---
title: "RippleAlpha"
description: "RippleAlpha defines the alpha of the ripple / state layer for different [Interaction]s.

On Android, because the press ripple is drawn using the framework's RippleDrawable, there are
constraints / different behaviours for the actual press alpha used on different API versions.
Note that this *only* affects [pressedAlpha] - the other values are guaranteed to be consistent,
as they do not rely on framework code. Specifically:

API 21-27: The actual ripple is split into two 'layers', with the alpha applied to both layers,
so there is no uniform 'alpha'. API 28-32: The ripple is just one layer, but the alpha is clamped
to a maximum of 0.5f - it is not possible to have a fully opaque ripple. API 33: There is a bug
where the ripple is clamped to a *minimum* of 0.5, instead of a maximum like before - this should
be resolved in future versions."
type: "class"
---

<div class='type'>Class</div>


<a id='references'></a>

<div class='sourceset sourceset-common'>Common</div>


```kotlin
public class RippleAlpha(
    public val draggedAlpha: Float,
    public val focusedAlpha: Float,
    public val hoveredAlpha: Float,
    public val pressedAlpha: Float,
)
```


RippleAlpha defines the alpha of the ripple / state layer for different `Interaction`s.

On Android, because the press ripple is drawn using the framework's RippleDrawable, there are
constraints / different behaviours for the actual press alpha used on different API versions.
Note that this *only* affects `pressedAlpha` - the other values are guaranteed to be consistent,
as they do not rely on framework code. Specifically:

API 21-27: The actual ripple is split into two 'layers', with the alpha applied to both layers,
so there is no uniform 'alpha'. API 28-32: The ripple is just one layer, but the alpha is clamped
to a maximum of 0.5f - it is not possible to have a fully opaque ripple. API 33: There is a bug
where the ripple is clamped to a *minimum* of 0.5, instead of a maximum like before - this should
be resolved in future versions.