@ue-too/board / index / ZoomControlStateMachine

Class: ZoomControlStateMachine

Defined in: packages/board/src/camera/camera-mux/animation-and-lock/zoom-control-state-machine.ts:436

State machine controlling zoom input flow and animations.

Remarks

This state machine manages the lifecycle of zoom operations:

User input handling: Accepts or blocks user zoom gestures based on state
Animation control: Manages smooth zoom-to animations
Object tracking: Supports locking camera to follow objects with zoom

State transitions:

ACCEPTING_USER_INPUT → TRANSITION: Start animation (initiateTransition)
ACCEPTING_USER_INPUT → LOCKED_ON_OBJECT: Lock to object (lockedOnObjectZoom...)
TRANSITION → ACCEPTING_USER_INPUT: User input interrupts animation
LOCKED_ON_OBJECT → ACCEPTING_USER_INPUT: User input unlocks

Helper methods simplify event dispatching without memorizing event names.

Example

typescript

const stateMachine = createDefaultZoomControlStateMachine(cameraRig);

// User zooms - accepted in ACCEPTING_USER_INPUT state
const result = stateMachine.notifyZoomByAtInput(1.2, { x: 400, y: 300 });

// Start animation - transitions to TRANSITION state
stateMachine.notifyZoomToAtWorldInput(2.0, { x: 1000, y: 500 });

// User input now may interrupt animation

See

createDefaultZoomControlStateMachine for factory function

Extends

TemplateStateMachine<ZoomEventPayloadMapping, BaseContext, ZoomControlStates, ZoomControlOutputMapping>

Constructors

Constructor

new ZoomControlStateMachine(states, initialState, context): ZoomControlStateMachine

Defined in: packages/board/src/camera/camera-mux/animation-and-lock/zoom-control-state-machine.ts:442

Parameters

states

Record<ZoomControlStates, State<ZoomEventPayloadMapping, BaseContext, ZoomControlStates, ZoomControlOutputMapping>>

initialState

ZoomControlStates

context

BaseContext

Returns

ZoomControlStateMachine

Overrides

TemplateStateMachine< ZoomEventPayloadMapping, BaseContext, ZoomControlStates, ZoomControlOutputMapping >.constructor

Properties

_context

protected _context: BaseContext

Defined in: packages/being/dist/interface.d.ts:468

Inherited from

TemplateStateMachine._context

_currentState

protected _currentState: ZoomControlStates | "INITIAL" | "TERMINAL"

Defined in: packages/being/dist/interface.d.ts:466

Inherited from

TemplateStateMachine._currentState

_eventResultCallbacks

protected _eventResultCallbacks: EventResultCallback<ZoomEventPayloadMapping, BaseContext, ZoomControlStates>[]

Defined in: packages/being/dist/interface.d.ts:472

Inherited from

TemplateStateMachine._eventResultCallbacks

_happensCallbacks

protected _happensCallbacks: (args, context) => void[]

Defined in: packages/being/dist/interface.d.ts:471

Parameters

args

["unlock"] | [string, unknown] | ["userZoomByAtInput", ZoomByAtInputPayload] | ["userZoomToAtInput", ZoomToAtInputPayload] | ["transitionZoomByAtInput", ZoomByAtInputPayload] | ["transitionZoomToAtInput", ZoomToAtInputPayload] | ["transitionZoomByAtCenterInput", ZoomByPayload] | ["transitionZoomToAtCenterInput", ZoomToAtInputPayload] | ["transitionZoomToAtWorldInput", ZoomToAtInputPayload] | ["lockedOnObjectZoomByAtInput", ZoomByAtInputPayload] | ["lockedOnObjectZoomToAtInput", ZoomToAtInputPayload] | ["initiateTransition"]

context

BaseContext

Returns

void

Inherited from

TemplateStateMachine._happensCallbacks

_initialState

protected _initialState: ZoomControlStates

Defined in: packages/being/dist/interface.d.ts:474

Inherited from

TemplateStateMachine._initialState

_stateChangeCallbacks

protected _stateChangeCallbacks: StateChangeCallback<ZoomControlStates>[]

Defined in: packages/being/dist/interface.d.ts:470

Inherited from

TemplateStateMachine._stateChangeCallbacks

_states

protected _states: Record<States, State<EventPayloadMapping, Context, States, EventOutputMapping>>

Defined in: packages/being/dist/interface.d.ts:467

Inherited from

TemplateStateMachine._states

_statesArray

protected _statesArray: ZoomControlStates[]

Defined in: packages/being/dist/interface.d.ts:469

Inherited from

TemplateStateMachine._statesArray

_timeouts

protected _timeouts: number | undefined

Defined in: packages/being/dist/interface.d.ts:473

Inherited from

TemplateStateMachine._timeouts

Accessors

context

Get Signature

get context(): Context

Defined in: packages/being/dist/interface.d.ts:487

Read-only access to the machine's live context object. Optional so existing StateMachine implementations remain valid; TemplateStateMachine always provides it. Intended for tooling/introspection (e.g. visualizers evaluating guards against the current context) — mutate state through events, not through this reference.

Returns

Context

Inherited from

TemplateStateMachine.context

currentState

Get Signature

get currentState(): States | "INITIAL" | "TERMINAL"

Defined in: packages/being/dist/interface.d.ts:485

Returns

States | "INITIAL" | "TERMINAL"

Inherited from

TemplateStateMachine.currentState

possibleStates

Get Signature

get possibleStates(): States[]

Defined in: packages/being/dist/interface.d.ts:488

Returns

States[]

Inherited from

TemplateStateMachine.possibleStates

states

Get Signature

get states(): Record<States, State<EventPayloadMapping, Context, States, EventOutputMapping>>

Defined in: packages/being/dist/interface.d.ts:489

Returns

Record<States, State<EventPayloadMapping, Context, States, EventOutputMapping>>

Inherited from

TemplateStateMachine.states

Methods

happens()

Call Signature

happens<K>(...args): EventResult<ZoomControlStates, K extends keyof ZoomControlOutputMapping ? ZoomControlOutputMapping[K<K>] : void>

Defined in: packages/being/dist/interface.d.ts:480

Type Parameters

K

K extends keyof ZoomEventPayloadMapping

Parameters

args

...EventArgs<ZoomEventPayloadMapping, K>

Returns

EventResult<ZoomControlStates, K extends keyof ZoomControlOutputMapping ? ZoomControlOutputMapping[K<K>] : void>

Inherited from

TemplateStateMachine.happens

Call Signature

happens<K>(...args): EventResult<ZoomControlStates, unknown>

Defined in: packages/being/dist/interface.d.ts:481

Type Parameters

K

K extends string

Parameters

args

...EventArgs<ZoomEventPayloadMapping, K>

Returns

EventResult<ZoomControlStates, unknown>

Inherited from

TemplateStateMachine.happens

initateTransition()

initateTransition(): EventResult<ZoomControlStates, void>

Defined in: packages/board/src/camera/camera-mux/animation-and-lock/zoom-control-state-machine.ts:533

Initiates transition to TRANSITION state.

Returns

EventResult<ZoomControlStates, void>

Remarks

Forces state change to begin animation or transition sequence. Called when starting programmatic camera movements.

notifyZoomByAtInput()

notifyZoomByAtInput(delta, at): EventResult<ZoomControlStates, ZoomControlOutputEvent>

Defined in: packages/board/src/camera/camera-mux/animation-and-lock/zoom-control-state-machine.ts:468

Notifies the state machine of user zoom input around an anchor point.

Parameters

delta

number

Zoom delta (multiplier)

at

Point

Anchor point for zoom

Returns

EventResult<ZoomControlStates, ZoomControlOutputEvent>

Event handling result with output event

Remarks

Dispatches userZoomByAtInput event. Accepted in ACCEPTING_USER_INPUT and TRANSITION states.

notifyZoomByAtInputAnimation()

notifyZoomByAtInputAnimation(delta, at): EventResult<ZoomControlStates, ZoomControlOutputEvent>

Defined in: packages/board/src/camera/camera-mux/animation-and-lock/zoom-control-state-machine.ts:485

Initiates a zoom animation around an anchor point.

Parameters

delta

number

Zoom delta (multiplier)

at

Point

Anchor point for zoom

Returns

EventResult<ZoomControlStates, ZoomControlOutputEvent>

Event handling result

Remarks

Dispatches transitionZoomByAtInput event, starting a zoom animation.

notifyZoomToAtCenterInput()

notifyZoomToAtCenterInput(targetZoom, at): EventResult<ZoomControlStates, ZoomControlOutputEvent>

Defined in: packages/board/src/camera/camera-mux/animation-and-lock/zoom-control-state-machine.ts:502

Initiates a zoom animation to target level around center anchor.

Parameters

targetZoom

number

Target zoom level

at

Point

Anchor point for zoom

Returns

EventResult<ZoomControlStates, ZoomControlOutputEvent>

Event handling result

Remarks

Dispatches transitionZoomToAtCenterInput event for center-anchored zoom animation.

notifyZoomToAtWorldInput()

notifyZoomToAtWorldInput(targetZoom, at): EventResult<ZoomControlStates, ZoomControlOutputEvent>

Defined in: packages/board/src/camera/camera-mux/animation-and-lock/zoom-control-state-machine.ts:519

Initiates a zoom animation to target level around world anchor.

Parameters

targetZoom

number

Target zoom level

at

Point

World anchor point for zoom

Returns

EventResult<ZoomControlStates, ZoomControlOutputEvent>

Event handling result

Remarks

Dispatches transitionZoomToAtWorldInput event for world-anchored zoom animation.

onEventResult()

onEventResult(callback): () => void

Defined in: packages/being/dist/interface.d.ts:484

Subscribe to every event result. Optional so existing StateMachine implementations remain valid; TemplateStateMachine always provides it. Returns a disposer on implementations that support one. Disposing during a dispatch takes effect starting with the next dispatch, not the one in progress — see EventResultCallback for the exact snapshot-iteration semantics.

Parameters

callback

EventResultCallback<ZoomEventPayloadMapping, BaseContext, ZoomControlStates>

Returns

(): void

Returns

void

Inherited from

TemplateStateMachine.onEventResult

onHappens()

onHappens(callback): () => void

Defined in: packages/being/dist/interface.d.ts:483

Subscribe to every happens() call, before the state handles it. Returns a disposer on implementations that support one. Disposing during a dispatch takes effect starting with the next dispatch, not the one in progress — see EventResultCallback for the exact snapshot-iteration semantics.

Parameters

callback

(args, context) => void

Returns

(): void

Returns

void

Inherited from

TemplateStateMachine.onHappens

onStateChange()

onStateChange(callback): () => void

Defined in: packages/being/dist/interface.d.ts:482

Subscribe to state changes. Returns a disposer on implementations that support one. Disposing during a dispatch takes effect starting with the next dispatch, not the one in progress — see EventResultCallback for the exact snapshot-iteration semantics.

Parameters

callback

StateChangeCallback<ZoomControlStates>

Returns

(): void

Returns

void

Inherited from

TemplateStateMachine.onStateChange

reset()

reset(): void

Defined in: packages/being/dist/interface.d.ts:476

Returns

void

Inherited from

TemplateStateMachine.reset

setContext()

setContext(context): void

Defined in: packages/being/dist/interface.d.ts:486

Parameters

context

BaseContext

Returns

void

Inherited from

TemplateStateMachine.setContext

start()

start(): void

Defined in: packages/being/dist/interface.d.ts:477

Returns

void

Inherited from

TemplateStateMachine.start

switchTo()

switchTo(state): void

Defined in: packages/being/dist/interface.d.ts:479

Parameters

state

ZoomControlStates | "INITIAL" | "TERMINAL"

Returns

void

Inherited from

TemplateStateMachine.switchTo

wrapup()

wrapup(): void

Defined in: packages/being/dist/interface.d.ts:478

Returns

void

Inherited from

TemplateStateMachine.wrapup

Class: ZoomControlStateMachine ​

Remarks ​

Example ​

See ​

Extends ​

Constructors ​

Constructor ​

Parameters ​

states ​

initialState ​

context ​

Returns ​

Overrides ​

Properties ​

_context ​

Inherited from ​

_currentState ​

Inherited from ​

_eventResultCallbacks ​

Inherited from ​

_happensCallbacks ​

Parameters ​

args ​

context ​

Returns ​

Inherited from ​

_initialState ​

Inherited from ​

_stateChangeCallbacks ​

Inherited from ​

_states ​

Inherited from ​

_statesArray ​

Inherited from ​

_timeouts ​

Inherited from ​

Accessors ​

context ​

Get Signature ​

Returns ​

Inherited from ​

currentState ​

Get Signature ​

Returns ​

Inherited from ​

possibleStates ​

Get Signature ​

Returns ​

Inherited from ​

states ​

Get Signature ​

Returns ​

Inherited from ​

Methods ​

happens() ​

Call Signature ​

Type Parameters ​

K ​

Parameters ​

args ​

Returns ​

Inherited from ​

Call Signature ​

Type Parameters ​

K ​

Parameters ​

args ​

Returns ​

Inherited from ​

initateTransition() ​

Returns ​

Remarks ​

notifyZoomByAtInput() ​

Parameters ​

delta ​

at ​

Returns ​

Remarks ​

notifyZoomByAtInputAnimation() ​

Parameters ​

Class: ZoomControlStateMachine

Remarks

Example

See

Extends

Constructors

Constructor

Parameters

states

initialState

context

Returns

Overrides

Properties

_context

Inherited from

_currentState

Inherited from

_eventResultCallbacks

Inherited from

_happensCallbacks

Parameters

args

context

Returns

Inherited from

_initialState

Inherited from

_stateChangeCallbacks

Inherited from

_states

Inherited from

_statesArray

Inherited from

_timeouts

Inherited from

Accessors

context

Get Signature

Returns

Inherited from

currentState

Get Signature

Returns

Inherited from

possibleStates

Get Signature

Returns

Inherited from

states

Get Signature

Returns

Inherited from

Methods

happens()

Call Signature

Type Parameters

K

Parameters

args

Returns

Inherited from

Call Signature

Type Parameters

K

Parameters

args

Returns

Inherited from

initateTransition()

Returns

Remarks

notifyZoomByAtInput()

Parameters

delta

at

Returns

Remarks

notifyZoomByAtInputAnimation()

Parameters