# `CameraLimits.gestures`

> Contract 2.0.0 · package sha256 `a857eca95b35921109faf997094bb4192f12527d9d0fcd4be7e97f06425bad6e` · generated from `configurator-runtime.d.ts` by `services/onsite-scripter/scripts/build-contract-docs.mjs`; edit the source, not this file.

Property of [`CameraLimits`](CameraLimits.md) · labs, `@experimental` · since 2.0.0

```ts
gestures?: 'greedy' | 'cooperative' | null;
```

How the view shares touch and the wheel with the page. 'greedy' (1.x's): every one-finger
drag turns the product and every wheel over the view dollies. 'cooperative': a vertical
one-finger swipe scrolls the page while a horizontal one turns the product (`touch-action:
pan-y` on the view; a touch reaches the view once its first 10 CSS px show its direction, so a
scroll never turns the product first), two fingers pinch and turn as before, and a plain wheel
scrolls the page while Ctrl or Cmd with the wheel (a trackpad pinch) dollies. Use it for a
full-width view on a phone page, where a shopper swiping to the options would otherwise turn
the product. A touch
drag of a part ([`input.drag`](Input.drag.md)) that starts vertical scrolls the page instead, so a page with
part drags keeps 'greedy'. The browser allows the intersection of `touch-action` over the view
and its ancestors up to the page's scroller, so `el` and every ancestor up to it must allow
`pan-y`: remove `touch-action: none` (Tailwind's `touch-none`) there, or a vertical swipe
still turns the product. Turning it on under such an ancestor records 'unsupported-spec'
(`path` '/camera/limits/gestures', the element in `message`); the wheel half applies. null
removes your value. Experimental: check [`supports('camera.limits.gestures')`](Session.supports.md) before writing
it.

**Default:** unchanged (the document's, else 'greedy')

## Example

Imports: values (`has`, `validate`, the `Holo*Error` classes, the pure helpers) from `@holostep-configurators/runtime-client`, types from `@holostep-configurators/runtime-client/contract`, `/math` and `/testing` names from those entries; `boot` from the runtime module the root's `loadRuntimeAtFloor` resolves to. A type your page defines is your app's: declare it there, never import it from the package.

Compiled under the contract's strict settings (`examples/declaration/10-CameraLimits.gestures.ts`):

```ts
import type { Session } from '@holostep-configurators/runtime-client/contract';
declare const session: Session;
declare const signal: AbortSignal;
// A full-width view on a phone page: one finger scrolls past it, two fingers turn the product.
if (session.supports('camera.limits.gestures')) {
  await session.camera.limits({ gestures: 'cooperative' });
}
```

## Generic-API test (spec 3.1)

| Rule | Result |
| --- | --- |
| 1. Neutral name | pass: `gestures` names no product |
| 2. A precedent | not recorded: no ledger row (coverage.json) names this member or its owner |
| 3. Two apps, or labs | labs (`@experimental` at a stable path, reached through `has()` or `supports()`): it graduates when a second app uses it |
| 4. The cheaper fix first | not recorded per member (Appendix B decides it per need) |