Struct HandlerCtx 

pub struct HandlerCtx<'a> {
    pub event: &'a DispatchEvent,
    pub current: WidgetId,
    pub phase: Phase,
    pub target: WidgetId,
    /* private fields */
}

Context handed to a handler during dispatch.

A handler reads the event and the current node/phase, and may queue registry edits (which apply only after dispatch). It returns its desired Propagation from EventHandler::handle.

Fields

event: &'a DispatchEvent

The event being dispatched.

current: WidgetId

The node whose handler is currently running.

phase: Phase

The phase this invocation belongs to.

target: WidgetId

The eventual target node (deepest in the path).

Implementations

impl HandlerCtx<'_>

pub fn add_handler( &mut self, id: WidgetId, phase: Phase, handler: Box<dyn EventHandler>, )

Queue a handler to be added to id for phase after dispatch finishes.

pub fn remove_handlers(&mut self, id: WidgetId)

Queue removal of every handler on id after dispatch finishes.

This is the safe way to “unregister during dispatch”: the removal is recorded now and applied once iteration is complete, so the handler list is never mutated while it is being walked.