<!--
{
  "availability" : [
    "macOS: -"
  ],
  "documentType" : "symbol",
  "framework" : "AppKit",
  "identifier" : "/documentation/AppKit/NSAnimationDelegate",
  "metadataVersion" : "0.1.0",
  "role" : "Protocol",
  "symbol" : {
    "kind" : "Protocol",
    "modules" : [
      "AppKit"
    ],
    "preciseIdentifier" : "c:objc(pl)NSAnimationDelegate"
  },
  "title" : "NSAnimationDelegate"
}
-->

# NSAnimationDelegate

A set of optional methods implemented by delegates of [`NSAnimation`](/documentation/AppKit/NSAnimation) objects.

```
protocol NSAnimationDelegate : NSObjectProtocol
```

## Topics

### Controlling and Monitoring an Animation

[`func animationDidEnd(NSAnimation)`](/documentation/AppKit/NSAnimationDelegate/animationDidEnd(_:))

Sent to the delegate when the specified animation completes its run.

[`func animationDidStop(NSAnimation)`](/documentation/AppKit/NSAnimationDelegate/animationDidStop(_:))

Sent to the delegate when the specified animation is stopped before it completes its run.

[`func animationShouldStart(NSAnimation) -> Bool`](/documentation/AppKit/NSAnimationDelegate/animationShouldStart(_:))

Sent to the delegate just after an animation is started.

[`func animation(NSAnimation, valueForProgress: NSAnimation.Progress) -> Float`](/documentation/AppKit/NSAnimationDelegate/animation(_:valueForProgress:))

Requests a custom curve value for the current progress value.

### Managing Progress Marks

[`func animation(NSAnimation, didReachProgressMark: NSAnimation.Progress)`](/documentation/AppKit/NSAnimationDelegate/animation(_:didReachProgressMark:))

Sent to the delegate when an animation reaches a specific progress mark.

## Relationships

### Inherits From

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

### Conforming Types

[`NSTitlebarAccessoryViewController`](/documentation/AppKit/NSTitlebarAccessoryViewController)

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)