Interface ViewportStore

Read-only view of the scroll store. Layers/panes read the current scroll here and subscribe for changes.

interface ViewportStore {
    getClient(): Size;
    getMetrics(): ViewportMetrics;
    getScroll(): TopLeft;
    getSnapshot(): TopLeft;
    getTarget(): TopLeft;
    getZoom(): number;
    isReady(): boolean;
    isSettled(): boolean;
    subscribe(listener: () => void): () => void;
}

Hierarchy (View Summary)

ViewportStore
- IViewport

Index

Methods

getClient getMetrics getScroll getSnapshot getTarget getZoom isReady isSettled subscribe

Methods

getClient

getClient(): Size

The raw cell-area client size = the measured client (uncapped by content). The grid reads this for its own pane layout (min(client, content)); getMetrics caps it at content.

Returns Size

getMetrics

getMetrics(): ViewportMetrics

The combined viewport (position + measured sizes) as one identity-stable object — what a subscribed ScrollPane reads to size and place its scrollbars.

Returns ViewportMetrics

getScroll

getScroll(): TopLeft

Convenience { left, top } of the current (rendered) scroll.

Returns TopLeft

getSnapshot

getSnapshot(): TopLeft

The current (rendered) scroll snapshot. The returned object is identity-stable until the scroll changes, so it is safe as a useSyncExternalStore snapshot.

Returns TopLeft

getTarget

getTarget(): TopLeft

The scroll TARGET the ticker is easing toward (equals current when settled).

Returns TopLeft

getZoom

getZoom(): number

The zoom factor (1 = none). Part of the viewport shape so a shared/synced viewport carries it.

Returns number

isReady

isReady(): boolean

Whether the viewport has everything it needs to clamp + emit: a measured client (observer fired or manual sizes pushed) AND real content AND a positive client. The shared readiness signal that replaces each grid's "pending until ready" gate.

Returns boolean

isSettled

isSettled(): boolean

Whether the current (rendered) position has reached the target — no easing in progress.

Returns boolean

subscribe(listener: () => void): () => void
Subscribe to scroll changes. Driven by the rAF ticker, so the listener fires at most once per animation frame (and only while current is advancing toward target). Returns a remover.
Parameters
- listener: () => void
Returns () => void