/**
 * What a calendar is showing: the days of a month, the months of a year, or a run of years.
 *
 * A calendar that only pages a month at a time makes a birth date thirty clicks away, so two of the
 * three renderers grew a month picker and a year picker — separately, with the same seven class
 * names, none of them in the catalogue, neither carrying a role. The third grew nothing, and nobody
 * decided that either.
 *
 * The mode is state, so it belongs to the controller for the kind rather than to each renderer, for
 * the reason the timepicker already demonstrates: it holds `viewMode` and its renderers ask.
 */
export declare const MDY_CALENDAR_VIEW_MODES: readonly ["days", "months", "years"];
export type MdyCalendarViewMode = (typeof MDY_CALENDAR_VIEW_MODES)[number];
/**
 * Where choosing in one view lands.
 *
 * Choosing a year narrows to its months, choosing a month narrows to its days — the funnel a user
 * expects, and the reason picking a year does not close the popup. Stated here so a renderer cannot
 * decide that a year jumps straight to the grid while another walks the funnel.
 */
export declare function calendarViewAfterPick(mode: MdyCalendarViewMode): MdyCalendarViewMode;
/**
 * Where the header's own control goes.
 *
 * The top of the funnel, not the next step down it: from the days it opens the *years*, because a
 * user reaching for the header is looking for a date far from the month on screen — a birth date, a
 * maturity — and walking through the months to get there is the paging the views exist to avoid.
 * From anywhere else it goes back to the days.
 *
 * Stated because the two renderers that had these views agreed on it by accident and a third,
 * written later, chose the other order.
 */
export declare function calendarViewOnToggle(mode: MdyCalendarViewMode): MdyCalendarViewMode;