Struct Nav 

pub struct Nav<R> { /* private fields */ }

A navigation stack the app holds in its Model. The core owns the stack (single source of truth); the framework reads its route/depth to drive the shell’s push/pop transitions and back button.

R is your screen-route type (typically a small enum). Hold it in the model, mutate it in update (push/pop/reset), match current() in view, and build the shell with nav_scaffold. Wire a Msg::Back (or similar) event to pop so the back affordance works.

#[derive(Clone, Serialize)] enum Route { List, Detail(u32) }
// model.nav: Nav<Route> = Nav::new(Route::List);
// update: Msg::Open(id) => model.nav.push(Route::Detail(id)),
//         Msg::Back      => model.nav.pop(),
// view:   nav_scaffold(title, dark, tabs, body, &model.nav, Msg::Back)

Implementations

impl<R: Clone + Serialize> Nav<R>

pub fn new(root: R) -> Self

A stack containing a single root route.

pub fn push(&mut self, route: R)

Push a new screen onto the stack.

pub fn pop(&mut self)

Pop the top screen (no-op at the root).

pub fn reset(&mut self, root: R)

Replace the whole stack with a fresh root (e.g. switching bottom-nav tabs).

pub fn current(&self) -> &R

The current (top) route — what view should render.

pub fn depth(&self) -> u32

Stack depth (root = 1).

pub fn can_go_back(&self) -> bool

Whether there is a screen to pop back to.

Trait Implementations

impl<R: Clone> Clone for Nav<R>

fn clone(&self) -> Nav<R>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<R: Debug> Debug for Nav<R>

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

Formats the value using the given formatter.