Skip to contents

Tree view

Source: R/widget-treeview.R
tree_view.Rd

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().

Value

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

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".

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)
#> <ScreenBuffer 24x5>
#> +------------------------+
#> |▼ Project               |
#> |├─▼ R                   |
#> |│ ├─  app.R             |
#> |│ └─  widget.R          |
#> |└─  README.md           |
#> +------------------------+