Usage
SplitButton pairs a default action with a menu of related alternates—"Export" as the common commit, with "Export CSV", "Export PDF", and "Export JSON" behind the chevron. It communicates hierarchy directly: the main click is the happy path, the chevron reveals depth. Use it instead of faking a ButtonGroup with a mystery icon, and keep the alternates related—if the menu's verbs don't share the primary's intent, the control has become two controls.
Buttons or a ButtonGroup.Dialog or a side panel.Menu sheet.Button standards; menu items parallel that voice. Localize every string with formatMessage.menuAlign keeps the chevron visually attached to its menu. Pick the alignment that matches reading order and avoids clipping inside sticky toolbars.