---
title: NSCollectionViewSectionHeaderView
framework: appkit
role: symbol
role_heading: Protocol
path: appkit/nscollectionviewsectionheaderview
---

# NSCollectionViewSectionHeaderView

A protocol that defines a button to control the collapse of a collection view’s section.

## Declaration

```swift
protocol NSCollectionViewSectionHeaderView : NSCollectionViewElement
```

## Overview

Overview A collection view can support a section that can collapse into a single horizontally scrollable row, similar to the groupings in the icon view in Finder. To ensure that the collection view can communicate with the button that controls the collapsing of a section, the section header view object should conform to this protocol and connect the button’s outlet to sectionCollapseButton.

## Topics

### Providing a Collapse Button

- [sectionCollapseButton](appkit/nscollectionviewsectionheaderview/sectioncollapsebutton.md)

## Relationships

### Inherits From

- [NSCollectionViewElement](appkit/nscollectionviewelement.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [NSUserInterfaceItemIdentification](appkit/nsuserinterfaceitemidentification.md)

## See Also

### View

- [NSCollectionView](appkit/nscollectionview.md)