/**
* @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
*/
/**
* Contains downcast (model-to-view) converters for {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher}.
*
* @module engine/conversion/downcasthelpers
*/
import { ModelRange } from "../model/range.js";
import { ModelSelection } from "../model/selection.js";
import { ModelDocumentSelection } from "../model/documentselection.js";
import { ModelElement } from "../model/element.js";
import { ModelPosition } from "../model/position.js";
import { ViewAttributeElement } from "../view/attributeelement.js";
import { ConversionHelpers } from "./conversionhelpers.js";
import type { DowncastDispatcher, DowncastConversionApi } from "./downcastdispatcher.js";
import { type ModelConsumable } from "./modelconsumable.js";
import { type ModelNode } from "../model/node.js";
import { type ModelItem } from "../model/item.js";
import { type ModelTextProxy } from "../model/textproxy.js";
import { type ModelText } from "../model/text.js";
import { type ViewDowncastWriter } from "../view/downcastwriter.js";
import { type ViewElementDefinition } from "../view/elementdefinition.js";
import { type ViewUIElement } from "../view/uielement.js";
import { type ViewElement } from "../view/element.js";
import { type EventInfo, type PriorityString } from "@ckeditor/ckeditor5-utils";
/**
* Downcast conversion helper functions.
*
* Learn more about {@glink framework/deep-dive/conversion/downcast downcast helpers}.
*
* @extends module:engine/conversion/conversionhelpers~ConversionHelpers
*/
export declare class DowncastHelpers extends ConversionHelpers<DowncastDispatcher> {
	/**
	* Model element to view element conversion helper.
	*
	* This conversion results in creating a view element. For example, model `<paragraph>Foo</paragraph>` becomes `<p>Foo</p>` in the view.
	*
	* ```ts
	* editor.conversion.for( 'downcast' ).elementToElement( {
	* 	model: 'paragraph',
	* 	view: 'p'
	* } );
	*
	* editor.conversion.for( 'downcast' ).elementToElement( {
	* 	model: 'paragraph',
	* 	view: 'div',
	* 	converterPriority: 'high'
	* } );
	*
	* editor.conversion.for( 'downcast' ).elementToElement( {
	* 	model: 'fancyParagraph',
	* 	view: {
	* 		name: 'p',
	* 		classes: 'fancy'
	* 	}
	* } );
	*
	* editor.conversion.for( 'downcast' ).elementToElement( {
	* 	model: 'heading',
	* 	view: ( modelElement, conversionApi ) => {
	* 		const { writer } = conversionApi;
	*
	* 		return writer.createContainerElement( 'h' + modelElement.getAttribute( 'level' ) );
	* 	}
	* } );
	* ```
	*
	* The element-to-element conversion supports the reconversion mechanism. It can be enabled by using either the `attributes` or
	* the `children` props on a model description. You will find a couple examples below.
	*
	* In order to reconvert an element if any of its direct children have been added or removed, use the `children` property on a `model`
	* description. For example, this model:
	*
	* ```xml
	* <box>
	* 	<paragraph>Some text.</paragraph>
	* </box>
	* ```
	*
	* will be converted into this structure in the view:
	*
	* ```html
	* <div class="box" data-type="single">
	* 	<p>Some text.</p>
	* </div>
	* ```
	*
	* But if more items were inserted in the model:
	*
	* ```xml
	* <box>
	* 	<paragraph>Some text.</paragraph>
	* 	<paragraph>Other item.</paragraph>
	* </box>
	* ```
	*
	* it will be converted into this structure in the view (note the element `data-type` change):
	*
	* ```html
	* <div class="box" data-type="multiple">
	* 	<p>Some text.</p>
	* 	<p>Other item.</p>
	* </div>
	* ```
	*
	* Such a converter would look like this (note that the `paragraph` elements are converted separately):
	*
	* ```ts
	* editor.conversion.for( 'downcast' ).elementToElement( {
	* 	model: {
	* 		name: 'box',
	* 		children: true
	* 	},
	* 	view: ( modelElement, conversionApi ) => {
	* 		const { writer } = conversionApi;
	*
	* 		return writer.createContainerElement( 'div', {
	* 			class: 'box',
	* 			'data-type': modelElement.childCount == 1 ? 'single' : 'multiple'
	* 		} );
	* 	}
	* } );
	* ```
	*
	* In order to reconvert element if any of its attributes have been updated, use the `attributes` property on a `model`
	* description. For example, this model:
	*
	* ```xml
	* <heading level="2">Some text.</heading>
	* ```
	*
	* will be converted into this structure in the view:
	*
	* ```html
	* <h2>Some text.</h2>
	* ```
	*
	* But if the `heading` element's `level` attribute has been updated to `3` for example, then
	* it will be converted into this structure in the view:
	*
	* ```html
	* <h3>Some text.</h3>
	* ```
	*
	* Such a converter would look as follows:
	*
	* ```ts
	* editor.conversion.for( 'downcast' ).elementToElement( {
	* 	model: {
	* 		name: 'heading',
	* 		attributes: 'level'
	* 	},
	* 	view: ( modelElement, conversionApi ) => {
	* 		const { writer } = conversionApi;
	*
	* 		return writer.createContainerElement( 'h' + modelElement.getAttribute( 'level' ) );
	* 	}
	* } );
	* ```
	*
	* See {@link module:engine/conversion/conversion~Conversion#for `conversion.for()`} to learn how to add a converter
	* to the conversion process.
	*
	* You can read more about the element-to-element conversion in the
	* {@glink framework/deep-dive/conversion/downcast downcast conversion} guide.
	*
	* @param config Conversion configuration.
	* @param config.model The description or a name of the model element to convert.
	* @param config.view A view element definition or a function that takes the model element and
	* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API}
	* as parameters and returns a view container element.
	* @param config.converterPriority Converter priority.
	*/
	elementToElement(config: {
		model: string | {
			name: string;
			attributes?: string | Array<string>;
			children?: boolean;
		};
		view: ViewElementDefinition | DowncastElementCreatorFunction;
		converterPriority?: PriorityString;
	}): this;
	/**
	* The model element to view structure (several elements) conversion helper.
	*
	* This conversion results in creating a view structure with one or more slots defined for the child nodes.
	* For example, a model `<table>` may become this structure in the view:
	*
	* ```html
	* <figure class="table">
	* 	<table>
	* 		<tbody>${ slot for table rows }</tbody>
	* 	</table>
	* </figure>
	* ```
	*
	* The children of the model's `<table>` element will be inserted into the `<tbody>` element.
	* If the `elementToElement()` helper was used, the children would be inserted into the `<figure>`.
	*
	* Imagine a table feature where for this model structure:
	*
	* ```xml
	* <table headingRows="1">
	* 	<tableRow> ... table cells 1 ... </tableRow>
	* 	<tableRow> ... table cells 2 ... </tableRow>
	* 	<tableRow> ... table cells 3 ... </tableRow>
	* 	<caption>Caption text</caption>
	* </table>
	* ```
	*
	* we want to generate this view structure:
	*
	* ```html
	* <figure class="table">
	* 	<table>
	* 		<thead>
	* 			<tr> ... table cells 1 ... </tr>
	* 		</thead>
	* 		<tbody>
	* 			<tr> ... table cells 2 ... </tr>
	* 			<tr> ... table cells 3 ... </tr>
	* 		</tbody>
	* 	</table>
	* 	<figcaption>Caption text</figcaption>
	* </figure>
	* ```
	*
	* The converter has to take the `headingRows` attribute into consideration when allocating the `<tableRow>` elements
	* into the `<tbody>` and `<thead>` elements. Hence, we need two slots and need to define proper filter callbacks for them.
	*
	* Additionally, all elements other than `<tableRow>` should be placed outside the `<table>` tag.
	* In the example above, this will handle the table caption.
	*
	* Such a converter would look like this:
	*
	* ```ts
	* editor.conversion.for( 'downcast' ).elementToStructure( {
	* 	model: {
	* 		name: 'table',
	* 		attributes: [ 'headingRows' ]
	* 	},
	* 	view: ( modelElement, conversionApi ) => {
	* 		const { writer } = conversionApi;
	*
	* 		const figureElement = writer.createContainerElement( 'figure', { class: 'table' } );
	* 		const tableElement = writer.createContainerElement( 'table' );
	*
	* 		writer.insert( writer.createPositionAt( figureElement, 0 ), tableElement );
	*
	* 		const headingRows = modelElement.getAttribute( 'headingRows' ) || 0;
	*
	* 		if ( headingRows > 0 ) {
	* 			const tableHead = writer.createContainerElement( 'thead' );
	*
	* 			const headSlot = writer.createSlot( node => node.is( 'element', 'tableRow' ) && node.index < headingRows );
	*
	* 			writer.insert( writer.createPositionAt( tableElement, 'end' ), tableHead );
	* 			writer.insert( writer.createPositionAt( tableHead, 0 ), headSlot );
	* 		}
	*
	* 		if ( headingRows < tableUtils.getRows( table ) ) {
	* 			const tableBody = writer.createContainerElement( 'tbody' );
	*
	* 			const bodySlot = writer.createSlot( node => node.is( 'element', 'tableRow' ) && node.index >= headingRows );
	*
	* 			writer.insert( writer.createPositionAt( tableElement, 'end' ), tableBody );
	* 			writer.insert( writer.createPositionAt( tableBody, 0 ), bodySlot );
	* 		}
	*
	* 		const restSlot = writer.createSlot( node => !node.is( 'element', 'tableRow' ) );
	*
	* 		writer.insert( writer.createPositionAt( figureElement, 'end' ), restSlot );
	*
	* 		return figureElement;
	* 	}
	* } );
	* ```
	*
	* Note: The children of a model element that's being converted must be allocated in the same order in the view
	* in which they are placed in the model.
	*
	* See {@link module:engine/conversion/conversion~Conversion#for `conversion.for()`} to learn how to add a converter
	* to the conversion process.
	*
	* @param config Conversion configuration.
	* @param config.model The description or a name of the model element to convert.
	* @param config.view A function that takes the model element and
	* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API} as parameters
	* and returns a view container element with slots for model child nodes to be converted into.
	* @param config.converterPriority Converter priority.
	*/
	elementToStructure(config: {
		model: string | {
			name: string;
			attributes?: string | Array<string>;
		};
		view: DowncastStructureCreatorFunction;
		converterPriority?: PriorityString;
	}): this;
	/**
	* Model attribute to view element conversion helper.
	*
	* This conversion results in wrapping view nodes with a view attribute element. For example, a model text node with
	* `"Foo"` as data and the `bold` attribute becomes `<strong>Foo</strong>` in the view.
	*
	* ```ts
	* editor.conversion.for( 'downcast' ).attributeToElement( {
	* 	model: 'bold',
	* 	view: 'strong'
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToElement( {
	* 	model: 'bold',
	* 	view: 'b',
	* 	converterPriority: 'high'
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToElement( {
	* 	model: 'invert',
	* 	view: {
	* 		name: 'span',
	* 		classes: [ 'font-light', 'bg-dark' ]
	* 	}
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToElement( {
	* 	model: {
	* 		key: 'fontSize',
	* 		values: [ 'big', 'small' ]
	* 	},
	* 	view: {
	* 		big: {
	* 			name: 'span',
	* 			styles: {
	* 				'font-size': '1.2em'
	* 			}
	* 		},
	* 		small: {
	* 			name: 'span',
	* 			styles: {
	* 				'font-size': '0.8em'
	* 			}
	* 		}
	* 	}
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToElement( {
	* 	model: 'bold',
	* 	view: ( modelAttributeValue, conversionApi ) => {
	* 		const { writer } = conversionApi;
	*
	* 		return writer.createAttributeElement( 'span', {
	* 			style: 'font-weight:' + modelAttributeValue
	* 		} );
	* 	}
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToElement( {
	* 	model: {
	* 		key: 'color',
	* 		name: '$text'
	* 	},
	* 	view: ( modelAttributeValue, conversionApi ) => {
	* 		const { writer } = conversionApi;
	*
	* 		return writer.createAttributeElement( 'span', {
	* 			style: 'color:' + modelAttributeValue
	* 		} );
	* 	}
	* } );
	* ```
	*
	* See {@link module:engine/conversion/conversion~Conversion#for `conversion.for()`} to learn how to add a converter
	* to the conversion process.
	*
	* @param config Conversion configuration.
	* @param config.model The key of the attribute to convert from or a `{ key, values }` object. `values` is an array
	* of `String`s with possible values if the model attribute is an enumerable.
	* @param config.view A view element definition or a function
	* that takes the model attribute value and
	* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API} as parameters and returns a view
	* attribute element. If `config.model.values` is given, `config.view` should be an object assigning values from `config.model.values`
	* to view element definitions or functions.
	* @param config.converterPriority Converter priority.
	*/
	attributeToElement<TValues extends string>(config: {
		model: string | {
			key: string;
			name?: string;
		};
		view: ViewElementDefinition | DowncastAttributeElementCreatorFunction;
		converterPriority?: PriorityString;
	} | {
		model: {
			key: string;
			name?: string;
			values: Array<TValues>;
		};
		view: Record<TValues, ViewElementDefinition | DowncastAttributeElementCreatorFunction>;
		converterPriority?: PriorityString;
	}): this;
	/**
	* Model attribute to view attribute conversion helper.
	*
	* This conversion results in adding an attribute to a view node, basing on an attribute from a model node. For example,
	* `<imageInline src='foo.jpg'></imageInline>` is converted to `<img src='foo.jpg'></img>`.
	*
	* ```ts
	* editor.conversion.for( 'downcast' ).attributeToAttribute( {
	* 	model: 'source',
	* 	view: 'src'
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToAttribute( {
	* 	model: 'source',
	* 	view: 'href',
	* 	converterPriority: 'high'
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToAttribute( {
	* 	model: {
	* 		name: 'imageInline',
	* 		key: 'source'
	* 	},
	* 	view: 'src'
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToAttribute( {
	* 	model: {
	* 		name: 'styled',
	* 		values: [ 'dark', 'light' ]
	* 	},
	* 	view: {
	* 		dark: {
	* 			key: 'class',
	* 			value: [ 'styled', 'styled-dark' ]
	* 		},
	* 		light: {
	* 			key: 'class',
	* 			value: [ 'styled', 'styled-light' ]
	* 		}
	* 	}
	* } );
	*
	* editor.conversion.for( 'downcast' ).attributeToAttribute( {
	* 	model: 'styled',
	* 	view: modelAttributeValue => ( {
	* 		key: 'class',
	* 		value: 'styled-' + modelAttributeValue
	* 	} )
	* } );
	* ```
	*
	* **Note**: Downcasting to a style property requires providing `value` as an object:
	*
	* ```ts
	* editor.conversion.for( 'downcast' ).attributeToAttribute( {
	* 	model: 'lineHeight',
	* 	view: modelAttributeValue => ( {
	* 		key: 'style',
	* 		value: {
	* 			'line-height': modelAttributeValue,
	* 			'border-bottom': '1px dotted #ba2'
	* 		}
	* 	} )
	* } );
	* ```
	*
	* See {@link module:engine/conversion/conversion~Conversion#for `conversion.for()`} to learn how to add a converter
	* to the conversion process.
	*
	* @param config Conversion configuration.
	* @param config.model The key of the attribute to convert from or a `{ key, values, [ name ] }` object describing
	* the attribute key, possible values and, optionally, an element name to convert from.
	* @param config.view A view attribute key, or a `{ key, value }` object or a function that takes the model attribute value and
	* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API}
	* as parameters and returns a `{ key, value }` object. If the `key` is `'class'`, the `value` can be a `String` or an
	* array of `String`s. If the `key` is `'style'`, the `value` is an object with key-value pairs. In other cases, `value` is a `String`.
	* If `config.model.values` is set, `config.view` should be an object assigning values from `config.model.values` to
	* `{ key, value }` objects or a functions.
	* @param config.converterPriority Converter priority.
	*/
	attributeToAttribute<TValues extends string>(config: {
		model: string | {
			key: string;
			name?: string;
		};
		view: string | DowncastAttributeDescriptor | DowncastAttributeCreatorFunction;
		converterPriority?: PriorityString;
	} | {
		model: {
			key: string;
			name?: string;
			values?: Array<TValues>;
		};
		view: Record<TValues, DowncastAttributeDescriptor | DowncastAttributeCreatorFunction>;
		converterPriority?: PriorityString;
	}): this;
	/**
	* Model marker to view element conversion helper.
	*
	* **Note**: This method should be used mainly for editing the downcast and it is recommended
	* to use the {@link #markerToData `#markerToData()`} helper instead.
	*
	* This helper may produce invalid HTML code (e.g. a span between table cells).
	* It should only be used when you are sure that the produced HTML will be semantically correct.
	*
	* This conversion results in creating a view element on the boundaries of the converted marker. If the converted marker
	* is collapsed, only one element is created. For example, a model marker set like this: `<paragraph>F[oo b]ar</paragraph>`
	* becomes `<p>F<span data-marker="search"></span>oo b<span data-marker="search"></span>ar</p>` in the view.
	*
	* ```ts
	* editor.conversion.for( 'editingDowncast' ).markerToElement( {
	* 	model: 'search',
	* 	view: 'marker-search'
	* } );
	*
	* editor.conversion.for( 'editingDowncast' ).markerToElement( {
	* 	model: 'search',
	* 	view: 'search-result',
	* 	converterPriority: 'high'
	* } );
	*
	* editor.conversion.for( 'editingDowncast' ).markerToElement( {
	* 	model: 'search',
	* 	view: {
	* 		name: 'span',
	* 		attributes: {
	* 			'data-marker': 'search'
	* 		}
	* 	}
	* } );
	*
	* editor.conversion.for( 'editingDowncast' ).markerToElement( {
	* 	model: 'search',
	* 	view: ( markerData, conversionApi ) => {
	* 		const { writer } = conversionApi;
	*
	* 		return writer.createUIElement( 'span', {
	* 			'data-marker': 'search',
	* 			'data-start': markerData.isOpening
	* 		} );
	* 	}
	* } );
	* ```
	*
	* If a function is passed as the `config.view` parameter, it will be used to generate both boundary elements. The function
	* receives the `data` object and {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API}
	* as a parameters and should return an instance of the
	* {@link module:engine/view/uielement~ViewUIElement view UI element}. The `data` object and
	* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi `conversionApi`} are passed from
	* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher#event:addMarker}. Additionally,
	* the `data.isOpening` parameter is passed, which is set to `true` for the marker start boundary element, and `false` for
	* the marker end boundary element.
	*
	* See {@link module:engine/conversion/conversion~Conversion#for `conversion.for()`} to learn how to add a converter
	* to the conversion process.
	*
	* @param config Conversion configuration.
	* @param config.model The name of the model marker (or model marker group) to convert.
	* @param config.view A view element definition or a function that takes the model marker data and
	* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API} as a parameters
	* and returns a view UI element.
	* @param config.converterPriority Converter priority.
	*/
	markerToElement(config: {
		model: string;
		view: ViewElementDefinition | DowncastMarkerElementCreatorFunction;
		converterPriority?: PriorityString;
	}): this;
	/**
	* Model marker to highlight conversion helper.
	*
	* This conversion results in creating a highlight on view nodes. For this kind of conversion,
	* the {@link module:engine/conversion/downcasthelpers~DowncastHighlightDescriptor} should be provided.
	*
	* For text nodes, a `<span>` {@link module:engine/view/attributeelement~ViewAttributeElement} is created and it wraps all text nodes
	* in the converted marker range. For example, a model marker set like this: `<paragraph>F[oo b]ar</paragraph>` becomes
	* `<p>F<span class="comment">oo b</span>ar</p>` in the view.
	*
	* {@link module:engine/view/containerelement~ViewContainerElement} may provide a custom way of handling highlight. Most often,
	* the element itself is given classes and attributes described in the highlight descriptor (instead of being wrapped in `<span>`).
	* For example, a model marker set like this:
	* `[<imageInline src="foo.jpg"></imageInline>]` becomes `<img src="foo.jpg" class="comment"></img>` in the view.
	*
	* For container elements, the conversion is two-step. While the converter processes the highlight descriptor and passes it
	* to a container element, it is the container element instance itself that applies values from the highlight descriptor.
	* So, in a sense, the converter takes care of stating what should be applied on what, while the element decides how to apply that.
	*
	* ```ts
	* editor.conversion.for( 'downcast' ).markerToHighlight( { model: 'comment', view: { classes: 'comment' } } );
	*
	* editor.conversion.for( 'downcast' ).markerToHighlight( {
	* 	model: 'comment',
	* 	view: { classes: 'comment' },
	* 	converterPriority: 'high'
	* } );
	*
	* editor.conversion.for( 'downcast' ).markerToHighlight( {
	* 	model: 'comment',
	* 	view: ( data, conversionApi ) => {
	* 		// Assuming that the marker name is in a form of comment:commentType:commentId.
	* 		const [ , commentType, commentId ] = data.markerName.split( ':' );
	*
	* 		return {
	* 			classes: [ 'comment', 'comment-' + commentType ],
	* 			attributes: { 'data-comment-id': commentId }
	* 		};
	* 	}
	* } );
	* ```
	*
	* If a function is passed as the `config.view` parameter, it will be used to generate the highlight descriptor. The function
	* receives the `data` object and {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API}
	* as the parameters and should return a
	* {@link module:engine/conversion/downcasthelpers~DowncastHighlightDescriptor highlight descriptor}.
	* The `data` object properties are passed from {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher#event:addMarker}.
	*
	* See {@link module:engine/conversion/conversion~Conversion#for `conversion.for()`} to learn how to add a converter
	* to the conversion process.
	*
	* @param config Conversion configuration.
	* @param config.model The name of the model marker (or model marker group) to convert.
	* @param config.view A highlight descriptor that will be used for highlighting or a function that takes the model marker data and
	* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API} as a parameters
	* and returns a highlight descriptor.
	* @param config.converterPriority Converter priority.
	*/
	markerToHighlight(config: {
		model: string;
		view: DowncastHighlightDescriptor | DowncastHighlightDescriptorCreatorFunction;
		converterPriority?: PriorityString;
	}): this;
	/**
	* Model marker converter for data downcast.
	*
	* This conversion creates a representation for model marker boundaries in the view:
	*
	* * If the marker boundary is before or after a model element, a view attribute is set on a corresponding view element.
	* * In other cases, a view element with the specified tag name is inserted at the corresponding view position.
	*
	* Typically, the marker names use the `group:uniqueId:otherData` convention. For example: `comment:e34zfk9k2n459df53sjl34:zx32c`.
	* The default configuration for this conversion is that the first part is the `group` part and the rest of
	* the marker name becomes the `name` part.
	*
	* Tag and attribute names and values are generated from the marker name:
	*
	* * The templates for attributes are `data-[group]-start-before="[name]"`, `data-[group]-start-after="[name]"`,
	* `data-[group]-end-before="[name]"` and `data-[group]-end-after="[name]"`.
	* * The templates for view elements are `<[group]-start name="[name]">` and `<[group]-end name="[name]">`.
	*
	* Attributes mark whether the given marker's start or end boundary is before or after the given element.
	* The `data-[group]-start-before` and `data-[group]-end-after` attributes are favored.
	* The other two are used when the former two cannot be used.
	*
	* The conversion configuration can take a function that will generate different group and name parts.
	* If such a function is set as the `config.view` parameter, it is passed a marker name and it is expected to return an object with two
	* properties: `group` and `name`. If the function returns a falsy value, the conversion will not take place.
	*
	* Basic usage:
	*
	* ```ts
	* // Using the default conversion.
	* // In this case, all markers with names starting with 'comment:' will be converted.
	* // The `group` parameter will be set to `comment`.
	* // The `name` parameter will be the rest of the marker name (without the `:`).
	* editor.conversion.for( 'dataDowncast' ).markerToData( {
	* 	model: 'comment'
	* } );
	* ```
	*
	* An example of a view that may be generated by this conversion (assuming a marker with the name `comment:commentId:uid` marked
	* by `[]`):
	*
	* ```
	* // Model:
	* <paragraph>Foo[bar</paragraph>
	* <imageBlock src="abc.jpg"></imageBlock>]
	*
	* // View:
	* <p>Foo<comment-start name="commentId:uid"></comment-start>bar</p>
	* <figure data-comment-end-after="commentId:uid" class="image"><img src="abc.jpg" /></figure>
	* ```
	*
	* In the example above, the comment starts before "bar" and ends after the image.
	*
	* If the `name` part is empty, the following view may be generated:
	*
	* ```html
	* <p>Foo <myMarker-start></myMarker-start>bar</p>
	* <figure data-myMarker-end-after="" class="image"><img src="abc.jpg" /></figure>
	* ```
	*
	* **Note:** A situation where some markers have the `name` part and some do not, is incorrect and should be avoided.
	*
	* Examples where `data-group-start-after` and `data-group-end-before` are used:
	*
	* ```
	* // Model:
	* <blockQuote>[]<paragraph>Foo</paragraph></blockQuote>
	*
	* // View:
	* <blockquote><p data-group-end-before="name" data-group-start-before="name">Foo</p></blockquote>
	* ```
	*
	* Similarly, when a marker is collapsed after the last element:
	*
	* ```
	* // Model:
	* <blockQuote><paragraph>Foo</paragraph>[]</blockQuote>
	*
	* // View:
	* <blockquote><p data-group-end-after="name" data-group-start-after="name">Foo</p></blockquote>
	* ```
	*
	* When there are multiple markers from the same group stored in the same attribute of the same element, their
	* name parts are put together in the attribute value, for example: `data-group-start-before="name1,name2,name3"`.
	*
	* Other examples of usage:
	*
	* ```ts
	* // Using a custom function which is the same as the default conversion:
	* editor.conversion.for( 'dataDowncast' ).markerToData( {
	* 	model: 'comment',
	* 	view: markerName => ( {
	* 		group: 'comment',
	* 		name: markerName.substr( 8 ) // Removes 'comment:' part.
	* 	} )
	* } );
	*
	* // Using the converter priority:
	* editor.conversion.for( 'dataDowncast' ).markerToData( {
	* 	model: 'comment',
	* 	view: markerName => ( {
	* 		group: 'comment',
	* 		name: markerName.substr( 8 ) // Removes 'comment:' part.
	* 	} ),
	* 	converterPriority: 'high'
	* } );
	* ```
	*
	* This kind of conversion is useful for saving data into the database, so it should be used in the data conversion pipeline.
	*
	* See the {@link module:engine/conversion/conversion~Conversion#for `conversion.for()`} API guide to learn how to
	* add a converter to the conversion process.
	*
	* @param config Conversion configuration.
	* @param config.model The name of the model marker (or the model marker group) to convert.
	* @param config.view A function that takes the model marker name and
	* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API} as the parameters
	* and returns an object with the `group` and `name` properties.
	* @param config.converterPriority Converter priority.
	*/
	markerToData(config: {
		model: string;
		view?: DowncastMarkerDataCreatorFunction;
		converterPriority?: PriorityString;
	}): this;
}
/**
* Function factory that creates a default downcast converter for text insertion changes.
*
* The converter automatically consumes the corresponding value from the consumables list and stops the event (see
* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher}).
*
* ```ts
* modelDispatcher.on( 'insert:$text', insertText() );
* ```
*
* @returns Insert text event converter.
* @internal
*/
export declare function insertText(): (evt: EventInfo, data: {
	item: ModelText | ModelTextProxy;
	range: ModelRange;
}, conversionApi: DowncastConversionApi) => void;
/**
* Function factory that creates a default downcast converter for triggering attributes and children conversion.
*
* @returns The converter.
* @internal
*/
export declare function insertAttributesAndChildren(): (evt: unknown, data: {
	item: ModelItem;
	reconversion?: boolean;
}, conversionApi: DowncastConversionApi) => void;
/**
* Function factory that creates a default downcast converter for node remove changes.
*
* ```ts
* modelDispatcher.on( 'remove', remove() );
* ```
*
* @returns Remove event converter.
* @internal
*/
export declare function remove(): (evt: unknown, data: {
	position: ModelPosition;
	length: number;
	reconversion?: boolean;
}, conversionApi: DowncastConversionApi) => void;
/**
* Creates a `<span>` {@link module:engine/view/attributeelement~ViewAttributeElement view attribute element} from the information
* provided by the {@link module:engine/conversion/downcasthelpers~DowncastHighlightDescriptor highlight descriptor} object. If the priority
* is not provided in the descriptor, the default priority will be used.
*
* @internal
*/
export declare function createViewElementFromDowncastHighlightDescriptor(writer: ViewDowncastWriter, descriptor: DowncastHighlightDescriptor): ViewAttributeElement;
/**
* Function factory that creates a converter which converts a non-collapsed
* {@link module:engine/model/selection~ModelSelection model selection}
* to a {@link module:engine/view/documentselection~ViewDocumentSelection view selection}. The converter consumes appropriate
* value from the `consumable` object and maps model positions from the selection to view positions.
*
* ```ts
* modelDispatcher.on( 'selection', convertRangeSelection() );
* ```
*
* @returns Selection converter.
* @internal
*/
export declare function convertRangeSelection(): (evt: EventInfo, data: {
	selection: ModelSelection | ModelDocumentSelection;
}, conversionApi: DowncastConversionApi) => void;
/**
* Function factory that creates a converter which converts a collapsed
* {@link module:engine/model/selection~ModelSelection model selection} to
* a {@link module:engine/view/documentselection~ViewDocumentSelection view selection}. The converter consumes appropriate
* value from the `consumable` object, maps the model selection position to the view position and breaks
* {@link module:engine/view/attributeelement~ViewAttributeElement attribute elements} at the selection position.
*
* ```ts
* modelDispatcher.on( 'selection', convertCollapsedSelection() );
* ```
*
* An example of the view state before and after converting the collapsed selection:
*
* ```
*    <p><strong>f^oo<strong>bar</p>
* -> <p><strong>f</strong>^<strong>oo</strong>bar</p>
* ```
*
* By breaking attribute elements like `<strong>`, the selection is in a correct element. Then, when the selection attribute is
* converted, broken attributes might be merged again, or the position where the selection is may be wrapped
* with different, appropriate attribute elements.
*
* See also {@link module:engine/conversion/downcasthelpers~cleanSelection} which does a clean-up
* by merging attributes.
*
* @returns Selection converter.
* @internal
*/
export declare function convertCollapsedSelection(): (evt: EventInfo, data: {
	selection: ModelSelection | ModelDocumentSelection;
}, conversionApi: DowncastConversionApi) => void;
/**
* Function factory that creates a converter which cleans artifacts after the previous
* {@link module:engine/model/selection~ModelSelection model selection} conversion. It removes all empty
* {@link module:engine/view/attributeelement~ViewAttributeElement view attribute elements} and merges
* sibling attributes at all start and end positions of all ranges.
*
* ```
*    <p><strong>^</strong></p>
* -> <p>^</p>
*
*    <p><strong>foo</strong>^<strong>bar</strong>bar</p>
* -> <p><strong>foo^bar<strong>bar</p>
*
*    <p><strong>foo</strong><em>^</em><strong>bar</strong>bar</p>
* -> <p><strong>foo^bar<strong>bar</p>
* ```
*
* This listener should be assigned before any converter for the new selection:
*
* ```ts
* modelDispatcher.on( 'cleanSelection', cleanSelection() );
* ```
*
* See {@link module:engine/conversion/downcasthelpers~convertCollapsedSelection}
* which does the opposite by breaking attributes in the selection position.
*
* @returns Selection converter.
* @internal
*/
export declare function cleanSelection(): (evt: EventInfo, data: unknown, conversionApi: DowncastConversionApi) => void;
/**
* Function factory that creates a converter which converts the set/change/remove attribute changes from the model to the view.
* It can also be used to convert selection attributes. In that case, an empty attribute element will be created and the
* selection will be put inside it.
*
* Attributes from the model are converted to a view element that will be wrapping these view nodes that are bound to
* model elements having the given attribute. This is useful for attributes like `bold` that may be set on text nodes in the model
* but are represented as an element in the view:
*
* ```
* [paragraph]              MODEL ====> VIEW        <p>
* 	|- a {bold: true}                             |- <b>
* 	|- b {bold: true}                             |   |- ab
* 	|- c                                          |- c
* 	```
*
* Passed `Function` will be provided with the attribute value and then all the parameters of the
* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher#event:attribute `attribute` event}.
* It is expected that the function returns an {@link module:engine/view/element~ViewElement}.
* The result of the function will be the wrapping element.
* When the provided `Function` does not return any element, no conversion will take place.
*
* The converter automatically consumes the corresponding value from the consumables list and stops the event (see
* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher}).
*
* ```ts
* modelDispatcher.on( 'attribute:bold', wrap( ( modelAttributeValue, { writer } ) => {
* 	return writer.createAttributeElement( 'strong' );
* } );
* ```
*
* @internal
* @param elementCreator Function returning a view element that will be used for wrapping.
* @returns Set/change attribute converter.
*/
export declare function wrap(elementCreator: DowncastAttributeElementCreatorFunction): (evt: EventInfo, data: {
	item: ModelItem | ModelSelection | ModelDocumentSelection;
	range: ModelRange;
	attributeKey: string;
	attributeOldValue: unknown;
	attributeNewValue: unknown;
}, conversionApi: DowncastConversionApi) => void;
/**
* Function factory that creates a converter which converts node insertion changes from the model to the view.
* The function passed will be provided with all the parameters of the dispatcher's
* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher#event:insert `insert` event}.
* It is expected that the function returns an {@link module:engine/view/element~ViewElement}.
* The result of the function will be inserted into the view.
*
* The converter automatically consumes the corresponding value from the consumables list and binds the model and view elements.
*
* ```ts
* downcastDispatcher.on(
* 	'insert:myElem',
* 	insertElement( ( modelItem, { writer } ) => {
* 		const text = writer.createText( 'myText' );
* 		const myElem = writer.createElement( 'myElem', { myAttr: 'my-' + modelItem.getAttribute( 'myAttr' ) }, text );
*
* 		// Do something fancy with `myElem` using `modelItem` or other parameters.
*
* 		return myElem;
* 	}
* ) );
* ```
*
* @internal
* @param  elementCreator Function returning a view element, which will be inserted.
* @param consumer Function defining element consumption process.
* By default this function just consume passed item insertion.
* @returns Insert element event converter.
*/
export declare function insertElement(elementCreator: DowncastElementCreatorFunction, consumer?: ConsumerFunction): (evt: unknown, data: {
	item: ModelElement;
	range: ModelRange;
	reconversion?: boolean;
}, conversionApi: DowncastConversionApi) => void;
/**
* Function factory that creates a converter which converts a single model node insertion to a view structure.
*
* It is expected that the passed element creator function returns an {@link module:engine/view/element~ViewElement} with attached slots
* created with `writer.createSlot()` to indicate where child nodes should be converted.
*
* @see module:engine/conversion/downcasthelpers~DowncastHelpers#elementToStructure
*
* @internal
* @param elementCreator Function returning a view structure, which will be inserted.
* @param consumer A callback that is expected to consume all the consumables
* that were used by the element creator.
* @returns Insert element event converter.
*/
export declare function insertStructure(elementCreator: DowncastStructureCreatorFunction, consumer: ConsumerFunction): (evt: unknown, data: {
	item: ModelElement;
	range: ModelRange;
	reconversion?: boolean;
}, conversionApi: DowncastConversionApi) => void;
/**
* Function factory that creates a converter which converts marker adding change to the
* {@link module:engine/view/uielement~ViewUIElement view UI element}.
*
* The view UI element that will be added to the view depends on the passed parameter. See {@link ~insertElement}.
* In case of a non-collapsed range, the UI element will not wrap nodes but separate elements will be placed at the beginning
* and at the end of the range.
*
* This converter binds created UI elements with the marker name using {@link module:engine/conversion/mapper~Mapper#bindElementToMarker}.
*
* @internal
* @param elementCreator A view UI element or a function returning the view element that will be inserted.
* @returns Insert element event converter.
*/
export declare function insertUIElement(elementCreator: DowncastMarkerElementCreatorFunction): (evt: EventInfo, data: {
	markerRange: ModelRange;
	markerName: string;
	isOpening?: boolean;
}, conversionApi: DowncastConversionApi) => void;
/**
* An object describing how the marker highlight should be represented in the view.
*
* Each text node contained in a highlighted range will be wrapped in a `<span>`
* {@link module:engine/view/attributeelement~ViewAttributeElement view attribute element} with CSS class(es), attributes and a priority
* described by this object.
*
* Additionally, each {@link module:engine/view/containerelement~ViewContainerElement container element} can handle displaying the highlight
* separately by providing the `addHighlight` and `removeHighlight` custom properties. In this case:
*
*  * The `DowncastHighlightDescriptor` object is passed to the `addHighlight` function upon conversion and
*  should be used to apply the highlight to the element.
*  * The descriptor `id` is passed to the `removeHighlight` function upon conversion and should be used to remove the highlight with the
*  given ID from the element.
*/
export interface DowncastHighlightDescriptor {
	/**
	* A CSS class or an array of classes to set. If the descriptor is used to
	* create an {@link module:engine/view/attributeelement~ViewAttributeElement attribute element} over text nodes,
	* these classes will be set on that attribute element. If the descriptor is applied to an element, usually these
	* classes will be set on that element, however, this depends on how the element converts the descriptor.
	*/
	classes: string | Array<string>;
	/**
	* Descriptor identifier. If not provided, it defaults to the converted marker's name.
	*/
	id?: string;
	/**
	* Descriptor priority. If not provided, it defaults to `10`. If the descriptor is used to create
	* an {@link module:engine/view/attributeelement~ViewAttributeElement attribute element}, it will be that element's
	* {@link module:engine/view/attributeelement~ViewAttributeElement#priority priority}. If the descriptor is applied to an element,
	* the priority will be used to determine which descriptor is more important.
	*/
	priority?: number;
	/**
	* Attributes to set. If the descriptor is used to create
	* an {@link module:engine/view/attributeelement~ViewAttributeElement attribute element} over text nodes, these attributes will be set
	* on that attribute element. If the descriptor is applied to an element, usually these attributes will be set on that element, however,
	* this depends on how the element converts the descriptor.
	*/
	attributes?: Record<string, string>;
}
/**
* A filtering function used to choose model child nodes to be downcasted into the specific view
* {@link module:engine/view/downcastwriter~ViewDowncastWriter#createSlot "slot"} while executing the
* {@link module:engine/conversion/downcasthelpers~DowncastHelpers#elementToStructure `elementToStructure()`} converter.
*
* @callback module:engine/conversion/downcasthelpers~DowncastSlotFilter
*
* @param node A model node.
* @returns Whether the provided model node should be downcasted into this slot.
*
* @see module:engine/view/downcastwriter~ViewDowncastWriter#createSlot
* @see module:engine/conversion/downcasthelpers~DowncastHelpers#elementToStructure
* @see module:engine/conversion/downcasthelpers~insertStructure
*/
export type DowncastSlotFilter = (node: ModelNode) => boolean;
/**
* A view element creator function that takes the model element and {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi
* downcast conversion API} as parameters and returns a view container element.
*
* @callback module:engine/conversion/downcasthelpers~DowncastElementCreatorFunction
*
* @param element The model element to be converted to the view structure.
* @param conversionApi The conversion interface.
* @param data Additional information about the change (same as for
* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher#event:insert `insert`} event).
* @param data.item Inserted item.
* @param data.range Range spanning over inserted item.
* @returns The view element.
*
* @see module:engine/conversion/downcasthelpers~DowncastHelpers#elementToElement
* @see module:engine/conversion/downcasthelpers~insertElement
*/
export type DowncastElementCreatorFunction = (element: ModelElement, conversionApi: DowncastConversionApi, data: {
	item: ModelItem;
	range: ModelRange;
}) => ViewElement | null;
/**
* A function that takes the model element and {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast
* conversion API} as parameters and returns a view container element with slots for model child nodes to be converted into.
*
* @callback module:engine/conversion/downcasthelpers~DowncastStructureCreatorFunction
*
* @param element The model element to be converted to the view structure.
* @param conversionApi The conversion interface.
* @param data Additional information about the change (same as for
* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher#event:insert `insert`} event).
* @param data.item Inserted item.
* @param data.range Range spanning over inserted item.
* @returns The view structure with slots for model child nodes.
*
* @see module:engine/conversion/downcasthelpers~DowncastHelpers#elementToStructure
* @see module:engine/conversion/downcasthelpers~insertStructure
*/
export type DowncastStructureCreatorFunction = DowncastElementCreatorFunction;
/**
* A view element creator function that takes the model attribute value and
* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API} as parameters and returns a view
* attribute element.
*
* @callback module:engine/conversion/downcasthelpers~DowncastAttributeElementCreatorFunction
*
* @param attributeValue The model attribute value to be converted to the view attribute element.
* @param conversionApi The conversion interface.
* @param data Additional information about the change (same as for
* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher#event:attribute `attribute`} event).
* @param data.item Changed item or converted selection.
* @param data.range Range spanning over changed item or selection range.
* @param data.attributeKey Attribute key.
* @param data.attributeOldValue Attribute value before the change. This is `null` when selection attribute is converted.
* @param data.attributeNewValue New attribute value.
* @returns The view attribute element.
*
* @see module:engine/conversion/downcasthelpers~DowncastHelpers#attributeToElement
* @see module:engine/conversion/downcasthelpers~wrap
*/
export type DowncastAttributeElementCreatorFunction = (attributeValue: any, conversionApi: DowncastConversionApi, data: {
	item: ModelItem | ModelSelection | ModelDocumentSelection;
	range: ModelRange;
	attributeKey: string;
	attributeOldValue: unknown;
	attributeNewValue: unknown;
}) => ViewAttributeElement | null;
/**
* A function that takes the model attribute value and
* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi downcast conversion API}
* as parameters.
*
* @callback module:engine/conversion/downcasthelpers~DowncastAttributeCreatorFunction
*
* @param attributeValue The model attribute value to be converted to the view attribute element.
* @param conversionApi The conversion interface.
* @param data Additional information about the change (same as for
* {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher#event:attribute `attribute`} event).
* @param data.item Changed item or converted selection.
* @param data.range Range spanning over changed item or selection range.
* @param data.attributeKey Attribute key.
* @param data.attributeOldValue Attribute value before the change. This is `null` when selection attribute is converted.
* @param data.attributeNewValue New attribute value.
* @returns A `{ key, value }` object. If `key` is `'class'`, `value` can be a `String` or an
* array of `String`s. If `key` is `'style'`, `value` is an object with key-value pairs. In other cases, `value` is a `String`.
*
* @see module:engine/conversion/downcasthelpers~DowncastHelpers#attributeToAttribute
*/
export type DowncastAttributeCreatorFunction = (attributeValue: unknown, conversionApi: DowncastConversionApi, data: {
	item: ModelItem;
	range: ModelRange;
	attributeKey: string;
	attributeOldValue: unknown;
	attributeNewValue: unknown;
}) => DowncastAttributeDescriptor | null;
export type DowncastAttributeDescriptor = {
	key: "class";
	value: string | Array<string>;
} | {
	key: "style";
	value: Record<string, string>;
} | {
	key: Exclude<string, "class" | "style">;
	value: string;
};
export type DowncastMarkerElementCreatorFunction = (data: {
	markerRange: ModelRange;
	markerName: string;
	isOpening?: boolean;
}, conversionApi: DowncastConversionApi) => ViewUIElement | null;
export type DowncastHighlightDescriptorCreatorFunction = (data: {
	markerRange: ModelRange;
	markerName: string;
}, conversionApi: DowncastConversionApi) => DowncastHighlightDescriptor | null;
export type DowncastAddHighlightCallback = (viewElement: ViewElement, descriptor: DowncastHighlightDescriptor, writer: ViewDowncastWriter) => void;
export type DowncastRemoveHighlightCallback = (viewElement: ViewElement, id: string, writer: ViewDowncastWriter) => void;
export type DowncastMarkerDataCreatorFunction = (markerName: string, conversionApi: DowncastConversionApi) => {
	name: string;
	group: string;
} | null;
/**
* A function that is expected to consume all the consumables that were used by the element creator.
*
* @callback module:engine/conversion/downcasthelpers~ConsumerFunction
*
* @internal
* @param element The model element to be converted to the view structure.
* @param consumable The `ModelConsumable` same as in
* {@link module:engine/conversion/downcastdispatcher~DowncastConversionApi#consumable `DowncastConversionApi.consumable`}.
* @param options.preflight Whether should consume or just check if can be consumed.
* @returns `true` if all consumable values were available and were consumed, `false` otherwise.
*
* @see module:engine/conversion/downcasthelpers~insertStructure
*/
export type ConsumerFunction = (element: ModelElement, consumable: ModelConsumable, options?: {
	preflight?: boolean;
}) => boolean | null;