Struct Node

pub struct Node<'a>(/* private fields */);

Type-erased widget with input data

This type is a &mut dyn Widget<Data = A> paired with input data &A, where the type A is erased.

The default implementation of this type uses a boxed trait object. The unsafe_node feature enables a more efficient unboxed implementation (this must make assumptions about VTables beyond what Rust specifies, thus lacks even the usual programmer-provided verification of unsafe code).

Implementations

impl<'a> Node<'a>

pub fn new<T>(widget: &'a mut dyn Widget<Data = T>, data: &'a T) -> Node<'a>

where T: 'a,

Construct

pub fn re<'b>(&'b mut self) -> Node<'b>

where 'a: 'b,

Reborrow with a new lifetime

Rust allows references like &T or &mut T to be “reborrowed” through coercion: essentially, the pointer is copied under a new, shorter, lifetime. Until rfcs#1403 lands, reborrows on user types require a method call.

pub fn as_layout(&self) -> &dyn Layout

Reborrow as a dyn Layout

pub fn id_ref(&self) -> &Id

Get the widget’s identifier

pub fn id(&self) -> Id

Get the widget’s identifier

pub fn eq_id<T>(&self, rhs: T) -> bool

where Id: PartialEq<T>,

Test widget identifier for equality

This method may be used to test against Id, Option<Id> and Option<&Id>.

pub fn is_ancestor_of(&self, id: &Id) -> bool

Check whether id is self or a descendant

This function assumes that id is a valid widget.

pub fn is_strict_ancestor_of(&self, id: &Id) -> bool

Check whether id is not self and is a descendant

This function assumes that id is a valid widget.

pub fn rect(&self) -> Rect

Get the widget’s region, relative to its parent.

pub fn num_children(&self) -> usize

Get the number of child widgets

Every value in the range 0..self.num_children() is a valid child index.

pub fn for_child<R>( &mut self, index: usize, f: impl FnOnce(Node<'_>) -> R, ) -> Option<R>

Run f on some child by index and, if valid, return the result.

Calls the closure and returns Some(result) exactly when index < self.num_children().

pub fn for_children(&mut self, f: impl FnMut(Node<'_>))

Run a f on all children

pub fn find_child_index(&self, id: &Id) -> Option<usize>

Find the child which is an ancestor of this id, if any

If Some(index) is returned, this is probably but not guaranteed to be a valid child index.

pub fn find_node<F, T>(&mut self, id: &Id, cb: F) -> Option<T>

where F: FnOnce(Node<'_>) -> T,

Find the descendant with this id, if any, and call cb on it

Returns Some(result) if and only if node id was found.