---
title: automaticMaximumThickness
framework: appkit
role: symbol
role_heading: Instance Property
path: appkit/nssplitviewitem/automaticmaximumthickness
---

# automaticMaximumThickness

The maximum thickness of the split view item when it resizes due to automatic sizing.

## Declaration

```swift
var automaticMaximumThickness: CGFloat { get set }
```

## Discussion

Discussion Automatic sizing may happen when the split view item has a set preferredThicknessFraction and the app enters full-screen mode, or when other split view items cause the item to change size. The user can still resize the item up to its absolute maximum size in maximumThickness by dragging the divider. The default value of this property is unspecifiedDimension, which means the split view item doesn’t enforce an automatic maximum size.

## See Also

### Managing the item thickness

- [preferredThicknessFraction](appkit/nssplitviewitem/preferredthicknessfraction.md)
- [minimumThickness](appkit/nssplitviewitem/minimumthickness.md)
- [maximumThickness](appkit/nssplitviewitem/maximumthickness.md)
- [unspecifiedDimension](appkit/nssplitviewitem/unspecifieddimension.md)