List Tree

Tree views provide a hierarchical structure for displaying nested items, such as files and folders. They allow users to expand and collapse nodes to navigate through different levels of content.

Overview

Tree views allow users to explore and interact with deeply nested content dynamically, offering flexibility in how data is presented and navigated.

When to use

• Use tree views to display nested, structured data that requires user interaction to explore its various levels.

• Use a tree view when information is categorized into multiple layers or subcategories, allowing users to explore data progressively.

• Tree views are effective when handling vast amounts of data that would be overwhelming to display in a flat list or grid view.

When not to use

• Avoid using a tree view if the content isn’t arranged hierarchically. Use a simple list view for flat data sets.

• If the content structure is simple with only one level, a list view or card component might be a better option.

• If you're building a menu for simple category navigation (without nested levels), a navigation menu or tab component is more appropriate.

• Tree view might seem similar in allowing content expansion with accordions, but accordions are used to display sections of content, not nested items like tree views.

Types

Anatomy

1. Check Box: Allows the user to select or deselect the item.

2. Leading Content: A visual element on the left side of the tree item. (Chevron, Icon, Checkbox, Switch, etc.)

3. Text (Title): The primary label for each item in the tree view, representing the core content or category.

4. Helper: An optional element providing additional information or context for the item.

5. Trailing Content: An optional visual element representing status or interaction options on the right side. (Shortcut, Icon, Chevron, etc.)

6. Slot: A placeholder element that can be swapped with other components.

7. Switch: A toggle element enabling on/off states for the item.

8. Description: A brief summary or explanation of the tree item, giving further detail if necessary.

9. Container: The structural component that holds all the tree view items, ensuring alignment, spacing, and visual grouping.

Styles

States

Size

Size	Text (px)	Description (px)	Icon (px)	Corner (px)	Container Height (px)
Small	14	12	16	8	37
Medium	16	12	20	8	44
Large	18	14	20	8	45

Accessibility

• Keyboard Navigation: Ensure tree views are fully accessible using a keyboard, allowing users to expand, collapse, and navigate through nodes with arrow keys.

• Screen Reader Support: Tree views should provide clear labels and roles for screen readers, ensuring that hierarchical levels and node states (expanded/collapsed) are communicated effectively.

• Focus Management: Proper focus management is essential, especially when expanding or collapsing nodes, to avoid disorienting users who rely on assistive technology.

• Clear Visual Cues: Use clear indicators like arrows or chevrons to signal expandable and collapsible nodes, improving usability for all users.

Example

• File Explorer: Display a hierarchical file system where users can expand folders to view subfolders and files.

• Category Management: In an e-commerce application, allow users to navigate product categories, expanding subcategories as needed.

• Organizational Chart: Visualize and navigate the structure of a company, allowing users to expand and collapse departments and teams.

• Documentation Navigation: Present a multi-level documentation index, enabling users to collapse sections they don’t need.

• Navigation Sidebar in a Web Application: Organize different sections such as Dashboard, Profile, and Settings in a collapsible list, with chevrons indicating expandable groups.