# Pan and zoom

> Package `@umriss-ui/schedule`, version 0.40.0. Demo page: <https://romanhaendler.github.io/umriss-ui/schedule/pan-and-zoom/>. Every page in one line: [llms.txt](https://romanhaendler.github.io/umriss-ui/schedule/llms.txt); every page in full: [llms-full.txt](https://romanhaendler.github.io/umriss-ui/schedule/llms-full.txt).

Moving through a plan with the gestures of any scrolling surface: drag, wheel, Ctrl with the wheel, and a pinch. Only the view moves; the plan stays as it is.

```ts
import { useSchedule } from "@umriss-ui/schedule";
```

Demo page: https://romanhaendler.github.io/umriss-ui/schedule/pan-and-zoom/

Dragging the background pans through time and through the lanes. The wheel scrolls the lanes and hands the scroll back to the page at their end; Shift with the wheel pans through time; Ctrl or ⌘ with the wheel, or a pinch, zooms around the pointer.

No intent is raised: pan and zoom change the visible span and nothing else ([ADR-0001](https://github.com/romanhaendler/umriss-ui/blob/main/docs/adr/0001-affine-scale-contract.md)). The span is part of the schedule's view, which `onViewChange` reports at most once per frame - see [View](https://romanhaendler.github.io/umriss-ui/schedule/view/) and [Linked schedules](https://romanhaendler.github.io/umriss-ui/schedule/linked-schedules/).

## Examples

### Move through the plan

Drag, wheel, Ctrl with the wheel and a pinch need nothing switched on; `zoomLimits` only bounds the span, here two hours to two days.

```tsx
import { useSchedule } from "@umriss-ui/schedule";
import type { Subtask, Task } from "@umriss-ui/schedule";

/* Without `zoomLimits` the span may run from an hour to twenty-eight days. */

const at = (hours: number, minutes = 0) => new Date(2026, 2, 17, hours, minutes).getTime();
const min = (n: number) => n * 60_000;
const HOUR = 60 * 60_000;

const TASKS: Task[] = [
  { id: "release", name: "Release 4.12", color: "light-dark(#2563eb, #6b9bff)" },
  { id: "inc-1048", name: "INC-1048 follow-up", color: "light-dark(#c2410c, #f08a52)" },
];

const ENGINEERS = [
  { id: "priya", label: "Priya Raman" },
  { id: "jonas", label: "Jonas Keller" },
  { id: "ada", label: "Ada Mwangi" },
];

const WORK: Subtask[] = [
  { id: "build", task: "release", lane: "priya", from: at(6), to: at(7), leadIn: min(15), leadOut: min(10) },
  { id: "rollout", task: "release", lane: "jonas", from: at(8), to: at(10, 30), leadIn: min(30), leadOut: min(15) },
  { id: "timeline", task: "inc-1048", lane: "ada", from: at(6, 30), to: at(8), leadIn: min(30), leadOut: min(15) },
  { id: "postmortem", task: "inc-1048", lane: "jonas", from: at(12), to: at(13, 30), leadIn: min(15) },
];

export default function PanAndZoom() {
  const { Schedule, Lane, Subtasks } = useSchedule({ initialView: { domain: [at(5, 30), at(18)] } });
  return (
    <Schedule
      ariaLabel="A plan to pan and zoom"
      height={196}
      zoomLimits={{ min: 2 * HOUR, max: 48 * HOUR }}
    >
      {ENGINEERS.map((engineer) => (
        <Lane key={engineer.id} id={engineer.id} label={engineer.label} />
      ))}
      <Subtasks data={WORK} tasks={TASKS} />
    </Schedule>
  );
}
```

## Keyboard

| Key | Action |
|---|---|
| `Home / End` | The first or last subtask on the lane; the view pans to bring it in. |
| `PageUp / PageDown` | Along the lane by about a tenth of the visible span, the view following. |

The keys of [First schedule](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#keyboard-schedule) apply here.

## Props on this page

From `ScheduleProps` — the full table stands on [First schedule](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#type-ScheduleProps).

| Prop | Type | Default | Description |
|---|---|---|---|
| [`height`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#ScheduleProps-height) | `number` | `400` | Height in CSS pixels, both bands included. The width is the host's. |
| [`zoomLimits`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#ScheduleProps-zoomLimits) | [`ZoomLimits`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#type-ZoomLimits) | one hour to 28 days | The narrowest and widest time span zoom may reach, in milliseconds. |
| [`children`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#ScheduleProps-children) | `ReactNode` | — | `Lane`, `Dependencies` and `Subtasks`, in the order they are to stand and be drawn. |

#### Accessibility

| Prop | Type | Default | Description |
|---|---|---|---|
| [`ariaLabel`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#ScheduleProps-ariaLabel) *required* | `string` | — | What the schedule shows, for a screen reader: "Plan of week 38". |

From `LaneProps` — the full table stands on [Lanes](https://romanhaendler.github.io/umriss-ui/schedule/lane/#type-LaneProps).

| Prop | Type | Default | Description |
|---|---|---|---|
| [`id`](https://romanhaendler.github.io/umriss-ui/schedule/lane/#LaneProps-id) *required* | `string` | — | The identity subtasks name in their `lane`. |
| [`label`](https://romanhaendler.github.io/umriss-ui/schedule/lane/#LaneProps-label) | `ReactNode` | `id` | What the lane header says - the person, vehicle or room. Real text, read by a screen reader. |

From `SubtasksProps` — the full table stands on [Subtasks](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#type-SubtasksProps).

| Prop | Type | Default | Description |
|---|---|---|---|
| [`data`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#SubtasksProps-data) *required* | `readonly `[`Subtask`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#type-Subtask)`[]` | — | The subtasks, as the caller holds them. The schedule never changes one. |
| [`tasks`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#SubtasksProps-tasks) *required* | `readonly `[`Task`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#type-Task)`[]` | — | The tasks the subtasks belong to - their identity and their colour. A subtask whose task is not among them is drawn in a muted colour. |

From `Subtask` — the full table stands on [Subtasks](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#type-Subtask).

| Prop | Type | Default | Description |
|---|---|---|---|
| [`id`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Subtask-id) *required* | `string` | — | The caller's identity of the subtask. |
| [`task`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Subtask-task) *required* | `string` | — | The id of the task it belongs to. |
| [`lane`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Subtask-lane) *required* | `string` | — | The id of the lane it sits on. |
| [`from`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Subtask-from) *required* | `number` | — | Start of the main time. |
| [`to`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Subtask-to) *required* | `number` | — | End of the main time. |
| [`leadIn`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Subtask-leadIn) | `number` | — | Duration of the lead-in before the main time; none is zero. |
| [`leadOut`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Subtask-leadOut) | `number` | — | Duration of the lead-out after the main time; none is zero. |

From `Task` — the full table stands on [Subtasks](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#type-Task).

| Prop | Type | Default | Description |
|---|---|---|---|
| [`id`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Task-id) *required* | `string` | — | The caller's identity of the task. |
| [`color`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Task-color) *required* | `string` | — | Any CSS colour - a literal, a token, `light-dark(…)`. The colour means what the caller's domain needs it to mean. |
| [`name`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Task-name) | `string` | — | What the task is called, where the schedule names it. |

From `ScheduleOptions` — the full table stands on [View](https://romanhaendler.github.io/umriss-ui/schedule/view/#type-ScheduleOptions).

| Prop | Type | Default | Description |
|---|---|---|---|
| [`initialView`](https://romanhaendler.github.io/umriss-ui/schedule/view/#ScheduleOptions-initialView) | [`ScheduleView`](https://romanhaendler.github.io/umriss-ui/schedule/view/#type-ScheduleView) | — | The view to start from, read once when the hook first runs; a different value on a later render is ignored, as React ignores a changed `defaultValue`. To go to a view later, call `setView`. The schedule remembers none: where a view is kept is the application's decision. |

From `ScheduleView` — the full table stands on [View](https://romanhaendler.github.io/umriss-ui/schedule/view/#type-ScheduleView).

| Prop | Type | Default | Description |
|---|---|---|---|
| [`domain`](https://romanhaendler.github.io/umriss-ui/schedule/view/#ScheduleView-domain) | `readonly [number, number]` | — | The span in view, as two wall-clock instants. Absent, the schedule shows the extent of its subtasks, within `zoomLimits`. |