How can a tab system with navigation history be implemented without using fragments?

To implement a tab system with navigation history preservation without using fragments, several approaches can be used:

1. Using multiple Activities. Each tab is a separate Activity. When switching between tabs, the corresponding Activity is launched, and the navigation history within each Activity is maintained by the system.

2. ViewPager with ViewGroup and custom state management. Instead of fragments, you can use a ViewPager or a custom container, where each tab has its own View (e.g., a custom Layout). To preserve navigation history, you can store the stack of states within each View or use separate data structures.

3. Using Navigation Component with NavHostFragment replaced by a custom container — but this is closer to fragments.

4. Manually saving state. When switching tabs, save the current screen state (e.g., form data, scroll position) in a ViewModel or Bundle, and restore it upon return.

Example of a simple approach with View and ViewModel:

class TabManager {
    private val tabStates = mutableMapOf<Int, Bundle>()

    fun saveState(tabId: Int, state: Bundle) {
        tabStates[tabId] = state
    }

    fun restoreState(tabId: Int): Bundle? {
        return tabStates[tabId]
    }
}

Thus, you can manually manage the state and navigation history without fragments, using ViewModel and custom Views for each tab.