Struct WindowMetrics 

pub struct WindowMetrics {
    pub size: Size,
    pub scale: f64,
    pub orientation: Orientation,
    pub insets: WindowInsets,
}

The window-shape value recovered via use_context::<WindowMetrics>() inside Component::build — lifted alongside WindowInsets for the same reason: a widget or component laying itself out around window size/scale/orientation cannot otherwise name the value. See WindowMetrics’s own doc for the plain-value delivery contract, the alongside-not-superseding relationship with WindowInsets, and the derived-orientation/rebuild-cost notes. The window’s shape and platform-occlusion state, delivered to app code as a plain provide_context-carried value — logical size, device-pixel scale, a derived orientation, and the current WindowInsets.

Plain value, not a signal

WindowMetrics is delivered exactly like Theme and WindowInsets already are: a shell calls provide_context with a freshly-built value on change, and app code recovers it with use_context::<WindowMetrics>() inside Component::build. It is not an RwSignal — only deep_link and back are true signals in frust-reactive; every other host-signal carrier (theme, insets, and now this) is a re-provided plain value.

Alongside WindowInsets, not superseding it

WindowInsets already reaches Component::build on Android and iOS today (each shell’s push_insets calls provide_context(insets) independently of anything here — desktop has no such arm for either value yet). WindowMetrics is additive: a shell that starts providing it keeps providing the standalone WindowInsets context too, so an existing use_context::<WindowInsets>() call site never breaks. insets on this type is a copy of that same value for convenience (a widget laying itself out around window shape wants size/scale/orientation/insets together), not a replacement for the independent context.

Orientation is derived, not platform-sourced

No platform callback in either mobile shell carries an orientation enum — Android’s nativeOnSurfaceChanged and iOS’s frust_resize each hand the shell only a (width, height, scale) triple. Orientation is therefore always computed from size via Orientation::from_size (portrait when height >= width, so an exact square reads as portrait); it never tracks a device orientation-lock setting or a platform rotation event directly.

Context is not reactive

provide_context is a plain insert into the owner’s context map — it notifies nothing — and use_context inside Component::build (or the root build closure) creates no subscription, so re-providing a changed WindowMetrics does not itself mark anything dirty or wake a frame. A new value becomes visible only on the next rebuild, which the resize or inset change that produced it already drives; do not write a shell that assumes a provide_context write triggers one. A shell wiring this up (see docs/SHELLS_ARCHITECTURE.md) must still re-provide WindowMetrics only on an actual change (mirroring RenderRoot::set_insets’s PartialEq-guarded no-op) — the reason is cost at the FFI boundary (a lock write plus an allocation every frame), not a rebuild storm. Separately, there is no per-component rebuild skipping in this framework (a component always re-runs build on any rebuild it does take part in), which is affordable only because builds are cheap by construction.

Fields

size: Size

The window’s logical (density-independent) size.

scale: f64

The device-pixel scale factor (logical → physical px multiplier).

orientation: Orientation

The orientation derived from size — see the type’s doc for why this is computed, never platform-sourced.

insets: WindowInsets

A copy of the window’s current insets — see the type’s doc for why this does not replace the standalone WindowInsets context.

Implementations

impl WindowMetrics

pub fn new(size: Size, scale: f64, insets: WindowInsets) -> WindowMetrics

Construct a WindowMetrics from its transported fields, deriving orientation from size rather than accepting it as an input — see the type’s doc for why orientation is never platform-sourced.

Trait Implementations

impl Clone for WindowMetrics

fn clone(&self) -> WindowMetrics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for WindowMetrics

impl Debug for WindowMetrics

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

Formats the value using the given formatter.

impl PartialEq for WindowMetrics

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for WindowMetrics