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@jsvision/ui / Window

Class: Window ​

Defined in: ui/src/window/window.ts:77

A titled, framed container. Add your content children and give it to a desktop with desktop.addWindow(w); the desktop then manages its z-order, focus, and drag gestures.

Example ​

ts
import { createApplication, Window, Text, Commands, statusLine, statusItem } from '@jsvision/ui';
import { resolveCapabilities } from '@jsvision/core';

const caps = resolveCapabilities().profile;
const app = createApplication({
  caps,
  statusLine: statusLine([statusItem('~Q~uit', Commands.quit, 'Alt+X')]),
});

const w = new Window('Editor');
w.number = 1;                                  // shows "1" in the frame; Alt+1 activates it
w.layout.rect = { x: 1, y: 2, width: 30, height: 10 };
w.add(new Text('Hello from a window.'));
app.desktop.addWindow(w);                      // raises + focuses it

Extends ​

Extended by ​

Constructors ​

Constructor ​

new Window(title?): Window

Defined in: ui/src/window/window.ts:127

Parameters ​

title? ​

string

Initial window title (default empty).

Returns ​

Window

Overrides ​

Group.constructor

Properties ​

active ​

readonly active: Signal<boolean>

Defined in: ui/src/window/window.ts:95

true when this is the active (top-most, focused) window, false when it sits behind another. The desktop keeps it in sync as windows are raised, added, and removed; the frame chrome reads it to switch between the active and inactive look. A standalone window defaults to true.

background? ​

optional background?: keyof Theme

Defined in: ui/src/view/group.ts:64

Optional background theme role filled before children compose, so overlap never leaks cells.

Inherited from ​

Group.background

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 ​

Group.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 ​

Group.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 ​

Group.centered

children ​

readonly children: View[] = []

Defined in: ui/src/view/group.ts:62

Ordered children; array order is paint order (back-to-front).

Inherited from ​

Group.children

closable ​

closable: boolean = true

Defined in: ui/src/window/window.ts:105

Whether the window can be closed (shows the close box).

dragging ​

readonly dragging: Signal<boolean>

Defined in: ui/src/window/window.ts:89

true while the window is being dragged (moved or resized), false otherwise. The desktop flips it around a gesture; bind to it if you want to react to drag start/end. A standalone window (never added to a desktop) stays false.

focusable ​

focusable: boolean = true

Defined in: ui/src/window/window.ts:79

A window is a focus target so raising it (and resolving the active window) works.

Overrides ​

Group.focusable

layout ​

layout: LayoutProps

Defined in: ui/src/window/window.ts:81

Absolute placement — the desktop writes layout.rect; padding: 1 insets content past the border.

Overrides ​

Group.layout

minHeight ​

minHeight: number = 3

Defined in: ui/src/window/window.ts:111

minWidth ​

minWidth: number = 10

Defined in: ui/src/window/window.ts:110

The smallest size a resize gesture will shrink the window to. Raise these in a subclass whose content assumes a fixed minimum (e.g. a dialog whose child rects need at least 49×19).

movable ​

movable: boolean = true

Defined in: ui/src/window/window.ts:99

Whether the title bar can be dragged to move the window.

number? ​

optional number?: number

Defined in: ui/src/window/window.ts:97

An accelerator number 1–9 shown in the frame (Alt+N activates the window); undefined = none.

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 ​

Group.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 ​

Group.preProcess

resizable ​

resizable: boolean = true

Defined in: ui/src/window/window.ts:101

Whether the window can be resized via the corner grips.

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 ​

Group.state

title ​

readonly title: Signal<string>

Defined in: ui/src/window/window.ts:83

The window title, centered in the top border. Set it to repaint the frame.

zoomable ​

zoomable: boolean = true

Defined in: ui/src/window/window.ts:103

Whether the window can be maximized/restored (shows the zoom box).

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 ​

Group.accelerators

add() ​

add(child): void

Defined in: ui/src/view/group.ts:88

Add a child, appending it on top (later in the array draws in front). If this group is already mounted, the child mounts immediately — its scope nested under this group's — and a reflow is scheduled for the new layout; otherwise the child mounts when this group itself mounts.

Parameters ​

child ​

View

The view to append.

Returns ​

void

Inherited from ​

Group.add

addDynamic() ​

addDynamic(build): void

Defined in: ui/src/view/group.ts:135

Add children reactively from a Show/For accessor, so the set of children updates itself as signals change. When the group is mounted, an effect reads the accessor, mounts any newly produced views, unmounts any that disappeared (firing their onCleanup), and schedules a reflow on change. Pass a factory that builds the combinator inside itself, not an already-built accessor — this lets the group own and dispose the combinator's reactive nodes on unmount.

Parameters ​

build ​

DynamicBuilder

A factory that constructs the combinator, e.g. () => Show(cond, then) or () => For(each, key, render).

Returns ​

void

Example ​

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

const open = signal(false);
const group = new Group();
group.addDynamic(() => Show(() => open(), () => new Panel())); // Panel appears when `open` is true

Inherited from ​

Group.addDynamic

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 ​

Group.bind

close() ​

close(): void

Defined in: ui/src/window/window.ts:212

Close the window, removing it from the desktop (which disposes its scope). No-op if not closable.

Returns ​

void

commitPlacement() ​

commitPlacement(): void

Defined in: ui/src/window/window.ts:159

Freeze the current on-screen position into layout.rect and stop auto-centering, if this window is still centered. The desktop calls this at the start of a move/resize gesture: a centered window's real position lives in bounds (computed each reflow) rather than in layout.rect (which stays at the origin), so a gesture that read layout.rect would snap it to the top-left. After this runs once, the window behaves as a normally-placed window. No-op if not centered.

Returns ​

void

currentRect() ​

protected currentRect(): Rect

Defined in: ui/src/window/window.ts:166

The window's current WM rect (the layout rect, or a degenerate fallback before placement).

Returns ​

Rect

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 ​

Group.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 ​

Group.desiredCaret

draw() ​

draw(ctx): void

Defined in: ui/src/window/window.ts:218

Paint the frame chrome, choosing the active or inactive colours from the current active state.

Parameters ​

ctx ​

DrawContext

Returns ​

void

Overrides ​

Group.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 ​

Group.focusSignal

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 ​

Group.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 ​

Group.invalidateLayout

isZoomed() ​

isZoomed(): boolean

Defined in: ui/src/window/window.ts:171

Whether the window is currently zoomed (maximized).

Returns ​

boolean

measure()? ​

optional measure(available): Size2D

Defined in: ui/src/view/view.ts:71

Optional intrinsic-size hook for auto sizing — return the size this view wants for available.

Parameters ​

available ​

Size2D

Returns ​

Size2D

Inherited from ​

Group.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 ​

Group.onCleanup

onDesktopResize() ​

onDesktopResize(size): void

Defined in: ui/src/window/window.ts:203

Re-fit to a resized desktop: a zoomed window re-maximizes to the new desktop size, and its saved restore rect is clamped so a later un-zoom still lands on-screen. A non-zoomed window is left where it is (a window may overflow the desktop edge).

Parameters ​

size ​

Size2D

The new desktop content size.

Returns ​

void

onEvent() ​

onEvent(ev): void

Defined in: ui/src/window/window.ts:259

On a frame mouse-down, act on the zone the click landed in: close, zoom, start a title drag-move, or start a corner resize. The window has already been raised by selectByClick, so this is affordance-only. Non-mouse events and mouse events other than a press are ignored (an in-flight drag is driven by the desktop, not here).

Parameters ​

ev ​

DispatchEvent

Returns ​

void

Overrides ​

Group.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 ​

Group.onMount

onResized() ​

onResized(): void

Defined in: ui/src/window/window.ts:148

Called by the desktop right after a resize changed layout.rect, before the next reflow. The base window does nothing — flow-laid content reflows on its own. Override it in a subclass whose absolutely-placed children must be repositioned to track the new size (e.g. anchoring a button to the bottom-right corner).

Returns ​

void

remove() ​

remove(child): void

Defined in: ui/src/view/group.ts:104

Remove a child: dispose its scope (recursively disposing its descendants and running their onCleanup), detach it, and schedule a reflow. Removing a non-child (or removing twice) is a safe no-op.

Parameters ​

child ​

View

The view to remove.

Returns ​

void

Inherited from ​

Group.remove

resetZoom() ​

resetZoom(): void

Defined in: ui/src/window/window.ts:176

Forget the zoom state without restoring the rect (used by cascade/tile, which place the window).

Returns ​

void

selectByClick() ​

selectByClick(): void

Defined in: ui/src/window/window.ts:247

Select and raise the window on a mouse-down. The hit-test calls this before the event descends into the window's interior, so the window comes to the front even when an interior child ends up consuming the click. It first records whether the window was already active (so onEvent can make the first click on an inactive window only raise it, not act on a frame button). A standalone window (no desktop) is a safe no-op; re-selecting the already-active window just re-raises it harmlessly.

Returns ​

void

Overrides ​

Group.selectByClick

zoom() ​

zoom(): void

Defined in: ui/src/window/window.ts:184

Toggle maximized ↔ restored. Maximizing saves the current rect and fills the desktop; restoring re-applies the exact saved rect. No-op if the window is not zoomable or has no desktop parent.

Returns ​

void