@ue-too/board / index / expandKmtInputStateMachine

Function: expandKmtInputStateMachine()

expandKmtInputStateMachine<E, C, S, O>(context, define, initialState): TemplateStateMachine<E, C, S, O>

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-state-machine.ts:884

Builds a KMT input state machine with more events, states, context or outputs than the stock one, reusing every built-in state.

Type Parameters

E

E extends KmtInputEventMapping

C

C extends KmtInputContext

S

S extends string

O

O extends KmtInputEventOutputMapping & Partial<Record<keyof E, unknown>>

Parameters

context

C

The expanded context; must satisfy KmtInputContext

define

["IDLE" | "READY_TO_PAN_VIA_SPACEBAR" | "READY_TO_PAN_VIA_SCROLL_WHEEL" | "PAN" | "INITIAL_PAN" | "PAN_VIA_SCROLL_WHEEL" | "DISABLED"] extends [S] ? KmtInputStateMachineExpansion<E, C, S, O> : object

Receives the stock states and an extend helper, returns the expanded state map. See KmtInputStateMachineExpansion.

initialState

S = ...

Defaults to 'IDLE'

Returns

TemplateStateMachine<E, C, S, O>

A machine over the expanded generics

Remarks

The generics must be supersets of the stock ones: E extends KmtInputEventMapping, C extends KmtInputContext, O extends KmtInputEventOutputMapping, and S must include every KmtInputStates member (a type error otherwise). Shared events must keep the stock payload. Untouched stock states keep their stock behaviour and simply ignore events they do not know.

Example

type ExpEvents = KmtInputEventMapping & { rightPointerUp: PointerEventPayload };
type ExpStates = KmtInputStates | 'PLACEMENT';
type ExpOut = KmtInputEventOutputMapping & { rightPointerUp: KmtOutputEvent };

const machine = expandKmtInputStateMachine<ExpEvents, ExpContext, ExpStates, ExpOut>(
    context,
    (stock, extend) => ({
        ...stock,
        IDLE: extend(stock.IDLE, {
            eventReactions: { rightPointerUp: { action: openMenu, defaultTargetState: 'PLACEMENT' } },
        }),
        PLACEMENT: new PlacementState(),
    })
);