@ckeditor/ckeditor5-list/src/listproperties/listpropertiesediting.js

/**
 * @license Copyright (c) 2003-2023, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */
/**
 * @module list/listproperties/listpropertiesediting
 */
import { Plugin } from 'ckeditor5/src/core';
import ListEditing from '../list/listediting';
import ListStyleCommand from './liststylecommand';
import ListReversedCommand from './listreversedcommand';
import ListStartCommand from './liststartcommand';
import { getSiblingListItem, getSiblingNodes } from '../list/utils';
const DEFAULT_LIST_TYPE = 'default';
/**
 * The engine of the list properties feature.
 *
 * It sets the value for the `listItem` attribute of the {@link module:list/list~List `<listItem>`} element that
 * allows modifying the list style type.
 *
 * It registers the `'listStyle'`, `'listReversed'` and `'listStart'` commands if they are enabled in the configuration.
 * Read more in {@link module:list/listconfig~ListPropertiesConfig}.
 */
export default class ListPropertiesEditing extends Plugin {
    /**
     * @inheritDoc
     */
    static get requires() {
        return [ListEditing];
    }
    /**
     * @inheritDoc
     */
    static get pluginName() {
        return 'ListPropertiesEditing';
    }
    /**
     * @inheritDoc
     */
    constructor(editor) {
        super(editor);
        editor.config.define('list', {
            properties: {
                styles: true,
                startIndex: false,
                reversed: false
            }
        });
    }
    /**
     * @inheritDoc
     */
    init() {
        const editor = this.editor;
        const model = editor.model;
        const enabledProperties = editor.config.get('list.properties');
        const strategies = createAttributeStrategies(enabledProperties);
        // Extend schema.
        model.schema.extend('listItem', {
            allowAttributes: strategies.map(s => s.attributeName)
        });
        for (const strategy of strategies) {
            strategy.addCommand(editor);
        }
        // Fix list attributes when modifying their nesting levels (the `listIndent` attribute).
        this.listenTo(editor.commands.get('indentList'), '_executeCleanup', fixListAfterIndentListCommand(editor, strategies));
        this.listenTo(editor.commands.get('outdentList'), '_executeCleanup', fixListAfterOutdentListCommand(editor, strategies));
        this.listenTo(editor.commands.get('bulletedList'), '_executeCleanup', restoreDefaultListStyle(editor));
        this.listenTo(editor.commands.get('numberedList'), '_executeCleanup', restoreDefaultListStyle(editor));
        // Register a post-fixer that ensures that the attributes is specified in each `listItem` element.
        model.document.registerPostFixer(fixListAttributesOnListItemElements(editor, strategies));
        // Set up conversion.
        editor.conversion.for('upcast').add(upcastListItemAttributes(strategies));
        editor.conversion.for('downcast').add(downcastListItemAttributes(strategies));
        // Handle merging two separated lists into the single one.
        this._mergeListAttributesWhileMergingLists(strategies);
    }
    /**
     * @inheritDoc
     */
    afterInit() {
        const editor = this.editor;
        // Enable post-fixer that removes the attributes from to-do list items only if the "TodoList" plugin is on.
        // We need to registry the hook here since the `TodoList` plugin can be added after the `ListPropertiesEditing`.
        if (editor.commands.get('todoList')) {
            editor.model.document.registerPostFixer(removeListItemAttributesFromTodoList(editor));
        }
    }
    /**
     * Starts listening to {@link module:engine/model/model~Model#deleteContent} and checks whether two lists will be merged into a single
     * one after deleting the content.
     *
     * The purpose of this action is to adjust the `listStyle`, `listReversed` and `listStart` values
     * for the list that was merged.
     *
     * Consider the following model's content:
     *
     * ```xml
     * <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 1</listItem>
     * <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 2</listItem>
     * <paragraph>[A paragraph.]</paragraph>
     * <listItem listIndent="0" listType="bulleted" listStyle="circle">UL List item 1</listItem>
     * <listItem listIndent="0" listType="bulleted" listStyle="circle">UL List item 2</listItem>
     * ```
     *
     * After removing the paragraph element, the second list will be merged into the first one.
     * We want to inherit the `listStyle` attribute for the second list from the first one.
     *
     * ```xml
     * <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 1</listItem>
     * <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 2</listItem>
     * <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 1</listItem>
     * <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 2</listItem>
     * ```
     *
     * See https://github.com/ckeditor/ckeditor5/issues/7879.
     *
     * @param attributeStrategies Strategies for the enabled attributes.
     */
    _mergeListAttributesWhileMergingLists(attributeStrategies) {
        const editor = this.editor;
        const model = editor.model;
        // First the outer-most`listItem` in the first list reference.
        // If found, the lists should be merged and this `listItem` provides the attributes
        // and it is also a starting point when searching for items in the second list.
        let firstMostOuterItem;
        // Check whether the removed content is between two lists.
        this.listenTo(model, 'deleteContent', (evt, [selection]) => {
            const firstPosition = selection.getFirstPosition();
            const lastPosition = selection.getLastPosition();
            // Typing or removing content in a single item. Aborting.
            if (firstPosition.parent === lastPosition.parent) {
                return;
            }
            // An element before the content that will be removed is not a list.
            if (!firstPosition.parent.is('element', 'listItem')) {
                return;
            }
            const nextSibling = lastPosition.parent.nextSibling;
            // An element after the content that will be removed is not a list.
            if (!nextSibling || !nextSibling.is('element', 'listItem')) {
                return;
            }
            // Find the outermost list item based on the `listIndent` attribute. We can't assume that `listIndent=0`
            // because the selection can be hooked in nested lists.
            //
            // <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 1</listItem>
            // <listItem listIndent="1" listType="bulleted" listStyle="square">UL List [item 1.1</listItem>
            // <listItem listIndent="0" listType="bulleted" listStyle="circle">[]UL List item 1.</listItem>
            // <listItem listIndent="1" listType="bulleted" listStyle="circle">UL List ]item 1.1</listItem>
            //
            // After deleting the content, we would like to inherit the "square" attribute for the last element:
            //
            // <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 1</listItem>
            // <listItem listIndent="1" listType="bulleted" listStyle="square">UL List []item 1.1</listItem>
            const mostOuterItemList = getSiblingListItem(firstPosition.parent, {
                sameIndent: true,
                listIndent: nextSibling.getAttribute('listIndent')
            });
            // The outermost list item may not exist while removing elements between lists with different value
            // of the `listIndent` attribute. In such a case we don't want to update anything. See: #8073.
            if (!mostOuterItemList) {
                return;
            }
            if (mostOuterItemList.getAttribute('listType') === nextSibling.getAttribute('listType')) {
                firstMostOuterItem = mostOuterItemList;
            }
        }, { priority: 'high' });
        // If so, update the `listStyle` attribute for the second list.
        this.listenTo(model, 'deleteContent', () => {
            if (!firstMostOuterItem) {
                return;
            }
            model.change(writer => {
                // Find the first most-outer item list in the merged list.
                // A case when the first list item in the second list was merged into the last item in the first list.
                //
                // <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 1</listItem>
                // <listItem listIndent="0" listType="bulleted" listStyle="square">UL List item 2</listItem>
                // <listItem listIndent="0" listType="bulleted" listStyle="circle">[]UL List item 1</listItem>
                // <listItem listIndent="0" listType="bulleted" listStyle="circle">UL List item 2</listItem>
                const secondListMostOuterItem = getSiblingListItem(firstMostOuterItem.nextSibling, {
                    sameIndent: true,
                    listIndent: firstMostOuterItem.getAttribute('listIndent'),
                    direction: 'forward'
                });
                // If the selection ends in a non-list element, there are no <listItem>s that would require adjustments.
                // See: #8642.
                if (!secondListMostOuterItem) {
                    firstMostOuterItem = null;
                    return;
                }
                const items = [
                    secondListMostOuterItem,
                    ...getSiblingNodes(writer.createPositionAt(secondListMostOuterItem, 0), 'forward')
                ];
                for (const listItem of items) {
                    for (const strategy of attributeStrategies) {
                        if (strategy.appliesToListItem(listItem)) {
                            const attributeName = strategy.attributeName;
                            const value = firstMostOuterItem.getAttribute(attributeName);
                            writer.setAttribute(attributeName, value, listItem);
                        }
                    }
                }
            });
            firstMostOuterItem = null;
        }, { priority: 'low' });
    }
}
/**
 * Creates an array of strategies for dealing with enabled listItem attributes.
 */
function createAttributeStrategies(enabledProperties) {
    const strategies = [];
    if (enabledProperties.styles) {
        strategies.push({
            attributeName: 'listStyle',
            defaultValue: DEFAULT_LIST_TYPE,
            addCommand(editor) {
                editor.commands.add('listStyle', new ListStyleCommand(editor, DEFAULT_LIST_TYPE));
            },
            appliesToListItem() {
                return true;
            },
            setAttributeOnDowncast(writer, listStyle, element) {
                if (listStyle && listStyle !== DEFAULT_LIST_TYPE) {
                    writer.setStyle('list-style-type', listStyle, element);
                }
                else {
                    writer.removeStyle('list-style-type', element);
                }
            },
            getAttributeOnUpcast(listParent) {
                return listParent.getStyle('list-style-type') || DEFAULT_LIST_TYPE;
            }
        });
    }
    if (enabledProperties.reversed) {
        strategies.push({
            attributeName: 'listReversed',
            defaultValue: false,
            addCommand(editor) {
                editor.commands.add('listReversed', new ListReversedCommand(editor));
            },
            appliesToListItem(item) {
                return item.getAttribute('listType') == 'numbered';
            },
            setAttributeOnDowncast(writer, listReversed, element) {
                if (listReversed) {
                    writer.setAttribute('reversed', 'reversed', element);
                }
                else {
                    writer.removeAttribute('reversed', element);
                }
            },
            getAttributeOnUpcast(listParent) {
                return listParent.hasAttribute('reversed');
            }
        });
    }
    if (enabledProperties.startIndex) {
        strategies.push({
            attributeName: 'listStart',
            defaultValue: 1,
            addCommand(editor) {
                editor.commands.add('listStart', new ListStartCommand(editor));
            },
            appliesToListItem(item) {
                return item.getAttribute('listType') == 'numbered';
            },
            setAttributeOnDowncast(writer, listStart, element) {
                if (listStart == 0 || listStart > 1) {
                    writer.setAttribute('start', listStart, element);
                }
                else {
                    writer.removeAttribute('start', element);
                }
            },
            getAttributeOnUpcast(listParent) {
                const startAttributeValue = listParent.getAttribute('start');
                return startAttributeValue >= 0 ? startAttributeValue : 1;
            }
        });
    }
    return strategies;
}
/**
 * Returns a converter consumes the `style`, `reversed` and `start` attribute.
 * In `style` it searches for the `list-style-type` definition.
 * If not found, the `"default"` value will be used.
 */
function upcastListItemAttributes(attributeStrategies) {
    return (dispatcher) => {
        dispatcher.on('element:li', (evt, data, conversionApi) => {
            // https://github.com/ckeditor/ckeditor5/issues/13858
            if (!data.modelRange) {
                return;
            }
            const listParent = data.viewItem.parent;
            const listItem = data.modelRange.start.nodeAfter || data.modelRange.end.nodeBefore;
            for (const strategy of attributeStrategies) {
                if (strategy.appliesToListItem(listItem)) {
                    const listStyle = strategy.getAttributeOnUpcast(listParent);
                    conversionApi.writer.setAttribute(strategy.attributeName, listStyle, listItem);
                }
            }
        }, { priority: 'low' });
    };
}
/**
 * Returns a converter that adds `reversed`, `start` attributes and adds `list-style-type` definition as a value for the `style` attribute.
 * The `"default"` values are removed and not present in the view/data.
 */
function downcastListItemAttributes(attributeStrategies) {
    return (dispatcher) => {
        for (const strategy of attributeStrategies) {
            dispatcher.on(`attribute:${strategy.attributeName}:listItem`, (evt, data, conversionApi) => {
                const viewWriter = conversionApi.writer;
                const currentElement = data.item;
                const previousElement = getSiblingListItem(currentElement.previousSibling, {
                    sameIndent: true,
                    listIndent: currentElement.getAttribute('listIndent'),
                    direction: 'backward'
                });
                const viewItem = conversionApi.mapper.toViewElement(currentElement);
                // A case when elements represent different lists. We need to separate their container.
                if (!areRepresentingSameList(currentElement, previousElement)) {
                    viewWriter.breakContainer(viewWriter.createPositionBefore(viewItem));
                }
                strategy.setAttributeOnDowncast(viewWriter, data.attributeNewValue, viewItem.parent);
            }, { priority: 'low' });
        }
    };
    /**
     * Checks whether specified list items belong to the same list.
     */
    function areRepresentingSameList(listItem1, listItem2) {
        return listItem2 &&
            listItem1.getAttribute('listType') === listItem2.getAttribute('listType') &&
            listItem1.getAttribute('listIndent') === listItem2.getAttribute('listIndent') &&
            listItem1.getAttribute('listStyle') === listItem2.getAttribute('listStyle') &&
            listItem1.getAttribute('listReversed') === listItem2.getAttribute('listReversed') &&
            listItem1.getAttribute('listStart') === listItem2.getAttribute('listStart');
    }
}
/**
 * When indenting list, nested list should clear its value for the attributes or inherit from nested lists.
 *
 * ■ List item 1.
 * ■ List item 2.[]
 * ■ List item 3.
 * editor.execute( 'indentList' );
 *
 * ■ List item 1.
 *     ○ List item 2.[]
 * ■ List item 3.
 */
function fixListAfterIndentListCommand(editor, attributeStrategies) {
    return (evt, changedItems) => {
        const root = changedItems[0];
        const rootIndent = root.getAttribute('listIndent');
        const itemsToUpdate = changedItems.filter(item => item.getAttribute('listIndent') === rootIndent);
        // A case where a few list items are indented must be checked separately
        // since `getSiblingListItem()` returns the first changed element.
        // ■ List item 1.
        //     ○ [List item 2.
        //     ○ List item 3.]
        // ■ List item 4.
        //
        // List items: `2` and `3` should be adjusted.
        let previousSibling = null;
        if (root.previousSibling.getAttribute('listIndent') + 1 !== rootIndent) {
            previousSibling = getSiblingListItem(root.previousSibling, {
                sameIndent: true, direction: 'backward', listIndent: rootIndent
            });
        }
        editor.model.change(writer => {
            for (const item of itemsToUpdate) {
                for (const strategy of attributeStrategies) {
                    if (strategy.appliesToListItem(item)) {
                        const valueToSet = previousSibling == null ?
                            strategy.defaultValue :
                            previousSibling.getAttribute(strategy.attributeName);
                        writer.setAttribute(strategy.attributeName, valueToSet, item);
                    }
                }
            }
        });
    };
}
/**
 * When outdenting a list, a nested list should copy attribute values
 * from the previous sibling list item including the same value for the `listIndent` value.
 *
 * ■ List item 1.
 *     ○ List item 2.[]
 * ■ List item 3.
 *
 * editor.execute( 'outdentList' );
 *
 * ■ List item 1.
 * ■ List item 2.[]
 * ■ List item 3.
 */
function fixListAfterOutdentListCommand(editor, attributeStrategies) {
    return (evt, changedItems) => {
        changedItems = changedItems.reverse().filter(item => item.is('element', 'listItem'));
        if (!changedItems.length) {
            return;
        }
        const indent = changedItems[0].getAttribute('listIndent');
        const listType = changedItems[0].getAttribute('listType');
        let listItem = changedItems[0].previousSibling;
        // ■ List item 1.
        //     ○ List item 2.
        //     ○ List item 3.[]
        // ■ List item 4.
        //
        // After outdenting a list, `List item 3` should inherit the `listStyle` attribute from `List item 1`.
        //
        // ■ List item 1.
        //     ○ List item 2.
        // ■ List item 3.[]
        // ■ List item 4.
        if (listItem.is('element', 'listItem')) {
            while (listItem.getAttribute('listIndent') !== indent) {
                listItem = listItem.previousSibling;
            }
        }
        else {
            listItem = null;
        }
        // Outdenting such a list should restore values based on `List item 4`.
        // ■ List item 1.[]
        //     ○ List item 2.
        //     ○ List item 3.
        // ■ List item 4.
        if (!listItem) {
            listItem = changedItems[changedItems.length - 1].nextSibling;
        }
        // And such a list should not modify anything.
        // However, `listItem` can indicate a node below the list. Be sure that we have the `listItem` element.
        // ■ List item 1.[]
        //     ○ List item 2.
        //     ○ List item 3.
        // <paragraph>The later if check.</paragraph>
        if (!listItem || !listItem.is('element', 'listItem')) {
            return;
        }
        // Do not modify the list if found `listItem` represents other type of list than outdented list items.
        if (listItem.getAttribute('listType') !== listType) {
            return;
        }
        editor.model.change(writer => {
            const itemsToUpdate = changedItems.filter(item => item.getAttribute('listIndent') === indent);
            for (const item of itemsToUpdate) {
                for (const strategy of attributeStrategies) {
                    if (strategy.appliesToListItem(item)) {
                        const attributeName = strategy.attributeName;
                        const valueToSet = listItem.getAttribute(attributeName);
                        writer.setAttribute(attributeName, valueToSet, item);
                    }
                }
            }
        });
    };
}
/**
 * Each `listItem` element must have specified the `listStyle`, `listReversed` and `listStart` attributes
 * if they are enabled and supported by its `listType`.
 * This post-fixer checks whether inserted elements `listItem` elements should inherit the attribute values from
 * their sibling nodes or should use the default values.
 *
 * Paragraph[]
 * ■ List item 1. // [listStyle="square", listType="bulleted"]
 * ■ List item 2. // ...
 * ■ List item 3. // ...
 *
 * editor.execute( 'bulletedList' )
 *
 * ■ Paragraph[]  // [listStyle="square", listType="bulleted"]
 * ■ List item 1. // [listStyle="square", listType="bulleted"]
 * ■ List item 2.
 * ■ List item 3.
 *
 * It also covers a such change:
 *
 * [Paragraph 1
 * Paragraph 2]
 * ■ List item 1. // [listStyle="square", listType="bulleted"]
 * ■ List item 2. // ...
 * ■ List item 3. // ...
 *
 * editor.execute( 'numberedList' )
 *
 * 1. [Paragraph 1 // [listStyle="default", listType="numbered"]
 * 2. Paragraph 2] // [listStyle="default", listType="numbered"]
 * ■ List item 1.  // [listStyle="square", listType="bulleted"]
 * ■ List item 2.  // ...
 * ■ List item 3.  // ...
 */
function fixListAttributesOnListItemElements(editor, attributeStrategies) {
    return (writer) => {
        let wasFixed = false;
        const insertedListItems = getChangedListItems(editor.model.document.differ.getChanges())
            .filter(item => {
            // Don't touch todo lists. They are handled in another post-fixer.
            return item.getAttribute('listType') !== 'todo';
        });
        if (!insertedListItems.length) {
            return wasFixed;
        }
        // Check whether the last inserted element is next to the `listItem` element.
        //
        // ■ Paragraph[]  // <-- The inserted item.
        // ■ List item 1.
        let existingListItem = insertedListItems[insertedListItems.length - 1].nextSibling;
        // If it doesn't, maybe the `listItem` was inserted at the end of the list.
        //
        // ■ List item 1.
        // ■ Paragraph[]  // <-- The inserted item.
        if (!existingListItem || !existingListItem.is('element', 'listItem')) {
            existingListItem = insertedListItems[0].previousSibling;
            if (existingListItem) {
                const indent = insertedListItems[0].getAttribute('listIndent');
                // But we need to find a `listItem` with the `listIndent=0` attribute.
                // If doesn't, maybe the `listItem` was inserted at the end of the list.
                //
                // ■ List item 1.
                //     ○ List item 2.
                // ■ Paragraph[]  // <-- The inserted item.
                while (existingListItem.is('element', 'listItem') && existingListItem.getAttribute('listIndent') !== indent) {
                    existingListItem = existingListItem.previousSibling;
                    // If the item does not exist, most probably there is no other content in the editor. See: #8072.
                    if (!existingListItem) {
                        break;
                    }
                }
            }
        }
        for (const strategy of attributeStrategies) {
            const attributeName = strategy.attributeName;
            for (const item of insertedListItems) {
                if (!strategy.appliesToListItem(item)) {
                    writer.removeAttribute(attributeName, item);
                    continue;
                }
                if (!item.hasAttribute(attributeName)) {
                    if (shouldInheritListType(existingListItem, item, strategy)) {
                        writer.setAttribute(attributeName, existingListItem.getAttribute(attributeName), item);
                    }
                    else {
                        writer.setAttribute(attributeName, strategy.defaultValue, item);
                    }
                    wasFixed = true;
                }
                else {
                    // Adjust the `listStyle`, `listReversed` and `listStart`
                    // attributes for inserted (pasted) items. See #8160.
                    //
                    // ■ List item 1. // [listStyle="square", listType="bulleted"]
                    //     ○ List item 1.1. // [listStyle="circle", listType="bulleted"]
                    //     ○ [] (selection is here)
                    //
                    // Then, pasting a list with different attributes (listStyle, listType):
                    //
                    // 1. First. // [listStyle="decimal", listType="numbered"]
                    // 2. Second // [listStyle="decimal", listType="numbered"]
                    //
                    // The `listType` attribute will be corrected by the `ListEditing` converters.
                    // We need to adjust the `listStyle` attribute. Expected structure:
                    //
                    // ■ List item 1. // [listStyle="square", listType="bulleted"]
                    //     ○ List item 1.1. // [listStyle="circle", listType="bulleted"]
                    //     ○ First. // [listStyle="circle", listType="bulleted"]
                    //     ○ Second // [listStyle="circle", listType="bulleted"]
                    const previousSibling = item.previousSibling;
                    if (shouldInheritListTypeFromPreviousItem(previousSibling, item, strategy.attributeName)) {
                        writer.setAttribute(attributeName, previousSibling.getAttribute(attributeName), item);
                        wasFixed = true;
                    }
                }
            }
        }
        return wasFixed;
    };
}
/**
 * Checks whether the `listStyle`, `listReversed` and `listStart` attributes
 * should be copied from the `baseItem` element.
 *
 * The attribute should be copied if the inserted element does not have defined it and
 * the value for the element is other than default in the base element.
 */
function shouldInheritListType(baseItem, itemToChange, attributeStrategy) {
    if (!baseItem) {
        return false;
    }
    const baseListAttribute = baseItem.getAttribute(attributeStrategy.attributeName);
    if (!baseListAttribute) {
        return false;
    }
    if (baseListAttribute == attributeStrategy.defaultValue) {
        return false;
    }
    if (baseItem.getAttribute('listType') !== itemToChange.getAttribute('listType')) {
        return false;
    }
    return true;
}
/**
 * Checks whether the `listStyle`, `listReversed` and `listStart` attributes
 * should be copied from previous list item.
 *
 * The attribute should be copied if there's a mismatch of styles of the pasted list into a nested list.
 * Top-level lists are not normalized as we allow side-by-side list of different types.
 */
function shouldInheritListTypeFromPreviousItem(previousItem, itemToChange, attributeName) {
    if (!previousItem || !previousItem.is('element', 'listItem')) {
        return false;
    }
    if (itemToChange.getAttribute('listType') !== previousItem.getAttribute('listType')) {
        return false;
    }
    const previousItemIndent = previousItem.getAttribute('listIndent');
    if (previousItemIndent < 1 || previousItemIndent !== itemToChange.getAttribute('listIndent')) {
        return false;
    }
    const previousItemListAttribute = previousItem.getAttribute(attributeName);
    if (!previousItemListAttribute || previousItemListAttribute === itemToChange.getAttribute(attributeName)) {
        return false;
    }
    return true;
}
/**
 * Removes the `listStyle`, `listReversed` and `listStart` attributes from "todo" list items.
 */
function removeListItemAttributesFromTodoList(editor) {
    return (writer) => {
        const todoListItems = getChangedListItems(editor.model.document.differ.getChanges())
            .filter(item => {
            // Handle the todo lists only. The rest is handled in another post-fixer.
            return item.getAttribute('listType') === 'todo' && (item.hasAttribute('listStyle') ||
                item.hasAttribute('listReversed') ||
                item.hasAttribute('listStart'));
        });
        if (!todoListItems.length) {
            return false;
        }
        for (const item of todoListItems) {
            writer.removeAttribute('listStyle', item);
            writer.removeAttribute('listReversed', item);
            writer.removeAttribute('listStart', item);
        }
        return true;
    };
}
/**
 * Restores the `listStyle` attribute after changing the list type.
 */
function restoreDefaultListStyle(editor) {
    return (evt, changedItems) => {
        changedItems = changedItems.filter(item => item.is('element', 'listItem'));
        editor.model.change(writer => {
            for (const item of changedItems) {
                // Remove the attribute. Post-fixer will restore the proper value.
                writer.removeAttribute('listStyle', item);
            }
        });
    };
}
/**
 * Returns the `listItem` that was inserted or changed.
 *
 * @param changes The changes list returned by the differ.
 */
function getChangedListItems(changes) {
    const items = [];
    for (const change of changes) {
        const item = getItemFromChange(change);
        if (item && item.is('element', 'listItem')) {
            items.push(item);
        }
    }
    return items;
}
function getItemFromChange(change) {
    if (change.type === 'attribute') {
        return change.range.start.nodeAfter;
    }
    if (change.type === 'insert') {
        return change.position.nodeAfter;
    }
    return null;
}