Bug: efc-arrow-keys-skip-subfolders #1007

• Work Mode: full-bug

Summary

In the EFC viewer's folder tree, expanded subfolder rows can be selected with the mouse but not with the Up and Down arrow keys. Keyboard navigation does not move the selection onto any subfolder. This is a gap in the fix delivered for issue #1002 (PR #1003).

Environment

• OS/version: Windows 11, Outlook desktop (VSTO add-in), QuickFiler EFC viewer (WebView2 breadcrumb tree)
• Python version: not applicable (C# .NET Framework 4.8 and JavaScript in QuickFiler/Resources/FolderBreadcrumb.js)
• Command/flags used: interactive use of the EFC viewer in Outlook
• Data source or fixture: any mail folder hierarchy with nested subfolders

Steps to Reproduce

1. Open the EFC viewer on a mail item.
2. Expand a folder row so that its subfolder rows are shown.
3. Click a subfolder row: it is selected, as expected after Bug: efc-qfc-folder-tree-selection-and-nesting #1002.
4. Press the Up or Down arrow key to move through the list.

Expected Behavior

The arrow keys move the selection through the visible rows, including expanded subfolder rows, the same way mouse selection reaches them.

Actual Behavior

The arrow keys do not select any subfolder row. Keyboard navigation reaches only the top-level rows.

Logs / Screenshots

• Attached minimal logs or screenshot
• Snippet: reported by the maintainer from interactive use; no log captured.

Impact / Severity

• Blocker
• High
• Medium
• Low

Source

From: docs/features/potential/2026-10-22-efc-arrow-keys-skip-subfolders.md