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@jsvision/ui / ColorSwatch

Class: ColorSwatch ​

Documented in: Color swatch

Defined in: ui/src/color/color-swatch.ts:85

A focusable grid of color cells. Selection is live — the bound value changes on every arrow key, click, and drag (each firing onInput), and the ◘ marker tracks it. Enter/Space or a mouse-up over a cell is the discrete commit and fires onChange (used by a hosting ColorPicker to close its dropdown).

Example ​

ts
import { Group, ColorSwatch, signal } from '@jsvision/ui';
import { ANSI16_ORDER } from '@jsvision/core';
import type { Color } from '@jsvision/core';

const g = new Group();
const value = signal<Color>('brightCyan');

// A 4×4 grid of the 16 DOS colors, bound two-way to `value`.
const swatch = new ColorSwatch({
  value,
  colors: ANSI16_ORDER as readonly Color[],
  columns: 4,
  onInput: (c) => console.log('previewing', c), // arrows / click / drag update `value` live
  onChange: (c) => console.log('committed', c), // Enter / Space / mouse-up commits
});
swatch.layout = { position: 'absolute', rect: { x: 1, y: 1, width: 12, height: 4 } };
g.add(swatch);

Extends ​

Constructors ​

Constructor ​

new ColorSwatch(opts): ColorSwatch

Defined in: ui/src/color/color-swatch.ts:106

Parameters ​

opts ​

ColorSwatchOptions

The two-way value + optional colors/columns/onInput/onChange/nameFor.

Returns ​

ColorSwatch

Overrides ​

View.constructor

Properties ​

bounds ​

bounds: Rect

Defined in: ui/src/view/view.ts:65

Parent-relative integer rect; written by the layout pass — read it in draw/hit-testing.

Inherited from ​

View.bounds

castsShadow ​

castsShadow: boolean = false

Defined in: ui/src/view/view.ts:78

When true, the renderer paints a drop shadow on the cells just below and to the right of this view, in paint order (a later sibling's shadow falls over an earlier one). Default false. The Desktop sets it per window.

Inherited from ​

View.castsShadow

centered ​

centered: boolean = false

Defined in: ui/src/view/view.ts:86

When true, the layout pass recentres this view within its parent after layout — origin = (parent - self) / 2 on both axes. Intended for absolutely-placed views (a modal dialog, a message box) whose size is fixed and whose origin would otherwise be placed by the caller. Default false; Dialog sets it when centered.

Inherited from ​

View.centered

colors ​

protected readonly colors: readonly Color[]

Defined in: ui/src/color/color-swatch.ts:94

columns ​

protected readonly columns: number

Defined in: ui/src/color/color-swatch.ts:95

cursor ​

protected readonly cursor: Signal<number>

Defined in: ui/src/color/color-swatch.ts:99

The cell the arrow keys move from; kept in sync with value on every change.

focusable ​

focusable: boolean = true

Defined in: ui/src/color/color-swatch.ts:87

The swatch takes focus so its arrow-key navigation is scoped to it.

Overrides ​

View.focusable

layout ​

layout: LayoutProps = {}

Defined in: ui/src/view/view.ts:69

Layout props for this view (direction, size, padding, absolute placement, …).

Inherited from ​

View.layout

nameFor? ​

readonly optional nameFor?: (c) => string

Defined in: ui/src/color/color-swatch.ts:92

Optional pure color-name accessor, read by a hosting ColorPicker caption.

Parameters ​

c ​

Color

Returns ​

string

onChange? ​

protected readonly optional onChange?: (c) => void

Defined in: ui/src/color/color-swatch.ts:97

Parameters ​

c ​

Color

Returns ​

void

onInput? ​

protected readonly optional onInput?: (c) => void

Defined in: ui/src/color/color-swatch.ts:96

Parameters ​

c ​

Color

Returns ​

void

postProcess ​

postProcess: boolean = false

Defined in: ui/src/view/view.ts:98

Take part in the post-process sweep (after the focused view sees the event).

Inherited from ​

View.postProcess

preProcess ​

preProcess: boolean = false

Defined in: ui/src/view/view.ts:96

Take part in the pre-process sweep (root→down, before the focused view sees the event).

Inherited from ​

View.preProcess

state ​

readonly state: ViewState

Defined in: ui/src/view/view.ts:67

Draw-against flags. The object reference is fixed; individual fields mutate (e.g. focused).

Inherited from ​

View.state

value ​

readonly value: Signal<Color>

Defined in: ui/src/color/color-swatch.ts:90

Two-way selected color.

Methods ​

accelerators() ​

accelerators(): readonly string[]

Defined in: ui/src/view/view.ts:114

The Alt+hotkey accelerator characters (lowercase) this view claims in its focus scope, for duplicate-accelerator detection. The base returns none; accelerator-bearing widgets (Button/Label/CheckGroup/RadioGroup) override it to report their ~X~ hotkey(s).

Returns ​

readonly string[]

The claimed accelerator chars, or an empty list when the view claims none.

Inherited from ​

View.accelerators

applyHit() ​

protected applyHit(localX, localY): void

Defined in: ui/src/color/color-swatch.ts:252

Select the cell under a view-local pointer: revert outside the grid, clamp a partial-row overshoot.

Parameters ​

localX ​

number

localY ​

number

Returns ​

void

bind() ​

bind<T>(reader, apply?, opts?): void

Defined in: ui/src/view/view.ts:228

Bind a reactive value to a redraw. Creates an effect (owned by this view's scope) that reads reader() — subscribing to whatever signals it touches — runs the optional apply(value), then requests a frame: a repaint by default, or a reflow when { relayout: true }. It re-runs automatically whenever those signals change, and is disposed when the view unmounts.

Call it from onMount, not the constructor — the view's scope only exists once mounted, so a pre-mount bind throws rather than silently dropping the binding.

Type Parameters ​

T ​

T

Parameters ​

reader ​

() => T

Reads the reactive source; the signals it reads become dependencies.

apply? ​

(v) => void

Optional: apply the read value to the widget (e.g. store it in a field).

opts? ​

Pass { relayout: true } when the change affects layout, so it reflows instead of just repainting.

relayout? ​

boolean

Returns ​

void

Example ​

ts
import { signal } from '@jsvision/ui';

const count = signal(0);
// `status` is a View whose draw() reads count():
status.onMount(() => {
  status.bind(() => count()); // repaint the status line whenever `count` changes
});

Inherited from ​

View.bind

close() ​

protected close(): void

Defined in: ui/src/color/color-swatch.ts:157

Fire the commit callback (onChange) with the current value (Enter/Space or a mouse-up over a cell).

Returns ​

void

derived() ​

protected derived<T>(fn): () => T

Defined in: ui/src/view/view.ts:261

Create a stable derived accessor owned by this view's scope. The returned () => T keeps the same identity for the life of the view, so it is safe to build in the constructor and hand to child views before this view mounts. The backing computed is created lazily under the view's own scope, so it is always owned and disposed at unmount — unlike a bare computed() in the constructor, which would run before any scope exists, leak, and warn.

Reads behave sensibly across the lifecycle:

  • Before mount: evaluates fn() directly (correct current value, nothing persisted). Good for a pre-mount natural-size measure.
  • After mount: builds and memoizes a computed(fn) under the view's scope.
  • After an unmount→remount: the memo is keyed to the scope it was built under, so a remounted view (which gets a fresh scope) re-derives under the new scope instead of returning the previous mount's disposed, now-frozen computed — keeping a Show/For-remounted widget reactive.

Type Parameters ​

T ​

T

Parameters ​

fn ​

() => T

The derivation (pure; the signals it reads become the computed's dependencies).

Returns ​

A stable accessor; call it to read the derived value.

() => T

Inherited from ​

View.derived

desiredCaret() ​

desiredCaret(): Point | null

Defined in: ui/src/view/view.ts:192

Where this view wants the hardware text cursor, in view-local cells, or null for no cursor (the default — most views never show one). A focused text input overrides this to place the caret at the edit position; the event loop reads it after each frame, converts it to an absolute cell, and moves the terminal cursor there.

Returns ​

Point | null

The view-local caret point (0-based, relative to this view's origin), or null.

Inherited from ​

View.desiredCaret

draw() ​

draw(ctx): void

Defined in: ui/src/color/color-swatch.ts:162

Paint the color cells, then the ◘ marker on the selected cell (contrasting colour if near-black).

Parameters ​

ctx ​

DrawContext

Returns ​

void

Overrides ​

View.draw

focusSignal() ​

focusSignal(): Signal<void>

Defined in: ui/src/view/view.ts:136

Subscribe to this view's focus changes. Reading the returned signal inside a bind/effect re-runs that effect whenever this view gains or loses focus — including from another view (e.g. a Label repainting when the control it labels is focused). The signal notifies on every poke even without a value change. Lazy: the backing signal is created on first call.

Returns ​

Signal<void>

A signal that ticks whenever this view gains or loses focus.

Example ​

ts
// Inside a widget's onMount, repaint whenever `other` view's focus changes:
this.onMount(() => this.bind(() => other.focusSignal()()));

Inherited from ​

View.focusSignal

handleMouse() ​

protected handleMouse(ev): void

Defined in: ui/src/color/color-swatch.ts:225

Mouse down snapshots the current cell (as the revert target), selects the cell under the pointer, and captures the pointer so the drag keeps tracking even off the grid. A drag selects the cell under the pointer live, reverting to the snapshot when the pointer moves outside the grid. A mouse-up over a real cell fires the close hook (so a hosting ColorPicker closes); a release outside the grid does not close.

Parameters ​

ev ​

DispatchEvent

The dispatch envelope (carries local plus the pointer-capture seams).

Returns ​

void

invalidate() ​

invalidate(): void

Defined in: ui/src/view/view.ts:197

Request a repaint of this view. A no-op before the view is mounted (the first frame paints everything).

Returns ​

void

Inherited from ​

View.invalidate

invalidateLayout() ​

invalidateLayout(): void

Defined in: ui/src/view/view.ts:202

Request a reflow (re-run layout, then repaint). Use this when a change affects size/position, not just pixels.

Returns ​

void

Inherited from ​

View.invalidateLayout

measure() ​

measure(): Size2D

Defined in: ui/src/color/color-swatch.ts:132

Advertise the grid's intrinsic size (width × rows) for auto sizing.

Returns ​

Size2D

Overrides ​

View.measure

onCleanup() ​

onCleanup(fn): void

Defined in: ui/src/view/view.ts:298

Register a teardown callback that runs once when this view unmounts. Requires a mounted view — so call it from within onMount. Use it to release anything the view acquired (a timer, an external subscription).

Parameters ​

fn ​

() => void

The teardown callback.

Returns ​

void

Inherited from ​

View.onCleanup

onEvent() ​

onEvent(ev): void

Defined in: ui/src/color/color-swatch.ts:185

Handle keyboard (wrap-around arrows + Enter/Space commit) and mouse (click/drag selection). Plain arrow keys are always consumed so navigation never leaves the swatch.

Parameters ​

ev ​

DispatchEvent

The dispatch envelope.

Returns ​

void

Overrides ​

View.onEvent

onMount() ​

onMount(fn): void

Defined in: ui/src/view/view.ts:283

Register a callback to run once when the view becomes live (after its first layout gives it bounds). This is where to call bind, since the view's reactive scope exists by then. Registering after the view is already live runs the callback immediately.

Parameters ​

fn ​

() => void

Post-mount setup.

Returns ​

void

Inherited from ​

View.onMount

select() ​

select(color): void

Defined in: ui/src/color/color-swatch.ts:138

Programmatically select a color: set value and fire both the live onInput and commit onChange.

Parameters ​

color ​

Color

Returns ​

void

selectByClick()? ​

optional selectByClick(): void

Defined in: ui/src/view/view.ts:182

Optional "select + raise on click" hook. Left undefined on the base, so a plain view is not a select/raise target. A container that owns z-order (a Window) overrides it to select and raise itself. The hit-test invokes the first ancestor that defines this — before delivering the mouse-down — so a click always raises the window even if the interior also consumes the click.

Returns ​

void

Inherited from ​

View.selectByClick

setLive() ​

protected setLive(idx): void

Defined in: ui/src/color/color-swatch.ts:148

Select cell idx and update value immediately so the ◘ marker tracks it. A no-op for an out-of-range index. This does NOT close a hosting ColorPicker — that is the close hook.

Parameters ​

idx ​

number

Returns ​

void