import { LitElement } from "lit";
export type FormState = string | File | FormData | null | string;
export declare abstract class FormControlBase extends LitElement {
    /** Enables form-associated custom element behavior */
    static formAssociated: boolean;
    protected internals: ElementInternals;
    protected defaultValue: string;
    /** Native form attributes you’ll reuse everywhere */
    name: string;
    formId: string | null;
    disabled: boolean;
    readonly: boolean;
    required: boolean;
    requiredMessage: string;
    constructor();
    get form(): HTMLFormElement | null;
    get validity(): ValidityState;
    get validationMessage(): string;
    get willValidate(): boolean;
    checkValidity(): boolean;
    reportValidity(): boolean;
    formResetCallback(): void;
    formDisabledCallback(disabled: boolean): void;
    formStateRestoreCallback(state: FormState): void;
    /** Must return current “submission value” (string/file/formdata) */
    protected abstract getFormValue(): FormState;
    /** Must set the component state from restored state (usually string) */
    protected abstract setValueFromFormState(state: FormState): void;
    /** Must return the internal focusable control to anchor validity bubbles */
    protected abstract getValidityAnchor(): HTMLElement | undefined;
    /** Must return true if empty (for required) */
    protected abstract isEmpty(): boolean;
    /** Must return the native control you want to proxy to (input/textarea/select/...) */
    protected abstract getNativeControl(): HTMLElement | null;
    /** Optional: return first custom error message (or empty string) */
    protected getCustomErrorMessage(): string;
    protected validateForForm(): string;
    /** Optional: reset component to default */
    protected onFormReset(): void;
    /** Optional: react to fieldset disabled */
    protected onFormDisabled(_disabled: boolean): void;
    /** Optional: handle BFCache restore */
    protected onFormStateRestore(state: FormState): void;
    /**
     * Called by base after a proxy method mutates the native control.
     * Subclasses should pull native.value into their state and optionally validate.
     */
    protected onNativeValueMutated(_native: any): void;
    protected syncFormValue(): void;
    protected syncValidity(): void;
    protected reemitNativeEvent(type: string, originalEvent: Event, init?: Partial<EventInit> & {
        detail?: any;
    }): void;
    /** Call once after initial render */
    protected captureDefaultValue(initial: string): void;
    protected get nativeControl(): any | null;
    protected get nativeInput(): HTMLInputElement | null;
    protected get nativeTextarea(): HTMLTextAreaElement | null;
    /** Central sync after proxy calls */
    protected syncFromNative(runValidity?: boolean): void;
    focus(options?: FocusOptions): void;
    blur(): void;
    click(): void;
    showPicker(): boolean;
    protected getSelectionTarget(): HTMLInputElement | HTMLTextAreaElement | null;
    get selectionStart(): number | null;
    set selectionStart(v: number | null);
    get selectionEnd(): number | null;
    set selectionEnd(v: number | null);
    get selectionDirection(): "forward" | "backward" | "none" | null;
    select(): void;
    setSelectionRange(start: number, end: number, direction?: "forward" | "backward" | "none"): void;
    setRangeText(replacement: string, start?: number, end?: number, selectionMode?: "select" | "start" | "end" | "preserve"): void;
    get valueAsNumber(): number;
    set valueAsNumber(v: number);
    get valueAsDate(): Date | null;
    set valueAsDate(v: Date | null);
    stepUp(n?: number): void;
    stepDown(n?: number): void;
    setCustomValidity(message: string): void;
}