import { FlowGraphAsyncExecutionBlock } from "./flowGraphAsyncExecutionBlock.js";
import type { FlowGraphContext } from "./flowGraphContext.js";
import { FlowGraphEventType } from "./flowGraphEventType.js";
/**
 * A type of block that listens to an event observable and activates
 * its output signal when the event is triggered.
 */
export declare abstract class FlowGraphEventBlock extends FlowGraphAsyncExecutionBlock {
    /**
     * the priority of initialization of this block.
     * For example, scene start should have a negative priority because it should be initialized last.
     */
    initPriority: number;
    /**
     * The type of the event
     */
    readonly type: FlowGraphEventType;
    /**
     * @internal
     */
    _execute(context: FlowGraphContext): void;
    /**
     * Execute the event. This function should be called by the flow graph when the event is triggered.
     * @param context the context in which the event is executed
     * @param payload the payload of the event
     * @returns a boolean indicating if the event should stop propagation. if false, the event will stop propagating.
     */
    abstract _executeEvent(context: FlowGraphContext, payload: any): boolean;
}