Struct SceneChange 

#[non_exhaustive]
pub struct SceneChange {
    pub txn: TxnId,
    pub source: ChangeSource,
    pub history: HistoryMode,
    pub ephemeral: bool,
    pub change: ItemChange,
}

One ItemChange plus the context the notification channel needs in order to be usable as a change feed rather than just a repaint trigger.

This is what Scene::item_change_signal carries.

#[non_exhaustive]: consumers read it, the scene constructs it.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

txn: TxnId

The transaction this change belongs to. Every change emitted inside one write scope — or one SceneTransaction — shares it.

source: ChangeSource

Whose change it is. See ChangeSource.

history: HistoryMode

What a history above the scene should do with it. See HistoryMode.

ephemeral: bool

A change that must be rendered but must not be recorded.

Set for per-frame model churn that is an artefact of animation rather than an edit: the scene’s own refresh_dynamic_bounds, which re-reads every signal-driven AABB each build and so emits a LocalBoundsChanged per frame for an animating item. An app driving its own per-frame stream — an item whose transform follows a rotation signal — marks it the same way with SceneTransaction::ephemeral, so the knob is not one-sided across the seam.

change: ItemChange

The change itself.

Implementations

impl SceneChange

pub fn id(&self) -> ItemId

The item this change is about.

Trait Implementations

impl Clone for SceneChange

fn clone(&self) -> SceneChange

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SceneChange

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

Formats the value using the given formatter.