text: /**
   * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
   * For licensing, see LICENSE.md.
   */
  
  /**
   * @module image/imagecaption/utils
   */
  
  import { enablePlaceholder } from '@ckeditor/ckeditor5-engine/src/view/placeholder';
  import { toWidgetEditable } from '@ckeditor/ckeditor5-widget/src/utils';
  
  /**
   * Returns a function that creates a caption editable element for the given {@link module:engine/view/document~Document}.
   *
   * @param {module:engine/view/view~View} view
   * @param {String} placeholderText The text to be displayed when the caption is empty.
   * @returns {Function}
   */
  export function captionElementCreator( view, placeholderText ) {
  	return writer => {
  		const editable = writer.createEditableElement( 'figcaption' );
  		writer.setCustomProperty( 'imageCaption', true, editable );
  
  		enablePlaceholder( {
  			view,
  			element: editable,
  			text: placeholderText
  		} );
  
  		return toWidgetEditable( editable, writer );
  	};
  }
  
  /**
   * Returns `true` if a given view element is the image caption editable.
   *
   * @param {module:engine/view/element~Element} viewElement
   * @returns {Boolean}
   */
  export function isCaption( viewElement ) {
  	return !!viewElement.getCustomProperty( 'imageCaption' );
  }
  
  /**
   * Returns the caption model element from a given image element. Returns `null` if no caption is found.
   *
   * @param {module:engine/model/element~Element} imageModelElement
   * @returns {module:engine/model/element~Element|null}
   */
  export function getCaptionFromImage( imageModelElement ) {
  	for ( const node of imageModelElement.getChildren() ) {
  		if ( !!node && node.is( 'caption' ) ) {
  			return node;
  		}
  	}
  
  	return null;
  }
  
  /**
   * {@link module:engine/view/matcher~Matcher} pattern. Checks if a given element is a `<figcaption>` element that is placed
   * inside the image `<figure>` element.
   *
   * @param {module:engine/view/element~Element} element
   * @returns {Object|null} Returns the object accepted by {@link module:engine/view/matcher~Matcher} or `null` if the element
   * cannot be matched.
   */
  export function matchImageCaption( element ) {
  	const parent = element.parent;
  
  	// Convert only captions for images.
  	if ( element.name == 'figcaption' && parent && parent.name == 'figure' && parent.hasClass( 'image' ) ) {
  		return { name: true };
  	}
  
  	return null;
  }
  