How to customize the style of the action button in the Snackbar

Question

I am using the Snackbar provided by the Material Components Library.
I am looking for a way to customize the style of the ACTION Button.

I know that the Snackbar uses this layout (layout.mtrl_layout_snackbar_include) with this Button:

  <Button
    android:id="@+id/snackbar_action"

but I am trying to avoid to use some workarounds that can stop to work with the next releases.
In particular I would like to use a OutlinedButton style and a custom shape as an arrow.

Answer 1

With the version 1.1.0 of the Material Components Library you can define in your app theme the style used by the action button within a Snackbar using the snackbarButtonStyle attribute.

<style name="AppTheme" parent="Theme.MaterialComponents.*">

    <!-- Style to use for action button within a Snackbar in this theme. -->
    <item name="snackbarButtonStyle">@style/Widget.MaterialComponents.Button.TextButton.Snackbar</item>
    ....
</style>

You can customize the style using:

  <style name="Custom.MaterialComponents.Button.TextButton.Snackbar" parent="@style/Widget.MaterialComponents.Button.TextButton.Snackbar">
    <item name="strokeColor">@color/...</item>
    <item name="strokeWidth">1dp</item>
    ....
    <item name="shapeAppearanceOverlay">@style/Snackbar.ShapeAppearanceOverlay.Arrow</item>
  </style>

With the shapeAppearanceOverlay you can customize the shape:

  <style name="Snackbar.ShapeAppearanceOverlay.Button.Arrow" parent="">
    <item name="cornerFamily">rounded</item>
    <item name="cornerFamilyTopRight">cut</item>
    <item name="cornerFamilyBottomRight">cut</item>

    <item name="cornerSizeTopLeft">0dp</item>
    <item name="cornerSizeBottomLeft">0dp</item>
    <item name="cornerSizeTopRight">50%</item>
    <item name="cornerSizeBottomRight">50%</item>
  </style>

You can obtain an OutlinedButton style in same way. Just define a custom style with:

  <style name="Outlined.MaterialComponents.Button.TextButton.Snackbar" parent="@style/Widget.MaterialComponents.Button.OutlinedButton">
    <item name="strokeColor">@color/...</item>
    <item name="strokeWidth">1dp</item>
    <item name="android:textColor">@color/...</item>
  </style>