Struct druid::Notification

pub struct Notification { /* fields omitted */ }

A message passed up the tree from a Widget to its ancestors.

In the course of handling an event, a Widget may change some internal state that is of interest to one of its ancestors. In this case, the widget may submit a Notification.

In practice, a Notification is very similar to a Command; the main distinction relates to delivery. Commands are delivered from the root of the tree down towards the target, and this delivery occurs after the originating event call has returned. Notifications are delivered up the tree, and this occurs during event handling; immediately after the child widget's event method returns, the notification will be delivered to the child's parent, and then the parent's parent, until the notification is handled.

Implementations

impl Notification

pub fn is<T>(&self, selector: Selector<T>) -> bool

Returns true if self matches this Selector.

pub fn get<T: Any>(&self, selector: Selector<T>) -> Option<&T>

Returns the payload for this Selector, if the selector matches.

Panics

Panics when the payload has a different type, than what the selector is supposed to carry. This can happen when two selectors with different types but the same key are used.

pub fn source(&self) -> WidgetId

The WidgetId of the Widget that sent this Notification.

Trait Implementations

impl Clone for Notification

pub fn clone(&self) -> Notification

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Notification

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

Formats the value using the given formatter.