Module roving 

Roving focus: one tab stop for a set of items, arrows to move within it.

A port of the arrow handling in upstream’s tabs.ts and toolbar.ts: arrows follow the writing direction (in RTL, Left moves forward), orientation decides which arrows apply, Home and End jump to the ends, and the step wraps.

Enums

Move

Where a key asks focus to go.

Functions

intent

The move a key makes, or None for keys the set leaves alone, such as Left and Right in a vertical list, so the page can still scroll sideways.

target

The index focus moves to from current, skipping items reachable rejects. None when nothing is reachable.