/**
* @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 engine/view/view
*/
import { ViewDocument } from "./document.js";
import { ViewDowncastWriter } from "./downcastwriter.js";
import { ViewDomConverter } from "./domconverter.js";
import { ViewPosition, type ViewPositionOffset } from "./position.js";
import { ViewRange } from "./range.js";
import { ViewSelection, type ViewPlaceOrOffset, type ViewSelectable, type ViewSelectionOptions } from "./selection.js";
import type { Observer, ObserverConstructor } from "./observer/observer.js";
import type { ViewDocumentFragment } from "./documentfragment.js";
import type { StylesProcessor } from "./stylesmap.js";
import { type ViewElement } from "./element.js";
import type { ViewNode } from "./node.js";
import { type ViewItem } from "./item.js";
import { KeyObserver } from "./observer/keyobserver.js";
import { FakeSelectionObserver } from "./observer/fakeselectionobserver.js";
import { MutationObserver } from "./observer/mutationobserver.js";
import { SelectionObserver } from "./observer/selectionobserver.js";
import { FocusObserver } from "./observer/focusobserver.js";
import { CompositionObserver } from "./observer/compositionobserver.js";
import { InputObserver } from "./observer/inputobserver.js";
import { ArrowKeysObserver } from "./observer/arrowkeysobserver.js";
import { TabObserver } from "./observer/tabobserver.js";
import { type IfTrue, type ObservableMixinConstructor } from "@ckeditor/ckeditor5-utils";
type DomRange = globalThis.Range;
declare const EditingViewBase: ObservableMixinConstructor;
/**
* Editor's view controller class. Its main responsibility is DOM - View management for editing purposes, to provide
* abstraction over the DOM structure and events and hide all browsers quirks.
*
* View controller renders view document to DOM whenever view structure changes. To determine when view can be rendered,
* all changes need to be done using the {@link module:engine/view/view~EditingView#change} method, using
* {@link module:engine/view/downcastwriter~ViewDowncastWriter}:
*
* ```ts
* view.change( writer => {
* 	writer.insert( position, writer.createText( 'foo' ) );
* } );
* ```
*
* View controller also register {@link module:engine/view/observer/observer~Observer observers} which observes changes
* on DOM and fire events on the {@link module:engine/view/document~ViewDocument Document}.
* Note that the following observers are added by the class constructor and are always available:
*
* * {@link module:engine/view/observer/selectionobserver~SelectionObserver},
* * {@link module:engine/view/observer/focusobserver~FocusObserver},
* * {@link module:engine/view/observer/keyobserver~KeyObserver},
* * {@link module:engine/view/observer/fakeselectionobserver~FakeSelectionObserver}.
* * {@link module:engine/view/observer/compositionobserver~CompositionObserver}.
* * {@link module:engine/view/observer/inputobserver~InputObserver}.
* * {@link module:engine/view/observer/arrowkeysobserver~ArrowKeysObserver}.
* * {@link module:engine/view/observer/tabobserver~TabObserver}.
*
* This class also {@link module:engine/view/view~EditingView#attachDomRoot binds the DOM and the view elements}.
*
* If you do not need full a DOM - view management, and only want to transform a tree of view elements to a tree of DOM
* elements you do not need this controller. You can use the {@link module:engine/view/domconverter~ViewDomConverter ViewDomConverter}
* instead.
*/
export declare class EditingView extends EditingViewBase {
	/**
	* Instance of the {@link module:engine/view/document~ViewDocument} associated with this view controller.
	*/
	readonly document: ViewDocument;
	/**
	* Instance of the {@link module:engine/view/domconverter~ViewDomConverter domConverter} used by
	* {@link module:engine/view/view~EditingView#_renderer renderer}
	* and {@link module:engine/view/observer/observer~Observer observers}.
	*/
	readonly domConverter: ViewDomConverter;
	/**
	* Roots of the DOM tree. Map on the `HTMLElement`s with roots names as keys.
	*/
	readonly domRoots: Map<string, HTMLElement>;
	/**
	* Used to prevent calling {@link #forceRender} and {@link #change} during rendering view to the DOM.
	*
	* @observable
	* @readonly
	*/
	isRenderingInProgress: boolean;
	/**
	* Informs whether the DOM selection is inside any of the DOM roots managed by the view.
	*
	* @observable
	* @readonly
	*/
	hasDomSelection: boolean;
	/**
	* Instance of the {@link module:engine/view/renderer~ViewRenderer renderer}.
	*/
	private readonly _renderer;
	/**
	* A DOM root attributes cache. It saves the initial values of DOM root attributes before the DOM element
	* is {@link module:engine/view/view~EditingView#attachDomRoot attached} to the view so later on, when
	* the view is destroyed ({@link module:engine/view/view~EditingView#detachDomRoot}), they can be easily restored.
	* This way, the DOM element can go back to the (clean) state as if the editing view never used it.
	*/
	private readonly _initialDomRootAttributes;
	/**
	* Map of registered {@link module:engine/view/observer/observer~Observer observers}.
	*/
	private readonly _observers;
	/**
	* ViewDowncastWriter instance used in {@link #change change method} callbacks.
	*/
	private readonly _writer;
	/**
	* Is set to `true` when {@link #change view changes} are currently in progress.
	*/
	private _ongoingChange;
	/**
	* Used to prevent calling {@link #forceRender} and {@link #change} during rendering view to the DOM.
	*/
	private _postFixersInProgress;
	/**
	* Internal flag to temporary disable rendering. See the usage in the {@link #_disableRendering}.
	*/
	private _renderingDisabled;
	/**
	* Internal flag that disables rendering when there are no changes since the last rendering.
	* It stores information about changed selection and changed elements from attached document roots.
	*/
	private _hasChangedSinceTheLastRendering;
	/**
	* @param stylesProcessor The styles processor instance.
	*/
	constructor(stylesProcessor: StylesProcessor);
	/**
	* Attaches a DOM root element to the view element and enable all observers on that element.
	* Also {@link module:engine/view/renderer~ViewRenderer#markToSync mark element} to be synchronized
	* with the view what means that all child nodes will be removed and replaced with content of the view root.
	*
	* This method also will change view element name as the same as tag name of given dom root.
	* Name is always transformed to lower case.
	*
	* **Note:** Use {@link #detachDomRoot `detachDomRoot()`} to revert this action.
	*
	* @param domRoot DOM root element.
	* @param name Name of the root.
	*/
	attachDomRoot(domRoot: HTMLElement, name?: string): void;
	/**
	* Detaches a DOM root element from the view element and restores its attributes to the state before
	* {@link #attachDomRoot `attachDomRoot()`}.
	*
	* @param name Name of the root to detach.
	*/
	detachDomRoot(name: string): void;
	/**
	* Gets DOM root element.
	*
	* @param name  Name of the root.
	* @returns DOM root element instance.
	*/
	getDomRoot(name?: string): HTMLElement | undefined;
	/**
	* Creates observer of the given type if not yet created, {@link module:engine/view/observer/observer~Observer#enable enables} it
	* and {@link module:engine/view/observer/observer~Observer#observe attaches} to all existing and future
	* {@link #domRoots DOM roots}.
	*
	* Note: Observers are recognized by their constructor (classes). A single observer will be instantiated and used only
	* when registered for the first time. This means that features and other components can register a single observer
	* multiple times without caring whether it has been already added or not.
	*
	* @param ObserverConstructor The constructor of an observer to add.
	* Should create an instance inheriting from {@link module:engine/view/observer/observer~Observer}.
	* @returns Added observer instance.
	*/
	addObserver(ObserverConstructor: ObserverConstructor): Observer;
	getObserver<T extends ObserverConstructor>(ObserverConstructor: T): T extends AlwaysRegisteredViewObservers ? InstanceType<T> : InstanceType<T> | undefined;
	/**
	* Disables all added observers.
	*/
	disableObservers(): void;
	/**
	* Enables all added observers.
	*/
	enableObservers(): void;
	/**
	* Scrolls the page viewport and {@link #domRoots} with their ancestors to reveal the
	* caret, **if not already visible to the user**.
	*
	* **Note**: Calling this method fires the {@link module:engine/view/view~ViewScrollToTheSelectionEvent} event that
	* allows custom behaviors.
	*
	* @param options Additional configuration of the scrolling behavior.
	* @param options.viewportOffset A distance between the DOM selection and the viewport boundary to be maintained
	* while scrolling to the selection (default is 20px). Setting this value to `0` will reveal the selection precisely at
	* the viewport boundary.
	* @param options.ancestorOffset A distance between the DOM selection and scrollable DOM root ancestor(s) to be maintained
	* while scrolling to the selection (default is 20px). Setting this value to `0` will reveal the selection precisely at
	* the scrollable ancestor(s) boundary.
	* @param options.alignToTop When set `true`, the DOM selection will be aligned to the top of the viewport if not already visible
	* (see `forceScroll` to learn more).
	* @param options.forceScroll When set `true`, the DOM selection will be aligned to the top of the viewport and scrollable ancestors
	* whether it is already visible or not. This option will only work when `alignToTop` is `true`.
	*/
	scrollToTheSelection<
		T extends boolean,
		U extends IfTrue<T>
	>({ alignToTop, forceScroll, viewportOffset, ancestorOffset }?: {
		readonly viewportOffset?: number | {
			top: number;
			bottom: number;
			left: number;
			right: number;
		};
		readonly ancestorOffset?: number;
		readonly alignToTop?: T;
		readonly forceScroll?: U;
	}): void;
	/**
	* It will focus DOM element representing {@link module:engine/view/editableelement~ViewEditableElement ViewEditableElement}
	* that is currently having selection inside.
	*/
	focus(): void;
	/**
	* The `change()` method is the primary way of changing the view. You should use it to modify any node in the view tree.
	* It makes sure that after all changes are made the view is rendered to the DOM (assuming that the view will be changed
	* inside the callback). It prevents situations when the DOM is updated when the view state is not yet correct. It allows
	* to nest calls one inside another and still performs a single rendering after all those changes are made.
	* It also returns the return value of its callback.
	*
	* ```ts
	* const text = view.change( writer => {
	* 	const newText = writer.createText( 'foo' );
	* 	writer.insert( position1, newText );
	*
	* 	view.change( writer => {
	* 		writer.insert( position2, writer.createText( 'bar' ) );
	* 	} );
	*
	* 	writer.remove( range );
	*
	* 	return newText;
	* } );
	* ```
	*
	* When the outermost change block is done and rendering to the DOM is over the
	* {@link module:engine/view/view~EditingView#event:render `View#render`} event is fired.
	*
	* This method throws a `applying-view-changes-on-rendering` error when
	* the change block is used after rendering to the DOM has started.
	*
	* @param callback Callback function which may modify the view.
	* @returns Value returned by the callback.
	*/
	change<TReturn>(callback: (writer: ViewDowncastWriter) => TReturn): TReturn;
	/**
	* Forces rendering {@link module:engine/view/document~ViewDocument view document} to DOM. If any view changes are
	* currently in progress, rendering will start after all {@link #change change blocks} are processed.
	*
	* Note that this method is dedicated for special cases. All view changes should be wrapped in the {@link #change}
	* block and the view will automatically check whether it needs to render DOM or not.
	*
	* Throws {@link module:utils/ckeditorerror~CKEditorError CKEditorError} `applying-view-changes-on-rendering` when
	* trying to re-render when rendering to DOM has already started.
	*/
	forceRender(): void;
	/**
	* Destroys this instance. Makes sure that all observers are destroyed and listeners removed.
	*/
	destroy(): void;
	/**
	* Creates position at the given location. The location can be specified as:
	*
	* * a {@link module:engine/view/position~ViewPosition position},
	* * parent element and offset (offset defaults to `0`),
	* * parent element and `'end'` (sets position at the end of that element),
	* * {@link module:engine/view/item~ViewItem view item} and `'before'` or `'after'` (sets position before or after given view item).
	*
	* This method is a shortcut to other constructors such as:
	*
	* * {@link #createPositionBefore},
	* * {@link #createPositionAfter},
	*
	* @param offset Offset or one of the flags. Used only when first parameter is a {@link module:engine/view/item~ViewItem view item}.
	*/
	createPositionAt(itemOrPosition: ViewItem | ViewPosition, offset?: ViewPositionOffset): ViewPosition;
	/**
	* Creates a new position after given view item.
	*
	* @param item View item after which the position should be located.
	*/
	createPositionAfter(item: ViewItem): ViewPosition;
	/**
	* Creates a new position before given view item.
	*
	* @param item View item before which the position should be located.
	*/
	createPositionBefore(item: ViewItem): ViewPosition;
	/**
	* Creates a range spanning from `start` position to `end` position.
	*
	* **Note:** This factory method creates it's own {@link module:engine/view/position~ViewPosition} instances basing on passed values.
	*
	* @param start Start position.
	* @param end End position. If not set, range will be collapsed at `start` position.
	*/
	createRange(start: ViewPosition, end?: ViewPosition | null): ViewRange;
	/**
	* Creates a range that starts before given {@link module:engine/view/item~ViewItem view item} and ends after it.
	*/
	createRangeOn(item: ViewItem): ViewRange;
	/**
	* Creates a range inside an {@link module:engine/view/element~ViewElement element} which starts before the first child of
	* that element and ends after the last child of that element.
	*
	* @param element Element which is a parent for the range.
	*/
	createRangeIn(element: ViewElement | ViewDocumentFragment): ViewRange;
	/**
	* Creates new {@link module:engine/view/selection~ViewSelection} instance.
	*
	* ```ts
	* // Creates collapsed selection at the position of given item and offset.
	* const paragraph = view.createContainerElement( 'paragraph' );
	* const selection = view.createSelection( paragraph, offset );
	*
	* // Creates a range inside an {@link module:engine/view/element~ViewElement element} which starts before the
	* // first child of that element and ends after the last child of that element.
	* const selection = view.createSelection( paragraph, 'in' );
	*
	* // Creates a range on an {@link module:engine/view/item~ViewItem item} which starts before the item and ends
	* // just after the item.
	* const selection = view.createSelection( paragraph, 'on' );
	* ```
	*
	* `Selection`'s factory method allow passing additional options (`backward`, `fake` and `label`) as the last argument.
	*
	* ```ts
	* // Creates backward selection.
	* const selection = view.createSelection( paragraph, 'in', { backward: true } );
	* ```
	*
	* Fake selection does not render as browser native selection over selected elements and is hidden to the user.
	* This way, no native selection UI artifacts are displayed to the user and selection over elements can be
	* represented in other way, for example by applying proper CSS class.
	*
	* Additionally fake's selection label can be provided. It will be used to describe fake selection in DOM
	* (and be  properly handled by screen readers).
	*
	* ```ts
	* // Creates fake selection with label.
	* const selection = view.createSelection( element, 'in', { fake: true, label: 'foo' } );
	* ```
	*
	* See also: {@link #createSelection:SELECTABLE `createSelection( selectable, options )`}.
	*
	* @label NODE_OFFSET
	*/
	createSelection(selectable: ViewNode, placeOrOffset: ViewPlaceOrOffset, options?: ViewSelectionOptions): ViewSelection;
	/**
	* Creates new {@link module:engine/view/selection~ViewSelection} instance.
	*
	* ```ts
	* // Creates empty selection without ranges.
	* const selection = view.createSelection();
	*
	* // Creates selection at the given range.
	* const range = view.createRange( start, end );
	* const selection = view.createSelection( range );
	*
	* // Creates selection at the given ranges
	* const ranges = [ view.createRange( start1, end2 ), view.createRange( star2, end2 ) ];
	* const selection = view.createSelection( ranges );
	*
	* // Creates selection from the other selection.
	* const otherSelection = view.createSelection();
	* const selection = view.createSelection( otherSelection );
	*
	* // Creates selection from the document selection.
	* const selection = view.createSelection( editor.editing.view.document.selection );
	*
	* // Creates selection at the given position.
	* const position = view.createPositionFromPath( root, path );
	* const selection = view.createSelection( position );
	* ```
	*
	* `Selection`'s factory method allow passing additional options (`backward`, `fake` and `label`) as the last argument.
	*
	* ```ts
	* // Creates backward selection.
	* const selection = view.createSelection( range, { backward: true } );
	* ```
	*
	* Fake selection does not render as browser native selection over selected elements and is hidden to the user.
	* This way, no native selection UI artifacts are displayed to the user and selection over elements can be
	* represented in other way, for example by applying proper CSS class.
	*
	* Additionally fake's selection label can be provided. It will be used to describe fake selection in DOM
	* (and be  properly handled by screen readers).
	*
	* ```ts
	* // Creates fake selection with label.
	* const selection = view.createSelection( range, { fake: true, label: 'foo' } );
	* ```
	*
	* See also: {@link #createSelection:NODE_OFFSET `createSelection( node, placeOrOffset, options )`}.
	*
	* @label SELECTABLE
	*/
	createSelection(selectable?: Exclude<ViewSelectable, ViewNode>, options?: ViewSelectionOptions): ViewSelection;
	/**
	* Disables or enables rendering. If the flag is set to `true` then the rendering will be disabled.
	* If the flag is set to `false` and if there was some change in the meantime, then the rendering action will be performed.
	*
	* @internal
	* @param flag A flag indicates whether the rendering should be disabled.
	*/
	_disableRendering(flag: boolean): void;
	/**
	* Renders all changes. In order to avoid triggering the observers (e.g. selection) all observers are disabled
	* before rendering and re-enabled after that.
	*/
	private _render;
}
/**
* Fired after a topmost {@link module:engine/view/view~EditingView#change change block} and all
* {@link module:engine/view/document~ViewDocument#registerPostFixer post-fixers} are executed.
*
* Actual rendering is performed as a first listener on 'normal' priority.
*
* ```ts
* view.on( 'render', () => {
* 	// Rendering to the DOM is complete.
* } );
* ```
*
* This event is useful when you want to update interface elements after the rendering, e.g. position of the
* balloon panel. If you wants to change view structure use
* {@link module:engine/view/document~ViewDocument#registerPostFixer post-fixers}.
*
* @eventName ~EditingView#render
*/
export type ViewRenderEvent = {
	name: "render";
	args: [];
};
/**
* An event fired at the moment of {@link module:engine/view/view~EditingView#scrollToTheSelection} being called. It
* carries two objects in its payload (`args`):
*
* * The first argument is the {@link module:engine/view/view~ViewScrollToTheSelectionEventData object containing data} that gets
*   passed down to the {@link module:utils/dom/scroll~scrollViewportToShowTarget} helper. If some event listener modifies it, it can
*   adjust the behavior of the scrolling (e.g. include additional `viewportOffset`).
* * The second argument corresponds to the original arguments passed to {@link module:utils/dom/scroll~scrollViewportToShowTarget}.
*   It allows listeners to re-execute the `scrollViewportToShowTarget()` method with its original arguments if there is such a need,
*   for instance, if the integration requires re–scrolling after certain interaction.
*
* @eventName ~EditingView#scrollToTheSelection
*/
export type ViewScrollToTheSelectionEvent = {
	name: "scrollToTheSelection";
	args: [ViewScrollToTheSelectionEventData, Parameters<EditingView["scrollToTheSelection"]>[0]];
};
/**
* An object passed down to the {@link module:utils/dom/scroll~scrollViewportToShowTarget} helper while calling
* {@link module:engine/view/view~EditingView#scrollToTheSelection}.
*/
export type ViewScrollToTheSelectionEventData = {
	target: DomRange;
	viewportOffset: {
		top: number;
		bottom: number;
		left: number;
		right: number;
	};
	ancestorOffset: number;
	alignToTop?: boolean;
	forceScroll?: boolean;
};
/**
* Observers that are always registered.
*/
export type AlwaysRegisteredViewObservers = typeof MutationObserver | typeof FocusObserver | typeof SelectionObserver | typeof KeyObserver | typeof FakeSelectionObserver | typeof CompositionObserver | typeof ArrowKeysObserver | typeof InputObserver | typeof TabObserver;
export {};