File Tree Browser: UX and accessibility review for file title button interaction pattern

Summary

The File Tree Browser (FTB) currently implements two separate <button> elements for directory rows:

1. A chevron button for expanding/collapsing directories
2. A file title button for navigation

This implementation was chosen to follow accessibility best practices (interactive elements should not be nested), as discussed in the kickoff for #577191 (closed).

Related discussions:

• MR !212108 (merged) note
• Issue #577191 (closed) kickoff notes
• MR !210274 (merged)

Questions for UX and Accessibility

Should keyboard interactions (Space, Enter) and mouse click on already expanded directory file title button collapse the directory?

Current Behaviour

	Space Key	Enter Key	Mouse Click
Chevron button	Expands/collapses directory (does not navigate)	Expands/collapses directory (does not navigate)	Expands/collapses directory (does not navigate)
File title button	Navigates to directory and expand (if the directory is not opened yet)	Navigates to directory and expand (if the directory is not opened yet)	Navigates to directory and expand (if the directory is not opened yet)