Struct RouteObserver 

pub struct RouteObserver { /* private fields */ }

The reactive route-state observable: RouteObserver is the signal face over frust_widgets’ signal-free RouteStack/NavChange — the counterpart to RouteNavigator (intent, queued requests) that reads fact (the last-published stack) instead. Construct once (typically in Component::init) and attach with observe(navigator(...)); RouterDeepLinks::routes hands out the one it wired for a router-driven navigator. See route_state’s module docs for why this bridge lives in the facade rather than frust-widgets. Reactive face of one navigator’s route stack: Copy + Send + Sync (five RwSignals and nothing else), so it rides provide_context — the navigator’s own NavigatorController/ Router never can (see frust_widgets::nav::route’s module docs for why).

Implementations

impl RouteObserver

pub fn new() -> Self

A fresh observer at rest (NavChange::Initial, depth 0, generation 0, no current route) — construct once, typically in Component::init, and keep the result in State.

pub fn observe<State: 'static>( self, view: NavigatorView<State>, ) -> NavigatorView<State>

Attach: installs NavigatorView::on_route_change, writing these signals from inside the navigator’s own rebuild whenever the published RouteStack actually changes. Chainable and cheap to call again (RouteObserver is Copy), so a second navigator elsewhere in the app gets its own observer the same way: state.routes.observe(navigator(&controller, initial)).

Wake correctness

The write happens inside the navigator’s rebuild, after apply_ops: a navigation requested in frame N is published in N, read by the app’s build in N+1, and the write itself schedules N+1 — the same tracked-write-wakes-the-shell bridge every other signal in the framework rides (docs/CODE_STANDARDS.md’s tracked-scope rule), not a manual ReactiveRuntime::wake() call. One frame behind is possible; silently behind is not (a page transition runs ~300ms; 16ms of bar lag is below the perceptual floor).

pub fn current(&self) -> Option<Location>

The topmost page that has a route — skips a route-less (overlay/dialog) page on top, the read chrome (an app bar title, e.g.) wants. Tracked read; see RouteStack::current_route’s doc for the full contract.

pub fn path(&self) -> String

current’s path, or an empty string before the first publish (or if no page in the stack carries a route at all).

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

A query parameter off current’s location. None if there is no current routed page, or the key is absent.

pub fn stack(&self) -> Vec<Option<Location>>

The full stack, bottom→top; None at a route-less (overlay/dialog) page — the tracked-read mirror of RouteStack::entries.

pub fn depth(&self) -> usize

The stack depth as of the last publish.

pub fn change(&self) -> NavChange

The diff label for the most recent publish — see NavChange.

pub fn is_back(&self) -> bool

Whether the most recent change was a NavChange::Pop — the direction chrome resolves a title-transition from, e.g. .title_direction(if routes.is_back() { Back } else { Forward }).

Trait Implementations

impl Clone for RouteObserver

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for RouteObserver

impl Default for RouteObserver

fn default() -> Self

Returns the “default value” for a type.