# WidgetResizer

class

Represents a resizer for a single resizable object.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L33)

<a id="properties">

## Properties

<a id="member-_domResizerWrapper">

### `_domResizerWrapper: HTMLElement | null` _(readonly)_

DOM container of the entire resize UI.

Note that this property will have a value only after the element bound with the resizer is rendered (otherwise `null`).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L449)

<a id="member-isEnabled">

### `isEnabled: boolean` _(observable)_

Flag that indicates whether resizer can be used.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L39)

<a id="member-isSelected">

### `isSelected: boolean` _(observable)_

Flag that indicates that resizer is currently focused.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L46)

<a id="member-isVisible">

### `isVisible: boolean` _(readonly)_

Flag that indicates whether resizer is rendered (visible on the screen).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L54)

<a id="member-state">

### `state: WidgetResizeState` _(readonly)_

Stores the state of the resizable host geometry, such as the original width, the currently proposed height, etc.

Note that a new state is created for each resize transaction.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L116)

<a id="member-_initialViewWidth">

### `_initialViewWidth: string | undefined` _(private)_

The width of the resized [viewElement](module_widget_widgetresize-WidgetResizerOptions.md#member-viewElement) before the resizing started.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L81)

<a id="member-_options">

### `_options: WidgetResizerOptions` _(private)_

Options passed to the [`constructor`](#function-constructor).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L71)

<a id="member-_sizeView">

### `_sizeView: SizeView` _(private)_

A view displaying the proposed new element size during the resizing.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L66)

<a id="member-_state">

### `_state: WidgetResizeState` _(private)_

Stores the state of the resizable host geometry, such as the original width, the currently proposed height, etc.

Note that a new state is created for each resize transaction.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L61)

<a id="member-_viewResizerWrapper">

### `_viewResizerWrapper: ViewElement | null` _(private)_

A wrapper that is controlled by the resizer. This is usually a widget element.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L76)

<a id="methods">

## Methods

<a id="function-constructor">

### `constructor( options )`

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L86)

#### Parameters

* `options: WidgetResizerOptions`

  Resizer options.

<a id="function-attach">

### `attach() → void`

Attaches the resizer to the DOM.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L145)

#### Returns

* `void`

<a id="function-begin">

### `begin( domResizeHandle ) → void`

Starts the resizing process.

Creates a new [`state`](#member-state) for the current process.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L192)

#### Parameters

* `domResizeHandle: HTMLElement`

  Clicked handle.

#### Returns

* `void`

#### Fires

* [begin](#event-begin)

<a id="function-bind:DUAL_BIND">

### `bind( bindProperty1, bindProperty2 ) → ObservableDualBindChain<K1, WidgetResizer[ K1 ], K2, WidgetResizer[ K2 ]>` _(inherited)_

Binds [observable properties](#function-set:KEY_VALUE) to other objects implementing the [`Observable`](module_utils_observablemixin-Observable.md) interface.

Read more in the [dedicated](../framework/deep-dive/observables.md#property-bindings) 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:

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

or even shorter:

```typescript
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`](module_utils_observablemixin-Observable.md#function-unbind).

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

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

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

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

which corresponds to:

```typescript
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:

```typescript
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:

```typescript
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:

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L996)

#### 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

* `ObservableDualBindChain<K1, WidgetResizer[ K1 ], K2, WidgetResizer[ K2 ]>`

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

<a id="function-bind:MANY_BIND">

### `bind( bindProperties ) → ObservableMultiBindChain` _(inherited)_

Binds [observable properties](#function-set:KEY_VALUE) to other objects implementing the [`Observable`](module_utils_observablemixin-Observable.md) interface.

Read more in the [dedicated](../framework/deep-dive/observables.md#property-bindings) 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:

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

or even shorter:

```typescript
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`](module_utils_observablemixin-Observable.md#function-unbind).

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

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

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

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

which corresponds to:

```typescript
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:

```typescript
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:

```typescript
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:

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L1074)

#### Parameters

* `bindProperties: Array<'off' | 'set' | 'bind' | 'unbind' | 'decorate' | 'stopListening' | 'on' | 'once' | 'listenTo' | 'fire' | 'delegate' | 'stopDelegating' | 'cancel' | 'destroy' | 'isEnabled' | 'state' | 'show' | 'hide' | 'isVisible' | 'begin' | 'isSelected' | 'attach' | 'updateSize' | 'commit' | 'redraw' | 'containsHandle'>`

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

#### Returns

* `ObservableMultiBindChain`

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

<a id="function-bind:SINGLE_BIND">

### `bind( bindProperty ) → ObservableSingleBindChain<K, WidgetResizer[ K ]>` _(inherited)_

Binds [observable properties](#function-set:KEY_VALUE) to other objects implementing the [`Observable`](module_utils_observablemixin-Observable.md) interface.

Read more in the [dedicated](../framework/deep-dive/observables.md#property-bindings) 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:

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

or even shorter:

```typescript
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`](module_utils_observablemixin-Observable.md#function-unbind).

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

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

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

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

which corresponds to:

```typescript
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:

```typescript
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:

```typescript
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:

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L918)

#### Type parameters

* `K`

#### Parameters

* `bindProperty: K`

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

#### Returns

* `ObservableSingleBindChain<K, WidgetResizer[ K ]>`

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

<a id="function-cancel">

### `cancel() → void`

Cancels and rejects the proposed resize dimensions, hiding the UI.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L263)

#### Returns

* `void`

#### Fires

* [cancel](#event-cancel)

<a id="function-commit">

### `commit() → void`

Applies the geometry proposed with the resizer.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L247)

#### Returns

* `void`

#### Fires

* [commit](#event-commit)

<a id="function-containsHandle">

### `containsHandle( domElement ) → boolean`

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L338)

#### Parameters

* `domElement: HTMLElement`

#### Returns

* `boolean`

<a id="function-decorate">

### `decorate( methodName ) → void` _(inherited)_

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](../framework/deep-dive/observables.md#decorating-object-methods) 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](module_utils_eventinfo-EventInfo.md#member-stop):

```typescript
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](module_utils_priorities-PriorityString.md) 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:

```typescript
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:

```typescript
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'
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L1159)

#### Parameters

* `methodName: 'off' | 'set' | 'bind' | 'unbind' | 'decorate' | 'stopListening' | 'on' | 'once' | 'listenTo' | 'fire' | 'delegate' | 'stopDelegating' | 'cancel' | 'destroy' | 'isEnabled' | 'state' | 'show' | 'hide' | 'isVisible' | 'begin' | 'isSelected' | 'attach' | 'updateSize' | 'commit' | 'redraw' | 'containsHandle'`

  Name of the method to decorate.

#### Returns

* `void`

<a id="function-delegate">

### `delegate( events ) → EmitterMixinDelegateChain` _(inherited)_

Delegates selected events to another [`Emitter`](module_utils_emittermixin-Emitter.md). For instance:

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

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

```typescript
emitterA.fire( 'eventX', data );
```

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

```typescript
emitterA.fire( 'eventY', data );
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L539)

#### Parameters

* `events: Array<string>`

  Event names that will be delegated to another emitter.

#### Returns

* `EmitterMixinDelegateChain`

<a id="function-destroy">

### `destroy() → void`

Destroys the resizer.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L270)

#### Returns

* `void`

<a id="function-fire">

### `fire( eventOrInfo, args ) → GetEventInfo<TEvent>[ 'return' ]` _(inherited)_

Fires an event, executing all callbacks registered for it.

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L512)

#### Type parameters

* `TEvent: extends BaseEvent`

  The type describing the event. See [`BaseEvent`](module_utils_emittermixin-BaseEvent.md).

#### 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`](module_utils_eventinfo-EventInfo.md#member-return)'s property (the event info is the first param of every callback).

<a id="function-hide">

### `hide() → void`

Hides resizer in the UI.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L134)

#### Returns

* `void`

<a id="function-listenTo:BASE_EMITTER">

### `listenTo( emitter, event, callback, options? ) → void` _(inherited)_

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.

```typescript
// 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](module_utils_eventinfo-EventInfo.md#member-stop) and set the [return value](module_utils_eventinfo-EventInfo.md#member-return) of the [`fire`](#function-fire) method.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L475)

#### Type parameters

* `TEvent: extends BaseEvent`

  The type describing the event. See [`BaseEvent`](module_utils_emittermixin-BaseEvent.md).

#### 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`

<a id="function-off">

### `off( event, callback ) → void` _(inherited)_

Stops executing the callback on the given event. Shorthand for [`this.stopListening( this, event, callback )`](#function-stopListening:BASE_STOP).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L444)

#### Parameters

* `event: string`

  The name of the event.

* `callback: Function`

  The function to stop being called.

#### Returns

* `void`

<a id="function-on">

### `on( event, callback, options? ) → void` _(inherited)_

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

Shorthand for [`this.listenTo( this, event, callback, options )`](#function-listenTo:BASE_EMITTER) (it makes the emitter listen on itself).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L416)

#### Type parameters

* `TEvent: extends BaseEvent`

  The type descibing the event. See [`BaseEvent`](module_utils_emittermixin-BaseEvent.md).

#### 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`

<a id="function-once">

### `once( event, callback, options? ) → void` _(inherited)_

Registers a callback function to be executed on the next time the event is fired only. This is similar to calling [`on`](#function-on) followed by [`off`](#function-off) in the callback.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L431)

#### Type parameters

* `TEvent: extends BaseEvent`

  The type descibing the event. See [`BaseEvent`](module_utils_emittermixin-BaseEvent.md).

#### 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`

<a id="function-redraw">

### `redraw( handleHostRect? ) → void`

Redraws the resizer.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L279)

#### Parameters

* `handleHostRect?: Rect`

  Handle host rectangle might be given to improve performance.

#### Returns

* `void`

<a id="function-set:OBJECT">

### `set( values ) → void` _(inherited)_

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:

```typescript
public declare myProp1: number;
public declare myProp2: string;

constructor() {
	this.set( {
		'myProp1: 2,
		'myProp2: 'foo'
	} );
}
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L843)

#### Parameters

* `values: object & object`

  An object with `name=>value` pairs.

#### Returns

* `void`

<a id="function-set:KEY_VALUE">

### `set( name, value ) → void` _(inherited)_

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:

```typescript
public declare myProp: number;

constructor() {
	this.set( 'myProp', 2 );
}
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L815)

#### Type parameters

* `K`

#### Parameters

* `name: K`

  The property's name.

* `value: WidgetResizer[ K ]`

  The property's value.

#### Returns

* `void`

<a id="function-show">

### `show() → void`

Makes resizer visible in the UI.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L123)

#### Returns

* `void`

<a id="function-stopDelegating">

### `stopDelegating( event?, emitter? ) → void` _(inherited)_

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.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L552)

#### 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`

<a id="function-stopListening:BASE_STOP">

### `stopListening( emitter?, event?, callback? ) → void` _(inherited)_

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.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L497)

#### 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`

<a id="function-unbind">

### `unbind( unbindProperties ) → void` _(inherited)_

Removes the binding created with [`bind`](#function-bind:SINGLE_BIND).

```typescript
// Removes the binding for the 'a' property.
A.unbind( 'a' );

// Removes bindings for all properties.
A.unbind();
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L1090)

#### Parameters

* `unbindProperties: Array<'off' | 'set' | 'bind' | 'unbind' | 'decorate' | 'stopListening' | 'on' | 'once' | 'listenTo' | 'fire' | 'delegate' | 'stopDelegating' | 'cancel' | 'destroy' | 'isEnabled' | 'state' | 'show' | 'hide' | 'isVisible' | 'begin' | 'isSelected' | 'attach' | 'updateSize' | 'commit' | 'redraw' | 'containsHandle'>`

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

#### Returns

* `void`

<a id="function-updateSize">

### `updateSize( domEventData ) → void`

Updates the proposed size based on `domEventData`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L207)

#### Parameters

* `domEventData: MouseEvent`

#### Returns

* `void`

#### Fires

* [updateSize](#event-updateSize)

<a id="function-_appendHandles">

### `_appendHandles( domElement ) → void` _(private)_

Renders the resize handles in the DOM.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L458)

#### Parameters

* `domElement: HTMLElement`

  The resizer wrapper.

#### Returns

* `void`

<a id="function-_appendSizeUI">

### `_appendSizeUI( domElement ) → void` _(private)_

Sets up the [`_sizeView`](#member-_sizeView) property and adds it to the passed `domElement`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L474)

#### Parameters

* `domElement: HTMLElement`

#### Returns

* `void`

<a id="function-_cleanup">

### `_cleanup() → void` _(private)_

Cleans up the context state.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L349)

#### Returns

* `void`

<a id="function-_getHandleHost">

### `_getHandleHost() → HTMLElement` _(private)_

Obtains the handle host.

Handle host is an object that the handles are aligned to.

Handle host will not always be an entire widget itself. Take an image as an example. The image widget contains an image and a caption. Only the image should be surrounded with handles.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L437)

#### Returns

* `HTMLElement`

<a id="function-_getResizeHost">

### `_getResizeHost() → HTMLElement` _(private)_

Obtains the resize host.

Resize host is an object that receives dimensions which are the result of resizing.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L423)

#### Returns

* `HTMLElement`

<a id="function-_proposeNewSize">

### `_proposeNewSize( domEventData ) → object` _(private)_

Calculates the proposed size as the resize handles are dragged.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L364)

#### Parameters

* `domEventData: MouseEvent`

  Event data that caused the size update request. It should be used to calculate the proposed size.

#### Returns

* `object`

#### Static methods

<a id="static-function-isResizeHandle">

### `isResizeHandle( domElement ) → boolean` _(static)_

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L342)

#### Parameters

* `domElement: HTMLElement`

#### Returns

* `boolean`

<a id="events">

## Events

<a id="event-begin">

### `begin( eventInfo, <anonymous> )`

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L487)

#### Parameters

* `eventInfo: EventInfo`

  An object containing information about the fired event.

* `<anonymous>: Parameters<TObservable[ TName ]>`

<a id="event-cancel">

### `cancel( eventInfo, <anonymous> )`

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L492)

#### Parameters

* `eventInfo: EventInfo`

  An object containing information about the fired event.

* `<anonymous>: Parameters<TObservable[ TName ]>`

<a id="event-change:isEnabled">

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

Fired when the `isEnabled` property changed value.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L39)

#### 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.

<a id="event-change:isSelected">

### `change:isSelected( eventInfo, name, value, oldValue )`

Fired when the `isSelected` property changed value.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L46)

#### Parameters

* `eventInfo: EventInfo`

  An object containing information about the fired event.

* `name: string`

  Name of the changed property (`isSelected`).

* `value: boolean`

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

* `oldValue: boolean`

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

<a id="event-change:isVisible">

### `change:isVisible( eventInfo, name, value, oldValue )`

Fired when the `isVisible` property changed value.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L54)

#### Parameters

* `eventInfo: EventInfo`

  An object containing information about the fired event.

* `name: string`

  Name of the changed property (`isVisible`).

* `value: boolean`

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

* `oldValue: boolean`

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

<a id="event-change:%7Bproperty%7D">

### `change:{property}( eventInfo, name, value, oldValue )` _(inherited)_

Fired when a property changed value.

```typescript
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'
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L1190)

#### 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.

<a id="event-commit">

### `commit( eventInfo, <anonymous> )`

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L497)

#### Parameters

* `eventInfo: EventInfo`

  An object containing information about the fired event.

* `<anonymous>: Parameters<TObservable[ TName ]>`

<a id="event-set:isEnabled">

### `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).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L39)

#### 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.

<a id="event-set:isSelected">

### `set:isSelected( eventInfo, name, value, oldValue )`

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L46)

#### Parameters

* `eventInfo: EventInfo`

  An object containing information about the fired event.

* `name: string`

  Name of the changed property (`isSelected`).

* `value: boolean`

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

* `oldValue: boolean`

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

<a id="event-set:isVisible">

### `set:isVisible( eventInfo, name, value, oldValue )`

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L54)

#### Parameters

* `eventInfo: EventInfo`

  An object containing information about the fired event.

* `name: string`

  Name of the changed property (`isVisible`).

* `value: boolean`

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

* `oldValue: boolean`

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

<a id="event-set:%7Bproperty%7D">

### `set:{property}( eventInfo, name, value, oldValue )` _(inherited)_

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](module_utils_eventinfo-EventInfo.md#member-return).

```typescript
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.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/observablemixin.ts#L1228)

#### 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.

<a id="event-updateSize">

### `updateSize( eventInfo, <anonymous> )`

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-widget/src/widgetresize/resizer.ts#L502)

#### Parameters

* `eventInfo: EventInfo`

  An object containing information about the fired event.

* `<anonymous>: Parameters<TObservable[ TName ]>`

---

Full index of the CKEditor 5 API reference: [llms.txt](llms.txt)