# feat(flow): rotate directive
Adds a selector-targeted two-finger rotation directive to flows:
`rotate: { on?, by }`. `on` resolves like `tap` (settled tree +
auto-wait); omitted, the rotation centers on the screen. `by` is
degrees, positive = clockwise. Distinct from `tool: rotate`, which
changes device orientation — the docs and step labels call this out.
## Design
**One continuous gesture, fixed pace, no duration option.** Fingers
orbit at ~90°/300 ms; duration derives from the angle. Unlike pinch
there is no sub-gesture chaining — any angle dispatches as one sweep, so
the angular delta is exact with no settle delays. `by` is parse-bounded
to ±3000°: the largest sweep the 10 s single-gesture envelope delivers
at that pace, derived from the constants rather than picked as policy —
rejected at parse, never silently clamped. A consequence embraced here:
frame count always scales with the angle, so a speed-sensitive recording
stays a raw `tool:` step (the create-flow skill's polish list covers the
conversion).
**Fixed centroid, constant physical radius.** Drifting the centroid
would couple pan into the turn; growing the radius would couple pinch.
Both stay fixed — the trade is a smaller orbit near edges and small
targets, in exchange for a pure rotation.
**Physical circle, not a normalized-space ellipse.** A single normalized
radius on a non-square screen traces a physical ellipse, coupling an
unintended pinch into every turn. `gesture-rotate` grows optional
per-axis `radiusX`/`radiusY` (fractions of width/height with `radiusX·W
= radiusY·H`), and the flow tree adapters surface screen dimensions via
an optional `screen` field on `DescribeTreeData` so the directive can
compute the aspect. Missing dimensions fail soft to the legacy
single-radius call rather than erroring.
**Placement reuses pinch's edge model.** The initial finger axis
(horizontal or vertical) is scored against the same per-platform
system-edge guards, preferring a start parallel to the nearest violated
edge and staying inside the target's axis-matching span. Guards only
score placement — they never shrink the radius, and a violated guard is
attempted, never rejected. The only geometry failure is no positive
on-screen orbit radius.
**Abort correctness.** `gesture-rotate` now honors `ctx.signal`: each
frame checks it, lifts the synthetic fingers with a terminal Up (so a
cancelled run doesn't leave them held on the glass), then throws with
name `AbortError`; the directive maps a mid-gesture abort to the run's
aborted skip rather than a step failure.
**Explicit `inputSchema`.** The radius requirement is a zod `.refine()`
cross-field rule, which `z.toJSONSchema` drops — so the tool ships a
derived schema plus an explicit `anyOf` (`radius` or
`radiusX`+`radiusY`) to keep invalid calls rejected at the schema layer.
**Platform rejections.** Vega is remote-driven (no touch) and Chromium
has no rotate-gesture idiom at all — both fail upfront with guidance to
drive the app's rotate controls directly.
## Tests
Unit tests cover the geometry module (duration derivation, candidate
construction, aspect handling, edge-guard ranking), the directive
end-to-end against a fake device, and `gesture-rotate`'s per-axis radii
and abort path.
Jakub Piasecki