React · SwiftUI · agent guides
Needle
A tapered pointer on a pivot cap over a scale printed on glass, with a zone past its threshold. A value turns it; in a gadget it swings to it and overshoots a little, pegged at the ends of its scale.
Use it for
- A level read at a glance: minutes read today, storage used, a health that rises and falls.
- A measure with a point that matters: its threshold zone marks where it becomes news.
Don't use it for
- A count: that's the Drum.
- A setting a person moves: that's a fader cap or a knob.