import { NgControl } from '@angular/forms';
import { Observable } from 'rxjs';
/** An interface which allows a control to work inside of a `KbqFormField`. */
export declare abstract class KbqFormFieldControl<T> {
    /** The value of the control. */
    value: T | null;
    /**
     * Stream that emits whenever the state of the control changes such that the parent `KbqFormField`
     * needs to run change detection.
     */
    readonly stateChanges: Observable<void>;
    /** The element ID for this control. */
    readonly id: string;
    /** The placeholder for this control. */
    readonly placeholder: string;
    /** Gets the NgControl for this control. */
    readonly ngControl: NgControl | null;
    /** Whether the control is focused. */
    readonly focused: boolean;
    /** Whether the control is empty. */
    readonly empty: boolean;
    /** Whether the control is required. */
    readonly required: boolean;
    /** Whether the control is disabled. */
    readonly disabled: boolean;
    /** Whether the control is in an error state. */
    readonly errorState: boolean;
    /**
     * An optional name for the control type that can be used to distinguish `kbq-form-field` elements
     * based on their control type. The form field will add a class,
     * `kbq-form-field-type-{{controlType}}` to its root element.
     */
    readonly controlType?: string;
    /** Handles a click on the control's container. */
    abstract onContainerClick(event: MouseEvent): void;
    /** Focuses the control. */
    abstract focus(options?: FocusOptions): void;
    /** Opens control's overlay. */
    abstract open?(): void;
}