---
title: UIDocumentBrowserTransitionController
framework: uikit
role: symbol
role_heading: Class
path: uikit/uidocumentbrowsertransitioncontroller
---

# UIDocumentBrowserTransitionController

An object that implements the standard loading and transition animations for a document browser.

## Declaration

```swift
@MainActor class UIDocumentBrowserTransitionController
```

## Overview

Overview Each transition controller is associated with a document in the document browser. The transition controller can provide two separate animation sequences for this document: If you set the loadingProgress property, the document browser shows the loading progress in the document’s thumbnail. If you set the targetView property, the transition controller acts as a UIViewControllerAnimatedTransitioning object, providing a custom transition between the document’s thumbnail and the target view. This transitioning object can be used both when presenting and when dismissing the document. You don’t instantiate instances of UIDocumentBrowserTransitionController yourself. Instead, call the document browser’s transitionController(forDocumentURL:) method to get a transition controller for the specified document. note: In Mac apps built with Mac Catalyst, the transition controller doesn’t trigger animations because the macOS design doesn’t use animations for opening or closing documents.

## Topics

### Animating transitions

- [loadingProgress](uikit/uidocumentbrowsertransitioncontroller/loadingprogress.md)
- [targetView](uikit/uidocumentbrowsertransitioncontroller/targetview.md)

## Relationships

### Inherits From

- [NSObject](objectivec/nsobject-swift.class.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [Sendable](swift/sendable.md)
- [UIViewControllerAnimatedTransitioning](uikit/uiviewcontrolleranimatedtransitioning.md)

## See Also

### Related Documentation

- [UIDocumentBrowserViewController](uikit/uidocumentbrowserviewcontroller.md)

### Animating transitions

- [transitionController(forDocumentAt:)](uikit/uidocumentbrowserviewcontroller/transitioncontroller(fordocumentat:).md)