Menus and pickers

Five ways to open a list and pick from it, each with its job. Several components for one purpose is fine; confusion about which is which is the mess.

Dropdown

A positioning primitive: a trigger, a floating panel, one gesture that opens it. It knows nothing about lists or values.

Reach for it: When the panel is not a pick at all: a row's kebab menu, a hover card, a small form under a button.
Not for: As a value picker. If the panel's job is to hand a value back, that is Select.

Select, single

One value in, one value out; keyboard-navigable, type-to-filter on long lists, closes on pick.

Dana P.

Reach for it: A form field or a toolbar control whose answer is exactly one thing: an owner, a taxonomy, a page size.
Not for: For a set of values (that is multiple), or for navigation (that is a Dropdown of links).

Select, multiple

The same control with an array in and the whole next array out; the panel stays open while you pick, and the closed control leads with the property word ("Owner · 2").

Owner · 2

Reach for it: A toolbar facet or a form field that takes several values, especially where the applied set must stay readable when closed.
Not for: As a replacement for FacetBar when there is more than one facet with counts, chips, and a refresh; that composition is the bar's job.

FacetBar

The list toolbar's filter row: several standing facets (Select multiple or single under the hood), applied chips, a count, an optional refresh, all in one bar.

Filter

Module · 1

All statuses

Module: Extract

1 applied

Reach for it: Above any table or list that filters on more than one property. Both apps ship it on their job and part lists.
Not for: For a single field in a form. One facet alone is a Select.

Split button

A Button with a caret joined to its main action; the caret opens a floating panel of related actions.

Reach for it: When one action is primary and its variants are secondary: Export as CSV or JSON, Run or Run with options.
Not for: As a picker that stores a value; the panel is actions, not state.

Command palette

A modal search over everything the app can navigate to, opened from a topbar trigger or the keyboard.

Reach for it: App-wide navigation and search: the playground's Cmd-K, an app's jump-to-record.
Not for: As a form control or a filter; it navigates, it does not pick a value into a field.