/** * @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 enter/shiftentercommand */ import Command from '@ckeditor/ckeditor5-core/src/command'; import { getCopyOnEnterAttributes } from './utils'; /** * ShiftEnter command. It is used by the {@link module:enter/shiftenter~ShiftEnter ShiftEnter feature} to handle * the Shift+Enter keystroke. * * @extends module:core/command~Command */ export default class ShiftEnterCommand extends Command { /** * @inheritDoc */ execute() { const model = this.editor.model; const doc = model.document; model.change( writer => { softBreakAction( model, writer, doc.selection ); this.fire( 'afterExecute', { writer } ); } ); } refresh() { const model = this.editor.model; const doc = model.document; this.isEnabled = isEnabled( model.schema, doc.selection ); } } // Checks whether the ShiftEnter command should be enabled in the specified selection. // // @param {module:engine/model/schema~Schema} schema // @param {module:engine/model/selection~Selection|module:engine/model/documentselection~DocumentSelection} selection function isEnabled( schema, selection ) { // At this moment it is okay to support single range selections only. // But in the future we may need to change that. if ( selection.rangeCount > 1 ) { return false; } const anchorPos = selection.anchor; // Check whether the break element can be inserted in the current selection anchor. if ( !anchorPos || !schema.checkChild( anchorPos, 'softBreak' ) ) { return false; } const range = selection.getFirstRange(); const startElement = range.start.parent; const endElement = range.end.parent; // Do not modify the content if selection is cross-limit elements. if ( ( isInsideLimitElement( startElement, schema ) || isInsideLimitElement( endElement, schema ) ) && startElement !== endElement ) { return false; } return true; } // Creates a break in the way that the Shift+Enter keystroke is expected to work. // // @param {module:engine/model~Model} model // @param {module:engine/model/writer~Writer} writer // @param {module:engine/model/selection~Selection|module:engine/model/documentselection~DocumentSelection} selection // Selection on which the action should be performed. function softBreakAction( model, writer, selection ) { const isSelectionEmpty = selection.isCollapsed; const range = selection.getFirstRange(); const startElement = range.start.parent; const endElement = range.end.parent; const isContainedWithinOneElement = ( startElement == endElement ); if ( isSelectionEmpty ) { const attributesToCopy = getCopyOnEnterAttributes( model.schema, selection.getAttributes() ); insertBreak( model, writer, range.end ); writer.removeSelectionAttribute( selection.getAttributeKeys() ); writer.setSelectionAttribute( attributesToCopy ); } else { const leaveUnmerged = !( range.start.isAtStart && range.end.isAtEnd ); model.deleteContent( selection, { leaveUnmerged } ); // Selection within one element: // // x[xx]x -> x^x -> x
^x
if ( isContainedWithinOneElement ) { insertBreak( model, writer, selection.focus ); } // Selection over multiple elements. // // x[x

y]y

-> x^

y

-> x

^y

// // We chose not to insert a line break in this case because: // // * it's not a very common scenario, // * it actually surprised me when I saw the "expected behavior" in real life. // // It's ok if the user will need to be more specific where they want the
to be inserted. else { // Move the selection to the 2nd element (last step of the example above). if ( leaveUnmerged ) { writer.setSelection( endElement, 0 ); } } } } function insertBreak( model, writer, position ) { const breakLineElement = writer.createElement( 'softBreak' ); model.insertContent( breakLineElement, position ); writer.setSelection( breakLineElement, 'after' ); } // Checks whether the specified `element` is a child of the limit element. // // Checking whether the `

` element is inside a limit element: // - <$root>

Text.

=> false // - <$root>

Text

=> true // // @param {module:engine/model/element~Element} element // @param {module:engine/schema~Schema} schema // @returns {Boolean} function isInsideLimitElement( element, schema ) { // `$root` is a limit element but in this case is an invalid element. if ( element.is( 'rootElement' ) ) { return false; } return schema.isLimit( element ) || isInsideLimitElement( element.parent, schema ); }