/**
 * @license
 * Copyright 2020 Google Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
import type { MDCListTextAndIndex } from './types';
/**
 * State of a typeahead instance.
 */
export interface TypeaheadState {
    typeaheadBuffer: string;
    currentFirstChar: string;
    sortedIndexCursor: number;
    bufferClearTimeout: number;
}
/**
 * Initializes a state object for typeahead. Use the same reference for calls to
 * typeahead functions.
 *
 * @return The current state of the typeahead process. Each state reference
 *     represents a typeahead instance as the reference is typically mutated
 *     in-place.
 */
export declare function initState(): TypeaheadState;
/**
 * Initializes typeahead state by indexing the current list items by primary
 * text into the sortedIndexByFirstChar data structure.
 *
 * @param listItemCount numer of items in the list
 * @param getPrimaryTextByItemIndex function that returns the primary text at a
 *     given index
 *
 * @return Map that maps the first character of the primary text to the full
 *     list text and its index
 */
export declare function initSortedIndex(listItemCount: number, getPrimaryTextByItemIndex: (index: number) => string): Map<string, MDCListTextAndIndex[]>;
/**
 * Arguments for matchItem
 */
export interface TypeaheadMatchItemOpts {
    focusItemAtIndex: (index: number) => void;
    nextChar: string;
    focusedItemIndex: number;
    sortedIndexByFirstChar: Map<string, MDCListTextAndIndex[]>;
    skipFocus: boolean;
    isItemAtIndexDisabled: (index: number) => boolean;
}
/**
 * Given the next desired character from the user, it attempts to find the next
 * list option matching the buffer. Wraps around if at the end of options.
 *
 * @param opts Options and accessors
 *   - nextChar - the next character to match against items
 *   - sortedIndexByFirstChar - output of `initSortedIndex(...)`
 *   - focusedItemIndex - the index of the currently focused item
 *   - focusItemAtIndex - function that focuses a list item at given index
 *   - skipFocus - whether or not to focus the matched item
 *   - isItemAtIndexDisabled - function that determines whether an item at a
 *        given index is disabled
 * @param state The typeahead state instance. See `initState`.
 *
 * @return The index of the matched item, or -1 if no match.
 */
export declare function matchItem(opts: TypeaheadMatchItemOpts, state: TypeaheadState): number;
/**
 * Whether or not the given typeahead instaance state is currently typing.
 *
 * @param state The typeahead state instance. See `initState`.
 */
export declare function isTypingInProgress(state: TypeaheadState): boolean;
/**
 * Options for handleKeydown.
 */
export interface HandleKeydownOpts {
    event: KeyboardEvent;
    isTargetListItem: boolean;
    focusItemAtIndex: (index: number) => void;
    focusedItemIndex: number;
    sortedIndexByFirstChar: Map<string, MDCListTextAndIndex[]>;
    isItemAtIndexDisabled: (index: number) => boolean;
}
/**
 * Clears the typeahaed buffer so that it resets item matching to the first
 * character.
 *
 * @param state The typeahead state instance. See `initState`.
 */
export declare function clearBuffer(state: TypeaheadState): void;
/**
 * Given a keydown event, it calculates whether or not to automatically focus a
 * list item depending on what was typed mimicking the typeahead functionality
 * of a standard <select> element that is open.
 *
 * @param opts Options and accessors
 *   - event - the KeyboardEvent to handle and parse
 *   - sortedIndexByFirstChar - output of `initSortedIndex(...)`
 *   - focusedItemIndex - the index of the currently focused item
 *   - focusItemAtIndex - function that focuses a list item at given index
 *   - isItemAtFocusedIndexDisabled - whether or not the currently focused item
 *      is disabled
 *   - isTargetListItem - whether or not the event target is a list item
 * @param state The typeahead state instance. See `initState`.
 *
 * @return index of the item matched by the keydown. -1 if not matched.
 */
export declare function handleKeydown(opts: HandleKeydownOpts, state: TypeaheadState): number;