isRectCenterWithin(rect, tierZoneRect)
+		);
+	});
+	if (itemsInTierZone.length === 0) return [tierZoneCollision];
+
+	return closestCenter({ ...args, droppableContainers: itemsInTierZone });
 };
 
 const restrictTierDragToVerticalAxis: Modifier = (args) =>
@@ -412,3 +433,15 @@ function ResetPopover({ handleReset }: { handleReset: () => void }) {
 		</SendouPopover>
 	);
 }
+
+function isRectCenterWithin(rect: ClientRect, container: ClientRect) {
+	const centerX = rect.left + rect.width / 2;
+	const centerY = rect.top + rect.height / 2;
+
+	return (
+		centerX >= container.left &&
+		centerX <= container.right &&
+		centerY >= container.top &&
+		centerY <= container.bottom
+	);
+}
diff --git a/changelog/2026-09-22-tier-list-maker-drag-preview.md b/changelog/2026-09-22-tier-list-maker-drag-preview.md
new file mode 100644
index 000000000..c6c63479f
--- /dev/null
+++ b/changelog/2026-09-22-tier-list-maker-drag-preview.md
@@ -0,0 +1,5 @@
+---
+navItem: tier-list-maker
+type: bug
+---
+Dragging items in tier list maker tiers with multiple rows no longer jumps around or leaves gaps in the preview