ckeditor/ckeditor5-engine

/**
 * @license Copyright (c) 2003-2020, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */

/**
 * @module engine/view/text
 */

import Node from './node';

/**
 * Tree view text node.
 *
 * The constructor of this class should not be used directly. To create a new text node instance
 * use the {@link module:engine/view/downcastwriter~DowncastWriter#createText `DowncastWriter#createText()`}
 * method when working on data downcasted from the model or the
 * {@link module:engine/view/upcastwriter~UpcastWriter#createText `UpcastWriter#createText()`}
 * method when working on non-semantic views.
 *
 * @extends module:engine/view/node~Node
 */
export default class Text extends Node {
    /**
     * Creates a tree view text node.
     *
     * @protected
     * @param {module:engine/view/document~Document} document The document instance to which this text node belongs.
     * @param {String} data The text's data.
     */
    constructor( document, data ) {
        super( document );

        /**
         * The text content.
         *
         * Setting the data fires the {@link module:engine/view/node~Node#event:change:text change event}.
         *
         * @protected
         * @member {String} module:engine/view/text~Text#_textData
         */
        this._textData = data;
    }

    /**
     * Checks whether this object is of the given type.
     *
     *        text.is( 'text' ); // -> true
     *        text.is( 'node' ); // -> true
     *        text.is( 'view:text' ); // -> true
     *        text.is( 'view:node' ); // -> true
     *
     *        text.is( 'model:text' ); // -> false
     *        text.is( 'element' ); // -> false
     *        text.is( 'range' ); // -> false
     *
     * {@link module:engine/view/node~Node#is Check the entire list of view objects} which implement the `is()` method.
     *
     * @param {String} type
     * @returns {Boolean}
     */
    is( type ) {
        return type === 'text' || type === 'view:text' ||
            // From super.is(). This is highly utilised method and cannot call super. See ckeditor/ckeditor5#6529.
            type === 'node' || type === 'view:node';
    }

    /**
     * The text content.
     *
     * @readonly
     * @type {String}
     */
    get data() {
        return this._textData;
    }

    /**
     * This getter is required when using the addition assignment operator on protected property:
     *
     *        const foo = downcastWriter.createText( 'foo' );
     *        const bar = downcastWriter.createText( 'bar' );
     *
     *        foo._data += bar.data;   // executes: `foo._data = foo._data + bar.data`
     *        console.log( foo.data ); // prints: 'foobar'
     *
     * If the protected getter didn't exist, `foo._data` will return `undefined` and result of the merge will be invalid.
     *
     * @protected
     * @type {String}
     */
    get _data() {
        return this.data;
    }

    /**
     * Sets data and fires the {@link module:engine/view/node~Node#event:change:text change event}.
     *
     * @protected
     * @fires change:text
     * @param {String} data New data for the text node.
     */
    set _data( data ) {
        this._fireChange( 'text', this );

        this._textData = data;
    }

    /**
     * Checks if this text node is similar to other text node.
     * Both nodes should have the same data to be considered as similar.
     *
     * @param {module:engine/view/text~Text} otherNode Node to check if it is same as this node.
     * @returns {Boolean}
     */
    isSimilar( otherNode ) {
        if ( !( otherNode instanceof Text ) ) {
            return false;
        }

        return this === otherNode || this.data === otherNode.data;
    }

    /**
     * Clones this node.
     *
     * @protected
     * @returns {module:engine/view/text~Text} Text node that is a clone of this node.
     */
    _clone() {
        return new Text( this.document, this.data );
    }

    // @if CK_DEBUG_ENGINE // toString() {
    // @if CK_DEBUG_ENGINE //     return `#${ this.data }`;
    // @if CK_DEBUG_ENGINE // }

    // @if CK_DEBUG_ENGINE // log() {
    // @if CK_DEBUG_ENGINE //     console.log( 'ViewText: ' + this );
    // @if CK_DEBUG_ENGINE // }

    // @if CK_DEBUG_ENGINE // logExtended() {
    // @if CK_DEBUG_ENGINE //     console.log( 'ViewText: ' + this );
    // @if CK_DEBUG_ENGINE // }
}