From 57e87aace0d4bbd2740de32d38aa5aeb233d3b8e Mon Sep 17 00:00:00 2001
From: Eugene Fox <eugene@xfox111.net>
Date: Fri, 18 Jul 2025 21:01:28 +0300
Subject: [PATCH] chore: minor dnd collision detection improvements

---
 .../sidepanel/utils/dnd/collisionDetector.ts  | 36 +++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/entrypoints/sidepanel/utils/dnd/collisionDetector.ts b/entrypoints/sidepanel/utils/dnd/collisionDetector.ts
index b175d20..7e4ec75 100644
--- a/entrypoints/sidepanel/utils/dnd/collisionDetector.ts
+++ b/entrypoints/sidepanel/utils/dnd/collisionDetector.ts
@@ -33,9 +33,11 @@ export function collisionDetector(vertical?: boolean): CollisionDetection
 
 			if (activeItem.item.type === "collection")
 			{
+				// If we drag a collection, we should ignore other items, like tabs or groups
 				if (droppableItem.item.type !== "collection")
 					continue;
 
+				// Using distance between centers
 				value = distanceBetween(centerOfRectangle(rect), centerRect);
 				collisions.push({ id, data: { droppableContainer, value } });
 				continue;
@@ -44,14 +46,20 @@ export function collisionDetector(vertical?: boolean): CollisionDetection
 			const intersectionRatio: number = getIntersectionRatio(rect, collisionRect);
 			const intersectionCoefficient: number = intersectionRatio / getMaxIntersectionRatio(rect, collisionRect);
 
+			// Dragging a tab or a group over a collection
 			if (droppableItem.item.type === "collection")
 			{
+				// Ignoring collection, if the tab or the group is inside that collection
 				if (activeItem.indices.length === 2 && activeItem.indices[0] === droppableItem.indices[0])
 					continue;
 
-				if (intersectionCoefficient < 0.7 && activeItem.item.type === "tab")
+				// Ignoring collection if we're dragging a tab or a group that doesn't belong to the collection,
+				// but intersection ratio is less than 0.7
+				if (intersectionCoefficient < 0.7)
 					continue;
 
+				// If we're dragging a tab, that's inside a group that belongs to the collection,
+				// we substract the group's intersection from the collection's one
 				if (activeItem.indices.length === 3 && activeItem.indices[0] === droppableItem.indices[0])
 				{
 					const [collectionId, groupId] = activeItem.indices;
@@ -62,16 +70,23 @@ export function collisionDetector(vertical?: boolean): CollisionDetection
 
 					value = 1 / (intersectionRatio - getIntersectionRatio(groupRect, collisionRect));
 				}
+				// Otherwise, use intersection ratio
+				// At this point we're dragging either:
+				// - a group, that doesn't belong to the collection
+				// - a tab, that either belongs to the collection's group, or has intersection coefficient >= .7
 				else
 				{
-					value = 1 / intersectionRatio;
+					value = 2 / intersectionRatio;
 				}
 			}
+			// If we're dragging a tab or a group over another group's dropzone
 			else if (droppableItem.item.type === "group" && (id as string).endsWith("_dropzone"))
 			{
+				// Ignore, if we're dragging a group
 				if (activeItem.item.type === "group")
 					continue;
 
+				// Ignore, if we're dragging a tab, that's inside the group
 				if (
 					activeItem.indices.length === 3 &&
 					activeItem.indices[0] === droppableItem.indices[0] &&
@@ -79,11 +94,15 @@ export function collisionDetector(vertical?: boolean): CollisionDetection
 				)
 					continue;
 
+				// Ignore, if coefficient is less than .5
+				// (at this point we're dragging a tab, that's outside of the group's dropzone)
 				if (intersectionCoefficient < 0.5)
 					continue;
 
+				// Use intersection between the tab and the group's dropzone
 				value = 1 / intersectionRatio;
 			}
+			// We're dragging a group or a tab over its sibling
 			else if (activeItem.indices.length === droppableItem.indices.length)
 			{
 				if (activeItem.indices[0] !== droppableItem.indices[0])
@@ -92,9 +111,22 @@ export function collisionDetector(vertical?: boolean): CollisionDetection
 				if (activeItem.indices.length === 3 && activeItem.indices[1] !== droppableItem.indices[1])
 					continue;
 
+				// Ignore pinned groups
 				if (droppableItem.item.type === "group" && droppableItem.item.pinned === true)
 					continue;
 
+				const collectionRect: ClientRect | undefined = droppableRects.get(activeItem.indices[0].toString());
+
+				if (!collectionRect)
+					continue;
+
+				const collectionIntersectionRatio: number = getIntersectionRatio(collectionRect, collisionRect);
+				const collectionIntersectionCoefficient: number = collectionIntersectionRatio / getMaxIntersectionRatio(collectionRect, collisionRect);
+
+				// Ignore if we are outside of the home collection
+				if (collectionIntersectionCoefficient < 0.7)
+					continue;
+
 				if (activeItem.item.type === "tab" && droppableItem.item.type === "tab")
 				{
 					value = distanceBetween(centerOfRectangle(rect), centerRect);