import { type Data } from '../common/types';
export type ControlMessage<Payload = Data> = {
    [key: string]: Data;
} & {
    type: string;
    payload?: Payload;
};
export type ControlInstanceKey = {
    elementKey: string;
    propPath: string;
};
export type ControlInstanceArgs<M extends ControlMessage = ControlMessage> = {
    instanceKey: ControlInstanceKey;
    sendMessage: SendMessage<M>;
};
export type SendMessage<M extends ControlMessage = ControlMessage> = (message: M) => void;
export declare abstract class ControlInstance<M extends ControlMessage = ControlMessage> {
    readonly instanceKey: ControlInstanceKey;
    protected readonly sendMessage: SendMessage<M>;
    constructor({ instanceKey, sendMessage }: ControlInstanceArgs<M>);
    get elementKey(): string;
    get propPath(): string;
    abstract recv(message: M): void;
    /**
     * Subscribe to changes to the instance state; returns an unsubscribe function.
     */
    abstract subscribe(listener: () => void): () => void;
    /**
     * Returns true if the control represents a composite prop value (a prop that contains other props).
     *
     * In contrast with `children()`, this return value doesn't change over the control lifetime.
     */
    abstract isCompositeProp(): boolean;
    /**
     * Returns a list of child control instances for this control's immediate nested props.
     */
    abstract children(): ControlInstance[];
    /**
     * Returns the control instance for the nested prop identified by `key`.
     *
     * For list controls, `key` is a stringified item index.
     */
    abstract child(key: string): ControlInstance | undefined;
    /**
     * Returns true if the control resolves to a renderable node.
     *
     * In React, that means the resolved value is a `ReactNode`. In other renderers, it is the equivalent
     * renderable node type.
     */
    abstract resolvesToRenderableNode(): boolean;
}
export declare class DefaultControlInstance extends ControlInstance {
    recv(_message: ControlMessage): void;
    subscribe(_listener: () => void): () => void;
    isCompositeProp(): boolean;
    children(): ControlInstance[];
    child(_key: string): undefined;
    resolvesToRenderableNode(): boolean;
}
export type SendMessageType<I> = I extends ControlInstance<infer M> ? M : never;
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