From 2f78c0461e00e0c8ccd81f330872fcdabc74d3b1 Mon Sep 17 00:00:00 2001
From: bkennedy <bryan@mysteryexperience.com>
Date: Tue, 30 Jun 2026 18:35:34 +0000
Subject: [PATCH] fix(board): slow the edge auto-scroll while dragging a card
 on mobile
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With a card held at the board's left/right edge, dnd-kit's default auto-scroll
(acceleration 10) pans the column strip at ~2000px/s — far too fast to land in
the intended column on a phone, where only ~one column is visible at a time, so
moving a card across columns overshoots constantly.

Pass autoScroll={{ acceleration: 5 }} to DndContext to halve the top edge-scroll
speed (~800px/s measured) while keeping the smooth 5ms scroll cadence — lowering
acceleration caps speed without the choppiness that raising `interval` would add.
acceleration is the single knob to dial further if it's still fast.
---
 src/client/pages/Home.tsx | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/client/pages/Home.tsx b/src/client/pages/Home.tsx
index 2de6417..dff30d1 100644
--- a/src/client/pages/Home.tsx
+++ b/src/client/pages/Home.tsx
@@ -485,6 +485,14 @@ export default function Home({ workspace }: { workspace: WorkspacePayload }) {
       <DndContext
         sensors={sensors}
         collisionDetection={collisionDetection}
+        // Tame the edge auto-scroll. dnd-kit's default acceleration (10) scrolls
+        // the board ~2000px/s when a dragged card reaches the left/right edge —
+        // far too fast to land in the intended column on a phone, where only
+        // ~one column is visible (PROG-79 follow-up). Halving acceleration caps
+        // the top speed while keeping the smooth 5ms scroll cadence (lowering it
+        // further is the knob to turn if it's still fast; raising `interval`
+        // instead would make the motion choppy).
+        autoScroll={{ acceleration: 5 }}
         onDragStart={onDragStart}
         onDragOver={onDragOver}
         onDragEnd={onDragEnd}