Enum EventDetail 

#[non_exhaustive]
pub enum EventDetail {
    None,
    String(String),
    Transition(Box<TransitionDetail>),
    Input(Box<InputDetail>),
    Submit(Box<SubmitDetail>),
    Toggle(Box<ToggleDetail>),
    Mouse(MouseDetail),
    Keyboard(Box<KeyboardDetail>),
}

Typed payload carried on Event::detail.

Replaces the pre-M4 Option<String> detail with a closed enum of typed variants. The EventDetail::String variant preserves the one-shot escape hatch authors used to lean on via Event::new("custom").with_detail("payload").

Variant boxing

Variants whose largest field is a String are boxed; inline for fixed-size variants. This keeps the enum under 32 bytes on 64-bit (a const-assert below enforces that).

Accessor pattern

Listeners read typed detail through the as_* accessors:

let mut e = Event::new("custom");
e.detail = EventDetail::String("payload".into());
assert_eq!(e.detail.as_string(), Some("payload"));

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

None

No detail attached. Default for plain events (click, focus, blur, …) and the initial state on Event::new.

String(String)

Free-form string payload. Used for CustomEvent-style author-fired events; also the migration target for any pre-M4 reader that stored a string in Option<String>.

Transition(Box<TransitionDetail>)

transitionstart / transitionend / transitioncancel payload — emitted by runtime::animation.

Input(Box<InputDetail>)

beforeinput / input event payload — emitted by <input> / <textarea> and contenteditable elements.

Submit(Box<SubmitDetail>)

submit event payload — emitted by <form>.

Toggle(Box<ToggleDetail>)

toggle event payload — emitted by <details> and <dialog>.

Mouse(MouseDetail)

Pointer event payload — click / mousedown / mouseup / mousemove / wheel / contextmenu. Inline; the struct is fixed-size.

Keyboard(Box<KeyboardDetail>)

keydown / keypress / keyup payload. Boxed because the inner key: String would otherwise push the enum past its 32-byte budget.

Implementations

impl EventDetail

pub fn as_string(&self) -> Option<&str>

Borrow the payload as a &str iff this is EventDetail::String. Returns None for every other variant — typed-detail readers should use the matching as_* accessor instead.

pub fn as_transition(&self) -> Option<&TransitionDetail>

Borrow the transition payload iff this is EventDetail::Transition.

pub fn as_input(&self) -> Option<&InputDetail>

Borrow the input payload iff this is EventDetail::Input.

pub fn as_submit(&self) -> Option<&SubmitDetail>

Borrow the submit payload iff this is EventDetail::Submit.

pub fn as_toggle(&self) -> Option<&ToggleDetail>

Borrow the toggle payload iff this is EventDetail::Toggle.

pub fn as_mouse(&self) -> Option<&MouseDetail>

Borrow the mouse payload iff this is EventDetail::Mouse.

pub fn as_keyboard(&self) -> Option<&KeyboardDetail>

Borrow the keyboard payload iff this is EventDetail::Keyboard.

Trait Implementations

impl Clone for EventDetail

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EventDetail

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

Formats the value using the given formatter.

impl Default for EventDetail

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for EventDetail

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for EventDetail