---
title: "animation(_:didReachProgressMark:)"
framework: appkit
role: symbol
role_heading: Instance Method
path: "appkit/nsanimationdelegate/animation(_:didreachprogressmark:)"
---

# animation(_:didReachProgressMark:)

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

## Declaration

```swift
nonisolated optional func animation(_ animation: NSAnimation, didReachProgressMark progress: NSAnimation.Progress)
```

## Parameters

- `animation`: A running NSAnimation object that has reached a progress mark.
- `progress`: A float value (typed as NSAnimationProgress) that indicates a progress mark of animation.

## Discussion

Discussion The delegate typically implements this method to perform some animation effect for the time slice indicated by progress, such as redrawing objects in a view with new coordinates or changing the frame location or size of a window or view. As an alternative to this delegation message, you may choose to observe the progressMarkNotification notification.