Struct PointerId 

pub struct PointerId {
    pub source: PointerSource,
    pub slot: u32,
}

The identity of one pointer contact: which device it comes from and which slot on that device.

It rides beside a PointerEvent, never inside it: a shell hands a touch contact to the root as InputEvent::PointerContact, the root unwraps it, and the widget receiving the plain InputEvent::Pointer reads the identity from EventCtx::pointer_id. A bare InputEvent::Pointer from a shell means PointerId::MOUSE.

A slot is the shell’s own numbering of simultaneous contacts on one source: slot 0 is the gesture’s first contact, and a slot is free again once its contact ended. The mouse only ever has slot 0.

Multi-contact contract

Applied at the root (crate::app::RenderRoot::event):

• (a) With no live pointer capture, a slot-0 contact is hit-tested exactly like a plain InputEvent::Pointer — the same overlay, hover, focus and blur bookkeeping — and a capture taken on its Down latches this id as the gesture’s claimant.
• (b) With no live capture, a contact on slot 1 or above is dropped at the root. Additional contacts exist only inside a captured gesture.
• (c) While a capture is live, the claimant’s own events take the captured path as usual. An event with any other id reaches the captor — and only the captor: the containers above it on that path forward it without running their own handling — only if the captor opted in with EventCtx::capture_contacts on its capturing Down; otherwise the root drops it. Only the claimant’s Up/Cancel ends the capture: another contact’s Up/Cancel never releases it, whether it came from a touch while a mouse holds the capture or the other way round. A container that takes the gesture over from the captor (EventCtx::release_captured_child) ends the opt-in, and the other contacts are dropped from then on.

See InputEvent::PointerContact for the full contract.

Fields

source: PointerSource

The device the contact comes from.

slot: u32

The contact’s slot on that device (0 for the first contact).

Implementations

impl PointerId

pub const MOUSE: PointerId

The mouse pointer: the identity a bare InputEvent::Pointer carries, and what EventCtx::pointer_id reports when nothing else is known.

pub const fn touch(slot: u32) -> PointerId

The touch contact in slot (0 for the gesture’s first finger).

Trait Implementations

impl Clone for PointerId

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for PointerId

impl Debug for PointerId

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

Formats the value using the given formatter.

impl Eq for PointerId

impl Hash for PointerId

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for PointerId

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for PointerId