How to implement saving and restoring the state of the user interface when using Jetpack Compose?

In Jetpack Compose, the mechanism of State and special APIs for saving state during component recreation are used to preserve and restore the user interface state.

Main methods:

• rememberSaveable — saves the state during component recreation and even when changing configuration (e.g., screen rotation). It uses SavedStateHandle under the hood.

• ViewModel — stores state that survives Activity/Fragment recreation.

Example of using rememberSaveable:

var text by rememberSaveable { mutableStateOf("") }

TextField(
    value = text,
    onValueChange = { text = it }
)

Thus, if the user enters text, it will not be lost during screen rotation.

For more complex states, you can use ViewModel with state preservation via SavedStateHandle.