src/shiftentercommand.js
/**
* @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 <kbd>Shift</kbd>+<kbd>Enter</kbd> 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 <kbd>Shift</kbd>+<kbd>Enter</kbd> 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:
//
// <h>x[xx]x</h> -> <h>x^x</h> -> <h>x<br>^x</h>
if ( isContainedWithinOneElement ) {
insertBreak( model, writer, selection.focus );
}
// Selection over multiple elements.
//
// <h>x[x</h><p>y]y<p> -> <h>x^</h><p>y</p> -> <h>x</h><p>^y</p>
//
// 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 <br> 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 `<p>` element is inside a limit element:
// - <$root><p>Text.</p></$root> => false
// - <$root><limitElement><p>Text</p></limitElement></$root> => 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 );
}