src/widget.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 widget/widget
*/
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
import MouseObserver from '@ckeditor/ckeditor5-engine/src/view/observer/mouseobserver';
import { getLabel, isWidget, WIDGET_SELECTED_CLASS_NAME } from './utils';
import { keyCodes } from '@ckeditor/ckeditor5-utils/src/keyboard';
import env from '@ckeditor/ckeditor5-utils/src/env';
import '../theme/widget.css';
/**
* The widget plugin. It enables base support for widgets.
*
* See {@glink api/widget package page} for more details and documentation.
*
* This plugin enables multiple behaviors required by widgets:
*
* * The model to view selection converter for the editing pipeline (it handles widget custom selection rendering).
* If a converted selection wraps around a widget element, that selection is marked as
* {@link module:engine/view/selection~Selection#isFake fake}. Additionally, the `ck-widget_selected` CSS class
* is added to indicate that widget has been selected.
* * The mouse and keyboard events handling on and around widget elements.
*
* @extends module:core/plugin~Plugin
*/
export default class Widget extends Plugin {
/**
* @inheritDoc
*/
static get pluginName() {
return 'Widget';
}
/**
* @inheritDoc
*/
init() {
const view = this.editor.editing.view;
const viewDocument = view.document;
/**
* Holds previously selected widgets.
*
* @private
* @type {Set.<module:engine/view/element~Element>}
*/
this._previouslySelected = new Set();
// Model to view selection converter.
// Converts selection placed over widget element to fake selection
this.editor.editing.downcastDispatcher.on( 'selection', ( evt, data, conversionApi ) => {
// Remove selected class from previously selected widgets.
this._clearPreviouslySelectedWidgets( conversionApi.writer );
const viewWriter = conversionApi.writer;
const viewSelection = viewWriter.document.selection;
const selectedElement = viewSelection.getSelectedElement();
let lastMarked = null;
for ( const range of viewSelection.getRanges() ) {
for ( const value of range ) {
const node = value.item;
// Do not mark nested widgets in selected one. See: #57.
if ( isWidget( node ) && !isChild( node, lastMarked ) ) {
viewWriter.addClass( WIDGET_SELECTED_CLASS_NAME, node );
this._previouslySelected.add( node );
lastMarked = node;
// Check if widget is a single element selected.
if ( node == selectedElement ) {
viewWriter.setSelection( viewSelection.getRanges(), { fake: true, label: getLabel( selectedElement ) } );
}
}
}
}
}, { priority: 'low' } );
// If mouse down is pressed on widget - create selection over whole widget.
view.addObserver( MouseObserver );
this.listenTo( viewDocument, 'mousedown', ( ...args ) => this._onMousedown( ...args ) );
// Handle custom keydown behaviour.
this.listenTo( viewDocument, 'keydown', ( ...args ) => this._onKeydown( ...args ), { priority: 'high' } );
// Handle custom delete behaviour.
this.listenTo( viewDocument, 'delete', ( evt, data ) => {
if ( this._handleDelete( data.direction == 'forward' ) ) {
data.preventDefault();
evt.stop();
}
}, { priority: 'high' } );
}
/**
* Handles {@link module:engine/view/document~Document#event:mousedown mousedown} events on widget elements.
*
* @private
* @param {module:utils/eventinfo~EventInfo} eventInfo
* @param {module:engine/view/observer/domeventdata~DomEventData} domEventData
*/
_onMousedown( eventInfo, domEventData ) {
const editor = this.editor;
const view = editor.editing.view;
const viewDocument = view.document;
let element = domEventData.target;
// Do nothing for single or double click inside nested editable.
if ( isInsideNestedEditable( element ) ) {
// But at least triple click inside nested editable causes broken selection in Safari.
// For such event, we select the entire nested editable element.
// See: https://github.com/ckeditor/ckeditor5/issues/1463.
if ( env.isSafari && domEventData.domEvent.detail >= 3 ) {
const mapper = editor.editing.mapper;
const modelElement = mapper.toModelElement( element );
this.editor.model.change( writer => {
domEventData.preventDefault();
writer.setSelection( modelElement, 'in' );
} );
}
return;
}
// If target is not a widget element - check if one of the ancestors is.
if ( !isWidget( element ) ) {
element = element.findAncestor( isWidget );
if ( !element ) {
return;
}
}
domEventData.preventDefault();
// Focus editor if is not focused already.
if ( !viewDocument.isFocused ) {
view.focus();
}
// Create model selection over widget.
const modelElement = editor.editing.mapper.toModelElement( element );
this._setSelectionOverElement( modelElement );
}
/**
* Handles {@link module:engine/view/document~Document#event:keydown keydown} events.
*
* @private
* @param {module:utils/eventinfo~EventInfo} eventInfo
* @param {module:engine/view/observer/domeventdata~DomEventData} domEventData
*/
_onKeydown( eventInfo, domEventData ) {
const keyCode = domEventData.keyCode;
const isLtrContent = this.editor.locale.contentLanguageDirection === 'ltr';
const isForward = keyCode == keyCodes.arrowdown || keyCode == keyCodes[ isLtrContent ? 'arrowright' : 'arrowleft' ];
let wasHandled = false;
// Checks if the keys were handled and then prevents the default event behaviour and stops
// the propagation.
if ( isArrowKeyCode( keyCode ) ) {
wasHandled = this._handleArrowKeys( isForward );
} else if ( keyCode === keyCodes.enter ) {
wasHandled = this._handleEnterKey( domEventData.shiftKey );
}
if ( wasHandled ) {
domEventData.preventDefault();
eventInfo.stop();
}
}
/**
* Handles delete keys: backspace and delete.
*
* @private
* @param {Boolean} isForward Set to true if delete was performed in forward direction.
* @returns {Boolean|undefined} Returns `true` if keys were handled correctly.
*/
_handleDelete( isForward ) {
// Do nothing when the read only mode is enabled.
if ( this.editor.isReadOnly ) {
return;
}
const modelDocument = this.editor.model.document;
const modelSelection = modelDocument.selection;
// Do nothing on non-collapsed selection.
if ( !modelSelection.isCollapsed ) {
return;
}
const objectElement = this._getObjectElementNextToSelection( isForward );
if ( objectElement ) {
this.editor.model.change( writer => {
let previousNode = modelSelection.anchor.parent;
// Remove previous element if empty.
while ( previousNode.isEmpty ) {
const nodeToRemove = previousNode;
previousNode = nodeToRemove.parent;
writer.remove( nodeToRemove );
}
this._setSelectionOverElement( objectElement );
} );
return true;
}
}
/**
* Handles arrow keys.
*
* @private
* @param {Boolean} isForward Set to true if arrow key should be handled in forward direction.
* @returns {Boolean|undefined} Returns `true` if keys were handled correctly.
*/
_handleArrowKeys( isForward ) {
const model = this.editor.model;
const schema = model.schema;
const modelDocument = model.document;
const modelSelection = modelDocument.selection;
const objectElement = modelSelection.getSelectedElement();
// If object element is selected.
if ( objectElement && schema.isObject( objectElement ) ) {
const position = isForward ? modelSelection.getLastPosition() : modelSelection.getFirstPosition();
const newRange = schema.getNearestSelectionRange( position, isForward ? 'forward' : 'backward' );
if ( newRange ) {
model.change( writer => {
writer.setSelection( newRange );
} );
}
return true;
}
// If selection is next to object element.
// Return if not collapsed.
if ( !modelSelection.isCollapsed ) {
return;
}
const objectElement2 = this._getObjectElementNextToSelection( isForward );
if ( !!objectElement2 && schema.isObject( objectElement2 ) ) {
this._setSelectionOverElement( objectElement2 );
return true;
}
}
/**
* Handles the enter key, giving users and access to positions in the editable directly before
* (<kbd>Shift</kbd>+<kbd>Enter</kbd>) or after (<kbd>Enter</kbd>) the selected widget.
* It improves the UX, mainly when the widget is the first or last child of the root editable
* and there's no other way to type after or before it.
*
* @private
* @param {Boolean} isBackwards Set to true if the new paragraph is to be inserted before
* the selected widget (<kbd>Shift</kbd>+<kbd>Enter</kbd>).
* @returns {Boolean|undefined} Returns `true` if keys were handled correctly.
*/
_handleEnterKey( isBackwards ) {
const model = this.editor.model;
const modelSelection = model.document.selection;
const selectedElement = modelSelection.getSelectedElement();
if ( shouldInsertParagraph( selectedElement, model.schema ) ) {
model.change( writer => {
let position = writer.createPositionAt( selectedElement, isBackwards ? 'before' : 'after' );
const paragraph = writer.createElement( 'paragraph' );
// Split the parent when inside a block element.
// https://github.com/ckeditor/ckeditor5/issues/1529
if ( model.schema.isBlock( selectedElement.parent ) ) {
const paragraphLimit = model.schema.findAllowedParent( position, paragraph );
position = writer.split( position, paragraphLimit ).position;
}
writer.insert( paragraph, position );
writer.setSelection( paragraph, 'in' );
} );
return true;
}
}
/**
* Sets {@link module:engine/model/selection~Selection document's selection} over given element.
*
* @private
* @param {module:engine/model/element~Element} element
*/
_setSelectionOverElement( element ) {
this.editor.model.change( writer => {
writer.setSelection( writer.createRangeOn( element ) );
} );
}
/**
* Checks if {@link module:engine/model/element~Element element} placed next to the current
* {@link module:engine/model/selection~Selection model selection} exists and is marked in
* {@link module:engine/model/schema~Schema schema} as `object`.
*
* @private
* @param {Boolean} forward Direction of checking.
* @returns {module:engine/model/element~Element|null}
*/
_getObjectElementNextToSelection( forward ) {
const model = this.editor.model;
const schema = model.schema;
const modelSelection = model.document.selection;
// Clone current selection to use it as a probe. We must leave default selection as it is so it can return
// to its current state after undo.
const probe = model.createSelection( modelSelection );
model.modifySelection( probe, { direction: forward ? 'forward' : 'backward' } );
const objectElement = forward ? probe.focus.nodeBefore : probe.focus.nodeAfter;
if ( !!objectElement && schema.isObject( objectElement ) ) {
return objectElement;
}
return null;
}
/**
* Removes CSS class from previously selected widgets.
*
* @private
* @param {module:engine/view/downcastwriter~DowncastWriter} writer
*/
_clearPreviouslySelectedWidgets( writer ) {
for ( const widget of this._previouslySelected ) {
writer.removeClass( WIDGET_SELECTED_CLASS_NAME, widget );
}
this._previouslySelected.clear();
}
}
// Returns 'true' if provided key code represents one of the arrow keys.
//
// @param {Number} keyCode
// @returns {Boolean}
function isArrowKeyCode( keyCode ) {
return keyCode == keyCodes.arrowright ||
keyCode == keyCodes.arrowleft ||
keyCode == keyCodes.arrowup ||
keyCode == keyCodes.arrowdown;
}
// Returns `true` when element is a nested editable or is placed inside one.
//
// @param {module:engine/view/element~Element}
// @returns {Boolean}
function isInsideNestedEditable( element ) {
while ( element ) {
if ( element.is( 'editableElement' ) && !element.is( 'rootElement' ) ) {
return true;
}
// Click on nested widget should select it.
if ( isWidget( element ) ) {
return false;
}
element = element.parent;
}
return false;
}
// Checks whether the specified `element` is a child of the `parent` element.
//
// @param {module:engine/view/element~Element} element An element to check.
// @param {module:engine/view/element~Element|null} parent A parent for the element.
// @returns {Boolean}
function isChild( element, parent ) {
if ( !parent ) {
return false;
}
return Array.from( element.getAncestors() ).includes( parent );
}
// Checks if enter key should insert paragraph. This should be done only on elements of type object (excluding inline objects).
//
// @param {module:engine/model/element~Element} element And element to check.
// @param {module:engine/model/schema~Schema} schema
function shouldInsertParagraph( element, schema ) {
return element && schema.isObject( element ) && !schema.isInline( element );
}