Enum BackPolicy 

pub enum BackPolicy {
    Pop,
    DismissAnimated,
    Veto,
}

How a page participates in a back press routed through NavigatorController::request_back (Android hardware/gesture back, via the facade’s back-press wiring). A page declares its policy when pushed via PushOptions::back; every existing push defaults to Pop.

This is internal routing vocabulary — the user-facing overlay builder is dismissable(bool), which maps true → DismissAnimated and false → Veto when the overlay pushes its transparent page.

The DismissAnimated observation seam

A DismissAnimated page does not pop on the back press itself; instead the navigator increments the page’s dismiss_signal generation counter, which the page’s own widget subtree observes (comparing the shared Rc<Cell<u64>> against a last-seen value on its next paint/event) and turns into its own begin_exit staging — the overlay then pops itself on exit completion via its existing on-close path. This keeps frust-widgets reactive-free (a plain shared cell, mirroring NavigatorController::depth’s Rc<Cell<usize>>) — no frust-reactive dependency crosses into this crate. An overlay helper (show_command_palette/show_dialog/show_bottom_sheet) wires the seam by creating one cell, handing a clone to the overlay widget it builds and into PushOptions::dismiss_signal.

Variants

Pop

The default: a back press pops this page (the normal pop path, transitions preserved). A back press at the root (this being the only page) is a safe no-op.

DismissAnimated

A dismissable overlay: a back press fires the page’s dismiss_signal (see the seam above) rather than popping — the stack is unchanged immediately, and the overlay animates its own exit before popping itself.

Veto

A non-dismissable overlay (a modal barrier): a back press is consumed (the page claims it, so it never bubbles to the platform) but does nothing — the stack is unchanged and no signal fires.

Trait Implementations

impl Clone for BackPolicy

fn clone(&self) -> BackPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for BackPolicy

impl Debug for BackPolicy

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

Formats the value using the given formatter.

impl Eq for BackPolicy

impl PartialEq for BackPolicy

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for BackPolicy