---
title: "readinessCoordinator(_:captureReadinessDidChange:)"
framework: avfoundation
role: symbol
role_heading: Instance Method
path: "avfoundation/avcapturephotooutputreadinesscoordinatordelegate/readinesscoordinator(_:capturereadinessdidchange:)"
---

# readinessCoordinator(_:captureReadinessDidChange:)

Tells the delegate that the capture readiness state of a photo output changed.

## Declaration

```swift
optional func readinessCoordinator(_ coordinator: AVCapturePhotoOutputReadinessCoordinator, captureReadinessDidChange captureReadiness: AVCapturePhotoOutput.CaptureReadiness)
```

## Parameters

- `coordinator`: The delegate’s coordinator object.
- `captureReadiness`: An updated capture readiness value.

## Discussion

Discussion The system always performs this call on the main queue, so you can use it to update your user interface’s shutter button availability and appearance.