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Class

FocusObserver (engine/view/observer)

@ckeditor/ckeditor5-engine/src/view/observer/focusobserver

class
See source

Focus and blur events observer. Focus observer handle also isFocused property of the root elements.

Note that this observer is attached by the View and is available by default.

Filtering

Properties

  • readonly inherited

    document : Document

    See source

    A reference to the Document object.

  • readonly

    domEventType : readonly tuple

    See source

  • readonly inherited

    isEnabled : boolean

    See source

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

  • inherited

    useCapture : boolean

    See source

    If set to true DOM events will be listened on the capturing phase. Default value is false.

  • inherited

    usePassive : boolean

    See source

    If set to true, indicates that the function specified by listener will never call preventDefault(). Default value is false.

  • readonly inherited

    view : View

    See source

    An instance of the view controller.

  • private

    _isFocusChanging : boolean

    See source

    Set to true if the document is in the process of setting the focus.

    The flag is used to indicate that setting the focus is in progress.

  • private

    _renderTimeoutId : null | Timeout

    See source

    Identifier of the timeout currently used by focus listener to delay rendering execution.

Methods

  • constructor( view )

    See source

    Parameters

    view : View

  • inherited

    checkShouldIgnoreEventFromTarget( domTarget ) → boolean

    See source

    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 DowncastWriter#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.

  • inherited

    delegate( events ) → EmitterMixinDelegateChain

    See source

    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

  • destroy() → void

    See source

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

    Returns

    void

  • inherited

    disable() → void

    See source

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

    Returns

    void

    Related:

  • inherited

    enable() → void

    See source

    Enables the observer. This method is called when the observer is registered to the View 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:

  • inherited

    fire( eventType, domEvent, [ additionalData ] ) → void

    See source

    Calls Document#fire() if observer is enabled.

    Parameters

    eventType : string | EventInfo<string, unknown>

    The event type (name).

    domEvent : Event

    The DOM event.

    [ additionalData ] : object

    The additional data which should extend the event data object.

    Returns

    void

    Related:

  • flush() → void

    See source

    Finishes setting the document focus state.

    Returns

    void

  • inherited

    listenTo( emitter, event, callback, [ options ] ) → void

    See source

    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

  • inherited

    listenTo( emitter, event, callback, [ options ] ) → void

    See source

    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 | Node

    The object that fires the event.

    event : K

    The name of the event.

    callback : ( FocusObserver, EventInfo<string, unknown>, DomEventMap[ K ] ) => void

    The function to be called on event.

    [ options ] : object

    Additional options.

    Returns

    void

  • inherited

    observe( domElement ) → void

    See source

    Starts observing given DOM element.

    Parameters

    domElement : HTMLElement

    DOM element to observe.

    Returns

    void

  • inherited

    off( event, callback ) → void

    See source

    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

  • inherited

    on( event, callback, [ options ] ) → void

    See source

    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

  • onDomEvent( domEvent ) → void

    See source

    Callback which should be called when the DOM event occurred. Note that the callback will not be called if observer is not enabled.

    Parameters

    domEvent : FocusEvent

    Returns

    void

    Related:

  • inherited

    once( event, callback, [ options ] ) → void

    See source

    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

  • inherited

    stopDelegating( [ event ], [ emitter ] ) → void

    See source

    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

  • inherited

    stopListening( [ emitter ], [ event ], [ callback ] ) → void

    See source

    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 | 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

  • inherited

    stopObserving( domElement ) → void

    See source

    Stops observing given DOM element.

    Parameters

    domElement : HTMLElement

    Returns

    void

  • private

    _clearTimeout() → void

    See source

    Clears timeout.

    Returns

    void

  • private

    _handleBlur( data ) → void

    See source

    The blur event handler.

    Parameters

    data : DomEventData<FocusEvent>

    Returns

    void

  • private

    _handleFocus() → void

    See source

    The focus event handler.

    Returns

    void