Struct Tree 

pub struct Tree<T>(/* private fields */);

A hierarchical tree view component.

Displays data in a tree structure with expandable/collapsible nodes. Supports keyboard navigation and single selection.

Visual Format

▶ Documents
▼ Projects
  ├─ envision
  │  ├─ src
  │  └─ tests
  └─ other

Keyboard Navigation

• Up/Down - Move selection
• Right - Expand node
• Left - Collapse node
• Enter - Select/activate node

Example

use envision::component::{Tree, TreeMessage, TreeOutput, TreeState, TreeNode, Component};

// Build tree structure
let mut docs = TreeNode::new("Documents", "docs");
docs.add_child(TreeNode::new("readme.md", "readme"));
docs.add_child(TreeNode::new("guide.md", "guide"));

let mut projects = TreeNode::new_expanded("Projects", "projects");
projects.add_child(TreeNode::new("envision", "envision"));

let mut state = TreeState::new(vec![docs, projects]);

// Navigate
Tree::update(&mut state, TreeMessage::SelectNext);
Tree::update(&mut state, TreeMessage::Expand);

Trait Implementations

impl<T: Clone + 'static> Component for Tree<T>

type State = TreeState<T>

The component’s internal state type.

type Message = TreeMessage

Messages this component can receive.

type Output = TreeOutput

Messages this component can emit to its parent.

fn init() -> Self::State

Initialize the component state.

fn update(state: &mut Self::State, msg: Self::Message) -> Option<Self::Output>

Update component state based on a message.

fn view(state: &Self::State, frame: &mut Frame<'_>, area: Rect)

Render the component to the given area.

impl<T: Clone + 'static> Focusable for Tree<T>

fn is_focused(state: &Self::State) -> bool

Returns true if this component is currently focused.

fn set_focused(state: &mut Self::State, focused: bool)

Sets the focus state of this component.

fn focus(state: &mut Self::State)

Gives focus to this component.

fn blur(state: &mut Self::State)

Removes focus from this component.