---
title: "MutableTransform"
description: "An object that allows manual manipulation of the visual transformations (alpha, scale, offset, etc.) of content during the deferred phase (initiated by DeferredTransitionState.defer) of a DeferredTransition (e.g., for predictive back gestures)."
type: "class"
lastmod: "2026-05-20T01:13:52.640079Z"
---
## API Reference

> Source set: Common

```kotlin
@ExperimentalDeferredTransitionApi
public class MutableTransform(
    internal var veilMatchParentSize: Boolean = false,
    internal var offsetVelocityProvider: (() -> Offset)? = null,
    internal var block: (TransformScope.(fullSize: IntSize) -> Unit)? = null,
)
```

An object that allows manual manipulation of the visual transformations (alpha, scale, offset,
etc.) of content during the deferred phase (initiated by [DeferredTransitionState.defer](/jetpack-compose/androidx.compose.animation/animation-core/classes/DeferredTransitionState)) of a
[DeferredTransition](/jetpack-compose/androidx.compose.animation/animation-core/classes/DeferredTransition) (e.g., for predictive back gestures).

Manual transformations defined in this object are applied **on top of** the transition's initial
state.

This object provides an [invoke](#invoke) operator that accepts a [TransformScope](/jetpack-compose/androidx.compose.animation/animation/interfaces/TransformScope) lambda. This lambda is
evaluated repeatedly to ensure that state reads (e.g., from gesture progress) are deferred to the
layout phase, preventing unnecessary composition churn while keeping Draw-phase operations
performant.

Values set in this object are seamlessly handed off to the automatic transition animation when
the deferred phase ends.

#### Parameters

| | |
| --- | --- |
| veilMatchParentSize | Whether the veil should match the size of the parent. |
| offsetVelocityProvider | The velocity of the offset change in pixels/sec. The [offsetVelocityProvider](#offsetvelocityprovider) lambda is evaluated exactly once when the deferred phase ends to ensure a seamless handoff to the automatic transition. |
| block | A lambda that applies transformations to the provided [TransformScope](/jetpack-compose/androidx.compose.animation/animation/interfaces/TransformScope). This block executes dynamically to reflect state changes. |

## Functions

### invoke

```kotlin
public operator fun invoke(block: TransformScope.(fullSize: IntSize) -> Unit)
```

Define the manual transformation to apply during the deferred phase.

#### Parameters

| | |
| --- | --- |
| block | A lambda that applies transformations to the provided [TransformScope](/jetpack-compose/androidx.compose.animation/animation/interfaces/TransformScope). This block executes dynamically to reflect state changes. |