# Stretch, lead-in, lead-out

> Package `@umriss-ui/schedule`, version 0.40.0. Demo page: <https://romanhaendler.github.io/umriss-ui/schedule/stretch/>. 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).

Change how long work takes, or how long its preparation and its wrap-up take, by dragging an edge (also called resizing). Each part changes on its own and is reported for your application to apply.

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

Demo page: https://romanhaendler.github.io/umriss-ui/schedule/stretch/

`stretch` enables the two edges of the main time. `leadIn` and `leadOut` add a grip at the outer edge of each; the grips show on the selected subtask only, so click a bar first.

Stretching the main time leaves the lead-in and the lead-out as long as they were.

## Examples

### Stretch the main time

With `stretch` in `intents`, either edge of a bar drags to a new start or end; the other edge stays put.

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

const day = (d: number, hours = 9) => new Date(2026, 2, d, hours).getTime();

const PROJECTS: readonly Task[] = [{ id: "booking", name: "Booking app", color: "light-dark(#0d9488, #3cc7b8)" }];

const START: readonly Subtask[] = [
  { id: "w-111", task: "booking", lane: "hana", from: day(16), to: day(18, 17), name: "Push notifications" },
  { id: "w-116", task: "booking", lane: "david", from: day(16), to: day(19, 13), name: "Device test matrix" },
];

export default function StretchTheMainTime() {
  const { Schedule, Lane, Subtasks } = useSchedule({ initialView: { domain: [day(16, 0), day(21, 0)] } });
  const [work, setWork] = useState(START);
  return (
    <Schedule
      ariaLabel="Two estimates to adjust"
      height={140}
      intents={["stretch"]}
      onIntent={(intent) => setWork((current) => current.map((item) => applyIntent(item, intent)))}
    >
      <Lane id="hana" label="Hana Sato" />
      <Lane id="david" label="David Kowalski" />
      <Subtasks data={work} tasks={PROJECTS} />
    </Schedule>
  );
}
```

### Change lead-in and lead-out

Add `leadIn` and `leadOut`: a selected tour shows a grip for its loading and its unloading, each changed on its own.

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

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

const TOURS: Task[] = [{ id: "north", name: "North depot tours", color: "light-dark(#0d9488, #3cc7b8)" }];

/* Lead-in is loading at the depot, lead-out unloading the returns. */
const START: Subtask[] = [
  { id: "T-01", task: "north", lane: "van-214", from: at(8), to: at(10), leadIn: min(30), leadOut: min(15) },
  { id: "T-02", task: "north", lane: "van-377", from: at(11), to: at(12, 30), leadIn: min(15) },
];

export default function ChangeLeadInAndLeadOut() {
  const { Schedule, Lane, Subtasks } = useSchedule({ initialView: { domain: [at(6), at(13, 30)] } });
  const [tours, setTours] = useState(START);

  return (
    <Schedule
      ariaLabel="Two tours from North depot"
      height={150}
      intents={["stretch", "leadIn", "leadOut"]}
      onIntent={(intent) => setTours((current) => current.map((tour) => applyIntent(tour, intent)))}
    >
      <Lane id="van-214" label="Van FP 214 K" />
      <Lane id="van-377" label="E-van FP 377 K" />
      <Subtasks data={tours} tasks={TOURS} />
    </Schedule>
  );
}
```

## Keyboard

| Key | Action |
|---|---|
| `Alt+Shift+← Alt+Shift+→` | Proposes ending the active subtask one raster step earlier or later. |

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. |
| [`intents`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#ScheduleProps-intents) | `readonly `[`IntentKind`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#type-IntentKind)`[]` | `[]` | The intents the caller handles. Each one enables its interaction; none leaves a read-only schedule ([ADR-0023](https://github.com/romanhaendler/umriss-ui/blob/main/docs/adr/0023-editing-is-controlled-the-schedule-reports-intents.md)). |
| [`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. |

#### Events

| Prop | Type | Default | Description |
|---|---|---|---|
| [`onIntent`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#ScheduleProps-onIntent) | `(intent: `[`Intent`](https://romanhaendler.github.io/umriss-ui/schedule/schedule/#type-Intent)`) => void` | — | Called once per intent when a drag ends. The data changes only if the caller changes it. |

#### 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. |
| [`name`](https://romanhaendler.github.io/umriss-ui/schedule/subtasks/#Subtask-name) | `string` | — | What the subtask is called, where the schedule names it. |

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`. |

## Known limits

- A main time never becomes shorter than one raster step, or a minute without a raster.

What umriss deliberately does not build, and why: [ADR-0032](https://romanhaendler.github.io/umriss-ui/what-umriss-ui-is-not/).