TreeView-class: TreeView widget

In termr: Modern Reactive Terminal Applications with Data Workflows

TreeView widget

Description

Shows a tree of tree_node()s. See tree_view().

Super class

Widget -> TreeView

Public fields

paint_states

Cursor and scroll changes only repaint.

focusable

Trees can be focused.

show_root

Show the root node?

guides

Draw guide lines?

Active bindings

root

The root node.

cursor_node

The node under the cursor, or NULL.

visible_count

Number of visible (expanded) lines.

offset

First visible line minus one.

Methods

Public methods

• TreeView$new()

• TreeView$default_style()

• TreeView$default_bindings()

• TreeView$tree_changed()

• TreeView$select()

• TreeView$action_cursor_up()

• TreeView$action_cursor_down()

• TreeView$action_page_up()

• TreeView$action_page_down()

• TreeView$action_first()

• TreeView$action_last()

• TreeView$action_expand_or_child()

• TreeView$action_collapse_or_parent()

• TreeView$action_toggle()

• TreeView$action_activate()

• TreeView$on_mouse_down()

• TreeView$on_mouse_scroll()

• TreeView$content_width()

• TreeView$content_height()

• TreeView$paint()

• TreeView$clone()

Inherited methods

• Widget$add_class()
• Widget$ancestors()
• Widget$animate()
• Widget$arrange_children()
• Widget$bind()
• Widget$bind_reactive()
• Widget$bindings()
• Widget$blur()
• Widget$capture_mouse()
• Widget$child_clip()
• Widget$clear()
• Widget$computed_style()
• Widget$focus()
• Widget$format()
• Widget$get_state()
• Widget$has_class()
• Widget$invalidate()
• Widget$invalidate_paint()
• Widget$is_displayed()
• Widget$is_enabled()
• Widget$layout_descend()
• Widget$layout_differs()
• Widget$matches()
• Widget$mount()
• Widget$on()
• Widget$post_message()
• Widget$print()
• Widget$pseudo_states()
• Widget$query()
• Widget$query_one()
• Widget$refresh()
• Widget$release_mouse()
• Widget$remove()
• Widget$remove_children()
• Widget$remove_class()
• Widget$render()
• Widget$render_lines()
• Widget$replace()
• Widget$run_action()
• Widget$run_process()
• Widget$run_worker()
• Widget$set()
• Widget$set_interval()
• Widget$set_state()
• Widget$set_timeout()
• Widget$toggle_class()
• Widget$walk()

---

TreeView$new()

Create a tree view. See tree_view().

Usage

TreeView$new(
  root,
  show_root = TRUE,
  guides = TRUE,
  id = NULL,
  classes = NULL,
  style = NULL,
  disabled = FALSE
)

Arguments

root

The root TreeNode.

show_root, guides

See fields.

id, classes, style, disabled

See Widget.

---

TreeView$default_style()

The built-in style.

Usage

TreeView$default_style()

---

TreeView$default_bindings()

Navigation keys.

Usage

TreeView$default_bindings()

---

TreeView$tree_changed()

Called by nodes when the tree changes.

Usage

TreeView$tree_changed()

---

TreeView$select()

Move the cursor to a node (expanding its ancestors).

Usage

TreeView$select(node)

Arguments

node

A node of this tree.

---

TreeView$action_cursor_up()

Move up.

Usage

TreeView$action_cursor_up()

---

TreeView$action_cursor_down()

Move down.

Usage

TreeView$action_cursor_down()

---

TreeView$action_page_up()

Move a page up.

Usage

TreeView$action_page_up()

---

TreeView$action_page_down()

Move a page down.

Usage

TreeView$action_page_down()

---

TreeView$action_first()

Go to the first node.

Usage

TreeView$action_first()

---

TreeView$action_last()

Go to the last visible node.

Usage

TreeView$action_last()

---

TreeView$action_expand_or_child()

Expand, or go to the first child.

Usage

TreeView$action_expand_or_child()

---

TreeView$action_collapse_or_parent()

Collapse, or go to the parent.

Usage

TreeView$action_collapse_or_parent()

---

TreeView$action_toggle()

Toggle the cursor node.

Usage

TreeView$action_toggle()

---

TreeView$action_activate()

Toggle and send "tree.node_activated".

Usage

TreeView$action_activate()

---

TreeView$on_mouse_down()

Clicking selects; clicking the arrow toggles.

Usage

TreeView$on_mouse_down(event)

Arguments

event

A MouseEvent.

---

TreeView$on_mouse_scroll()

The wheel scrolls three lines.

Usage

TreeView$on_mouse_scroll(event)

Arguments

event

A MouseEvent.

---

TreeView$content_width()

Natural width: the widest visible line.

Usage

TreeView$content_width()

---

TreeView$content_height()

Natural height: visible lines (at most 1000).

Usage

TreeView$content_height(width)

Arguments

width

Content width.

---

TreeView$paint()

Draw the visible lines.

Usage

TreeView$paint(buffer, area, st)

Arguments

buffer

A ScreenBuffer.

area

Visible part of the region.

st

Computed style.

---

TreeView$clone()

The objects of this class are cloneable with this method.

Usage

TreeView$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

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