Description

A tree is a hierarchical List, allowing users to expand and collapse nodes to show or hide nested items.

Types

Image

Single selection

Multiple selection

Smart Selection

Read-only

Dependencies between nodes

Usage & Behavior

Trees are used to navigate within hierarchical lists of objects (e.g. organizations), and then to select one or more items in order to filter content or show additional information.
They usually appear inside a Filter Pane, a Details Panel, or a Widget.

General guidelines

Structure

A tree consists of multiple nodes.

A root node (optional)

Standard parent nodes:

Dependent parent nodes

Where a parent node depends on a child node, and is automatically selected when the child is selected, it is known as a dependent parent node. For example, in a permissions tree, enabling the child node Edit may also automatically enable the dependent parent node View.

Regular dependency indication

Hovered dependecy indication

Default State

Content

Internal logic

States

Parent node

Standard node

Regular

Hover

Active

Selected

Disabled

NA

Focused

Focused, Hover

Focused, Active

Focused, Disabled

NA

Interaction

Best practices

Use:

Don't use:

General

Accessibility compliance

Unless otherwise specified, see our general compliance information in Fundamentals - Accessibility.

Focus management

Keyboard

Node

Tab

  • From the previous component:

    • If no item is selected, moves focus to the first node in the tree.

    • If a node is selected, moves focus to the first selected node.

  • From the last node in the tree, navigates to the next component.

  • Where a tree contains a horizontal scrollbar, it will automatically adjust as the focus moves between components (e.g. between nodes and the expand-collapse button) to ensure that the currently-focused component is always in view.

Shift + Tab

  • From the next component:

    • If no item is selected, moves focus to the first node in the tree.

    • If a node is selected, move focus to the first selected node.

  • From the first node in the tree, navigates to the previous component.

Space

Selects or actions the item.

Enter

Selects or actions the item.

Esc

N/A

Arrows

Up/Down - Moves focus to the previous/next node accordingly. Only nodes which are visible without opening a parent node should be focused.

Right:

  • When focus is on a closed node, opens the node. Focus does not move.

  • When focus is on an open node, moves focus to the first child node.

  • When focus is on an end node, does nothing.

Left:

  • When focus is on an open node, closes the node.

  • When focus is on a child node that is also either an end node or a closed node, moves focus to its parent node.

  • When focus is on a root node that is also either an end node or a closed node, does nothing.

Home

Moves focus to the first/top node in the tree, without automatically opening or closing any nodes.

End

Moves focus to the last focusable node without expanding any closed nodes.

“*” (asterisk)

  • Expands all closed sibling nodes that are at the same level as the focused node.

  • Focus does not move.

  • See W3 for reference.

a-z, A-Z

  • Moves focus to the next node with a label starting with the typed character(s), if such an item exists.

  • Typing multiple characters in rapid succession moves the focus to the next node starting with the string of typed characters.

  • If no matching nodes are found below the focused node, the first node from the top of the tree should be focused (if exists).

  • Only nodes which are visible without opening a parent node should be focused.

  • If no node labels match the typed character(s), the focus does not move.

Design

Zeplin link

Screen thumbnail

Single Select

https://zpl.io/agwRA0a

Multi Select

https://zpl.io/a8L0Exa

Smart Select

https://zpl.io/VDePyea

Tree - Organization

https://zpl.io/adgoJlV

Code