/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
import { Direction } from '@angular/cdk/bidi';
import { ElementRef } from '@angular/core';
import { DragDropRegistry } from '../drag-drop-registry';
import { DropListSortStrategy, DropListSortStrategyItem, SortPredicate } from './drop-list-sort-strategy';
/**
 * Strategy that only supports sorting along a single axis.
 * Items are reordered using CSS transforms which allows for sorting to be animated.
 * @docs-private
 */
export declare class SingleAxisSortStrategy<T extends DropListSortStrategyItem> implements DropListSortStrategy<T> {
    private _element;
    private _dragDropRegistry;
    /** Function used to determine if an item can be sorted into a specific index. */
    private _sortPredicate;
    /** Cache of the dimensions of all the items inside the container. */
    private _itemPositions;
    /**
     * Draggable items that are currently active inside the container. Includes the items
     * that were there at the start of the sequence, as well as any items that have been dragged
     * in, but haven't been dropped yet.
     */
    private _activeDraggables;
    /** Direction in which the list is oriented. */
    orientation: 'vertical' | 'horizontal';
    /** Layout direction of the drop list. */
    direction: Direction;
    constructor(_element: HTMLElement | ElementRef<HTMLElement>, _dragDropRegistry: DragDropRegistry<T, unknown>);
    /**
     * Keeps track of the item that was last swapped with the dragged item, as well as what direction
     * the pointer was moving in when the swap occurred and whether the user's pointer continued to
     * overlap with the swapped item after the swapping occurred.
     */
    private _previousSwap;
    /**
     * To be called when the drag sequence starts.
     * @param items Items that are currently in the list.
     */
    start(items: readonly T[]): void;
    /**
     * To be called when an item is being sorted.
     * @param item Item to be sorted.
     * @param pointerX Position of the item along the X axis.
     * @param pointerY Position of the item along the Y axis.
     * @param pointerDelta Direction in which the pointer is moving along each axis.
     */
    sort(item: T, pointerX: number, pointerY: number, pointerDelta: {
        x: number;
        y: number;
    }): {
        previousIndex: number;
        currentIndex: number;
    };
    getActiveItem(index: number): T;
    /**
     * Called when an item is being moved into the container.
     * @param item Item that was moved into the container.
     * @param pointerX Position of the item along the X axis.
     * @param pointerY Position of the item along the Y axis.
     * @param index Index at which the item entered. If omitted, the container will try to figure it
     *   out automatically.
     */
    enter(item: T, pointerX: number, pointerY: number, index?: number): void;
    /**
     * Called when an item is being nested into the another item.
     * @param item Item that was nested into the target item.
     * @param pointerX Position of the item along the X axis.
     * @param pointerY Position of the item along the Y axis.
     * @param nestIndex Target Index at which the item will be neste. If omitted, the container will try to figure it
     *   out automatically.
     */
    nest(item: T, nestIndex: number, currentNestIndex: number): void;
    unnest(item: T, nestIndex: number): void;
    /** Sets the items that are currently part of the list. */
    withItems(items: readonly T[]): void;
    /** Assigns a sort predicate to the strategy. */
    withSortPredicate(predicate: SortPredicate<T>): void;
    /** Resets the strategy to its initial state before dragging was started. */
    reset(): void;
    /**
     * Gets a snapshot of items currently in the list.
     * Can include items that we dragged in from another list.
     */
    getActiveItemsSnapshot(): readonly T[];
    /** Gets the index of a specific item. */
    getItemIndex(item: T): number;
    /** Used to notify the strategy that the scroll position has changed. */
    updateOnScroll(topDifference: number, leftDifference: number): void;
    /** Refreshes the position cache of the items and sibling containers. */
    private _cacheItemPositions;
    /**
     * Gets the offset in pixels by which the item that is being dragged should be moved.
     * @param currentPosition Current position of the item.
     * @param newPosition Position of the item where the current item should be moved.
     * @param delta Direction in which the user is moving.
     */
    private _getItemOffsetPx;
    /**
     * Gets the offset in pixels by which the items that aren't being dragged should be moved.
     * @param currentIndex Index of the item currently being dragged.
     * @param siblings All of the items in the list.
     * @param delta Direction in which the user is moving.
     */
    private _getSiblingOffsetPx;
    /**
     * Checks if pointer is entering in the first position
     * @param pointerX Position of the user's pointer along the X axis.
     * @param pointerY Position of the user's pointer along the Y axis.
     */
    private _shouldEnterAsFirstChild;
    /**
     *
     * @returns ClientRect values of all items
     */
    getItemBoundaries(): ClientRect[];
    /**
     * Gets the index of an item in the drop container, based on the position of the user's pointer.
     * @param item Item that is being sorted.
     * @param pointerX Position of the user's pointer along the X axis.
     * @param pointerY Position of the user's pointer along the Y axis.
     * @param delta Direction in which the user is moving their pointer.
     */
    private _getItemIndexFromPointerPosition;
}