/**
 * @license
 * Copyright The Closure Library Authors.
 * SPDX-License-Identifier: Apache-2.0
 */
/**
 * @fileoverview Single-selection model implemenation.
 *
 * TODO(attila): Add keyboard & mouse event hooks?
 * TODO(attila): Add multiple selection?
 */
/**
 * Single-selection model.  Dispatches a {@link EventType.SELECT}
 * event when a selection is made.
 * @extends {EventsEventTarget}
 */
export class SelectionModel extends EventsEventTarget {
    /**
     * Single-selection model.  Dispatches a {@link EventType.SELECT}
     * event when a selection is made.
     * @param {Array<Object>=} opt_items Array of items; defaults to empty.
     */
    constructor(opt_items?: Array<any> | undefined);
    /**
     * The currently selected item (null if none).
     * @type {?Object}
     * @private
     */
    private selectedItem_;
    /**
     * Selection handler function.  Called with two arguments (the item to be
     * selected or deselected, and a Boolean indicating whether the item is to
     * be selected or deselected).
     * @type {?Function}
     * @private
     */
    private selectionHandler_;
    /**
     * Array of items controlled by the selection model.  If the items support
     * the `setSelected(Boolean)` interface, they will be (de)selected
     * as needed.
     * @type {!Array<Object>}
     * @private
     */
    private items_;
    /**
     * Returns the selection handler function used by the selection model to change
     * the internal selection state of items under its control.
     * @return {?Function} Selection handler function (null if none).
     */
    getSelectionHandler(): Function | null;
    /**
     * Sets the selection handler function to be used by the selection model to
     * change the internal selection state of items under its control.  The
     * function must take two arguments:  an item and a Boolean to indicate whether
     * the item is to be selected or deselected.  Selection handler functions are
     * only needed if the items in the selection model don't natively support the
     * `setSelected(Boolean)` interface.
     * @param {?Function} handler Selection handler function.
     */
    setSelectionHandler(handler: Function | null): void;
    /**
     * Returns the number of items controlled by the selection model.
     * @return {number} Number of items.
     */
    getItemCount(): number;
    /**
     * Returns the 0-based index of the given item within the selection model, or
     * -1 if no such item is found.
     * @param {Object|undefined} item Item to look for.
     * @return {number} Index of the given item (-1 if none).
     */
    indexOfItem(item: any | undefined): number;
    /**
     * @return {Object|undefined} The first item, or undefined if there are no items
     *     in the model.
     */
    getFirst(): any | undefined;
    /**
     * @return {Object|undefined} The last item, or undefined if there are no items
     *     in the model.
     */
    getLast(): any | undefined;
    /**
     * Returns the item at the given 0-based index.
     * @param {number} index Index of the item to return.
     * @return {?Object} Item at the given index (null if none).
     */
    getItemAt(index: number): any | null;
    /**
     * Bulk-adds items to the selection model.  This is more efficient than calling
     * {@link #addItem} for each new item.
     * @param {Array<Object>|undefined} items New items to add.
     */
    addItems(items: Array<any> | undefined): void;
    /**
     * Adds an item at the end of the list.
     * @param {?Object} item Item to add.
     */
    addItem(item: any | null): void;
    /**
     * Adds an item at the given index.
     * @param {?Object} item Item to add.
     * @param {number} index Index at which to add the new item.
     */
    addItemAt(item: any | null, index: number): void;
    /**
     * Removes the given item (if it exists).  Dispatches a `SELECT` event if
     * the removed item was the currently selected item.
     * @param {?Object} item Item to remove.
     */
    removeItem(item: any | null): void;
    /**
     * Removes the item at the given index.
     * @param {number} index Index of the item to remove.
     */
    removeItemAt(index: number): void;
    /**
     * @return {?Object} The currently selected item, or null if none.
     */
    getSelectedItem(): any | null;
    /**
     * @return {!Array<Object>} All items in the selection model.
     */
    getItems(): Array<any>;
    /**
     * Selects the given item, deselecting any previously selected item, and
     * dispatches a `SELECT` event.
     * @param {?Object} item Item to select (null to clear the selection).
     */
    setSelectedItem(item: any | null): void;
    /**
     * @return {number} The 0-based index of the currently selected item, or -1
     *     if none.
     */
    getSelectedIndex(): number;
    /**
     * Selects the item at the given index, deselecting any previously selected
     * item, and dispatches a `SELECT` event.
     * @param {number} index Index to select (-1 to clear the selection).
     */
    setSelectedIndex(index: number): void;
    /**
     * Clears the selection model by removing all items from the selection.
     */
    clear(): void;
    /**
     * Private helper; selects or deselects the given item based on the value of
     * the `select` argument.  If a selection handler has been registered
     * (via {@link #setSelectionHandler}, calls it to update the internal selection
     * state of the item.  Otherwise, attempts to call `setSelected(Boolean)`
     * on the item itself, provided the object supports that interface.
     * @param {?Object} item Item to select or deselect.
     * @param {boolean} select If true, the object will be selected; if false, it
     *     will be deselected.
     * @private
     */
    private selectItem_;
}
import { EventTarget as EventsEventTarget } from "../events/eventhandler.js";