Variable: MAX_ROOT_TABS

const MAX_ROOT_TABS: 4 = 4;

Defined in: packages/media-session/src/browse.ts:50

How many tabs the root may have.

Google, on the content hierarchy: "expect this number to be four". Android Auto's own root hint (EXTRAS_KEY_ROOT_CHILDREN_LIMIT) can be smaller and is honoured natively on top of this; CarPlay's CPTabBarTemplate.maximumTabCount is a runtime value on the same footing. This is the floor both platforms agree on, applied in TypeScript so a tree that works on one car works on the other.

https://developer.android.com/training/cars/media/create-media-browser/content-hierarchy