Struct Tree

pub struct Tree {
    pub tag: Tag,
    pub id: Option<Id>,
    pub state: State,
    pub children: Vec<Tree>,
}

A persistent state widget tree.

A Tree is normally associated with a specific widget in the widget tree.

Fields

tag: Tag

The tag of the Tree.

id: Option<Id>

the Id of the Tree

state: State

The State of the Tree.

children: Vec<Tree>

The children of the root widget of the Tree.

Implementations

impl Tree

pub fn empty() -> Tree

Creates an empty, stateless Tree with no children.

pub fn new<'a, Message, Theme, Renderer>( widget: impl Borrow<dyn Widget<Message, Theme, Renderer> + 'a>, ) -> Tree

where Renderer: Renderer,

Creates a new Tree for the provided Widget.

pub fn take_all_named( &mut self, ) -> HashMap<Cow<'static, str>, (State, Vec<(usize, Tree)>)>

Takes all named widgets from the tree.

pub fn find<'a>(&'a self, id: &Id) -> Option<&'a Tree>

Finds a widget state in the tree by its id.

pub fn diff<'a, Message, Theme, Renderer>( &mut self, new: impl BorrowMut<dyn Widget<Message, Theme, Renderer> + 'a>, )

where Renderer: Renderer,

Reconciliates the current tree with the provided Widget.

If the tag of the Widget matches the tag of the Tree, then the Widget proceeds with the reconciliation (i.e. Widget::diff is called).

Otherwise, the whole Tree is recreated.

pub fn diff_children<'a, Message, Theme, Renderer>( &mut self, new_children: &mut [impl BorrowMut<dyn Widget<Message, Theme, Renderer> + 'a>], )

where Renderer: Renderer,

Reconciles the children of the tree with the provided list of widgets.

pub fn diff_children_custom<T>( &mut self, new_children: &mut [T], new_ids: Vec<Option<Id>>, diff: impl Fn(&mut Tree, &mut T), new_state: impl Fn(&T) -> Tree, )

Reconciles the children of the tree with the provided list of widgets using custom logic both for diffing and creating new widget state.

Trait Implementations

impl Debug for Tree

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

Formats the value using the given formatter.