SavedStateSupport

A class helps to support saved state in Compose.

The clear method will clear all saved state and clear the ViewModelStore. Usually, you should call clear in onDispose of a androidx.compose.runtime.DisposableEffect that runs in the root @Composable.

The performSave method will save all the saved state. Usually, you should call performSave in onDispose of a androidx.compose.runtime.DisposableEffect that runs in a child @Composable. That androidx.compose.runtime.DisposableEffect should be at the last of the child @Composable, because SaveableStateRegistry.Entrys are unregistered in reverse order. We want to save state first, before SaveableStateRegistry.Entrys are unregistered.

Example

// Remember a SavedStateSupport instance.
val savedStateSupport = remember { SavedStateSupport() }

// Clear the SavedStateSupport when the root @Composable exits the composition.
savedStateSupport.ClearOnDispose()

// Provide SavedStateSupport as ViewModelStoreOwner, SaveableStateRegistry and SavedStateHandleFactory.
savedStateSupport.ProvideCompositionLocals {
  MyApp()
}