# Interface: `ISingleWidgetShell`

[@jupyterlite/application](../modules/jupyterlite_application.md).ISingleWidgetShell

The single widget application shell interface.

## Hierarchy

- [`SingleWidgetShell`](../classes/jupyterlite_application.SingleWidgetShell.md)

  ↳ **`ISingleWidgetShell`**

## Properties

### `dataset`

> `Readonly` **`dataset`**: `DOMStringMap`

The dataset for the widget's DOM node.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[dataset](../classes/jupyterlite_application.SingleWidgetShell.md#dataset)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:81

### `disposed`

> `Readonly` **`disposed`**:
> `ISignal`<[`ISingleWidgetShell`](../modules/jupyterlite_application.md#isinglewidgetshell),
> `void`\>

A signal emitted when the widget is disposed.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[disposed](../classes/jupyterlite_application.SingleWidgetShell.md#disposed)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:34

### `hiddenMode`

> **`hiddenMode`**: `HiddenMode`

Set the method for hiding the widget.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[hiddenMode](../classes/jupyterlite_application.SingleWidgetShell.md#hiddenmode)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:88

### `id`

> **`id`**: `string`

Set the id of the widget's DOM node.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[id](../classes/jupyterlite_application.SingleWidgetShell.md#id)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:77

### `isAttached`

> `Readonly` **`isAttached`**: `boolean`

Test whether the widget's node is attached to the DOM.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[isAttached](../classes/jupyterlite_application.SingleWidgetShell.md#isattached)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:46

### `isDisposed`

> `Readonly` **`isDisposed`**: `boolean`

Test whether the widget has been disposed.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[isDisposed](../classes/jupyterlite_application.SingleWidgetShell.md#isdisposed)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:42

### `isHidden`

> `Readonly` **`isHidden`**: `boolean`

Test whether the widget is explicitly hidden.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[isHidden](../classes/jupyterlite_application.SingleWidgetShell.md#ishidden)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:50

### `isVisible`

> `Readonly` **`isVisible`**: `boolean`

Test whether the widget is visible.

#### Notes

A widget is visible when it is attached to the DOM, is not explicitly hidden, and has no
explicitly hidden ancestors.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[isVisible](../classes/jupyterlite_application.SingleWidgetShell.md#isvisible)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:58

### `layout`

> **`layout`**: `null` \| `Layout`

Set the layout for the widget.

#### Notes

The layout is single-use only. It cannot be changed after the first assignment.

The layout is disposed automatically when the widget is disposed.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[layout](../classes/jupyterlite_application.SingleWidgetShell.md#layout)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:116

### `node`

> `Readonly` **`node`**: `HTMLElement`

Get the DOM node owned by the widget.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[node](../classes/jupyterlite_application.SingleWidgetShell.md#node)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:38

### `parent`

> **`parent`**: `null` \| `Widget`

Set the parent of the widget.

#### Notes

Children are typically added to a widget by using a layout, which means user code will
not normally set the parent widget directly.

The widget will be automatically removed from its old parent.

This is a no-op if there is no effective parent change.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[parent](../classes/jupyterlite_application.SingleWidgetShell.md#parent)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:103

### `title`

> `Readonly` **`title`**: `Title`<`Widget`\>

The title object for the widget.

#### Notes

The title object is used by some container widgets when displaying the widget alongside
some title, such as a tab panel or side bar.

Since not all widgets will use the title, it is created on demand.

The `owner` property of the title is set to this widget.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[title](../classes/jupyterlite_application.SingleWidgetShell.md#title)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:70

## Accessors

### `currentChanged`

> `get` **`currentChanged`**():
> `ISignal`<[`ISingleWidgetShell`](../modules/jupyterlite_application.md#isinglewidgetshell),
> `void`\>

A signal emitted when the current widget changes.

#### Returns

`ISignal`<[`ISingleWidgetShell`](../modules/jupyterlite_application.md#isinglewidgetshell),
`void`\>

#### Inherited from

SingleWidgetShell.currentChanged

#### Defined in

[packages/application/src/singleWidgetShell.ts:46](https://github.com/jupyterlite/jupyterlite/blob/7971e0aa/packages/application/src/singleWidgetShell.ts#L46)

### `currentWidget`

> `get` **`currentWidget`**(): `null` \| `Widget`

The current widget in the shell's main area.

#### Returns

`null` \| `Widget`

#### Inherited from

SingleWidgetShell.currentWidget

#### Defined in

[packages/application/src/singleWidgetShell.ts:53](https://github.com/jupyterlite/jupyterlite/blob/7971e0aa/packages/application/src/singleWidgetShell.ts#L53)

## Methods

### `activate`

> **`activate`**(): `void`

Post an `'activate-request'` message to the widget.

#### Notes

This is a simple convenience method for posting the message.

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[activate](../classes/jupyterlite_application.SingleWidgetShell.md#activate)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:201

### `activateById`

> **`activateById`**(`id`): `void`

Activate a widget in its area.

#### Parameters

| Name | Type     |
| :--- | :------- |
| `id` | `string` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[activateById](../classes/jupyterlite_application.SingleWidgetShell.md#activatebyid)

#### Defined in

[packages/application/src/singleWidgetShell.ts:60](https://github.com/jupyterlite/jupyterlite/blob/7971e0aa/packages/application/src/singleWidgetShell.ts#L60)

### `add`

> **`add`**(`widget`, `area?`, `options?`): `void`

Add a widget to the application shell.

#### Parameters

| Name       | Type           | Description                                                         |
| :--------- | :------------- | :------------------------------------------------------------------ |
| `widget`   | `Widget`       | The widget being added.                                             |
| `area?`    | `"main"`       | Optional region in the shell into which the widget should be added. |
| `options?` | `IOpenOptions` | Optional open options.                                              |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[add](../classes/jupyterlite_application.SingleWidgetShell.md#add)

#### Defined in

[packages/application/src/singleWidgetShell.ts:78](https://github.com/jupyterlite/jupyterlite/blob/7971e0aa/packages/application/src/singleWidgetShell.ts#L78)

### `addClass`

> **`addClass`**(`name`): `void`

Add a class name to the widget's DOM node.

#### Parameters

| Name   | Type     | Description                                                                                                                                                |
| :----- | :------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `name` | `string` | The class name to add to the node. #### Notes If the class name is already added to the node, this is a no-op. The class name must not contain whitespace. |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[addClass](../classes/jupyterlite_application.SingleWidgetShell.md#addclass)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:154

### `children`

> **`children`**(): `IIterator`<`Widget`\>

Create an iterator over the widget's children.

#### Returns

`IIterator`<`Widget`\>

A new iterator over the children of the widget.

#### Notes

The widget must have a populated layout in order to have children.

If a layout is not installed, the returned iterator will be empty.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[children](../classes/jupyterlite_application.SingleWidgetShell.md#children)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:127

### `clearFlag`

> **`clearFlag`**(`flag`): `void`

Clear the given widget flag.

#### Notes

This will not typically be called directly by user code.

#### Parameters

| Name   | Type   |
| :----- | :----- |
| `flag` | `Flag` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[clearFlag](../classes/jupyterlite_application.SingleWidgetShell.md#clearflag)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:256

### `close`

> **`close`**(): `void`

Send a `'close-request'` message to the widget.

#### Notes

This is a simple convenience method for sending the message.

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[close](../classes/jupyterlite_application.SingleWidgetShell.md#close)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:208

### `contains`

> **`contains`**(`widget`): `boolean`

Test whether a widget is a descendant of this widget.

#### Parameters

| Name     | Type     | Description                        |
| :------- | :------- | :--------------------------------- |
| `widget` | `Widget` | The descendant widget of interest. |

#### Returns

`boolean`

`true` if the widget is a descendant, `false` otherwise.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[contains](../classes/jupyterlite_application.SingleWidgetShell.md#contains)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:135

### `dispose`

> **`dispose`**(): `void`

Dispose of the widget and its descendant widgets.

#### Notes

It is unsafe to use the widget after it has been disposed.

All calls made to this method after the first are a no-op.

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[dispose](../classes/jupyterlite_application.SingleWidgetShell.md#dispose)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:30

### `fit`

> **`fit`**(): `void`

Post a `'fit-request'` message to the widget.

#### Notes

This is a simple convenience method for posting the message.

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[fit](../classes/jupyterlite_application.SingleWidgetShell.md#fit)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:194

### `hasClass`

> **`hasClass`**(`name`): `boolean`

Test whether the widget's DOM node has the given class name.

#### Parameters

| Name   | Type     | Description                 |
| :----- | :------- | :-------------------------- |
| `name` | `string` | The class name of interest. |

#### Returns

`boolean`

`true` if the node has the class, `false` otherwise.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[hasClass](../classes/jupyterlite_application.SingleWidgetShell.md#hasclass)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:143

### `hide`

> **`hide`**(): `void`

Hide the widget and make it hidden to its parent widget.

#### Notes

This causes the [isHidden](jupyterlite_application.ISingleWidgetShell.md#ishidden)
property to be `true`.

If the widget is explicitly hidden, this is a no-op.

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[hide](../classes/jupyterlite_application.SingleWidgetShell.md#hide)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:226

### `notifyLayout`

> `Protected` **`notifyLayout`**(`msg`): `void`

Invoke the message processing routine of the widget's layout.

#### Parameters

| Name  | Type      | Description                                                                                                                                                      |
| :---- | :-------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg` | `Message` | The message to dispatch to the layout. #### Notes This is a no-op if the widget does not have a layout. This will not typically be called directly by user code. |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[notifyLayout](../classes/jupyterlite_application.SingleWidgetShell.md#notifylayout)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:276

### `onActivateRequest`

> `Protected` **`onActivateRequest`**(`msg`): `void`

A message handler invoked on an `'activate-request'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onActivateRequest](../classes/jupyterlite_application.SingleWidgetShell.md#onactivaterequest)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:311

### `onAfterAttach`

> `Protected` **`onAfterAttach`**(`msg`): `void`

A message handler invoked on an `'after-attach'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onAfterAttach](../classes/jupyterlite_application.SingleWidgetShell.md#onafterattach)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:353

### `onAfterDetach`

> `Protected` **`onAfterDetach`**(`msg`): `void`

A message handler invoked on an `'after-detach'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onAfterDetach](../classes/jupyterlite_application.SingleWidgetShell.md#onafterdetach)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:367

### `onAfterHide`

> `Protected` **`onAfterHide`**(`msg`): `void`

A message handler invoked on an `'after-hide'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onAfterHide](../classes/jupyterlite_application.SingleWidgetShell.md#onafterhide)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:339

### `onAfterShow`

> `Protected` **`onAfterShow`**(`msg`): `void`

A message handler invoked on an `'after-show'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onAfterShow](../classes/jupyterlite_application.SingleWidgetShell.md#onaftershow)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:325

### `onBeforeAttach`

> `Protected` **`onBeforeAttach`**(`msg`): `void`

A message handler invoked on a `'before-attach'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onBeforeAttach](../classes/jupyterlite_application.SingleWidgetShell.md#onbeforeattach)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:346

### `onBeforeDetach`

> `Protected` **`onBeforeDetach`**(`msg`): `void`

A message handler invoked on a `'before-detach'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onBeforeDetach](../classes/jupyterlite_application.SingleWidgetShell.md#onbeforedetach)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:360

### `onBeforeHide`

> `Protected` **`onBeforeHide`**(`msg`): `void`

A message handler invoked on a `'before-hide'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onBeforeHide](../classes/jupyterlite_application.SingleWidgetShell.md#onbeforehide)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:332

### `onBeforeShow`

> `Protected` **`onBeforeShow`**(`msg`): `void`

A message handler invoked on a `'before-show'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onBeforeShow](../classes/jupyterlite_application.SingleWidgetShell.md#onbeforeshow)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:318

### `onChildAdded`

> `Protected` **`onChildAdded`**(`msg`): `void`

A message handler invoked on a `'child-added'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type           |
| :---- | :------------- |
| `msg` | `ChildMessage` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onChildAdded](../classes/jupyterlite_application.SingleWidgetShell.md#onchildadded)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:374

### `onChildRemoved`

> `Protected` **`onChildRemoved`**(`msg`): `void`

A message handler invoked on a `'child-removed'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type           |
| :---- | :------------- |
| `msg` | `ChildMessage` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onChildRemoved](../classes/jupyterlite_application.SingleWidgetShell.md#onchildremoved)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:381

### `onCloseRequest`

> `Protected` **`onCloseRequest`**(`msg`): `void`

A message handler invoked on a `'close-request'` message.

#### Notes

The default implementation unparents or detaches the widget.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onCloseRequest](../classes/jupyterlite_application.SingleWidgetShell.md#oncloserequest)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:283

### `onFitRequest`

> `Protected` **`onFitRequest`**(`msg`): `void`

A message handler invoked on a `'fit-request'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onFitRequest](../classes/jupyterlite_application.SingleWidgetShell.md#onfitrequest)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:304

### `onResize`

> `Protected` **`onResize`**(`msg`): `void`

A message handler invoked on a `'resize'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type            |
| :---- | :-------------- |
| `msg` | `ResizeMessage` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onResize](../classes/jupyterlite_application.SingleWidgetShell.md#onresize)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:290

### `onUpdateRequest`

> `Protected` **`onUpdateRequest`**(`msg`): `void`

A message handler invoked on an `'update-request'` message.

#### Notes

The default implementation of this handler is a no-op.

#### Parameters

| Name  | Type      |
| :---- | :-------- |
| `msg` | `Message` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[onUpdateRequest](../classes/jupyterlite_application.SingleWidgetShell.md#onupdaterequest)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:297

### `processMessage`

> **`processMessage`**(`msg`): `void`

Process a message sent to the widget.

#### Parameters

| Name  | Type      | Description                                                                                  |
| :---- | :-------- | :------------------------------------------------------------------------------------------- |
| `msg` | `Message` | The message sent to the widget. #### Notes Subclasses may reimplement this method as needed. |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[processMessage](../classes/jupyterlite_application.SingleWidgetShell.md#processmessage)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:265

### `removeClass`

> **`removeClass`**(`name`): `void`

Remove a class name from the widget's DOM node.

#### Parameters

| Name   | Type     | Description                                                                                                                                                     |
| :----- | :------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `name` | `string` | The class name to remove from the node. #### Notes If the class name is not yet added to the node, this is a no-op. The class name must not contain whitespace. |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[removeClass](../classes/jupyterlite_application.SingleWidgetShell.md#removeclass)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:165

### `setFlag`

> **`setFlag`**(`flag`): `void`

Set the given widget flag.

#### Notes

This will not typically be called directly by user code.

#### Parameters

| Name   | Type   |
| :----- | :----- |
| `flag` | `Flag` |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[setFlag](../classes/jupyterlite_application.SingleWidgetShell.md#setflag)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:249

### `setHidden`

> **`setHidden`**(`hidden`): `void`

Show or hide the widget according to a boolean value.

#### Parameters

| Name     | Type      | Description                                                                                                          |
| :------- | :-------- | :------------------------------------------------------------------------------------------------------------------- |
| `hidden` | `boolean` | `true` to hide the widget, or `false` to show it. #### Notes This is a convenience method for `hide()` and `show()`. |

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[setHidden](../classes/jupyterlite_application.SingleWidgetShell.md#sethidden)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:235

### `show`

> **`show`**(): `void`

Show the widget and make it visible to its parent widget.

#### Notes

This causes the [isHidden](jupyterlite_application.ISingleWidgetShell.md#ishidden)
property to be `false`.

If the widget is not explicitly hidden, this is a no-op.

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[show](../classes/jupyterlite_application.SingleWidgetShell.md#show)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:217

### `testFlag`

> **`testFlag`**(`flag`): `boolean`

Test whether the given widget flag is set.

#### Notes

This will not typically be called directly by user code.

#### Parameters

| Name   | Type   |
| :----- | :----- |
| `flag` | `Flag` |

#### Returns

`boolean`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[testFlag](../classes/jupyterlite_application.SingleWidgetShell.md#testflag)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:242

### `toggleClass`

> **`toggleClass`**(`name`, `force?`): `boolean`

Toggle a class name on the widget's DOM node.

#### Parameters

| Name     | Type      | Description                                                                                                                                                     |
| :------- | :-------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `name`   | `string`  | The class name to toggle on the node.                                                                                                                           |
| `force?` | `boolean` | Whether to force add the class (`true`) or force remove the class (`false`). If not provided, the presence of the class will be toggled from its current state. |

#### Returns

`boolean`

`true` if the class is now present, `false` otherwise.

#### Notes

The class name must not contain whitespace.

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[toggleClass](../classes/jupyterlite_application.SingleWidgetShell.md#toggleclass)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:180

### `update`

> **`update`**(): `void`

Post an `'update-request'` message to the widget.

#### Notes

This is a simple convenience method for posting the message.

#### Returns

`void`

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[update](../classes/jupyterlite_application.SingleWidgetShell.md#update)

#### Defined in

node_modules/@lumino/widgets/types/widget.d.ts:187

### `widgets`

> **`widgets`**(`area`): `IIterator`<`Widget`\>

Return the list of widgets for the given area.

#### Parameters

| Name   | Type     | Description |
| :----- | :------- | :---------- |
| `area` | `"main"` | The area    |

#### Returns

`IIterator`<`Widget`\>

#### Inherited from

[SingleWidgetShell](../classes/jupyterlite_application.SingleWidgetShell.md).[widgets](../classes/jupyterlite_application.SingleWidgetShell.md#widgets)

#### Defined in

[packages/application/src/singleWidgetShell.ts:99](https://github.com/jupyterlite/jupyterlite/blob/7971e0aa/packages/application/src/singleWidgetShell.ts#L99)