Struct MagnetRef 

#[non_exhaustive]
pub struct MagnetRef {
    pub id: MagnetId,
    pub item: ItemId,
    pub role: MagnetRole,
    pub payload: Option<Rc<dyn Any>>,
    pub scene_pos: Point,
}

An owned, borrow-free snapshot of one magnet, handed to the accept/reject predicate and carried in a MagnetConnection.

The payload is an Rc clone, so a snapshot can outlive the borrow taken to collect candidates. The predicate inspects these snapshots while a shared (read-only) scene borrow is held — it may read the model but must not mutate it. The on_connect handler, by contrast, runs after every borrow is dropped and may freely mutate the model (add an edge item, reparent, fire an intent).

#[non_exhaustive]: the crate hands this to consumer code — it is what a predicate inspects — the same reason MagnetVisualState carries it. Build one with new.

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.

id: MagnetId

The magnet’s id.

item: ItemId

The item the magnet is attached to.

role: MagnetRole

The magnet’s advisory direction.

payload: Option<Rc<dyn Any>>

The magnet’s payload, if any (an Rc clone of the stored one).

scene_pos: Point

The magnet’s current position in scene coordinates.

Implementations

impl MagnetRef

pub fn new( id: MagnetId, item: ItemId, role: MagnetRole, payload: Option<Rc<dyn Any>>, scene_pos: Point, ) -> Self

A snapshot stated field by field — the constructor #[non_exhaustive] takes the place of a struct literal for. The scene builds its own; this is for a consumer testing its predicate.

pub fn payload_as<P: 'static>(&self) -> Option<&P>

Borrow the payload downcast to P, or None if absent or a different type. The ergonomic way to read a typed payload inside a predicate.

Trait Implementations

impl Clone for MagnetRef

fn clone(&self) -> MagnetRef

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MagnetRef

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

Formats the value using the given formatter.