---
title: NSSplitViewController
framework: appkit
role: symbol
role_heading: Class
path: appkit/nssplitviewcontroller
---

# NSSplitViewController

An object that manages an array of adjacent child views, and has a split view object for managing dividers between those views.

## Declaration

```swift
class NSSplitViewController
```

## Overview

Overview A split view controller manages a set of child views that it displays next to each other in a side-by-side or top-to-bottom arrangement. A split view controller owns an array of split view items (NSSplitViewItem), each of which has a view controller (NSViewController) and corresponding view. The split view controller’s splitView object manages those child views and the dividers between them. By default, a split view arranges its child views vertically from top to bottom. To specify a horizontal (side-by-side) arrangement, implement the isVertical property of the splitView object to return true. The split view controller serves as the delegate of its splitView object. If you override a split view delegate method, your override must call super. To use a split view controller, you must use Auto Layout for the child views and to support animations that collapse and reveal child views. For example, if you design a layout that contains two views, a content area and an optional sidebar, you employ Auto Layout constraints to specify whether the content area shrinks or remains the same size when the sidebar becomes visible. A split view controller employs lazy loading of its views. For example, adding a collapsed split view item as a new child doesn’t load the associated view until it shows. For more information about using NSSplitViewController in your app, see Navigating Hierarchical Data Using Outline and Split Views.

## Topics

### Configuring and Managing a Split View Controller

- [splitView](appkit/nssplitviewcontroller/splitview.md)
- [splitViewItem(for:)](appkit/nssplitviewcontroller/splitviewitem(for:).md)
- [splitViewItems](appkit/nssplitviewcontroller/splitviewitems.md)
- [NSSplitViewItem](appkit/nssplitviewitem.md)

### Modifying a Split View Controller

- [addSplitViewItem(_:)](appkit/nssplitviewcontroller/addsplitviewitem(_:).md)
- [insertSplitViewItem(_:at:)](appkit/nssplitviewcontroller/insertsplitviewitem(_:at:).md)
- [removeSplitViewItem(_:)](appkit/nssplitviewcontroller/removesplitviewitem(_:).md)

### Managing Sidebars

- [toggleSidebar(_:)](appkit/nssplitviewcontroller/togglesidebar(_:).md)
- [minimumThicknessForInlineSidebars](appkit/nssplitviewcontroller/minimumthicknessforinlinesidebars.md)
- [automaticDimension](appkit/nssplitviewcontroller/automaticdimension.md)

### Managing Inspectors

- [toggleInspector(_:)](appkit/nssplitviewcontroller/toggleinspector(_:).md)

### Responding to View Events

- [viewDidLoad()](appkit/nssplitviewcontroller/viewdidload().md)

### Supporting Protocol Requirements

- [Protocol Implementations](appkit/nssplitviewcontroller-protocol-implementations.md)

## Relationships

### Inherits From

- [NSViewController](appkit/nsviewcontroller.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCoding](foundation/nscoding.md)
- [NSEditor](appkit/nseditor.md)
- [NSExtensionRequestHandling](foundation/nsextensionrequesthandling.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [NSSeguePerforming](appkit/nssegueperforming.md)
- [NSSplitViewDelegate](appkit/nssplitviewdelegate.md)
- [NSStandardKeyBindingResponding](appkit/nsstandardkeybindingresponding.md)
- [NSTouchBarProvider](appkit/nstouchbarprovider.md)
- [NSUserActivityRestoring](appkit/nsuseractivityrestoring.md)
- [NSUserInterfaceItemIdentification](appkit/nsuserinterfaceitemidentification.md)
- [NSUserInterfaceValidations](appkit/nsuserinterfacevalidations.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Split View Interface

- [NSSplitView](appkit/nssplitview.md)
- [NSSplitViewItem](appkit/nssplitviewitem.md)