placeholder
Draws some skeleton UI which is typically used whilst content is 'loading'.
To customize the shape of the placeholder, you can use the clip modifier after this one if it match your needs.
A cross-fade transition will be applied to the content and placeholder UI when the visible value changes.
This placeholder display a fade animation.
You can find more information on the pattern at the Material Theming Placeholder UI guidelines.
Parameters
visible
whether the placeholder should be visible or not.