/**
* @license Copyright (c) 2003-2026, CKSource Holding sp. z o.o. All rights reserved.
* For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-licensing-options
*/
/**
* @module ui/panel/sticky/stickypanelview
*/
import { View } from "../../view.js";
import { type ViewCollection } from "../../viewcollection.js";
import { type Locale } from "@ckeditor/ckeditor5-utils";
import "../../../theme/components/panel/stickypanel.css";
/**
* The sticky panel view class.
*/
export declare class StickyPanelView extends View {
	/**
	* Collection of the child views which creates balloon panel contents.
	*/
	readonly content: ViewCollection;
	/**
	* Controls whether the sticky panel should be active.
	*
	* @readonly
	* @observable
	*/
	isActive: boolean;
	/**
	* Controls whether the sticky panel is in the "sticky" state.
	*
	* @readonly
	* @observable
	*/
	isSticky: boolean;
	/**
	* The limiter element for the sticky panel instance. Its bounding rect limits
	* the "stickyness" of the panel, i.e. when the panel reaches the bottom
	* edge of the limiter, it becomes sticky to that edge and does not float
	* off the limiter. It is mandatory for the panel to work properly and once
	* set, it cannot be changed.
	*
	* @readonly
	* @observable
	*/
	limiterElement: HTMLElement | null;
	/**
	* The offset from the bottom edge of {@link #limiterElement}
	* which stops the panel from stickying any further to prevent limiter's content
	* from being completely covered.
	*
	* @readonly
	* @observable
	* @default 50
	*/
	limiterBottomOffset: number;
	/**
	* The offset from the top edge of the web browser's viewport which makes the
	* panel become sticky. The default value is `0`, which means the panel becomes
	* sticky when it's upper edge touches the top of the page viewport.
	*
	* This attribute is useful when the web page has UI elements positioned to the top
	* either using `position: fixed` or `position: sticky`, which would cover the
	* sticky panel or vice–versa (depending on the `z-index` hierarchy).
	*
	* Bound to {@link module:ui/editorui/editorui~EditorUI#viewportOffset `EditorUI#viewportOffset`}.
	*
	* If {@link module:core/editor/editorconfig~EditorConfig#ui `EditorConfig#ui.viewportOffset.top`} is defined, then
	* it will override the default value.
	*
	* @observable
	* @default 0
	*/
	viewportTopOffset: number;
	/**
	* The panel which accepts children into {@link #content} collection.
	* Also an element which is positioned when {@link #isSticky}.
	*/
	contentPanelElement: HTMLElement;
	/**
	* Controls the `margin-left` CSS style of the panel.
	*
	* @private
	* @readonly
	* @observable
	*/
	_marginLeft: string | null;
	/**
	* Set `true` if the sticky panel reached the bottom edge of the
	* {@link #limiterElement}.
	*
	* @private
	* @readonly
	* @observable
	*/
	_isStickyToTheBottomOfLimiter: boolean;
	/**
	* The `top` CSS position of the panel when it is sticky to the top of the viewport or scrollable
	* ancestors of the {@link #limiterElement}.
	*
	* @private
	* @readonly
	* @observable
	*/
	_stickyTopOffset: number | null;
	/**
	* The `bottom` CSS position of the panel when it is sticky to the bottom of the {@link #limiterElement}.
	*
	* @private
	* @readonly
	* @observable
	*/
	_stickyBottomOffset: number | null;
	/**
	* A dummy element which visually fills the space as long as the
	* actual panel is sticky. It prevents flickering of the UI.
	*/
	private _contentPanelPlaceholder;
	/**
	* @inheritDoc
	*/
	constructor(locale?: Locale);
	/**
	* @inheritDoc
	*/
	override render(): void;
	/**
	* Analyzes the environment to decide whether the panel should be sticky or not.
	* Then handles the positioning of the panel.
	*/
	checkIfShouldBeSticky(): void;
	/**
	* Sticks the panel at the given CSS `top` offset.
	*
	* @private
	* @param topOffset
	*/
	private _stickToTopOfAncestors;
	/**
	* Sticks the panel at the bottom of the limiter with a given CSS `bottom` offset.
	*
	* @private
	* @param stickyBottomOffset
	*/
	private _stickToBottomOfLimiter;
	/**
	* Unsticks the panel putting it back to its original position.
	*
	* @private
	*/
	private _unstick;
	/**
	* Returns the bounding rect of the {@link #contentPanelElement}.
	*
	* @private
	*/
	private get _contentPanelRect();
}