/**
 * @description Framework-free periodic-table input shared by MolVis
 * consumers. It defaults to carbon (`"C"`), reflects `value` and `disabled`
 * between properties and attributes, and accepts `compact` as a presence-only
 * toolbar attribute. Element symbols are normalized and validated; assigning
 * an invalid `value` throws `TypeError` without changing the prior value.
 *
 * Importing this module does not register a tag. After explicit registration,
 * a user selection emits bubbling, composed `input` followed by `change`;
 * programmatic value changes emit neither event.
 *
 * @example
 * ```ts
 * import { defineMolvisElementPicker } from
 *   "@molcrafts/molvis-core/element-picker";
 *
 * defineMolvisElementPicker();
 * const picker = document.createElement("molvis-element-picker");
 * picker.value = "Fe";
 * picker.addEventListener("input", () => console.log(picker.value));
 * document.body.append(picker);
 * ```
 */
export declare class MolvisElementPickerElement extends HTMLElement {
    static get observedAttributes(): readonly string[];
    private currentValue;
    private reflectingValue;
    private readonly trigger;
    private readonly triggerSymbol;
    private readonly triggerName;
    private readonly popoverPanel;
    private readonly buttons;
    private connectionAbortController;
    constructor();
    /**
     * Selected chemical symbol. Defaults to `"C"`, normalizes letter case, and
     * reflects to the `value` attribute. Invalid symbols throw `TypeError`.
     */
    get value(): string;
    set value(value: string);
    /**
     * Whether interaction is disabled. This reflects the boolean `disabled`
     * attribute, prevents opening or selection, and closes an open picker.
     */
    get disabled(): boolean;
    set disabled(value: boolean);
    connectedCallback(): void;
    disconnectedCallback(): void;
    attributeChangedCallback(name: string, oldValue: string | null, newValue: string | null): void;
    private readonly repositionIfOpen;
    private createElementButton;
    private reflectValue;
    private setCurrentValue;
    private updateUi;
    private updateDisabled;
    private isPickerOpen;
    private togglePicker;
    private positionPopover;
    private handleGridKeydown;
    private findNeighbor;
    private selectFromUser;
}
/**
 * @description Idempotently register the shared periodic-table picker. The
 * function consults `customElements.get()` first, so repeated calls for the
 * same tag are safe. Importing the module alone has no registration side
 * effect.
 *
 * @param {string} tag - Custom-element tag to register. Defaults to
 * `"molvis-element-picker"`.
 * @returns {void}
 *
 * @example
 * ```ts
 * defineMolvisElementPicker();
 * document.body.append(document.createElement("molvis-element-picker"));
 * ```
 */
export declare function defineMolvisElementPicker(tag?: string): void;
declare global {
    interface HTMLElementTagNameMap {
        "molvis-element-picker": MolvisElementPickerElement;
    }
}