fix(ui): stop scrolling on leaving workflow sidebar for drag-drop

[TheodoreSpeaks]

Summary

Currently dragging and dropping a file past a scrollable workflow sidebar causes the sidebar to continuously scroll. Switched this to stop scrolling on leaving the container to prevent the issue.

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation
• Other: ___________

Testing

• Tested that dragging and dropping into mothership and copilot works as intended.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

Screenshots/Videos

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Project	Deployment	Actions	Updated (UTC)
docs	Ready	Preview, Comment	Apr 18, 2026 7:08pm

[cursor]

PR Summary

Low Risk
Low risk UI-only change, but it touches drag/drop event handling and requestAnimationFrame cancellation which could affect sidebar drag interactions if edge cases are missed.

Overview
Fixes a bug where the workflow sidebar could keep auto-scrolling after a drag leaves the scrollable container.

useDragDrop now restarts auto-scroll only when needed and adds drag-leave/window-drop listeners to cancel the scroll animation and clear hover/drop indicators when the pointer leaves the sidebar or a drop occurs outside it.

^{Reviewed by Cursor Bugbot for commit e70844f. Bugbot is set up for automated code reviews on this repo. Configure here.}

[greptile-apps]

Greptile Summary

This PR adds a useEffect to the useDragDrop hook that listens for native dragleave events on the scroll container and calls handleDragEnd() when the drag cursor exits the container boundary (i.e., relatedTarget is null or outside the container). This cleanly stops the auto-scroll loop that was previously left running whenever a file drag passed over the sidebar and then exited.

Confidence Score: 5/5

Safe to merge — the fix is minimal, correctly scoped, and idempotent.

The new useEffect is correctly structured: it only attaches when isDragging is true, uses the container.contains(relatedTarget) guard to avoid false positives from intra-container drag events, and the cleanup reliably removes the listener. handleDragEnd is idempotent so duplicate calls are harmless. All remaining observations are P2 or below.

No files require special attention.

Important Files Changed

Filename	Overview
apps/sim/app/workspace/[workspaceId]/w/components/sidebar/hooks/use-drag-drop.ts	Adds a useEffect that attaches a native dragleave listener to the scroll container while dragging; calls handleDragEnd() when the drag leaves the container boundary, stopping the runaway auto-scroll loop.

Sequence Diagram

sequenceDiagram
    participant User
    participant Browser
    participant ScrollContainer
    participant useDragDrop

    User->>Browser: Drag file/item over sidebar
    Browser->>ScrollContainer: dragover event
    ScrollContainer->>useDragDrop: initDragOver() → isDragging = true
    useDragDrop->>useDragDrop: useEffect attaches dragleave listener

    loop Auto-scroll loop (while isDragging)
        useDragDrop->>ScrollContainer: requestAnimationFrame(handleAutoScroll)
    end

    User->>Browser: Drag cursor leaves container boundary
    Browser->>ScrollContainer: dragleave (relatedTarget = null or outside)
    ScrollContainer->>useDragDrop: onLeave() → !container.contains(related)
    useDragDrop->>useDragDrop: handleDragEnd() → isDragging = false
    useDragDrop->>useDragDrop: useEffect cleanup removes dragleave listener
    useDragDrop->>ScrollContainer: cancelAnimationFrame (auto-scroll stops)

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[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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