---
title: boundsDidChangeNotification
framework: appkit
role: symbol
role_heading: Type Property
path: appkit/nsview/boundsdidchangenotification
---

# boundsDidChangeNotification

A notification that posts when the view’s bounds rectangle changes to a new value independently of the frame rectangle.

## Declaration

```swift
class let boundsDidChangeNotification: NSNotification.Name
```

## Discussion

Discussion This notification posts only when the view’s postsBoundsChangedNotifications property is true. The notification object is the NSView object whose bounds rectangle has changed. This notification does not contain a userInfo dictionary. The following methods can result in notification posting: bounds setBoundsOrigin(_:) boundsRotation setBoundsSize(_:) translateOrigin(to:) scaleUnitSquare(to:) rotate(byDegrees:) Note that the bounds rectangle resizes automatically to track the frame rectangle. However, changes to the frame rectangle do not result in this bounds-changed notification. To observe this notification using Swift concurrency, use NSView.BoundsDidChangeMessage.

## See Also

### Modifying the Bounds Rectangle

- [bounds](appkit/nsview/bounds.md)
- [setBoundsOrigin(_:)](appkit/nsview/setboundsorigin(_:).md)
- [setBoundsSize(_:)](appkit/nsview/setboundssize(_:).md)
- [boundsRotation](appkit/nsview/boundsrotation.md)
- [postsBoundsChangedNotifications](appkit/nsview/postsboundschangednotifications.md)