/**
* @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
* For licensing, see LICENSE.md.
*/
/**
* @module typing/deleteobserver
*/
import Observer from '@ckeditor/ckeditor5-engine/src/view/observer/observer';
import DomEventData from '@ckeditor/ckeditor5-engine/src/view/observer/domeventdata';
import { keyCodes } from '@ckeditor/ckeditor5-utils/src/keyboard';
/**
* Delete observer introduces the {@link module:engine/view/document~Document#event:delete} event.
*
* @extends module:engine/view/observer/observer~Observer
*/
export default class DeleteObserver extends Observer {
constructor( document ) {
super( document );
let sequence = 0;
document.on( 'keyup', ( evt, data ) => {
if ( data.keyCode == keyCodes.delete || data.keyCode == keyCodes.backspace ) {
sequence = 0;
}
} );
document.on( 'keydown', ( evt, data ) => {
const deleteData = {};
if ( data.keyCode == keyCodes.delete ) {
deleteData.direction = 'forward';
deleteData.unit = 'character';
} else if ( data.keyCode == keyCodes.backspace ) {
deleteData.direction = 'backward';
deleteData.unit = 'codePoint';
} else {
return;
}
deleteData.unit = data.altKey ? 'word' : deleteData.unit;
deleteData.sequence = ++sequence;
document.fire( 'delete', new DomEventData( document, data.domEvent, deleteData ) );
} );
}
/**
* @inheritDoc
*/
observe() {}
}
/**
* Event fired when the user tries to delete content (e.g. presses Delete or Backspace).
*
* Note: This event is fired by the {@link module:typing/deleteobserver~DeleteObserver observer}
* (usually registered by the {@link module:typing/delete~Delete delete feature}).
*
* @event module:engine/view/document~Document#event:delete
* @param {module:engine/view/observer/domeventdata~DomEventData} data
* @param {'forward'|'delete'} data.direction The direction in which the deletion should happen.
* @param {'character'|'word'} data.unit The "amount" of content that should be deleted.
* @param {Number} data.sequence A number describing which subsequent delete event it is without the key being released.
* If it's 2 or more it means that the key was pressed and hold.
*/