# ScrollTransitionPhase The phases that a view transitions between when it scrolls among other views. ``` @frozen enum ScrollTransitionPhase ``` ## Overview When a view with a scroll transition modifier applied is approaching the visible region of the containing scroll view or other container, the effect will first be applied with the `topLeading` or `bottomTrailing` phase (depending on which edge the view is approaching), then will be moved to the `identity` phase as the view moves into the visible area. The timing and behavior that determines when a view is visible within the container is controlled by the configuration that is provided to the `scrollTransition` modifier. In the `identity` phase, scroll transitions should generally not make any visual change to the view they are applied to, since the transition’s view modifications in the `identity` phase will be applied to the view as long as it is visible. In the `topLeading` and `bottomTrailing` phases, transitions should apply a change that will be animated to create the transition. ## Topics ### Getting the phase [`ScrollTransitionPhase.identity`](/documentation/SwiftUI/ScrollTransitionPhase/identity) The scroll transition is being applied to a view that is in the visible area. [`ScrollTransitionPhase.topLeading`](/documentation/SwiftUI/ScrollTransitionPhase/topLeading) The scroll transition is being applied to a view that is about to move into the visible area at the top edge of a vertical scroll view, or the leading edge of a horizont scroll view. [`ScrollTransitionPhase.bottomTrailing`](/documentation/SwiftUI/ScrollTransitionPhase/bottomTrailing) The scroll transition is being applied to a view that is about to move into the visible area at the bottom edge of a vertical scroll view, or the trailing edge of a horizontal scroll view. ### Accessing the phase state [`isIdentity`](/documentation/SwiftUI/ScrollTransitionPhase/isIdentity) [`value`](/documentation/SwiftUI/ScrollTransitionPhase/value) A phase-derived value that can be used to scale or otherwise modify effects. ## Relationships ### Conforms To [`Copyable`](/documentation/Swift/Copyable) [`Equatable`](/documentation/Swift/Equatable) [`Hashable`](/documentation/Swift/Hashable) [`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable) --- Copyright © 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)