/**
 * Copyright (c) Microsoft Corporation. All rights reserved.
 * Licensed under the MIT License.
 */
import { TurnContext } from '@microsoft/agents-hosting';
import { Prompt, PromptOptions, PromptRecognizerResult, PromptValidator } from './prompt';
import { Attachment } from '@microsoft/agents-activity';
/**
 * Prompts a user to upload attachments like images.
 *
 * @remarks
 * By default the prompt will return to the calling dialog an `Attachment[]`.
 *
 */
export declare class AttachmentPrompt extends Prompt<Attachment[]> {
    constructor(dialogId: string, validator?: PromptValidator<Attachment[]>);
    /**
       * Prompts the user for input.
       *
       * @param context Context for the current turn of conversation with the user.
       * @param state Contains state for the current instance of the prompt on the dialog stack.
       * @param options A prompt options object constructed from the options initially provided
       * in the call to Prompt.
       * @param isRetry `true` if this is the first time this prompt dialog instance
       * on the stack is prompting the user for input; otherwise, false.
       * @returns A Promise representing the asynchronous operation.
       */
    protected onPrompt(context: TurnContext, state: any, options: PromptOptions, isRetry: boolean): Promise<void>;
    /**
       * Attempts to recognize the user's input.
       *
       * @param context Context for the current turn of conversation with the user.
       * @param _state Contains state for the current instance of the prompt on the dialog stack.
       * @param _options A prompt options object constructed from the options initially provided
       * in the call to Prompt.
       * @returns A Promise representing the asynchronous operation.
       */
    protected onRecognize(context: TurnContext, _state: any, _options: PromptOptions): Promise<PromptRecognizerResult<Attachment[]>>;
}