Struct ContainerTransform 

pub struct ContainerTransform {
    pub source: Rect,
    pub target: Rect,
    pub fade: ContainerFade,
}

Material 3 “container transform” (Flutter OpenContainer semantics): the incoming content morphs from a captured source rect to a target rect while opacity fades the source content out and the incoming content in.

Pattern-local rect capture (no HeroFrames coupling)

Unlike nav::hero, this pattern carries its own source/target rects as data (captured from layout by the caller) — it never reaches into the navigator’s HeroFrames registry, so it composes inside a plain super::switcher::PatternSwitcher with no core/navigator plumbing. A zero-area target is resolved to the full container at resolve time (the common “incoming child fills the container” case).

v1 morph gap: uniform scale, not a true rect-to-rect affine

PatternLayer composites a uniform scale about the child’s paint centre plus an offset — it cannot express the non-uniform (independent width/height) scale a full rect-to-rect affine needs. So this pattern approximates the morph as a width-based uniform scale placed at the interpolated rect’s centre: exact when source/target share an aspect ratio, an approximation otherwise. A true non-uniform morph would need a richer layer type (a PatternLayer change rippling into the switcher’s paint_staged_child), deferred rather than hacked into the v1 contract.

Fields

source: Rect

The source container rect the morph grows from (container-local logical px).

target: Rect

The target rect the morph settles into; a zero-area rect means “the full container” (resolved from the size passed to resolve).

fade: ContainerFade

Opacity staging variant.

Implementations

impl ContainerTransform

pub const fn new(source: Rect, target: Rect) -> ContainerTransform

A fade-through container transform morphing source → target.

pub const fn from_source(source: Rect) -> ContainerTransform

A container transform whose incoming child fills the container: target is left zero-area and resolved to the full container size at paint time.

pub const fn with_fade(self, fade: ContainerFade) -> ContainerTransform

Select the opacity staging ContainerFade variant.

pub fn morph_rect(&self, p: f64, reverse: bool) -> Rect

The interpolated bounds at raw progress p (spatial-eased via [CONTAINER_TRANSFORM_MORPH_CURVE]), morphing source → target forward and target → source when reverse. target is used as configured here — see resolve for the zero-area full-container fallback.

Trait Implementations

impl Clone for ContainerTransform

fn clone(&self) -> ContainerTransform

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ContainerTransform

impl Debug for ContainerTransform

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

Formats the value using the given formatter.

impl PartialEq for ContainerTransform

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ContainerTransform

impl TransitionPattern for ContainerTransform

fn resolve( &self, p: f64, reverse: bool, size: Size, ) -> (PatternLayer, PatternLayer)

Resolve (incoming, exiting) layers at transition progress p (raw — may overshoot for a spring), reverse flipping any directional motion, at container size.