Struct SaveableScope 

pub struct SaveableScope { /* private fields */ }

Where the rememberSaveable calls in some content keep their values: a key namespace, and whether the values are saved in preferences or kept only in memory. A navigation host gives each back-stack entry its own, so two visits of one screen keep apart.

Implementations

impl SaveableScope

pub fn current() -> SaveableScope

The scope where this is composed: the one ProvideSaveableScope gives, else the root scope, which saves each key as it is in preferences. Call it while composing.

pub fn child(&self, name: impl Display) -> SaveableScope

The scope named name inside this one. It saves where this one does.

pub fn in_memory(self) -> SaveableScope

This scope with its values kept only in memory, until the scope is forgotten or the process ends.

pub fn namespace(&self) -> Option<&str>

The prefix of the keys this scope saves under; None for the root scope, whose keys stand as they are.

pub fn is_durable(&self) -> bool

Whether this scope saves its values in preferences, rather than keeping them in memory.

pub fn restore(&self, key: &str) -> Option<String>

The value last saved under key in this scope.

pub fn register( &self, key: &str, read: impl Fn() -> Option<String> + 'static, ) -> SaveableRegistration

Saves what read returns under key in this scope at each save boundary while the registration lives, and keeps its last value once it is dropped, as rememberSaveable does. read must not perform storage I/O.

pub fn forget(&self)

Forgets everything saved in this scope: the state of a back-stack entry once it is popped. Saves in it stop, and stored values are removed at the next save boundary. The root scope forgets nothing.

pub fn forget_children_except<N>(&self, keep: impl IntoIterator<Item = N>)

where N: Display,

Forgets everything saved in this scope apart from the child scopes named in keep, as SaveableScope::forget does.

Trait Implementations

impl Clone for SaveableScope

fn clone(&self) -> SaveableScope

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SaveableScope

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Eq for SaveableScope

impl PartialEq for SaveableScope

fn eq(&self, other: &SaveableScope) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SaveableScope