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Tree

Added in version 0.6.0

A tree control widget.

  • Focusable
  • Container

Example

The example below creates a simple tree.

TreeApp ▼ Dune └── ▼ Characters ├── Paul ├── Jessica └── Chani 

from textual.app import App, ComposeResult
from textual.widgets import Tree


class TreeApp(App):
    def compose(self) -> ComposeResult:
        tree: Tree[str] = Tree("Dune")
        tree.root.expand()
        characters = tree.root.add("Characters", expand=True)
        characters.add_leaf("Paul")
        characters.add_leaf("Jessica")
        characters.add_leaf("Chani")
        yield tree


if __name__ == "__main__":
    app = TreeApp()
    app.run()

Tree widgets have a "root" attribute which is an instance of a TreeNode. Call add() or add_leaf() to add new nodes underneath the root. Both these methods return a TreeNode for the child which you can use to add additional levels.

Reactive Attributes

Name Type Default Description
show_root bool True Show the root node.
show_guides bool True Show guide lines between levels.
guide_depth int 4 Amount of indentation between parent and child.

Messages

Bindings

The tree widget defines the following bindings:

Key(s) Description
enter Select the current item.
space Toggle the expand/collapsed state of the current item.
up Move the cursor up.
down Move the cursor down.

Component Classes

The tree widget provides the following component classes:

Class Description
tree--cursor Targets the cursor.
tree--guides Targets the indentation guides.
tree--guides-hover Targets the indentation guides under the cursor.
tree--guides-selected Targets the indentation guides that are selected.
tree--highlight Targets the highlighted items.
tree--highlight-line Targets the lines under the cursor.
tree--label Targets the (text) labels of the items.

Bases: Generic[TreeDataType], ScrollView

A widget for displaying and navigating data in a tree.

Parameters:

Name Type Description Default

label

TextType

The label of the root node of the tree.

 required

data

TreeDataType | None

The optional data to associate with the root node of the tree.

 None

name

str | None

The name of the Tree.

 None

id

str | None

The ID of the tree in the DOM.

 None

classes

str | None

The CSS classes of the tree.

 None

disabled

bool

Whether the tree is disabled or not.

 False

BINDINGS class-attribute 

BINDINGS = [
    Binding(
        "shift+left",
        "cursor_parent",
        "Cursor to parent",
        show=False,
    ),
    Binding(
        "shift+right",
        "cursor_parent_next_sibling",
        "Cursor to next ancestor",
        show=False,
    ),
    Binding(
        "shift+up",
        "cursor_previous_sibling",
        "Cursor to previous sibling",
        show=False,
    ),
    Binding(
        "shift+down",
        "cursor_next_sibling",
        "Cursor to next sibling",
        show=False,
    ),
    Binding("enter", "select_cursor", "Select", show=False),
    Binding("space", "toggle_node", "Toggle", show=False),
    Binding(
        "shift+space",
        "toggle_expand_all",
        "Expand or collapse all",
        show=False,
    ),
    Binding("up", "cursor_up", "Cursor Up", show=False),
    Binding(
        "down", "cursor_down", "Cursor Down", show=False
    ),
]
Key(s) Description
enter Select the current item.
space Toggle the expand/collapsed state of the current item.
up Move the cursor up.
down Move the cursor down.

COMPONENT_CLASSES class-attribute 

COMPONENT_CLASSES = {
    "tree--cursor",
    "tree--guides",
    "tree--guides-hover",
    "tree--guides-selected",
    "tree--highlight",
    "tree--highlight-line",
    "tree--label",
}
Class Description
tree--cursor Targets the cursor.
tree--guides Targets the indentation guides.
tree--guides-hover Targets the indentation guides under the cursor.
tree--guides-selected Targets the indentation guides that are selected.
tree--highlight Targets the highlighted items.
tree--highlight-line Targets the lines under the cursor.
tree--label Targets the (text) labels of the items.

ICON_NODE class-attribute instance-attribute 

ICON_NODE = '▶ '

Unicode 'icon' to use for an expandable node.

ICON_NODE_EXPANDED class-attribute instance-attribute 

ICON_NODE_EXPANDED = '▼ '

Unicode 'icon' to use for an expanded node.

auto_expand class-attribute instance-attribute 

auto_expand = var(True)

Auto expand tree nodes when they are selected.

center_scroll class-attribute instance-attribute