SelectionObserver

A reference to the ViewDocument object.

Reference to the domConverter.

Instance of the focus observer. Focus observer calls flush to mark the latest focus change as complete.

The state of the observer. If it is disabled, no events will be fired.

Instance of the mutation observer. Selection observer calls flush to ensure that the mutations will be handled before the event-selectionChange event is fired.

Reference to the view ViewDocumentSelection object used to compare new selection with it.

An instance of the view controller.

When called, starts clearing the _loopbackCounter counter in time intervals. When the number of selection changes exceeds a certain limit within the interval of time, the observer will not fire selectionChange but warn about possible infinite selection loop.

Unlocks the isSelecting state of the view document in case the selection observer did not record this fact correctly (for whatever reason). It is a safeguard (paranoid check), that returns document to the normal state after a certain period of time (debounced, postponed by each selectionchange event).

A set of documents which have added selectionchange listener to avoid adding a listener twice to the same document.

Fires debounced event selectionChangeDone. It uses es-toolkit#debounce method to delay function call.

Private property to check if the code does not enter infinite loop.

A set of DOM documents that have a pending selection change. Pending selection change is recorded while selection change event is detected on non focused editable.

Parameters

view : EditingView

Checks whether a given DOM event should be ignored (should not be turned into a synthetic view document event).

Currently, an event will be ignored only if its target or any of its ancestors has the data-cke-ignore-events attribute. This attribute can be used inside the structures generated by ViewDowncastWriter#createUIElement() to ignore events fired within a UI that should be excluded from CKEditor 5's realms.

Parameters

domTarget : null | Node

The DOM event target to check (usually an element, sometimes a text node and potentially sometimes a document, too).

Returns

boolean

Whether this event should be ignored by the observer.

Delegates selected events to another Emitter. For instance:

emitterA.delegate( 'eventX' ).to( emitterB );
emitterA.delegate( 'eventX', 'eventY' ).to( emitterC );

then eventX is delegated (fired by) emitterB and emitterC along with data:

emitterA.fire( 'eventX', data );

and eventY is delegated (fired by) emitterC along with data:

emitterA.fire( 'eventY', data );

Parameters

events : Array<string>

Event names that will be delegated to another emitter.

Returns

EmitterMixinDelegateChain

Disables and destroys the observer, among others removes event listeners created by the observer.

Returns

void

Disables the observer. This method is called before rendering to prevent firing events during rendering.

Returns

void

Related:

• Observer#enable

Enables the observer. This method is called when the observer is registered to the EditingView and after rendering (all observers are disabled before rendering).

A typical use case for disabling observers is that mutation observers need to be disabled for the rendering. However, a child class may not need to be disabled, so it can implement an empty method.

Returns

void

Related:

• Observer#disable

Fires an event, executing all callbacks registered for it.

The first parameter passed to callbacks is an EventInfo object, followed by the optional args provided in the fire() method call.

Type parameters

TEvent : extends BaseEvent

The type describing the event. See BaseEvent.

Parameters

eventOrInfo : GetNameOrEventInfo<TEvent>

The name of the event or EventInfo object if event is delegated.

args : TEvent[ 'args' ]

Additional arguments to be passed to the callbacks.

Returns

GetEventInfo<TEvent>[ 'return' ]

By default the method returns undefined. However, the return value can be changed by listeners through modification of the evt.return's property (the event info is the first param of every callback).

Registers a callback function to be executed when an event is fired in a specific (emitter) object.

Events can be grouped in namespaces using :. When namespaced event is fired, it additionally fires all callbacks for that namespace.

// myEmitter.on( ... ) is a shorthand for myEmitter.listenTo( myEmitter, ... ).
myEmitter.on( 'myGroup', genericCallback );
myEmitter.on( 'myGroup:myEvent', specificCallback );

// genericCallback is fired.
myEmitter.fire( 'myGroup' );
// both genericCallback and specificCallback are fired.
myEmitter.fire( 'myGroup:myEvent' );
// genericCallback is fired even though there are no callbacks for "foo".
myEmitter.fire( 'myGroup:foo' );

An event callback can stop the event and set the return value of the fire method.

Type parameters

TEvent : extends BaseEvent

The type describing the event. See BaseEvent.

Parameters

emitter : Emitter

The object that fires the event.

event : TEvent[ 'name' ]

The name of the event.

callback : GetCallback<TEvent>

The function to be called on event.

[ options ] : CallbackOptions

Additional options.

Returns

void

Registers a callback function to be executed when an event is fired in a specific Emitter or DOM Node. It is backwards compatible with listenTo.

Type parameters

K : extends keyof DomEventMap

Parameters

emitter : Window | EventTarget | Node

The object that fires the event.

event : K

The name of the event.

callback : ( this: this, ev: EventInfo, event: DomEventMap[ K ] ) => void

The function to be called on event.

[ options ] : object

Additional options.

Returns

void

Starts observing given DOM element.

Parameters

domElement : HTMLElement

DOM element to observe.

Returns

void

Stops executing the callback on the given event. Shorthand for this.stopListening( this, event, callback ).

Parameters

event : string

The name of the event.

callback : Function

The function to stop being called.

Returns

void

Registers a callback function to be executed when an event is fired.

Shorthand for this.listenTo( this, event, callback, options ) (it makes the emitter listen on itself).

Type parameters

TEvent : extends BaseEvent

The type descibing the event. See BaseEvent.

Parameters

event : TEvent[ 'name' ]

The name of the event.

callback : GetCallback<TEvent>

The function to be called on event.

[ options ] : GetCallbackOptions<TEvent>

Additional options.

Returns

void

Registers a callback function to be executed on the next time the event is fired only. This is similar to calling on followed by off in the callback.

Type parameters

TEvent : extends BaseEvent

The type descibing the event. See BaseEvent.

Parameters

event : TEvent[ 'name' ]

The name of the event.

callback : GetCallback<TEvent>

The function to be called on event.

[ options ] : GetCallbackOptions<TEvent>

Additional options.

Returns

void

Stops delegating events. It can be used at different levels:

• To stop delegating all events.
• To stop delegating a specific event to all emitters.
• To stop delegating a specific event to a specific emitter.

Parameters

[ event ] : string

The name of the event to stop delegating. If omitted, stops it all delegations.

[ emitter ] : Emitter

(requires event) The object to stop delegating a particular event to. If omitted, stops delegation of event to all emitters.

Returns

void

Stops listening for events. It can be used at different levels: It is backwards compatible with listenTo.

• To stop listening to a specific callback.
• To stop listening to a specific event.
• To stop listening to all events fired by a specific object.
• To stop listening to all events fired by all objects.

Parameters

[ emitter ] : Window | EventTarget | Node | Emitter

The object to stop listening to. If omitted, stops it for all objects.

[ event ] : string

(Requires the emitter) The name of the event to stop listening to. If omitted, stops it for all events from emitter.

[ callback ] : Function

(Requires the event) The function to be removed from the call list for the given event.

Returns

void

Stops observing given DOM element.

Parameters

domElement : HTMLElement

Returns

void

Clears SelectionObserver internal properties connected with preventing infinite loop.

Returns

void

Selection change listener. Flush mutations, check if a selection changes and fires event-selectionChange event on every change and event-selectionChangeDone when a selection stop changing.

Parameters

domDocument : Document

DOM document.

Returns

void

Returns

void