Android appCompat themes vs Base themes

Question

Wha's the difference between the Android Theme.AppCompat and Base.Theme.AppCompat? When should we use the Base theme?

<style name="flatButton" parent="Base.Widget.AppCompat.Button.Borderless">
    <item name="colorAccent">@color/colorAccent</item>
</style>

<style name="flatButton2" parent="Widget.AppCompat.Button.Borderless">
    <item name="colorAccent">@color/colorAccent</item>
</style>

Answer 1

You shouldn't use the Base theme at all - always use the standard themes. The Base themes are used internally to AppCompat and serve as a common base that applies to all API levels - it does not include the API level specific changes that are needed to properly function (something only the standard themes supply).