tree_view: Tree view

In termr: Modern Reactive Terminal Applications with Data Workflows

Tree view

Description

Shows a tree_node() hierarchy with expand/collapse arrows and guide lines. Only visible lines are painted, and children can be loaded lazily.

Usage

tree_view(
  root,
  show_root = TRUE,
  guides = TRUE,
  id = NULL,
  classes = NULL,
  style = NULL
)

Arguments

root	The root tree_node().
show_root	Show the root itself (otherwise its children are the top level and it is always expanded).
guides	Draw guide lines?
id	Optional identifier.
classes	Optional classes.
style	A style().

Details

Keys: Up/Down/Page Up/Page Down/Home/End move; Right expands (or goes to the first child); Left collapses (or goes to the parent); Space toggles; Enter toggles and sends "tree.node_activated". Clicking selects a node; clicking its arrow toggles it.

Messages (event$data: node, label, data, id): "tree.node_selected", "tree.node_expanded", "tree.node_collapsed", "tree.node_activated".

Value

A TreeView widget with method select(node) and fields root, cursor_node, visible_count.

Examples

root <- tree_node("Project", tree_node("R", "app.R", "widget.R", expanded = TRUE),
                  "README.md", expanded = TRUE)
render_widget(tree_view(root), 24, 5)

termr documentation built on Oct. 21, 2026, 5:13 p.m.