Crate tui_realm_treeview 

tui-realm-treeview

tui-realm-treeview is a tui-realm implementation of a treeview component. The tree engine is based on Orange-trees.

Get Started

Adding tui-realm-treeview as dependency

tui-realm-treeview = "2"

Or if you don’t use Crossterm, define the backend as you would do with tui-realm:

tui-realm-treeview = { version = "2", default-features = false, features = [ "termion" ] }

Component API

Commands:

Cmd	Result	Behaviour
Custom($TREE_CMD_CLOSE)	None	Close selected node
Custom($TREE_CMD_OPEN)	None	Open selected node
GoTo(Begin)	`Changed	None`
GoTo(End)	`Changed	None`
Move(Down)	`Changed	None`
Move(Up)	`Changed	None`
Scroll(Down)	`Changed	None`
Scroll(Up)	`Changed	None`
Submit	Submit	Just returns submit result with current state

State: the state returned is a One(String) containing the id of the selected node. If no node is selected None is returned.

Properties:

• Background(Color): background color. The background color will be used as background for unselected entry, but will be used as foreground for the selected entry when focus is true
• Borders(Borders): set borders properties for component
• Custom($TREE_IDENT_SIZE, Size): Set space to render for each each depth level
• Custom($TREE_INITIAL_NODE, String): Select initial node in the tree. This option has priority over keep_state
• Custom($TREE_PRESERVE_STATE, Flag): If true, the selected entry will be kept after an update of the tree (obviously if the entry still exists in the tree).
• FocusStyle(Style): inactive style
• Foreground(Color): foreground color. The foreground will be used as foreground for the selected item, when focus is false, otherwise as background
• HighlightedColor(Color): The provided color will be used to highlight the selected node. Foreground will be used if unset.
• HighlightedStr(String): The provided string will be displayed on the left side of the selected entry in the tree
• ScrollStep(Length): Defines the maximum amount of rows to scroll
• TextProps(TextModifiers): set text modifiers
• Title(Title): Set box title

Updating the tree

The tree in this component is not inside the props, but is a member of the TreeView mock component structure. In order to update and work with the tree you’ve got basically two ways to do this.

Remounting the component

In situation where you need to update the tree on the update routine (as happens in the example), the best way to update the tree is to remount the component from scratch.

Updating the tree from the “on” method

This method is probably better than remounting, but it is not always possible to use this. When you implement Component for your treeview, you have a mutable reference to the component, and so here you can call these methods to operate on the tree:

• pub fn tree(&self) -> &Tree: returns a reference to the tree
• pub fn tree_mut(&mut self) -> &mut Tree: returns a mutable reference to the tree; which allows you to operate on it
• pub fn set_tree(&mut self, tree: Tree): update the current tree with another
• pub fn tree_state(&self) -> &TreeState: get a reference to the current tree state. (See tree state docs)

You can access these methods from the on() method as said before. So these methods can be handy when you update the tree after a certain events or maybe even better, you can set the tree if you receive it from a UserEvent produced by a Port.

---

Setup a tree component

extern crate tui_realm_treeview;
extern crate tuirealm;

use tuirealm::{
    command::{Cmd, CmdResult, Direction, Position},
    event::{Event, Key, KeyEvent, KeyModifiers},
    props::{Alignment, BorderType, Borders, Color, Style},
    Component, MockComponent, NoUserEvent, State, StateValue,
};
// treeview
use tui_realm_treeview::{Node, Tree, TreeView, TREE_CMD_CLOSE, TREE_CMD_OPEN};

#[derive(Debug, PartialEq)]
pub enum Msg {
    ExtendDir(String),
    GoToUpperDir,
    None,
}

#[derive(MockComponent)]
pub struct FsTree {
    component: TreeView<String>,
}

impl FsTree {
    pub fn new(tree: Tree<String>, initial_node: Option<String>) -> Self {
        // Preserve initial node if exists
        let initial_node = match initial_node {
            Some(id) if tree.root().query(&id).is_some() => id,
            _ => tree.root().id().to_string(),
        };
        FsTree {
            component: TreeView::default()
                .foreground(Color::Reset)
                .borders(
                    Borders::default()
                        .color(Color::LightYellow)
                        .modifiers(BorderType::Rounded),
                )
                .inactive(Style::default().fg(Color::Gray))
                .indent_size(3)
                .scroll_step(6)
                .title(tree.root().id(), Alignment::Left)
                .highlighted_color(Color::LightYellow)
                .highlight_symbol("🦄")
                .with_tree(tree)
                .initial_node(initial_node),
        }
    }
}

impl Component<Msg, NoUserEvent> for FsTree {
    fn on(&mut self, ev: Event<NoUserEvent>) -> Option<Msg> {
        let result = match ev {
            Event::Keyboard(KeyEvent {
                code: Key::Left,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::Custom(TREE_CMD_CLOSE)),
            Event::Keyboard(KeyEvent {
                code: Key::Right,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::Custom(TREE_CMD_OPEN)),
            Event::Keyboard(KeyEvent {
                code: Key::PageDown,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::Scroll(Direction::Down)),
            Event::Keyboard(KeyEvent {
                code: Key::PageUp,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::Scroll(Direction::Up)),
            Event::Keyboard(KeyEvent {
                code: Key::Down,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::Move(Direction::Down)),
            Event::Keyboard(KeyEvent {
                code: Key::Up,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::Move(Direction::Up)),
            Event::Keyboard(KeyEvent {
                code: Key::Home,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::GoTo(Position::Begin)),
            Event::Keyboard(KeyEvent {
                code: Key::End,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::GoTo(Position::End)),
            Event::Keyboard(KeyEvent {
                code: Key::Enter,
                modifiers: KeyModifiers::NONE,
            }) => self.perform(Cmd::Submit),
            Event::Keyboard(KeyEvent {
                code: Key::Backspace,
                modifiers: KeyModifiers::NONE,
            }) => return Some(Msg::GoToUpperDir),
            _ => return None,
        };
        match result {
            CmdResult::Submit(State::One(StateValue::String(node))) => Some(Msg::ExtendDir(node)),
            _ => Some(Msg::None),
        }
    }
}

---

Tree widget

If you want, you can also implement your own version of a tree view mock component using the TreeWidget in order to render a tree. Keep in mind that if you want to create a stateful tree (with highlighted item), you’ll need to render it as a stateful widget, passing to it a TreeState, which is provided by this library.

Structs

OrangeNode

Describes a node inside the Tree U: is the type for the node indentifier (must implement PartialEq) T: is the type for the node value

OrangeTree

represent the tree data structure inside the component. U: is the type for the Node indentifier (must implement PartialEq) T: is the type for the Node value

TreeState

Tree state tracks the current state for the component tree.

TreeView

TreeView

TreeWidget

tui-rs widget implementation of a crate::TreeView

Constants

TREE_CMD_CLOSE

TREE_CMD_OPEN

TREE_INDENT_SIZE

TREE_INITIAL_NODE

TREE_PRESERVE_STATE

Traits

NodeValue

Tree node value.

Type Aliases

Node

Tree