Class

ContextualBalloon (ui/panel/balloon)

@ckeditor/ckeditor5-ui/src/panel/balloon/contextualballoon

class

Provides the common contextual balloon for the editor.

The role of this plugin is to unify the contextual balloons logic, simplify views management and help avoid the unnecessary complexity of handling multiple BalloonPanelView instances in the editor.

This plugin allows for creating single or multiple panel stacks.

Each stack may have multiple views, with the one on the top being visible. When the visible view is removed from the stack, the previous view becomes visible.

It might be useful to implement nested navigation in a balloon. For instance, a toolbar view may contain a link button. When you click it, a link view (which lets you set the URL) is created and put on top of the toolbar view, so the link panel is displayed. When you finish editing the link and close (remove) the link view, the toolbar view is visible again.

However, there are cases when there are multiple independent balloons to be displayed, for instance, if the selection is inside two inline comments at the same time. For such cases, you can create two independent panel stacks. The contextual balloon plugin will create a navigation bar to let the users switch between these panel stacks using the "Next" and "Previous" buttons.

If there are no views in the current stack, the balloon panel will try to switch to the next stack. If there are no panels in any stack, the balloon panel will be hidden.

Note: To force the balloon panel to show only one view, even if there are other stacks, use the singleViewMode=true option when adding a view to a panel.

From the implementation point of view, the contextual ballon plugin is reusing a single BalloonPanelView instance to display multiple contextual balloon panels in the editor. It also creates a special rotator view, used to manage multiple panel stacks. Rotator view is a child of the balloon panel view and the parent of the specific view you want to display. If there is more than one panel stack to be displayed, the rotator view will add a navigation bar. If there is only one stack, the rotator view is transparent (it does not add any UI elements).

Filtering

Properties

  • observable

    _numberOfStacks : number

    A total number of all stacks in the balloon.

  • observable

    _singleViewMode : boolean

    A flag that controls the single view mode.

  • readonly

    _visibleStack : Stack

    Returns the stack of the currently visible view.

  • readonly inherited

    editor : Editor

    The editor instance.

    Note that most editors implement the ui property. However, editors with an external UI (i.e. Bootstrap-based) or a headless editor may not have this property or throw an error when accessing it.

    Because of above, to make plugins more universal, it is recommended to split features into:

    • The "editing" part that uses the Editor class without ui property.
    • The "UI" part that uses the Editor class and accesses ui property.
  • inherited observable

    isEnabled : boolean

    Flag indicating whether a plugin is enabled or disabled. A disabled plugin will not transform text.

    Plugin can be simply disabled like that:

    // Disable the plugin so that no toolbars are visible.
    editor.plugins.get( 'TextTransformation' ).isEnabled = false;
    

    You can also use forceDisabled method.

  • positionLimiter : undefined | null | RectSource | () => ( null | RectSource )

    The position limiter for the balloon, used when no limiter has been passed into add or updatePosition.

    By default, a function that obtains the farthest DOM RootEditableElement of the selection.

  • readonly

    view : BalloonPanelView

    The common balloon panel view.

  • visibleStack : string | undefined

  • observable

    visibleView : null | View<HTMLElement>

    The currently visible view or null when there are no views in any stack.

  • private

    _fakePanelsView : null | FakePanelsView

    Displays fake panels under the balloon panel view when multiple stacks are added to the balloon.

  • private

    _idToStack : Map<string, Stack>

    The map of IDs and stacks.

  • private

    _rotatorView : null | RotatorView

    Rotator view embedded in the contextual balloon. Displays the currently visible view in the balloon and provides navigation for switching stacks.

  • private

    _view : null | BalloonPanelView

    The common balloon panel view.

  • private

    _viewToStack : Map<View<HTMLElement>, Stack>

    The map of views and their stacks.

Static properties

  • readonly inherited static

    isContextPlugin : false

  • readonly static

    pluginName : 'ContextualBalloon'

Methods

  • constructor( editor )

    Parameters

    editor : Editor
  • add( data ) → void

    Adds a new view to the stack and makes it visible if the current stack is visible or it is the first view in the balloon.

    Parameters

    data : ViewConfiguration

    The configuration of the view.

    Returns

    void
  • inherited

    bind( bindProperty1, bindProperty2 ) → DualBindChain<K1, ContextualBalloon[ K1 ], K2, ContextualBalloon[ K2 ]>

    Binds observable properties to other objects implementing the Observable interface.

    Read more in the dedicated guide covering the topic of property bindings with some additional examples.

    Consider two objects: a button and an associated command (both Observable).

    A simple property binding could be as follows:

    button.bind( 'isEnabled' ).to( command, 'isEnabled' );
    

    or even shorter:

    button.bind( 'isEnabled' ).to( command );
    

    which works in the following way:

    • button.isEnabled instantly equals command.isEnabled,
    • whenever command.isEnabled changes, button.isEnabled will immediately reflect its value.

    Note: To release the binding, use unbind.

    You can also "rename" the property in the binding by specifying the new name in the to() chain:

    button.bind( 'isEnabled' ).to( command, 'isWorking' );
    

    It is possible to bind more than one property at a time to shorten the code:

    button.bind( 'isEnabled', 'value' ).to( command );
    

    which corresponds to:

    button.bind( 'isEnabled' ).to( command );
    button.bind( 'value' ).to( command );
    

    The binding can include more than one observable, combining multiple data sources in a custom callback:

    button.bind( 'isEnabled' ).to( command, 'isEnabled', ui, 'isVisible',
    	( isCommandEnabled, isUIVisible ) => isCommandEnabled && isUIVisible );
    

    Using a custom callback allows processing the value before passing it to the target property:

    button.bind( 'isEnabled' ).to( command, 'value', value => value === 'heading1' );
    

    It is also possible to bind to the same property in an array of observables. To bind a button to multiple commands (also Observables) so that each and every one of them must be enabled for the button to become enabled, use the following code:

    button.bind( 'isEnabled' ).toMany( [ commandA, commandB, commandC ], 'isEnabled',
    	( isAEnabled, isBEnabled, isCEnabled ) => isAEnabled && isBEnabled && isCEnabled );
    

    Type parameters

    K1
    K2

    Parameters

    bindProperty1 : K1

    Observable property that will be bound to other observable(s).

    bindProperty2 : K2

    Observable property that will be bound to other observable(s).

    Returns

    DualBindChain<K1, ContextualBalloon[ K1 ], K2, ContextualBalloon[ K2 ]>

    The bind chain with the to() and toMany() methods.

  • inherited

    bind( bindProperties ) → MultiBindChain

    Binds observable properties to other objects implementing the Observable interface.

    Read more in the dedicated guide covering the topic of property bindings with some additional examples.

    Consider two objects: a button and an associated command (both Observable).

    A simple property binding could be as follows:

    button.bind( 'isEnabled' ).to( command, 'isEnabled' );
    

    or even shorter:

    button.bind( 'isEnabled' ).to( command );
    

    which works in the following way:

    • button.isEnabled instantly equals command.isEnabled,
    • whenever command.isEnabled changes, button.isEnabled will immediately reflect its value.

    Note: To release the binding, use unbind.

    You can also "rename" the property in the binding by specifying the new name in the to() chain:

    button.bind( 'isEnabled' ).to( command, 'isWorking' );
    

    It is possible to bind more than one property at a time to shorten the code:

    button.bind( 'isEnabled', 'value' ).to( command );
    

    which corresponds to:

    button.bind( 'isEnabled' ).to( command );
    button.bind( 'value' ).to( command );
    

    The binding can include more than one observable, combining multiple data sources in a custom callback:

    button.bind( 'isEnabled' ).to( command, 'isEnabled', ui, 'isVisible',
    	( isCommandEnabled, isUIVisible ) => isCommandEnabled && isUIVisible );
    

    Using a custom callback allows processing the value before passing it to the target property:

    button.bind( 'isEnabled' ).to( command, 'value', value => value === 'heading1' );
    

    It is also possible to bind to the same property in an array of observables. To bind a button to multiple commands (also Observables) so that each and every one of them must be enabled for the button to become enabled, use the following code:

    button.bind( 'isEnabled' ).toMany( [ commandA, commandB, commandC ], 'isEnabled',
    	( isAEnabled, isBEnabled, isCEnabled ) => isAEnabled && isBEnabled && isCEnabled );
    

    Parameters

    bindProperties : Array<'off' | 'on' | 'once' | 'listenTo' | 'stopListening' | 'fire' | 'delegate' | 'stopDelegating' | 'set' | 'bind' | 'unbind' | 'decorate' | 'view' | 'add' | 'remove' | 'destroy' | 'editor' | 'isEnabled' | 'updatePosition' | 'forceDisabled' | 'clearForceDisabled' | 'visibleView' | 'positionLimiter' | 'visibleStack' | '_numberOfStacks' | '_singleViewMode' | 'hasView' | 'showStack'>

    Observable properties that will be bound to other observable(s).

    Returns

    MultiBindChain

    The bind chain with the to() and toMany() methods.

  • inherited

    bind( bindProperty ) → SingleBindChain<K, ContextualBalloon[ K ]>

    Binds observable properties to other objects implementing the Observable interface.

    Read more in the dedicated guide covering the topic of property bindings with some additional examples.

    Consider two objects: a button and an associated command (both Observable).

    A simple property binding could be as follows:

    button.bind( 'isEnabled' ).to( command, 'isEnabled' );
    

    or even shorter:

    button.bind( 'isEnabled' ).to( command );
    

    which works in the following way:

    • button.isEnabled instantly equals command.isEnabled,
    • whenever command.isEnabled changes, button.isEnabled will immediately reflect its value.

    Note: To release the binding, use unbind.

    You can also "rename" the property in the binding by specifying the new name in the to() chain:

    button.bind( 'isEnabled' ).to( command, 'isWorking' );
    

    It is possible to bind more than one property at a time to shorten the code:

    button.bind( 'isEnabled', 'value' ).to( command );
    

    which corresponds to:

    button.bind( 'isEnabled' ).to( command );
    button.bind( 'value' ).to( command );
    

    The binding can include more than one observable, combining multiple data sources in a custom callback:

    button.bind( 'isEnabled' ).to( command, 'isEnabled', ui, 'isVisible',
    	( isCommandEnabled, isUIVisible ) => isCommandEnabled && isUIVisible );
    

    Using a custom callback allows processing the value before passing it to the target property:

    button.bind( 'isEnabled' ).to( command, 'value', value => value === 'heading1' );
    

    It is also possible to bind to the same property in an array of observables. To bind a button to multiple commands (also Observables) so that each and every one of them must be enabled for the button to become enabled, use the following code:

    button.bind( 'isEnabled' ).toMany( [ commandA, commandB, commandC ], 'isEnabled',
    	( isAEnabled, isBEnabled, isCEnabled ) => isAEnabled && isBEnabled && isCEnabled );
    

    Type parameters

    K

    Parameters

    bindProperty : K

    Observable property that will be bound to other observable(s).

    Returns

    SingleBindChain<K, ContextualBalloon[ K ]>

    The bind chain with the to() and toMany() methods.

  • inherited

    clearForceDisabled( id ) → void

    Clears forced disable previously set through forceDisabled. See forceDisabled.

    Parameters

    id : string

    Unique identifier, equal to the one passed in forceDisabled call.

    Returns

    void
  • inherited

    decorate( methodName ) → void

    Turns the given methods of this object into event-based ones. This means that the new method will fire an event (named after the method) and the original action will be plugged as a listener to that event.

    Read more in the dedicated guide covering the topic of decorating methods with some additional examples.

    Decorating the method does not change its behavior (it only adds an event), but it allows to modify it later on by listening to the method's event.

    For example, to cancel the method execution the event can be stopped:

    class Foo extends ObservableMixin() {
    	constructor() {
    		super();
    		this.decorate( 'method' );
    	}
    
    	method() {
    		console.log( 'called!' );
    	}
    }
    
    const foo = new Foo();
    foo.on( 'method', ( evt ) => {
    	evt.stop();
    }, { priority: 'high' } );
    
    foo.method(); // Nothing is logged.
    

    Note: The high priority listener has been used to execute this particular callback before the one which calls the original method (which uses the "normal" priority).

    It is also possible to change the returned value:

    foo.on( 'method', ( evt ) => {
    	evt.return = 'Foo!';
    } );
    
    foo.method(); // -> 'Foo'
    

    Finally, it is possible to access and modify the arguments the method is called with:

    method( a, b ) {
    	console.log( `${ a }, ${ b }`  );
    }
    
    // ...
    
    foo.on( 'method', ( evt, args ) => {
    	args[ 0 ] = 3;
    
    	console.log( args[ 1 ] ); // -> 2
    }, { priority: 'high' } );
    
    foo.method( 1, 2 ); // -> '3, 2'
    

    Parameters

    methodName : 'off' | 'on' | 'once' | 'listenTo' | 'stopListening' | 'fire' | 'delegate' | 'stopDelegating' | 'set' | 'bind' | 'unbind' | 'decorate' | 'view' | 'add' | 'remove' | 'destroy' | 'editor' | 'isEnabled' | 'updatePosition' | 'forceDisabled' | 'clearForceDisabled' | 'visibleView' | 'positionLimiter' | 'visibleStack' | '_numberOfStacks' | '_singleViewMode' | 'hasView' | 'showStack'

    Name of the method to decorate.

    Returns

    void
  • inherited

    delegate( events ) → EmitterMixinDelegateChain

    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

    Destroys the plugin.

    Note: This method is optional. A plugin instance does not need to have it defined.

    Returns

    void
  • inherited

    fire( eventOrInfo, args ) → GetEventInfo<TEvent>[ 'return' ]

    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).

  • inherited

    forceDisabled( id ) → void

    Disables the plugin.

    Plugin may be disabled by multiple features or algorithms (at once). When disabling a plugin, unique id should be passed (e.g. feature name). The same identifier should be used when enabling back the plugin. The plugin becomes enabled only after all features enabled it back.

    Disabling and enabling a plugin:

    plugin.isEnabled; // -> true
    plugin.forceDisabled( 'MyFeature' );
    plugin.isEnabled; // -> false
    plugin.clearForceDisabled( 'MyFeature' );
    plugin.isEnabled; // -> true
    

    Plugin disabled by multiple features:

    plugin.forceDisabled( 'MyFeature' );
    plugin.forceDisabled( 'OtherFeature' );
    plugin.clearForceDisabled( 'MyFeature' );
    plugin.isEnabled; // -> false
    plugin.clearForceDisabled( 'OtherFeature' );
    plugin.isEnabled; // -> true
    

    Multiple disabling with the same identifier is redundant:

    plugin.forceDisabled( 'MyFeature' );
    plugin.forceDisabled( 'MyFeature' );
    plugin.clearForceDisabled( 'MyFeature' );
    plugin.isEnabled; // -> true
    

    Note: some plugins or algorithms may have more complex logic when it comes to enabling or disabling certain plugins, so the plugin might be still disabled after clearForceDisabled was used.

    Parameters

    id : string

    Unique identifier for disabling. Use the same id when enabling back the plugin.

    Returns

    void
  • hasView( view ) → boolean

    Returns true when the given view is in one of the stacks. Otherwise returns false.

    Parameters

    view : View<HTMLElement>

    Returns

    boolean
  • inherited

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

    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 ] : GetCallbackOptions<TEvent>

    Additional options.

    Returns

    void
  • inherited

    off( event, callback ) → 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
  • inherited

    on( event, callback, [ options ] ) → 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
  • inherited

    once( event, callback, [ options ] ) → 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
  • remove( view ) → void

    Removes the given view from the stack. If the removed view was visible, the view preceding it in the stack will become visible instead. When there is no view in the stack, the next stack will be displayed. When there are no more stacks, the balloon will hide.

    Parameters

    view : View<HTMLElement>

    A view to be removed from the balloon.

    Returns

    void
  • inherited

    set( values ) → void

    Creates and sets the value of an observable properties of this object. Such a property becomes a part of the state and is observable.

    It accepts a single object literal containing key/value pairs with properties to be set.

    This method throws the observable-set-cannot-override error if the observable instance already has a property with the given property name. This prevents from mistakenly overriding existing properties and methods, but means that foo.set( 'bar', 1 ) may be slightly slower than foo.bar = 1.

    In TypeScript, those properties should be declared in class using declare keyword. In example:

    public declare myProp1: number;
    public declare myProp2: string;
    
    constructor() {
    	this.set( {
    		'myProp1: 2,
    		'myProp2: 'foo'
    	} );
    }
    

    Parameters

    values : object

    An object with name=>value pairs.

    Returns

    void
  • inherited

    set( name, value ) → void

    Creates and sets the value of an observable property of this object. Such a property becomes a part of the state and is observable.

    This method throws the observable-set-cannot-override error if the observable instance already has a property with the given property name. This prevents from mistakenly overriding existing properties and methods, but means that foo.set( 'bar', 1 ) may be slightly slower than foo.bar = 1.

    In TypeScript, those properties should be declared in class using declare keyword. In example:

    public declare myProp: number;
    
    constructor() {
    	this.set( 'myProp', 2 );
    }
    

    Type parameters

    K

    Parameters

    name : K

    The property's name.

    value : ContextualBalloon[ K ]

    The property's value.

    Returns

    void
  • showStack( id ) → void

    Shows the last view from the stack of a given ID.

    Parameters

    id : string

    Returns

    void
  • inherited

    stopDelegating( [ event ], [ emitter ] ) → 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
  • inherited

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

    Stops listening for events. It can be used at different levels:

    • 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 ] : 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

    unbind( unbindProperties ) → void

    Removes the binding created with bind.

    // Removes the binding for the 'a' property.
    A.unbind( 'a' );
    
    // Removes bindings for all properties.
    A.unbind();
    

    Parameters

    unbindProperties : Array<'off' | 'on' | 'once' | 'listenTo' | 'stopListening' | 'fire' | 'delegate' | 'stopDelegating' | 'set' | 'bind' | 'unbind' | 'decorate' | 'view' | 'add' | 'remove' | 'destroy' | 'editor' | 'isEnabled' | 'updatePosition' | 'forceDisabled' | 'clearForceDisabled' | 'visibleView' | 'positionLimiter' | 'visibleStack' | '_numberOfStacks' | '_singleViewMode' | 'hasView' | 'showStack'>

    Observable properties to be unbound. All the bindings will be released if no properties are provided.

    Returns

    void
  • updatePosition( [ position ] ) → void

    Updates the position of the balloon using the position data of the first visible view in the stack. When new position data is given, the position data of the currently visible view will be updated.

    Parameters

    [ position ] : Partial<Options>

    Position options.

    Returns

    void
  • private

    _createFakePanelsView() → FakePanelsView

    Creates a fake panels view.

    Returns

    FakePanelsView
  • private

    _createPanelView() → void

    Initializes view instances.

    Returns

    void
  • private

    _createRotatorView() → RotatorView

    Creates a rotator view.

    Returns

    RotatorView
  • private

    _getBalloonPosition() → undefined | Partial<Options>

    Returns position options of the last view in the stack. This keeps the balloon in the same position when the view is changed.

    Returns

    undefined | Partial<Options>
  • private

    _getStackId( stack ) → string

    Returns the ID of the given stack.

    Parameters

    stack : Stack

    Returns

    string
  • private

    _showNextStack() → void

    Shows the last view from the next stack.

    Returns

    void
  • private

    _showPrevStack() → void

    Shows the last view from the previous stack.

    Returns

    void
  • private

    _showView( data ) → void

    Sets the view as the content of the balloon and attaches the balloon using position options of the first view.

    Parameters

    data : ViewConfiguration

    Configuration.

    Returns

    void

Events

  • change:_numberOfStacks( eventInfo, name, value, oldValue )

    Fired when the _numberOfStacks property changed value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (_numberOfStacks).

    value : number

    New value of the _numberOfStacks property with given key or null, if operation should remove property.

    oldValue : number

    Old value of the _numberOfStacks property with given key or null, if property was not set before.

  • change:_singleViewMode( eventInfo, name, value, oldValue )

    Fired when the _singleViewMode property changed value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (_singleViewMode).

    value : boolean

    New value of the _singleViewMode property with given key or null, if operation should remove property.

    oldValue : boolean

    Old value of the _singleViewMode property with given key or null, if property was not set before.

  • inherited

    change:isEnabled( eventInfo, name, value, oldValue )

    Fired when the isEnabled property changed value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (isEnabled).

    value : boolean

    New value of the isEnabled property with given key or null, if operation should remove property.

    oldValue : boolean

    Old value of the isEnabled property with given key or null, if property was not set before.

  • change:visibleView( eventInfo, name, value, oldValue )

    Fired when the visibleView property changed value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (visibleView).

    value : null | View<HTMLElement>

    New value of the visibleView property with given key or null, if operation should remove property.

    oldValue : null | View<HTMLElement>

    Old value of the visibleView property with given key or null, if property was not set before.

  • inherited

    change:{property}( eventInfo, name, value, oldValue )

    Fired when a property changed value.

    observable.set( 'prop', 1 );
    
    observable.on<ObservableChangeEvent<number>>( 'change:prop', ( evt, propertyName, newValue, oldValue ) => {
    	console.log( `${ propertyName } has changed from ${ oldValue } to ${ newValue }` );
    } );
    
    observable.prop = 2; // -> 'prop has changed from 1 to 2'
    

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    The property name.

    value : TValue

    The new property value.

    oldValue : TValue

    The previous property value.

  • set:_numberOfStacks( eventInfo, name, value, oldValue )

    Fired when the _numberOfStacks property is going to be set but is not set yet (before the change event is fired).

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (_numberOfStacks).

    value : number

    New value of the _numberOfStacks property with given key or null, if operation should remove property.

    oldValue : number

    Old value of the _numberOfStacks property with given key or null, if property was not set before.

  • set:_singleViewMode( eventInfo, name, value, oldValue )

    Fired when the _singleViewMode property is going to be set but is not set yet (before the change event is fired).

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (_singleViewMode).

    value : boolean

    New value of the _singleViewMode property with given key or null, if operation should remove property.

    oldValue : boolean

    Old value of the _singleViewMode property with given key or null, if property was not set before.

  • inherited

    set:isEnabled( eventInfo, name, value, oldValue )

    Fired when the isEnabled property is going to be set but is not set yet (before the change event is fired).

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (isEnabled).

    value : boolean

    New value of the isEnabled property with given key or null, if operation should remove property.

    oldValue : boolean

    Old value of the isEnabled property with given key or null, if property was not set before.

  • set:visibleView( eventInfo, name, value, oldValue )

    Fired when the visibleView property is going to be set but is not set yet (before the change event is fired).

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (visibleView).

    value : null | View<HTMLElement>

    New value of the visibleView property with given key or null, if operation should remove property.

    oldValue : null | View<HTMLElement>

    Old value of the visibleView property with given key or null, if property was not set before.

  • inherited

    set:{property}( eventInfo, name, value, oldValue )

    Fired when a property value is going to be set but is not set yet (before the change event is fired).

    You can control the final value of the property by using the event's return property.

    observable.set( 'prop', 1 );
    
    observable.on<ObservableSetEvent<number>>( 'set:prop', ( evt, propertyName, newValue, oldValue ) => {
    	console.log( `Value is going to be changed from ${ oldValue } to ${ newValue }` );
    	console.log( `Current property value is ${ observable[ propertyName ] }` );
    
    	// Let's override the value.
    	evt.return = 3;
    } );
    
    observable.on<ObservableChangeEvent<number>>( 'change:prop', ( evt, propertyName, newValue, oldValue ) => {
    	console.log( `Value has changed from ${ oldValue } to ${ newValue }` );
    } );
    
    observable.prop = 2; // -> 'Value is going to be changed from 1 to 2'
                         // -> 'Current property value is 1'
                         // -> 'Value has changed from 1 to 3'
    

    Note: The event is fired even when the new value is the same as the old value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    The property name.

    value : TValue

    The new property value.

    oldValue : TValue

    The previous property value.